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Yao X, Zhao Z, Wang J, Kimirei IA, Sekadende BC, Mgana HF, Zhang L. Microbial nitrogen nutrition links to dissolved organic matter properties in East African lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175197. [PMID: 39094654 DOI: 10.1016/j.scitotenv.2024.175197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 07/18/2024] [Accepted: 07/30/2024] [Indexed: 08/04/2024]
Abstract
East African lakes, especially soda lakes, are home habitats for massive numbers of wildlife such as flamingos, mammals, and fishes. These lakes are known for their high primary production due to local high temperatures, light intensities, and alkalinity (inorganic carbon). However, these lakes, normally within remote areas, receive low nutrient inputs. Ammonium (NH4+) recycling and/or nitrogen fixation can become the major N supply mechanisms for phytoplankton. However, the driving forces on microbial N nutrition in lakes with minimal anthropogenic disturbance remain poorly understood. Using stable isotope tracer techniques, NH4+ recycling rates were measured in 18 lakes and reservoirs in East Africa (Tanzania and Kenya) during the dry season in early 2020. Three functional genes (nifH, gdh, and ureC) relating to microbial N nutrition were also measured. The regeneration of NH4+ supported up to 71 % of the NH4+ uptake. Positive community biological NH4+ demands (CBAD) for all lakes and reservoirs indicate an obvious N demand from microbial community. Our study provides clear evidence that microbial NH4+ uptake rates linked closely to the dissolved organic matter (DOM) properties (e.g., the absorption coefficient at 254 nm, percents of total fluorescence intensity contributed by microbial humic-like and protein-like components) and that water residence time drives microbial NH4+ recycling by regulating the duration of in-lake DOM processing and influencing algal growth. Phytoplankton, especially those of Cyanophyceae, showed maximum biomass and higher NH4+ recycling rates at a certain range of water residence time (e.g., 5-8 years). However, CBAD showed a decreasing trend with longer water residence time, which may be influenced by changes in the algal community composition (e.g., % Cyanophyceae vs. % Bacillariophyceae). These results indicate that DOM dynamics and the water residence time have the potential to facilitate the understanding of microbial nitrogen supply status in East African lakes.
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Affiliation(s)
- Xiaolong Yao
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Zhonghua Zhao
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Nanjing 211135, China
| | - Jianjun Wang
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Nanjing 211135, China
| | | | | | | | - Lu Zhang
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Nanjing 211135, China.
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Inácio M, Pinto L, Baltranaitė E, Kalinauskas M, Burkhard B, Barceló D, Pereira P. Mapping and assessing marine ecosystem services supply in the Baltic Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175199. [PMID: 39102961 DOI: 10.1016/j.scitotenv.2024.175199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2024] [Revised: 07/30/2024] [Accepted: 07/30/2024] [Indexed: 08/07/2024]
Abstract
Coastal and marine ecosystems supply multiple Ecosystem Services (ES). Nevertheless, these ecosystems are among the most impacted by human activities, harming the ES sustainable supply. Since ES are a spatial phenomenon, mapping can contribute to understand ES supply. For this, we use quantitative spatio-temporal frameworks to map and assess the supply of one provisioning (food from fisheries) and two regulating ES (nursery habitats and nutrient regulation), considering two periods: Baltic Sea Holistic Assessment (HOLAS) 2 (2011-2016) and 3 (2016-2021). The ES supply was assessed following a process-based modelling approach, using bio-physical indicators as proxies. The three ES models were applied and validated, showing moderate results. For fisheries and nursery ES the results showed a significantly higher supply in HOLAS 3 than in 2, and for nutrient ES the opposite. This indicates that the assessed ES changed due to environmental activities. The Anselin Local Moran's results showed that most ES index values aggregate in the High-High cluster; Moran's I and semi-variogram results showed a clustered pattern; and the Getis Ord* analysis showed that hot and cold spots corresponded to high and low supply areas. For fisheries, high ES supply areas were located in the central-southern part of the Baltic Sea, while low-supply regions were located in the northern part. For nursery ES, high supply areas were located in the southwestern Finnish and western Estonian coasts. For nutrient ES, high supply areas occurred in the central- and eastern-southern parts close to the coast. Correlations showed a statistically significant negative correlation between fisheries and nursery ES and a significant positive correlation between fisheries and nutrient ES. No statistically significant correlations were observed between nursery and nutrient ES supply. The results obtained are essential to support coastal and marine management and planning in the Baltic Sea as well as international environmental policies and directives.
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Affiliation(s)
- Miguel Inácio
- Environmental Management Laboratory, Mykolas Romeris University, Vilnius, Lithuania.
| | - Luís Pinto
- Environmental Management Laboratory, Mykolas Romeris University, Vilnius, Lithuania
| | - Eglė Baltranaitė
- Environmental Management Laboratory, Mykolas Romeris University, Vilnius, Lithuania
| | - Marius Kalinauskas
- Environmental Management Laboratory, Mykolas Romeris University, Vilnius, Lithuania
| | - Benjamin Burkhard
- Institute of Physical Geography and Landscape Ecology, Gottfried Wilhelm Leibniz University Hannover, Hannover, Germany
| | - Damià Barceló
- Department of Chemistry and Physics, University of Almería, Spain
| | - Paulo Pereira
- Environmental Management Laboratory, Mykolas Romeris University, Vilnius, Lithuania
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Mao X, Zhao H, Kattel G, Jiang G, Ji Y, Liu T, Yang J, Liu Z, Wang C, Zhao H, Liu L, Dong Q. Both nutrients and macrophytes regulate organic carbon burial: Insights from high-resolution spatiotemporal records of a large shallow lake (Baiyangdian) in eastern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175239. [PMID: 39111439 DOI: 10.1016/j.scitotenv.2024.175239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 07/15/2024] [Accepted: 08/01/2024] [Indexed: 08/13/2024]
Abstract
Both ecological regime shifts and carbon cycling in lakes have been the subject of global debates in recent years. However, the direct linkage between them is poorly understood. Lake Baiyangdian, a representative large shallow lake with the coexistence of a macrophyte-dominated area (MDA) and an algae-dominated area (ADA) in eastern China, allowing better understanding of the relationship between regime shifts and organic carbon (OC) burial in lakes. On the basis of Bayesian isotopic mixing modelling of C/N ratios and δ13C values, the sediment OC is primarily of autochthonous origin. The mean OC burial rate (OCBR) was 39 g C m-2 yr-1 before eutrophication occurred in 1990 and increased approximately 2.7-fold to 106 g C m-2 yr-1 after eutrophication. Partial least squares path modelling revealed that this change can be largely attributed to enhanced primary productivity and rapid burial as a result of intensified human perturbation. In terms of spatial patterns, the OCBR was greater in the MDA than in the ADA, which may be related to the different burial and mineralization processes of debris from macrophytes and algae. It then deduced that a decrease in the OCBR and an increase in the mineralization rate might have occurred after a shift from a macrophyte-dominated state to an algae-dominated state. Our findings highlight that eutrophication generally increases OC burial by enhancing lake primary productivity. However, once nutrient levels reach a critical range, lake ecosystems may shift from a macrophyte-dominated state to an algae-dominated state, which can lead to a significant reduction in the carbon burial capacity of lakes. Therefore, more attention should be given to avoiding shifts in eutrophic lakes, as such shifts can alter carbon cycling.
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Affiliation(s)
- Xin Mao
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Quaternary Chronology and Hydrological-Environment Evolution, China Geological Survey, Shijiazhuang 050061, China; Hebei Key Laboratory of Environmental Change and Ecological Construction, Hebei Normal University, Shijiazhuang 050024, China
| | - Hongmei Zhao
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Quaternary Chronology and Hydrological-Environment Evolution, China Geological Survey, Shijiazhuang 050061, China.
| | - Giri Kattel
- Department of Infrastructure Engineering, University of Melbourne, Melbourne 3010, Australia; Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China; School of Geographical Sciences, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Gaolei Jiang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Quaternary Chronology and Hydrological-Environment Evolution, China Geological Survey, Shijiazhuang 050061, China
| | - Yunping Ji
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Quaternary Chronology and Hydrological-Environment Evolution, China Geological Survey, Shijiazhuang 050061, China
| | - Taibei Liu
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Quaternary Chronology and Hydrological-Environment Evolution, China Geological Survey, Shijiazhuang 050061, China
| | - Jingsong Yang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Quaternary Chronology and Hydrological-Environment Evolution, China Geological Survey, Shijiazhuang 050061, China
| | - Zhe Liu
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Quaternary Chronology and Hydrological-Environment Evolution, China Geological Survey, Shijiazhuang 050061, China
| | - Chengmin Wang
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Quaternary Chronology and Hydrological-Environment Evolution, China Geological Survey, Shijiazhuang 050061, China
| | - Hua Zhao
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Quaternary Chronology and Hydrological-Environment Evolution, China Geological Survey, Shijiazhuang 050061, China
| | - Linjing Liu
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Quaternary Chronology and Hydrological-Environment Evolution, China Geological Survey, Shijiazhuang 050061, China
| | - Qiuyao Dong
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China; Key Laboratory of Quaternary Chronology and Hydrological-Environment Evolution, China Geological Survey, Shijiazhuang 050061, China
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Camarero JJ, Salinas-Bonillo MJ, Valeriano C, Rubio-Cuadrado Á, Fernández-Cortés Á, Tamudo E, Montes F, Cabello J. Watering the trees for the forest: Drought alleviation in oaks and pines by ancestral ditches. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175353. [PMID: 39116482 DOI: 10.1016/j.scitotenv.2024.175353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 07/22/2024] [Accepted: 08/05/2024] [Indexed: 08/10/2024]
Abstract
Traditional ditches ("acequias" in Spanish) derive meltwater and infiltrate groundwater providing ecological services downstream in the semi-arid Sierra Nevada range (SE Spain). Therefore, they may act as a nature-based solution by alleviating drought stress in trees growing near ditches by enhancing growth and reducing their intrinsic water-use efficiency (iWUE). Such a mitigation role of acequias is critical given that some oak (Quercus pyrenaica) and pine (Pinus sylvestris) stands reach their xeric distribution limits in Europe. We compared tree-ring width data and wood δ13C, a proxy of iWUE, in oak and pine stands located near or far (control) from ditches with different infiltration capacity in two watersheds. We assessed how trees responded to climate data, drought stress, and vegetation greenness through correlations and resilience indices. Oak trees located near ditches grew more and responded less to precipitation, soil moisture, a drought index, and greenness than control trees. In pines, we did not find this pattern, and ditch trees grew more than control trees only during an extremely dry year (1995). Climate-growth correlations suggested a longer growing season in ditch pines. Growth of ditch oaks from the "Acequia Nueva" (AN), with high infiltration capacity, responded more to autumn soil moisture and showed the lowest δ13C. Growth was enhanced by cool-wet spring conditions in pines and also by warm-wet conditions in the prior winter in the case of oaks. Control trees showed lower resistance to drought. Control trees presented higher wood δ13C values except for old oaks from the "Acequia Grande" (AG) site which may show long-term acclimation. Traditional ditches alleviate drought stress in oak and pine stands subjected to regional xeric climate conditions.
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Affiliation(s)
- J Julio Camarero
- Instituto Pirenaico de Ecología (IPE-CSIC), Avda. Montañana 1005, 50192 Zaragoza, Spain.
| | - María J Salinas-Bonillo
- Departamento de Biología y Geología, Universidad de Almería, 04120 Almería, Spain; Centro Andaluz para el Cambio Global, Hermelindo Castro (ENGLOBA), Universidad de Almería, Almería, Spain.
| | - Cristina Valeriano
- Instituto Pirenaico de Ecología (IPE-CSIC), Avda. Montañana 1005, 50192 Zaragoza, Spain; Laboratory of Tree-Ring Research, University of Arizona, 1215 E. Lowell Street, Building no. 45, Tucson, AZ 85721, USA.
| | - Álvaro Rubio-Cuadrado
- Instituto Pirenaico de Ecología (IPE-CSIC), Avda. Montañana 1005, 50192 Zaragoza, Spain; Departamento de Sistemas y Recursos Naturales, Escuela Técnica Superior de Ingeniería de Montes, Forestal y del Medio Natural, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain.
| | - Ángel Fernández-Cortés
- Departamento de Biología y Geología, Universidad de Almería, 04120 Almería, Spain; Centro Andaluz para el Cambio Global, Hermelindo Castro (ENGLOBA), Universidad de Almería, Almería, Spain.
| | - Elisa Tamudo
- Instituto Pirenaico de Ecología (IPE-CSIC), Avda. Montañana 1005, 50192 Zaragoza, Spain.
| | - Fernando Montes
- Departamento de Dinámica y Gestión Forestal, Instituto de Ciencias Forestales (ICIFOR-INIA), CSIC, Ctra. La Coruña km 7.5, 28040 Madrid, Spain.
| | - Javier Cabello
- Departamento de Biología y Geología, Universidad de Almería, 04120 Almería, Spain; Centro Andaluz para el Cambio Global, Hermelindo Castro (ENGLOBA), Universidad de Almería, Almería, Spain.
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Zhao Q, Zhou Y, Zhai J. Bridging beauty and biodiversity: Coupling diversity and aesthetics through optimized plant communities in urban riverfront landscapes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175278. [PMID: 39122026 DOI: 10.1016/j.scitotenv.2024.175278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Revised: 07/26/2024] [Accepted: 08/02/2024] [Indexed: 08/12/2024]
Abstract
Urban waterfront areas are dynamic interfaces where human and natural systems converge, forming complex ecosystems that encompass social, economic, and environmental elements. These areas offer ecological benefits and aesthetic experiences. However, a disparity between social aesthetic preferences and vegetation diversity along riverbanks impedes the integration of ecological and aesthetic values. To address this, a plant community optimization strategy based on a coupling coordination degree model (CCDM) is proposed. Using the Xietang River in Suzhou, China as a case study, surveys were conducted on 33 woody plant plots and 60 herbaceous plant plots, assessing plant diversity with Shannon-Wiener, richness, and Pielou indices. Landscape beauty was evaluated by 87 respondents using the Scenic Beauty Estimation method. Using six representative plant communities as mediators, CCDM was applied to quantitatively analyze the coordination between plant diversity and aesthetics. Based on this analysis and considering factors influencing plant diversity and scenic beauty, plant community optimization strategies were devised to enhance the coordinated development of ecological diversity and aesthetics, fostering a synergistic improvement in ecological and aesthetic quality. Results revealed a range of coupling coordination across plant communities (0.203 to 0.947), encompassing various types. Linear regression analysis demonstrated a non-linear relationship between plant diversity and landscape beauty, influenced by independent yet partially overlapping factors. Hence, both aspects should be simultaneously considered in the planning and enhancement of riverbank areas. The coupling coordination degree offers a comprehensive understanding of harmonizing plant diversity and aesthetic value, providing a quantitative and objective approach to integrated research. This perspective extends beyond urban waterfront landscapes, holding significance for achieving dual goals of ecology and social services in urban design and landscape management.
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Affiliation(s)
- Qianyu Zhao
- Department of Landscape Architecture, School of Architecture, Soochow University, Suzhou 215123, China
| | - Yue Zhou
- Department of Landscape Architecture, School of Architecture, Soochow University, Suzhou 215123, China
| | - Jun Zhai
- Department of Landscape Architecture, School of Architecture, Soochow University, Suzhou 215123, China.
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Zhou D, Luo Y, Luo Y, He Y, Chen Y, Wan Z, Wu Y. Chemodiversity of dissolved organic matter and its association with the bacterial community at a zinc smelting slag site after 10 years of direct revegetation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175322. [PMID: 39111427 DOI: 10.1016/j.scitotenv.2024.175322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 07/14/2024] [Accepted: 08/04/2024] [Indexed: 08/12/2024]
Abstract
Dissolved organic matter (DOM) plays a critical role in driving the development of biogeochemical functions in revegetated metal smelting slag sites, laying a fundamental basis for their sustainable rehabilitation. However, the DOM composition at the molecular level and its interaction with the microbial community in such sites undergoing long-term direct revegetation remain poorly understood. This study investigated the chemodiversity of DOM and its association with the bacterial community in the rhizosphere and non-rhizosphere slags of four plant species (Arundo donax, Broussonetia papyrifera, Cryptomeria fortunei, and Robinia pseudoacacia) planted at a zinc smelting slag site for 10 years. The results indicated that the relative abundance of lipids decreased from 18 % to 5 %, while the relative abundance of tannins and lignins/CRAM-like substances increased from 4 % to 10 % and from 44 % to 64 % in the revegetated slags, respectively. The chemical stability of the organic matter in the rhizosphere slag increased due to the retention of recalcitrant DOM components, such as lignins, aromatics, and tannins. As the diversity and relative abundance of the bacterial community increased, particularly within the Proteobacteria, there was better utilization of recalcitrant components (e.g., lignins/CRAM-like compounds), but this utilization was not invariable. In addition, potential preference associations between specific bacterial OTUs and DOM molecules were observed, possibly stimulated by heavy metal bioavailability. Network analysis revealed complex connectivity and strong interactions between the bacterial community and DOM molecules. These specific interactions between DOM molecules and the bacterial community enable adaptation to the harsh conditions of the slag environment. Overall, these findings provide novel insights into the transformation of DOM chemodiversity at the molecular level at a zinc smelting slag sites undergoing long-term revegetation. This knowledge could serve as a crucial foundation for developing direct revegetation strategies for the sustainable rehabilitation of metal smelting slag sites.
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Affiliation(s)
- Dongran Zhou
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Youfa Luo
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang 550025, China; Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang 550025, China.
| | - Yang Luo
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Yu He
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Yulu Chen
- Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 550025, China
| | - Zuyan Wan
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Yonggui Wu
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang 550025, China; Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang 550025, China
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Palviainen M, Pumpanen J, Mosquera V, Hasselquist EM, Laudon H, Ostonen I, Kull A, Wilson FR, Peltomaa E, Könönen M, Launiainen S, Peltola H, Ojala A, Laurén A. Extending the SUSI peatland simulator to include dissolved organic carbon formation, transport and biodegradation - Proper water management reduces lateral carbon fluxes and improves carbon balance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175173. [PMID: 39117189 DOI: 10.1016/j.scitotenv.2024.175173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 07/06/2024] [Accepted: 07/29/2024] [Indexed: 08/10/2024]
Abstract
Drainage intensity and forest management in peatlands affect carbon dioxide (CO2) emissions to the atmosphere and export of dissolved organic carbon (DOC) to water courses. The peatland carbon (C) balance results from a complex network of ecosystem processes from where lateral C fluxes have typically been ignored. Here, we present a new version of the SUSI Peatland simulator, the first advanced process-based ecosystem model that compiles a full C balance in drained forested peatland including DOC formation, transport and biodegradation. SUSI considers site, stand and terrain characteristics as well as the interactions and feedbacks between ecosystem processes and offers novel ways to evaluate and mitigate adverse environmental impacts with thorough management planning. Here, we extended SUSI by designing and parameterizing a mass-balance based decomposition module (ESOM) based on literature findings and tested the ESOM performance against an independent dataset measured in the laboratory using peat columns collected from Finland, Estonia, Sweden and Ireland. ESOM predicted the CO2 emissions and changes in DOC concentrations with a reasonable accuracy for the peat columns. We applied the new SUSI for drained peatland sites and found that reducing the depth to which ditches are cleaned by 0.3 m decreased the annual DOC export by 34 (17 %), 29 (19 %) and 7 (5 %) kg ha-1 in Finland, Estonia and Sweden, respectively, using typical ditch spacing for these countries. Correspondingly, site annual C sink increased by 305, 409 and 32 kg ha-1 in Finland, Estonia and Sweden, respectively. Our results also indicated that terrain slope can markedly alter the water residence time and consequently DOC biodegradation and export to ditches. We conclude that DOC export can be decreased and site C sink increased by reducing the depth to which ditches are cleaned or by increasing the ditch spacing.
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Affiliation(s)
- Marjo Palviainen
- Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Finland.
| | - Jukka Pumpanen
- Department of Environmental and Biological Sciences, Faculty of Science, Forestry and Technology, University of Eastern Finland, Kuopio, Finland
| | - Virginia Mosquera
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Eliza Maher Hasselquist
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Hjalmar Laudon
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Ivika Ostonen
- Institute of Ecology and Earth Sciences, University of Tartu, Estonia
| | - Ain Kull
- Institute of Ecology and Earth Sciences, University of Tartu, Estonia
| | - Florence Renou Wilson
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Elina Peltomaa
- Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Finland
| | - Mari Könönen
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki, Finland
| | - Samuli Launiainen
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki, Finland
| | - Heli Peltola
- School of Forest Sciences, Faculty of Science, Forestry and Technology, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland
| | - Anne Ojala
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki, Finland
| | - Annamari Laurén
- Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Finland; School of Forest Sciences, Faculty of Science, Forestry and Technology, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland
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Xie L, Palmroth S, Yin C, Oren R. Extramatrical mycelial biomass is mediated by fine root mass and ectomycorrhizal fungal community composition across tree species. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175175. [PMID: 39111434 DOI: 10.1016/j.scitotenv.2024.175175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 07/16/2024] [Accepted: 07/29/2024] [Indexed: 08/10/2024]
Abstract
In many ecosystems, a large fraction of gross primary production is invested in mycorrhiza. Ectomycorrhizal (ECM) mycelium is involved in regulating soil carbon and nutrient cycling. However, little is known about how mycelial biomass, production and turnover differ depending on ECM fungal community composition and associated tree species. We quantified fine root biomass and length using soil cores, and mycelial traits (biomass, production, and turnover) using mesh-bags and ergosterol analysis, and identified ECM exploration types by Illumina MiSeq sequencing of four ECM-dominated tree species (Picea asperata, Larix gmelinii, Quercus aquifolioides and Betula albosinensis) in subalpine forest. The ECM fungal community composition separated between needle-leaved and broadleaved species, and between evergreen and deciduous species. The ratio of mycelial to fine root biomass was similar across the species regardless of genus-scale community composition and the relative abundance of exploration types. Compared to the other species, Q. aquifolioides displayed higher fine root biomass and mycelial biomass and production, dominated by contact-short exploration type. Mycelial turnover rate tended to be lowest in P. asperata, dominated by medium-long exploration type. Much higher production of mycelium and only slightly higher turnover rate in Q. aquifolioides suggests that its steady-state mycelial biomass would be higher than of the other species. Moreover, compared to the two deciduous species, with similar production but somewhat lower turnover rate, the standing crop of mycelium in P. asperata may stabilize at a higher value. Our findings, that exploration type may affect production and turnover, highlight the importance of characterizing ECM fungal communities by exploration types when estimating the contribution of mycelium biomass to forest carbon sink and storage.
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Affiliation(s)
- Lulu Xie
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, PR China; University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, PR China
| | - Sari Palmroth
- Nicholas School of the Environment & Pratt School of Engineering, Duke University, Durham, NC 27708, USA; Department of Forest Sciences, University of Helsinki, FI-00014, Finland
| | - Chunying Yin
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, PR China.
| | - Ram Oren
- Nicholas School of the Environment & Pratt School of Engineering, Duke University, Durham, NC 27708, USA; Department of Forest Sciences, University of Helsinki, FI-00014, Finland
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Fedyń I, Sobociński W, Czyżowicz S, Wyka J, Ciach M. Ecosystem engineers cause biodiversity spill-over: Beavers are associated with breeding bird assemblages on both wetlands and adjacent terrestrial habitats. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175166. [PMID: 39094639 DOI: 10.1016/j.scitotenv.2024.175166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/30/2024] [Accepted: 07/29/2024] [Indexed: 08/04/2024]
Abstract
The influence of ecosystem engineers on habitats and communities is commonly acknowledged in a site-bounded context, i.e. in places directly affected by the presence of the focal species. However, the spatial extent of the effects of such engineering is poorly understood, raising the question as to what impact they have on ecosystems situated beyond the species' direct influence. Beavers Castor spp., iconic ecosystem engineers, are capable of significantly transforming aquatic ecosystems. Their presence boosts biodiversity in adjacent aquatic and riparian habitats, but as a result of cascading processes, beavers may affect terrestrial habitats situated beyond the range of their immediate activity. Our study investigates the breeding bird assemblage along a spatial gradient from the water to the forest interior on central European watercourses modified and unmodified by beavers. The results show that beaver sites are characterized by a higher species richness and abundance of breeding birds than unmodified watercourses. Such sites also host a different species pool, as 27 % of the recorded bird species occurred exclusively on the beaver sites. The effect of the beaver's presence on the bird assemblage extended to adjacent terrestrial habitats located up to 100 m from the water's edge, where the species richness and abundance was higher and the species composition was substantially modified. We also found a positive correlation between the total area of beaver wetland and the numbers of bird species and individuals recorded. Our study adds to the general understanding of the spatial context of the ecosystem engineering concept, as the changes brought about by engineers have an influence beyond the area of their immediate occurrence. Our work also has implications for landscape planning and management, where existing beaver sites with terrestrial buffer zones may constitute a network of biodiversity hotspots.
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Affiliation(s)
- Izabela Fedyń
- Department of Forest Biodiversity, Faculty of Forestry, University of Agriculture, al. 29 Listopada 46, 31-425 Kraków, Poland
| | - Wojciech Sobociński
- Institute of Biology, University of Bialystok, ul. Ciołkowskiego 1J, 15-245 Białystok, Poland
| | - Sławomir Czyżowicz
- Department of Forest Biodiversity, Faculty of Forestry, University of Agriculture, al. 29 Listopada 46, 31-425 Kraków, Poland
| | - Jakub Wyka
- Department of Forest Biodiversity, Faculty of Forestry, University of Agriculture, al. 29 Listopada 46, 31-425 Kraków, Poland
| | - Michał Ciach
- Department of Forest Biodiversity, Faculty of Forestry, University of Agriculture, al. 29 Listopada 46, 31-425 Kraków, Poland.
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60
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Wang Y, Chen Y, Zhang F, Li L, Ru S, Yang L. Responses of coastal phytoplankton communities to seasonal herbicide inputs: Tolerance or degeneration? JOURNAL OF HAZARDOUS MATERIALS 2024; 479:135671. [PMID: 39213765 DOI: 10.1016/j.jhazmat.2024.135671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 07/19/2024] [Accepted: 08/26/2024] [Indexed: 09/04/2024]
Abstract
Herbicide-induced phytoplankton inhibition threatens coastal biodiversity and ecosystem function. Although studies employing single-frequence exposure aid in understanding the phytoplankton community's responses to herbicides, it's difficult to objectively assess their response to cyclic herbicide inputs (long-term low-dose and short-term high-dose) in marine ecosystems. Here, we analyzed the concentration and distribution of herbicides in global coastal waters and simulated this cyclic process through a two-phase atrazine exposure mesocosm experiment and laboratory tests. The results indicated that, the herbicide concentrations (0.82 nmol L-1, 95 % CI 0.55, 1.74) from May to August were significantly higher than that (0.14 nmol L-1, 95 % CI 0.02, 0.38) in the remainder months, and highest concentrations typically emerged in summer; the changes in phytoplankton community composition under environmental concentrations of triazine herbicides could recover in the short term, but sustained inhibition of biomass was produced; the dominant populations were more likely to develop tolerance through preexposure and recover from subsequent impulse of atrazine, but this process was accompanied by the loss of rare groups and a decrease in biodiversity, meanwhile, affected the bacterial community in phycosphere. Consequently, we considered that the cyclic herbicide inputs may cause more detrimental effects than single-frequence exposure, potentially leading to a large-scale decline in coastal primary productivity.
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Affiliation(s)
- Yunsheng Wang
- College of Marine Life Sciences, Ocean University of China, 266101 Qingdao, China
| | - Ying Chen
- College of Marine Life Sciences, Ocean University of China, 266101 Qingdao, China
| | - Fuwei Zhang
- College of Marine Life Sciences, Ocean University of China, 266101 Qingdao, China
| | - Lingxiao Li
- College of Marine Life Sciences, Ocean University of China, 266101 Qingdao, China
| | - Shaoguo Ru
- College of Marine Life Sciences, Ocean University of China, 266101 Qingdao, China
| | - Liqiang Yang
- College of Marine Life Sciences, Ocean University of China, 266101 Qingdao, China.
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61
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Yao L, Wu C, Jiang B, Wu M, Shao X, Li N. Thinning alters nitrogen transformation processes in subtropical forest soil: Key roles of physicochemical properties. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175086. [PMID: 39074748 DOI: 10.1016/j.scitotenv.2024.175086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 07/25/2024] [Accepted: 07/25/2024] [Indexed: 07/31/2024]
Abstract
Thinning-a widely used forest management practice-can significantly influence soil nitrogen (N) cycling processes in subtropical forests. However, the effects of different thinning intensities on nitrification, denitrification, and their relationships with soil properties and microbial communities remain poorly understood. Here, we conducted a study in a subtropical forest in China and applied three thinning treatments, i.e., no thinning (0 %), intermediate thinning (10-15 %), and heavy thinning (20-25 %), and investigated the effects of thinning intensity on the potential nitrification rate (PNR), potential denitrification rate (PDR), and microbial communities. Moreover, we explored the relationships among soil physicochemical properties, microbial community structure, and nitrogen transformation rates under different thinning intensities. Our results showed that intermediate and heavy thinning significantly increased the PNR by 87 % and 61 % and decreased the PDR by 31 % and 50 % compared to that of the control, respectively. Although the bacterial community structure was markedly influenced by thinning, the fungal community structure remained stable. Importantly, changes in microbial community composition and diversity had minimal impacts on the nitrogen transformation processes, whereas soil physicochemical properties, such as pH, organic carbon content, and nitrogen forms, were identified as the primary drivers. These findings highlight the critical role of managing soil physicochemical properties to regulate nitrogen transformations in forest soils. Effective forest management should focus on precisely adjusting the thinning intensity to enhance the soil physicochemical conditions, thereby promoting more efficient nitrogen cycling and improving forest ecosystem health in subtropical regions.
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Affiliation(s)
- Liangjin Yao
- Zhejiang Academy of Forestry, Hangzhou 310023, China
| | - Chuping Wu
- Zhejiang Academy of Forestry, Hangzhou 310023, China
| | - Bo Jiang
- Zhejiang Academy of Forestry, Hangzhou 310023, China
| | - Ming Wu
- Wetland Ecosystem Research Station of Hangzhou Bay, Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Xuexin Shao
- Wetland Ecosystem Research Station of Hangzhou Bay, Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China
| | - Niu Li
- Wetland Ecosystem Research Station of Hangzhou Bay, Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China.
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Eklöf K, von Brömssen C, Huser B, Åkerblom S, Augustaitis A, Veiteberg Braaten HF, de Wit HA, Dirnböck T, Elustondo D, Grandin U, Holubová A, Kleemola S, Krám P, Lundin L, Löfgren S, Markensten H, Moldan F, Pihl Karlsson G, Rönnback P, Valinia S, Vuorenmaa J. Trends in mercury, lead and cadmium concentrations in 27 European streams and rivers: 2000-2020. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 360:124761. [PMID: 39154885 DOI: 10.1016/j.envpol.2024.124761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 08/11/2024] [Accepted: 08/16/2024] [Indexed: 08/20/2024]
Abstract
Temporal trends for concentrations of mercury (Hg), lead (Pb) and cadmium (Cd) were evaluated from year 2000-2020 in 20 (Hg), 23 (Pb) and 11 (Cd) watercourses in remote forest catchments in Europe. Decreasing trends were observed in 15% (Hg), 39% (Pb) and 45% (Cd) of the watercourses during the period of evaluation. Decreasing trends were mainly observed between 2000 and 2005 for Hg and between 2000 and 2015 for Pb and Cd. For the last five years of the studied time period (2015-2020), more watercourses showed significant increasing, rather than decreasing Hg, Pb and Cd trends. This was interpreted as a legacy effect of metals still retained in catchment soils. The overall negative trends during the earlier part of the study period were likely driven by declining deposition of metals over Europe, especially for Pb and Cd. Other changes related to metal transport and chemistry may have contributed to the observed trends as well, including recovery from acidification and the ongoing browning of surface waters at northern latitudes. Here we found that organic carbon could explain the seasonal variation in Hg and Pb, but was not related the interannual trends. This study highlights the need for long-term monitoring and robust statistical methods that can detect multidirectional, long-term change in water chemistry.
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Affiliation(s)
- Karin Eklöf
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, SE-75007, Uppsala, Sweden.
| | - Claudia von Brömssen
- Department of Energy and Technology, Applied Statistics and Mathematics, Swedish University of Agricultural Sciences, SE-75007, Uppsala, Sweden
| | - Brian Huser
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, SE-75007, Uppsala, Sweden
| | - Staffan Åkerblom
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, SE-75007, Uppsala, Sweden
| | - Algirdas Augustaitis
- Faculty of Forest Sciences and Ecology, Agriculture Academy, Vytautas Magnus University, LT-53362, Kaunas dstr., Lithuania
| | | | - Heleen A de Wit
- Norwegian Institute for Water Research (NIVA), Økernveien 94, 0579, Oslo, Norway
| | - Thomas Dirnböck
- Ecosystem Research and Environmental Information Management, Environment Agency Austria, Spittelauer Lände5, AT-1090, Vienna, Austria
| | - David Elustondo
- University of Navarra, BIOMA Institute for Biodiversity and the Environment, Irunlarrea 1, 31008, Pamplona, Spain
| | - Ulf Grandin
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, SE-75007, Uppsala, Sweden
| | - Adéla Holubová
- Air Quality Department, Czech Hydrometeorological Institute, Košetice Observatory, 394 24, Czech Republic
| | - Sirpa Kleemola
- Finnish Environment Institute, Latokartanonkaari 11, FI-00790, Helsinki, Finland
| | - Pavel Krám
- Department of Environmental Geochemistry and Biogeochemistry, Czech Geological Survey, Klárov 3, CZ-11821, Prague, Czech Republic
| | - Lars Lundin
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, SE-75007, Uppsala, Sweden
| | - Stefan Löfgren
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, SE-75007, Uppsala, Sweden
| | - Hampus Markensten
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, SE-75007, Uppsala, Sweden
| | - Filip Moldan
- IVL Swedish Environmental Research Institute, P.O. Box 53021, SE-40014, Gothenburg, Sweden
| | - Gunilla Pihl Karlsson
- IVL Swedish Environmental Research Institute, P.O. Box 53021, SE-40014, Gothenburg, Sweden
| | - Pernilla Rönnback
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, SE-75007, Uppsala, Sweden
| | - Salar Valinia
- Ensucon AB, Sankt Eriksgatan 63B, 11234, Stockholm, Sweden
| | - Jussi Vuorenmaa
- Finnish Environment Institute, Latokartanonkaari 11, FI-00790, Helsinki, Finland
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63
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Zamanian K. Deep-root respiration: The unknown CO 2 removed from the atmosphere. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175294. [PMID: 39106902 DOI: 10.1016/j.scitotenv.2024.175294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Revised: 07/30/2024] [Accepted: 08/03/2024] [Indexed: 08/09/2024]
Abstract
Carbon (C) sequestration in soils is a promising CO2 removal approach. So far, the focus has been on how to increase the content of soil organic C (SOC), while the management soil inorganic C (SIC), i.e. carbonate minerals, has received little attention, because SIC is thought to be much less involved in biotic C cycling than SOC. However, in principle SIC management potentially provides a long-term solution, with a much greater capacity for C sequestration than SOC. The forgotten link is the dissolved inorganic carbon (DIC), i.e. CO2 species dissolved in soil solution, and its fate throughout the unsaturated zone (USZ). The return of CO2 respired by deep roots to the atmosphere, either directly through CO2 degassing or indirectly through DIC leaching, may not necessarily take place over decades or centuries. CO2 diffusion decreases sharply with depth due to reduced porosity of the subsoil and more water-filled pores. The downward water percolation rate is often only a few centimeters per year, and the large amount of respired CO2 compared to the leached DIC results in a relatively small amount of CO2 being transferred to the groundwater. Therefore, respired CO2 at deeper soil depth can be defined as a hitherto unknown ecosystem service of deep-rooted plants i.e. providing a net C sink as inorganic C in the USZ. A conservative estimation suggests a C sink as SIC of at least 80 kg C ha-1 y-1, comparable to reported annual C sequestration as SOC in temperate grasslands.
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Affiliation(s)
- Kazem Zamanian
- Institute of Earth System Sciences, Section Soil Science, Leibniz University of Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany.
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64
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Jepsen JU, Arneberg P, Ims RA, Siwertsson A, Yoccoz NG, Fauchald P, Pedersen ÅØ, van der Meeren GI, von Quillfeldt CH. Panel-based assessment of ecosystem condition as a platform for adaptive and knowledge driven management. ENVIRONMENTAL MANAGEMENT 2024; 74:1020-1036. [PMID: 39271533 PMCID: PMC11438735 DOI: 10.1007/s00267-024-02042-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Accepted: 09/01/2024] [Indexed: 09/15/2024]
Abstract
Ecosystems are subjected to increasing exposure to multiple anthropogenic drivers. This has led to the development of national and international accounting systems describing the condition of ecosystems, often based on few, highly aggregated indicators. Such accounting systems would benefit from a stronger theoretical and empirical underpinning of ecosystem dynamics. Operational tools for ecosystem management require understanding of natural ecosystem dynamics, consideration of uncertainty at all levels, means for quantifying driver-response relationships behind observed and anticipated future trajectories of change, and an efficient and transparent synthesis to inform knowledge-driven decision processes. There is hence a gap between highly aggregated indicator-based accounting tools and the need for explicit understanding and assessment of the links between multiple drivers and ecosystem condition as a foundation for informed and adaptive ecosystem management. We describe here an approach termed PAEC (Panel-based Assessment of Ecosystem Condition) for combining quantitative and qualitative elements of evidence and uncertainties into an integrated assessment of ecosystem condition at spatial scales relevant to management and monitoring. The PAEC protocol is founded on explicit predictions, termed phenomena, of how components of ecosystem structure and functions are changing as a result of acting drivers. The protocol tests these predictions with observations and combines these tests to assess the change in the condition of the ecosystem as a whole. PAEC includes explicit, quantitative or qualitative, assessments of uncertainty at different levels and integrates these in the final assessment. As proofs-of-concept we summarize the application of the PAEC protocol to a marine and a terrestrial ecosystem in Norway.
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Affiliation(s)
- Jane U Jepsen
- Norwegian Institute for Nature Research, Department of Arctic Ecology, Fram Centre, 9296, Tromsø, Norway.
| | - Per Arneberg
- Institute of Marine Research, Department of Ecosystem Processes, Fram Centre, 9296, Tromsø, Norway
| | - Rolf A Ims
- UiT The Arctic University of Norway, Department of Arctic and Marine Biology, 9037, Tromsø, Norway
| | - Anna Siwertsson
- Institute of Marine Research, Department of Ecosystem Processes, Fram Centre, 9296, Tromsø, Norway
- Akvaplan-niva, Fram Centre, 9296, Tromsø, Norway
| | - Nigel G Yoccoz
- UiT The Arctic University of Norway, Department of Arctic and Marine Biology, 9037, Tromsø, Norway
| | - Per Fauchald
- Norwegian Institute for Nature Research, Department of Arctic Ecology, Fram Centre, 9296, Tromsø, Norway
| | | | - Gro I van der Meeren
- Institute of Marine Research, Department of Ecosystem Processes, 5392, Storebø, Norway
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65
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Aqdam MM, Baltzer JL, Branfireun BA, Low G, Low M, Swanson HK. Can remotely sensed catchment to lake area ratios predict mercury levels in subarctic fishes? ENVIRONMENTAL RESEARCH 2024; 260:119545. [PMID: 38986798 DOI: 10.1016/j.envres.2024.119545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 06/28/2024] [Accepted: 07/01/2024] [Indexed: 07/12/2024]
Abstract
Mercury concentrations ([Hg]) in fish reflect a complex array of interacting biogeochemical and ecological variables. In northern regions where fish are a critical subsistence food, understanding and predicting fish [Hg] can be particularly difficult, largely due to a paucity of comprehensive data associated with the logistical challenges of field sampling. Building on previous work where we elucidated causal relationships between fish [Hg] and a variety of catchment, water quality, and ecological variables in subarctic lakes, we investigated whether using only ratios of catchment area to lake area (CA:LA) can predict [Hg] in northern freshwater fish species. As CA:LA can be sensed remotely, they may be more feasible and practical to obtain than field data in far northern regions. Our study included thirteen remote lakes that represent a CA:LA gradient of 6.2-423.5 within an ∼66,000 km2 subarctic region of Northwest Territories, Canada. We found that size-standardized [Hg] in three widespread fish species, including Lake Whitefish (Coregonus clupeaformis), Walleye (Sander vitreus), and Northern Pike (Esox lucius), were significantly and positively related to CA:LA (p < 0.007, r2 = 67-80%), indicating higher fish [Hg] in smaller lakes surrounded by relatively larger catchments. Our findings provide compelling evidence that remotely sensed CA:LA can be used to predict [Hg] in northern fishes and aid in prioritizing understudied and subsistence fishing lakes of the Canadian subarctic for [Hg] monitoring programs.
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Affiliation(s)
- Mehdi M Aqdam
- Department of Biology, Wilfrid Laurier University, Waterloo, ON, Canada; Azimuth Consulting Group Inc., Vancouver, BC, Canada.
| | | | | | - George Low
- Dehcho Aboriginal Aquatic Resources & Oceans Management, Hay River, NT, Canada
| | - Mike Low
- Dehcho Aboriginal Aquatic Resources & Oceans Management, Hay River, NT, Canada
| | - Heidi K Swanson
- Department of Biology, Wilfrid Laurier University, Waterloo, ON, Canada.
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66
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Morales-Molino C, van Vugt L, van Leeuwen JFN, Gobet E, Schwörer C, Ganz K, Giagkoulis T, Brugger SO, Bogaard A, Hafner A, Kotsakis K, Lotter AF, Tinner W. Looking at the modern landscape of submediterranean Greece through a palaeoecological lens. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:174986. [PMID: 39053556 DOI: 10.1016/j.scitotenv.2024.174986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 07/20/2024] [Accepted: 07/21/2024] [Indexed: 07/27/2024]
Abstract
The importance of understanding the long-lasting legacy of past land use on modern ecosystems has long been acknowledged. However, the magnitude and persistence of such legacies have been assessed only occasionally. Northern Greece has been a gateway of farming into mainland Europe during the Neolithic, thus providing a perfect setting to assess the potential impact of land-use history on present-day ecosystems. Additionally, the marked Holocene climatic variability of the southern Balkans makes it possible to investigate climate-vegetation-land use interactions over long timescales. Here, we have studied a sediment record from Limni Vegoritis (Northern Greece) spanning the past ∼9000 years using palaeoecological proxies (pollen, spores, stomata, microscopic charcoal). We aimed to reconstruct long-term vegetation dynamics in submediterranean Greece, to assess the environmental factors controlling them and to establish the legacies of the long history of land use in the modern landscape. We found that the Early Holocene afforestation, mainly oak woodlands, was delayed because of suboptimal moisture conditions. Later, colder and drier conditions during the rapid climate change centred around the '8.2 ka event' triggered woodland opening and the spread of wooded (Juniperus) steppe vegetation. First indicators of farming activities are recorded during this period, but their abundances are too low to explain the concurrent large deforestation episode. Later, pinewoods (probably dominated by Pinus nigra) with deciduous Quercus spread and dominated the landscape for several millennia. These forests experienced repeated multi-centennial setback-recovery episodes associated with land-use intensification, but pines eventually declined ∼2500-2000 years ago during Classical times under heavy land use comprising intense pastoralism. This was the starting point for the present-day landscape, where the main 'foundation' taxon of the ancient forests (Pinus cf. nigra) is missing, therefore attesting to the strong imprint that historical land use has left on the modern landscape.
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Affiliation(s)
- César Morales-Molino
- Grupo de Ecología y Restauración Forestal (FORECO), Departamento de Ciencias de la Vida, Facultad de Ciencias, Universidad de Alcalá, Alcalá de Henares, Spain; Institute of Plant Sciences, University of Bern, Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland.
| | - Lieveke van Vugt
- Institute of Plant Sciences, University of Bern, Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Jacqueline F N van Leeuwen
- Institute of Plant Sciences, University of Bern, Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Erika Gobet
- Institute of Plant Sciences, University of Bern, Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Christoph Schwörer
- Institute of Plant Sciences, University of Bern, Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Kathrin Ganz
- Institute of Plant Sciences, University of Bern, Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Tryfon Giagkoulis
- School of History and Archaeology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Sandra O Brugger
- Institute of Plant Sciences, University of Bern, Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland; Geoecology, Department of Environmental Sciences, University of Basel, Basel, Switzerland; Analytical Chemistry Laboratory, Paul Scherrer Institute, Villigen, Switzerland
| | - Amy Bogaard
- School of Archaeology, University of Oxford, Oxford, United Kingdom
| | - Albert Hafner
- Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland; Institute of Archaeological Sciences, University of Bern, Bern, Switzerland
| | - Kostas Kotsakis
- School of History and Archaeology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - André F Lotter
- Institute of Plant Sciences, University of Bern, Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Willy Tinner
- Institute of Plant Sciences, University of Bern, Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
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67
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Cui P, Cui L, Zheng Y, Su F. Land use and urbanization indirectly control riverine CH 4 and CO 2 emissions by altering nutrient input. WATER RESEARCH 2024; 265:122266. [PMID: 39159507 DOI: 10.1016/j.watres.2024.122266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 08/04/2024] [Accepted: 08/12/2024] [Indexed: 08/21/2024]
Abstract
Urban rivers are recognized as significant sources of methane (CH4) and carbon dioxide (CO2) emissions. Despite this, the influence of land use and urbanization on carbon emissions across rural-urban rivers at the watershed scale has been insufficiently explored. This study utilized in-situ surveys of the Liao River in northern China to investigate the spatial and temporal variations of CH4 and CO2 emissions and their relationship with urbanization and its potential controlling factors. The findings revealed that CH4 emissions peaked in fall, whereas CO2 emissions were highest in summer. The average fluxes of CH4 and CO2 at the water-gas interface were 1387.22 ± 2474.98 µmol·m-2·d-1 and 52.78 ± 54.44 mmol·m-2·d-1, respectively. Water quality parameters accounted for 80.49 % of the total variation in CH4 and CO2 concentrations and fluxes. Structural equation modeling indicated that TN, TP, DTC, and conductivity had direct effects on riverine CH4 and CO2 emissions, with standardized direct effects of 0.50 and 0.49, respectively. Nutrient input emerged as the primary driver, increasing CH4 and CO2 concentrations and fluxes, particularly in urban-adjacent river sections likely receiving higher nutrient loads. This study underscores that land use and urbanization indirectly influence riverine CH4 and CO2 emissions by modifying nutrient inputs. Effective land use management and nutrient input control are recommended strategies to mitigate riverine CH4 and CO2 emissions.
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Affiliation(s)
- Panpan Cui
- College of Water Conservancy, Shenyang Agricultural University, Shenyang 110866, PR China
| | - Lijuan Cui
- Institute of Wetland Research, Chinese Academy of Forestry, Beijing 100091, PR China
| | - Yunlong Zheng
- College of Water Conservancy, Shenyang Agricultural University, Shenyang 110866, PR China
| | - Fangli Su
- College of Water Conservancy, Shenyang Agricultural University, Shenyang 110866, PR China; Liaoning Panjin Wetland Ecosystem National Observation and Research Station, Shenyang 110866, PR China; Liaoning Shuangtai Estuary Wetland Ecosystem Research Station, Panjin 124112, PR China.
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68
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Zeng J, Li X, Song R, Xie H, Li X, Liu W, Liu H, Du Y, Xu M, Ren C, Yang G, Han X. Mechanisms of litter input changes on soil organic carbon dynamics: a microbial carbon use efficiency-based perspective. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175092. [PMID: 39079645 DOI: 10.1016/j.scitotenv.2024.175092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2024] [Revised: 07/23/2024] [Accepted: 07/25/2024] [Indexed: 08/03/2024]
Abstract
Plant litter is an important source of soil organic carbon (SOC) in terrestrial ecosystems, and the pattern of litter inputs is also influenced by global change and human activities. However, the current understanding of the impact of changes in litter inputs on SOC dynamics remains contentious, and the mechanisms by which changes in litter inputs affect SOC have rarely been investigated from the perspective of microbial carbon use efficiency (CUE). We conducted a 1-year experiment with litter treatments (no aboveground litter (NL), natural aboveground litter (CK), and double aboveground litter (DL)) in Robinia pseudoacacia plantation forest on the Loess Plateau. The objective was to assess how changes in litter input affect SOC accumulation in forest soils from the perspective of microbial CUE. Results showed that NL increased soil microbial C limitation by 77.11 % (0-10 cm) compared to CK, while it had a negligible effect on nitrogen and phosphorus limitation. In contrast, DL had no significant effect on soil microbial nutrient limitation. Furthermore, NL was found to significantly increase microbial CUE and decrease microbial metabolic quotient (QCO2), while the opposite was observed with DL. It is noteworthy that NL significantly contributed to an increase in SOC of 30.72 %, while DL had no significant effect on SOC. Correlation analysis showed that CUE was directly proportional to SOC and inversely proportional to QCO2. The partial least squares pathway model indicated that NL indirectly regulated the accumulation of SOC, mainly through two pathways: promoting microbial CUE increase and reducing QCO2. Overall, this study elucidates the mechanism and novel insights regarding SOC accumulation under changes in litter input from the perspective of microbial CUE. These findings are critical for further comprehension of soil carbon dynamics and the terrestrial C-cycle.
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Affiliation(s)
- Jia Zeng
- College of Agronomy, Northwest Agriculture & Forestry University, Yangling 712100, Shaanxi, PR China; Shaanxi Engineering Research Center of Circular Agriculture, Yangling 712100, Shaanxi, PR China
| | - Xiangyang Li
- College of Agronomy, Northwest Agriculture & Forestry University, Yangling 712100, Shaanxi, PR China; Shaanxi Engineering Research Center of Circular Agriculture, Yangling 712100, Shaanxi, PR China
| | - Rui Song
- College of Agronomy, Northwest Agriculture & Forestry University, Yangling 712100, Shaanxi, PR China
| | - Haoxuan Xie
- College of Agronomy, Northwest Agriculture & Forestry University, Yangling 712100, Shaanxi, PR China
| | - Xiangnan Li
- College of Agronomy, Northwest Agriculture & Forestry University, Yangling 712100, Shaanxi, PR China
| | - Weichao Liu
- College of Agronomy, Northwest Agriculture & Forestry University, Yangling 712100, Shaanxi, PR China; Shaanxi Engineering Research Center of Circular Agriculture, Yangling 712100, Shaanxi, PR China
| | - Hanyu Liu
- College of Agronomy, Northwest Agriculture & Forestry University, Yangling 712100, Shaanxi, PR China; Shaanxi Engineering Research Center of Circular Agriculture, Yangling 712100, Shaanxi, PR China
| | - Yaoyao Du
- College of Agronomy, Northwest Agriculture & Forestry University, Yangling 712100, Shaanxi, PR China
| | - Miaoping Xu
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, Shaanxi, PR China
| | - Chengjie Ren
- College of Agronomy, Northwest Agriculture & Forestry University, Yangling 712100, Shaanxi, PR China; Shaanxi Engineering Research Center of Circular Agriculture, Yangling 712100, Shaanxi, PR China
| | - Gaihe Yang
- College of Agronomy, Northwest Agriculture & Forestry University, Yangling 712100, Shaanxi, PR China; Shaanxi Engineering Research Center of Circular Agriculture, Yangling 712100, Shaanxi, PR China
| | - Xinhui Han
- College of Agronomy, Northwest Agriculture & Forestry University, Yangling 712100, Shaanxi, PR China.
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69
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Liu Z, Zhao M, Tennakoon K, Liu C. Climate factors determine large-scale spatial patterns of stomatal index in Chinese herbaceous and woody dicotyledonous plants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175112. [PMID: 39084391 DOI: 10.1016/j.scitotenv.2024.175112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 07/03/2024] [Accepted: 07/27/2024] [Indexed: 08/02/2024]
Abstract
The stomatal index (SI, %) and its response to climate factors (temperature and precipitation) can help our understanding of terrestrial carbon and water cycling and plant adaptation in the ecosystem, however, consensus has not yet been reached in this regard. In this study, we compiled an extensive dataset from the Chinese flora to investigate the response of SI to environmental change, including 891 herbaceous and woody species from 188 published papers. The results showed that mean values of the adaxial SI and abaxial SI for all species were 14.06 and 19.22, respectively, and the ratio of adaxial to abaxial SI was 0.84. For the adaxial SI, abaxial SI, and the ratio of adaxial to abaxial SI, the range of these values varied between 0.05-43.67, 0.01-48.17, and 0.03-4.31, respectively. Compared with woody plants, herbaceous plants showed higher values in both adaxial and abaxial SI. In terms of the impact of climate factors, the abaxial SI of herbaceous plants changed slower than the adaxial SI, while woody plants showed the opposite trend. Threshold effects of increased temperature and precipitation on SI were observed, indicating that SI responded differently to changes in climate factors at different levels. Climate factors play a crucial role in driving the adaxial SI than abaxial SI. Our findings highlight the significant challenges posed by divergent responses of SI in forecasting future water and carbon cycles associated with climatic and environmental change.
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Affiliation(s)
- Zhaogang Liu
- College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China; Co-Innovation Center for Sustainable Forestry in Southern China, Laboratory of Biodiversity and Conservation, College of Ecology and Environment, Nanjing Forestry University, Nanjing 210037, China; Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ming Zhao
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Kushan Tennakoon
- Institute of Innovation, Science and Sustainability, Federation University Australia Berwick Campus, No.100 Clyde Road, Berwick, VIC 3806, Australia
| | - Congcong Liu
- College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
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70
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Xu Z, Wang Y, Xie L, Shi D, He J, Chen Y, Feng C, Giesy JP, Leung KMY, Wu F. Resilient water quality management: Insights from Japan's environmental quality standards for conserving aquatic life framework. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2024; 22:100472. [PMID: 39247804 PMCID: PMC11378256 DOI: 10.1016/j.ese.2024.100472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 07/27/2024] [Accepted: 07/29/2024] [Indexed: 09/10/2024]
Abstract
Currently, chemicals and waste are recognized as key drivers of habitat degradation and biodiversity loss in aquatic ecosystems. To ensure vibrant habitats for aquatic species and maintain a sustainable aquatic food supply system, Japan promulgated its Environmental Quality Standards for the Conservation of Aquatic Life (EQS-CAL), based on its own aquatic life water quality criteria (ALWQC) derivation method and application mechanism. Here we overview Japan's EQS-CAL framework and highlight their best practices by examining the framework systems and related policies. Key experiences from Japan's EQS-CAL system include: (1) Classifying six types of aquatic organisms according to their adaptability to habitat status; (2) Using a risk-based chemical screening system for three groups of chemical pollutants; (3) Recommending a five-step method for determining ALWQC values based on the most sensitive life stage of the most sensitive species; (4) Applying site-specific implementation mechanisms through a series of Plan-Do-Check-Act loops. This paper offers scientific references for other jurisdictions, aiding in the development of more resilient ALWQC systems that can maintain healthy environments for aquatic life and potentially mitigate ongoing threats to human societies and global aquatic biodiversity.
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Affiliation(s)
- Zihan Xu
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Ying Wang
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Li Xie
- Department of Civil Engineering, Nagoya Institute of Technology (Nitech), Nagoya, 4668555, Japan
| | - Di Shi
- Research & Development Affairs Office, Tsinghua University, Beijing, 100084, China
| | - Jia He
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China
| | - Yanqing Chen
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Chenglian Feng
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - John P Giesy
- Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5B3, Canada
- Department of Integrative Biology and Center for Integrative Toxicology, Michigan State University, East Lansing, MI, 48895, USA
- Department of Environmental Sciences, Baylor University, Waco, TX, 76798-7266, USA
| | - Kenneth M Y Leung
- State Key Laboratory of Marine Pollution and Department of Chemistry, City University of Hong Kong, Hong Kong, 999077, China
| | - Fengchang Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
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71
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Wang L, Lu W, Song Y, Liu S, Fu YV. Using machine learning to identify environmental factors that collectively determine microbial community structure of activated sludge. ENVIRONMENTAL RESEARCH 2024; 260:119635. [PMID: 39025351 DOI: 10.1016/j.envres.2024.119635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 07/12/2024] [Accepted: 07/15/2024] [Indexed: 07/20/2024]
Abstract
Activated sludge (AS) microbial communities are influenced by various environmental variables. However, a comprehensive analysis of how these variables jointly and nonlinearly shape the AS microbial community remains challenging. In this study, we employed advanced machine learning techniques to elucidate the collective effects of environmental variables on the structure and function of AS microbial communities. Applying Dirichlet multinomial mixtures analysis to 311 global AS samples, we identified four distinct microbial community types (AS-types), each characterized by unique microbial compositions and metabolic profiles. We used 14 classical linear and nonlinear machine learning methods to select a baseline model. The extremely randomized trees demonstrated optimal performance in learning the relationship between environmental factors and AS types (with an accuracy of 71.43%). Feature selection identified critical environmental factors and their importance rankings, including latitude (Lat), longitude (Long), precipitation during sampling (Precip), solids retention time (SRT), effluent total nitrogen (Effluent TN), average temperature during sampling month (Avg Temp), mixed liquor temperature (Mixed Temp), influent biochemical oxygen demand (Influent BOD), and annual precipitation (Annual Precip). Significantly, Lat, Long, Precip, Avg Temp, and Annual Precip, influenced metabolic variations among AS types. These findings emphasize the pivotal role of environmental variables in shaping microbial community structures and enhancing metabolic pathways within activated sludge. Our study encourages the application of machine learning techniques to design artificial activated sludge microbial communities for specific environmental purposes.
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Affiliation(s)
- Lu Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Weilai Lu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yang Song
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shuangjiang Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yu Vincent Fu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing, 100049, China.
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72
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Austin AT, Ballaré CL. Photodegradation in terrestrial ecosystems. THE NEW PHYTOLOGIST 2024; 244:769-785. [PMID: 39262084 DOI: 10.1111/nph.20105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 06/26/2024] [Indexed: 09/13/2024]
Abstract
The first step in carbon (C) turnover, where senesced plant biomass is converted through various pathways into compounds that are released to the atmosphere or incorporated into the soil, is termed litter decomposition. This review is focused on recent advances of how solar radiation can affect this important process in terrestrial ecosystems. We explore the photochemical degradation of plant litter and its consequences for biotic decomposition and C cycling. The ubiquitous presence of lignin in plant tissues poses an important challenge for enzymatic litter decomposition due to its biological recalcitrance, creating a substantial bottleneck for decomposer organisms. The recognition that lignin is also photolabile and can be rapidly altered by natural doses of sunlight to increase access to cell wall carbohydrates and even bolster the activity of cell wall degrading enzymes highlights a novel role for lignin in modulating rates of litter decomposition. Lignin represents a key functional connector between photochemistry and biochemistry with important consequences for our understanding of how sunlight exposure may affect litter decomposition in a wide range of terrestrial ecosystems. A mechanistic understanding of how sunlight controls litter decomposition and C turnover can help inform management and other decisions related to mitigating human impact on the planet.
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Affiliation(s)
- Amy T Austin
- IFEVA, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Buenos Aires, Argentina
| | - Carlos L Ballaré
- IFEVA, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Buenos Aires, Argentina
- IIBio, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de San Martín, B1650HMP, Buenos Aires, Argentina
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73
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Clower PO, Maiti K, Bowles M. Contrasting organic carbon respiration pathways in coastal wetlands undergoing accelerated sea level changes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:174898. [PMID: 39059644 DOI: 10.1016/j.scitotenv.2024.174898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 06/20/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024]
Abstract
Carbon cycling in coastal wetland soil is controlled by a complex interplay between microbial processes and porewater chemistry that are often influenced by various external forcings like wind, river discharge, and sea-level changes, where most of the organic carbon is mineralized to its inorganic form by various aerobic and anaerobic respiration pathways. The export of this inorganic carbon (DIC) from coastal wetlands has long been recognized as a significant component of the global carbon cycle. The major objective of this work is to determine the relative contribution of various respiration pathways to seasonal DIC production in two contrasting marshes (brackish and salt). The DIC fluxes estimates for the brackish and salt marshes were found to range between 36.52 ± 5.81 and 33.98 ± 2.21 mmol m-2 d-1 in winter and 133.10 ± 102.60 and 82.37 ± 30.87 mmol m-2 d-1 during summer of 2020. For the brackish marsh, aerobic respiration and iron reduction were found to be the primary contributors to DIC production representing 17.91-35.21 % and 61.13-81.97 % of total measured organic matter (OM) respiration respectively. On the other hand, aerobic respiration and sulfate reduction were the primary contributors to DIC production in the salt marsh, accounting for 37.91-83.93 % and 15.87-62.04 % of the total measured OM respiration respectively. The Mississippi River Deltaic Plain experiences high relative sea level rise and expected to undergo rapid change in salinity regime in near future from additional changes in river discharge, proposed sediment diversion plans, and storm surge intensities. The current study represents the first attempt to concurrently estimate various respiration pathways in this region and more studies are needed to understand the trajectories of soil OM respiration pathways and its impact on coastal carbon cycling.
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Affiliation(s)
- P Owen Clower
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Kanchan Maiti
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, USA.
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74
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Gianasi FM, de Andrade Maia V, Oliveira AM, Pompeu PV, de Souza CR, Farrapo CL, da Silva-Sene AM, de Oliveira F, Meireles TM, de Carvalho Rodrigues AL, Madeira DM, Araújo FC, Silva LCA, Ferreira LAS, Santos LR, Reis MG, Pereira RT, Souza TA, de Oliveira Alves Braga M, de Lima E Silva VFP, van Meerveld I, Dos Santos RM. Water level regime variation is a crucial driver for taxonomic, functional, and phylogenetic diversity in seasonally flooded tropical forests. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175195. [PMID: 39094665 DOI: 10.1016/j.scitotenv.2024.175195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 07/24/2024] [Accepted: 07/30/2024] [Indexed: 08/04/2024]
Abstract
Floodplains contribute significantly to terrestrial ecosystem service provision but are also among the most vulnerable and degraded ecosystems worldwide. Heterogeneity in floodplain properties arises from variations in river-specific flood regimes, watershed characteristics, and valley morphology, influencing seasonally flooded forests' taxonomic, functional, and phylogenetic diversity. This study addresses persisting knowledge gaps in floodplain ecology, focusing on the seasonally dry tropics. We explore the relationships between flood regime, environmental conditions, vegetation composition, functional and phylogenetic diversity, and the impact of environmental variables on above-ground biomass (AGB) and ecological strategies. The study spans six rivers in southeastern Brazil's main river basins: Rio Grande and São Francisco. We identified five eco-units in each floodplain based on flooding regimes and surveyed six plots per eco-unit. We measured trees with DBH > 5 cm and collected functional traits, along with detailed soil, climate, and water level data. We calculated plot-level floristic composition, taxonomic, functional, and phylogenetic diversity, wood density, and AGB. Functional and phylogenetic dissimilarity were analyzed, and the effects of climate, soil, and hydrological variables were quantified using generalized linear mixed models. We show how flood frequency and duration affect floristic composition across the floodplains. Taxonomic and phylogenetic diversity responded to climate, soil, and hydrological variables, while functional diversity responded primarily to hydrological variables, emphasizing the role of environmental filtering. Hydrological seasonality, soil fertility, and flood regime emerged as key factors shaping community structure and ecological strategies in the studied seasonally flooded tropical forests. Plot-level AGB responded to phosphorus but not to climate or hydrological variables. The study also highlights functional and phylogenetic dissimilarities among eco-units and basins, indicating potential climate change impacts.
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Affiliation(s)
- Fernanda Moreira Gianasi
- Department of Biology, Graduate Program in Applied Botany, Federal University of Lavras, Lavras, MG 37200-000, Brazil; Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil.
| | - Vinícius de Andrade Maia
- Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | | | | | - Cléber Rodrigo de Souza
- Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Camila Laís Farrapo
- Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - André Maciel da Silva-Sene
- Department of Biology, Graduate Program in Applied Botany, Federal University of Lavras, Lavras, MG 37200-000, Brazil; Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Fernanda de Oliveira
- Department of Biology, Graduate Program in Applied Botany, Federal University of Lavras, Lavras, MG 37200-000, Brazil; Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Thiago Magalhães Meireles
- Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Ana Lívia de Carvalho Rodrigues
- Department of Biology, Graduate Program in Applied Botany, Federal University of Lavras, Lavras, MG 37200-000, Brazil; Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Denise Moura Madeira
- Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Felipe Carvalho Araújo
- Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Lidiany Carolina Arantes Silva
- Department of Biology, Graduate Program in Applied Botany, Federal University of Lavras, Lavras, MG 37200-000, Brazil; Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Leony Aparecido Silva Ferreira
- Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Lucélia Rodrigues Santos
- Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Miguel Gama Reis
- Department of Biology, Graduate Program in Applied Botany, Federal University of Lavras, Lavras, MG 37200-000, Brazil; Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Rafaella Tavares Pereira
- Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Tatiane Almeida Souza
- Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Michael de Oliveira Alves Braga
- Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | | | | | - Rubens Manoel Dos Santos
- Department of Biology, Graduate Program in Applied Botany, Federal University of Lavras, Lavras, MG 37200-000, Brazil; Phytogeography and Evolutionary Ecology Laboratory, Department of Forest Sciences, Federal University of Lavras, Lavras, MG 37200-000, Brazil
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75
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Patel L, Singh R, Gowd SC, Thottathil SD. Environmental determinants of aerobic methane oxidation in a tropical river network. WATER RESEARCH 2024; 265:122257. [PMID: 39178592 DOI: 10.1016/j.watres.2024.122257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 07/08/2024] [Accepted: 08/12/2024] [Indexed: 08/26/2024]
Abstract
Aerobic methane oxidation (MOX) significantly reduces methane (CH4) emissions from inland water bodies and is, therefore, an important determinant of global CH4 budget. Yet, the magnitude and controls of MOX rates in rivers - a quantitatively significant natural source of atmospheric CH4 - are poorly constrained. Here, we conducted a series of incubation experiments to understand the magnitude and environmental controls of MOX rates in tropical fluvial systems. We observed a large variability in MOX rate (0.03 - 3.45 μmol l-1d-1) shaped by a suit of environmental variables. Accordingly, we developed an empirical model for MOX that incorporate key environmental drivers, including temperature, CH4, total phosphorus, and dissolved oxygen (O2) concentrations, based on the results of our incubation experiments. We show that temperature dependency of MOX (activation energy: 0.66 ± 0.18 eV) is lower than that of sediment methanogenesis (0.71 ± 0.21 eV) in the studied tropical fluvial network. Furthermore, we observed a non-linear relationship between O2 concentration and MOX, with the highest MOX rate occuring ∼135 μmol O2l-1, above or below this "optimal O2" concentration, MOX rate shows a gradual decline. Together, our results suggest that the relatively lower temperature response of MOX compared to methanogenesis along with the projected decrease of O2 concentration due to organic pollution may cause elevated CH4 emission from tropical southeast Asian rivers. Since estimation of CH4 oxidation is often neglected in routine CH4 monitoring programs, the model developed here may help to integrate MOX rate into process-based models for fluvial CH4 budget.
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Affiliation(s)
- Latika Patel
- Department of Environmental Science and Engineering, SRM University-AP, Amaravati, Andhra Pradesh 522 502, India
| | - Rashmi Singh
- Department of Environmental Science and Engineering, SRM University-AP, Amaravati, Andhra Pradesh 522 502, India
| | - Sarath C Gowd
- Department of Environmental Science and Engineering, SRM University-AP, Amaravati, Andhra Pradesh 522 502, India
| | - Shoji D Thottathil
- Department of Environmental Science and Engineering, SRM University-AP, Amaravati, Andhra Pradesh 522 502, India.
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76
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Valladares-Castellanos M, de Jesús Crespo R, Xu YJ, Douthat TH. A framework for validating watershed ecosystem service models in the United States using long-term water quality data: Applications with the InVEST Nutrient Delivery (NDR) model in Puerto Rico. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175111. [PMID: 39079631 DOI: 10.1016/j.scitotenv.2024.175111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 07/26/2024] [Accepted: 07/26/2024] [Indexed: 08/05/2024]
Abstract
Modeling of watershed Ecosystem Services (ES) processes has increased greatly in recent years, potentially improving environmental management and decision-making by describing the value of nature. ES models may be sensitive to different conditions and, therefore, should ideally be validated against observed data for their use as a decision-support instrument. However, outcomes from such ES modeling are barely validated, making it difficult to assess uncertainties associated with the modeling and justify their actual usefulness to develop generalizable management recommendations. This study proposes a framework for the systematic validation of one of such tools, the InVEST Nutrient Delivery Model (NDR) for nutrient retention estimates. The framework is divided into three stages: 1) running the NDR model inputs, processes, and outputs; 2) building a long-term reference dataset from open access water quality observations; and 3) using the reference data for model calibration and validation. We applied this framework to twenty watersheds in the Commonwealth of Puerto Rico, where data availability resembles thar of watersheds across the United States. Long-term water quality data from monitoring stations facilitated model calibration and validation. Our framework provided a reproducible method to linking the vast monitoring network in the U.S. and its territories for evaluating the InVEST's NDR model performance. Beyond the framework development, this study found that the InVEST NDR model explained 62.7 % and 79.3 % of the variance in the total nitrogen and total phosphorus between 2000 and 2022, respectively, supporting the suitability of the model for watershed scale ecosystem services assessment. The findings can also serve as a reference to support the use of InVEST for other locations in the tropics without publically available monitoring data.
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Affiliation(s)
| | | | - Y Jun Xu
- Department of Renewable Natural Resources, Louisiana State University, Baton Rouge, LA, USA; Coastal Studies Institute, Louisiana State University, Baton Rouge, LA, USA
| | - Thomas H Douthat
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA, USA.
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77
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Wang L, Wang Y, Sun D, Wang J, Lee SJ, Viscarra Rossel RA, Gan Y. Soil carbon stocks in temperate grasslands reach equilibrium with grazing duration. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175081. [PMID: 39069182 DOI: 10.1016/j.scitotenv.2024.175081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 07/13/2024] [Accepted: 07/25/2024] [Indexed: 07/30/2024]
Abstract
Lost soil organic carbon (SOC) in degraded grasslands can be restored via the 'grazing exclusion' practice, but it was unknown how long (# of years) the restoration process can take. A synthesis of four decades of studies revealed that grazing exclusion increased SOC stocks in the topsoil (0-0.30 m) by 14.8 % (±0.8 Std Err), on average, compared to moderate-to-heavy grazing (MtH); During which SOC stock increased steadily, peaked in Year 18.5, and then declined. At peak, SOC stock was 42.5 % greater under grazing exclusion than under MtH due to 100.4 ± 4.2 % increase in aboveground biomass and 80.3 ± 33.5 % increase in root biomass. Grazing exclusion also increased soil C:N ratio by 7.6 % while decreasing bulk density by 9.4 %. Grazing exclusion could be ceased 18.5 years after initiation of grazing exclusion as plant biomass input balances carbon decomposition and SOC equilibrium occurs then additional benefits start diminishing.
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Affiliation(s)
- Li Wang
- College of Life and Environmental Science, State & Local Joint Engineering Research Center for Ecological Treatment Technology of Urban Water Pollution, Zhejiang Provincial Key Lab for Water Environment and Marine Biological Resources Protection, Zhejiang Provincial Collaborative Innovation Center for Tideland Reclamation and Ecological Protection, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Yijia Wang
- College of Life and Environmental Science, State & Local Joint Engineering Research Center for Ecological Treatment Technology of Urban Water Pollution, Zhejiang Provincial Key Lab for Water Environment and Marine Biological Resources Protection, Zhejiang Provincial Collaborative Innovation Center for Tideland Reclamation and Ecological Protection, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Dandi Sun
- College of Life and Environmental Science, State & Local Joint Engineering Research Center for Ecological Treatment Technology of Urban Water Pollution, Zhejiang Provincial Key Lab for Water Environment and Marine Biological Resources Protection, Zhejiang Provincial Collaborative Innovation Center for Tideland Reclamation and Ecological Protection, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Junying Wang
- College of Life and Environmental Science, State & Local Joint Engineering Research Center for Ecological Treatment Technology of Urban Water Pollution, Zhejiang Provincial Key Lab for Water Environment and Marine Biological Resources Protection, Zhejiang Provincial Collaborative Innovation Center for Tideland Reclamation and Ecological Protection, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Soon-Jae Lee
- Department of Ecology and Evolution, University of Lausanne, Lausanne CH1015, Switzerland
| | | | - Yantai Gan
- College of Life and Environmental Science, State & Local Joint Engineering Research Center for Ecological Treatment Technology of Urban Water Pollution, Zhejiang Provincial Key Lab for Water Environment and Marine Biological Resources Protection, Zhejiang Provincial Collaborative Innovation Center for Tideland Reclamation and Ecological Protection, Wenzhou University, Wenzhou, Zhejiang 325035, China; Agroecosystems, The UBC-Soil Group, Tallus Heights, Kelowna, BC V4T 3M2, Canada.
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78
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Liu Q, Yin S, Yi Y. A bacteria-based index of biotic integrity indicates aquatic ecosystem restoration. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2024; 22:100451. [PMID: 39148555 PMCID: PMC11325675 DOI: 10.1016/j.ese.2024.100451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 07/04/2024] [Accepted: 07/05/2024] [Indexed: 08/17/2024]
Abstract
Intensive ecological interventions have been carried out in highly polluted shallow lakes to improve their environments and restore their ecosystems. However, certain treatments, such as dredging polluted sediment and stocking fish, can impact the aquatic communities, including benthos and fishes. These impacts can alter the composition and characteristics of aquatic communities, which makes community-based ecological assessments challenging. Here we develop a bacteria-based index of biotic integrity (IBI) that can clearly indicate the restoration of aquatic ecosystems with minimal artificial interventions. We applied this method to a restored shallow lake during 3-year intensive ecological interventions. The interventions reduced nutrients and heavy metals by 27.1% and 16.7% in the sediment, while the total organic carbon (TOC) increased by 8.0% due to the proliferation of macrophytes. Additionally, the abundance of sulfur-related metabolic pathways decreased by 10.5% as the responses to improved ecosystem. The score of bacteria-based IBI, which is calculated based on the diversity, composition, and function of benthic bacterial communities, increased from 0.62 in 2018 to 0.81 in 2021. Our study not only provides an applicable method for aquatic ecological assessment under intensive artificial interventions but also extends the application of IBI to complex application scenarios, such as ecosystems with significantly different aquatic communities and comparisons between different basins.
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Affiliation(s)
- Qi Liu
- School of Environment, Beijing Normal University, Beijing 100875, China
- State Key Laboratory of Water Environment Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China
| | - Senlu Yin
- School of Environment, Beijing Normal University, Beijing 100875, China
- State Key Laboratory of Water Environment Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China
| | - Yujun Yi
- School of Environment, Beijing Normal University, Beijing 100875, China
- State Key Laboratory of Water Environment Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China
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79
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Oostdijk M, Elsler LG, Van Deelen J, Auping WL, Kwakkel J, Schadeberg A, Vastenhoud BMJ, Nedelciu CE, Berzaghi F, Prellezo R, Wisz MS. Modeling fisheries and carbon sequestration ecosystem services under deep uncertainty in the ocean twilight zone. AMBIO 2024; 53:1632-1648. [PMID: 39207669 PMCID: PMC11436683 DOI: 10.1007/s13280-024-02044-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 02/17/2024] [Accepted: 05/21/2024] [Indexed: 09/04/2024]
Abstract
Mesopelagic fishes are a vital component of the biological carbon pump and are, to date, largely unexploited. In recent years, there has been an increased interest in harvesting the mesopelagic zone to produce fish feed for aquaculture. However, great uncertainties exist in how the mesopelagic zone interacts with the climate and food webs, presenting a dilemma for policy. Here, we investigate the consequences of potential policies relating to mesopelagic harvest quotas with a dynamic social-ecological modeling approach, combining system dynamics and global sensitivity analyses informed by participatory modeling. Our analyses reveal that, in simulations of mesopelagic fishing scenarios, uncertainties about mesopelagic fish population dynamics have the most pronounced influence on potential outcomes. The analysis also shows that prioritizing the development of the fishing industry over environmental protection would lead to a significantly higher social cost of climate change to society. Given the large uncertainties and the potential large impacts on oceanic carbon sequestration, a precautionary approach to developing mesopelagic fisheries is warranted.
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Affiliation(s)
- Maartje Oostdijk
- Faculty of Agricultural Sciences, Agricultural University of Iceland, Keldnaholt, Árleynir 22, 112, Reykjavík, Iceland.
| | - Laura G Elsler
- Harvard. T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Julie Van Deelen
- Policy Analysis Section, Department of Multi-Actor Systems, Faculty of Technology, Policy and Management, Delft University of Technology, Jaffalaan 5, 2628 BX, Delft, The Netherlands
| | - Willem L Auping
- Policy Analysis Section, Department of Multi-Actor Systems, Faculty of Technology, Policy and Management, Delft University of Technology, Jaffalaan 5, 2628 BX, Delft, The Netherlands.
| | - Jan Kwakkel
- Policy Analysis Section, Department of Multi-Actor Systems, Faculty of Technology, Policy and Management, Delft University of Technology, Jaffalaan 5, 2628 BX, Delft, The Netherlands
| | - Amanda Schadeberg
- Environmental Economics and Natural Resources Group, Wageningen University, Hollandseweg 1, 6706 KN, Wageningen, The Netherlands
- Environmental Policy Group, Wageningen University, Hollandseweg 1, 6706 KN, Wageningen, The Netherlands
| | - Berthe M J Vastenhoud
- National Institute of Aquatic Resources, Technical University of Denmark, Kemitorvet 201, 2800, Kgs. Lyngby, Denmark
| | - Claudiu Eduard Nedelciu
- Department of Geography, System Dynamics Group, University of Bergen, Fosswinckelsgate 6, 5007, Bergen, Norway
| | - Fabio Berzaghi
- Ocean Sustainability, Governance and Management, World Maritime University, Fiskehamnsgatan 1, 211 18, Malmö, Sweden
| | - Raul Prellezo
- AZTI. Marine Research Unit. Txatxarramendi Ugartea Z/G, 48395, Txatxarramendi, Sukarrieta, Spain
| | - Mary S Wisz
- Science Institute, University of Iceland, Saemundargata 2, 101, Reykjavik, Iceland
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80
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Cuartero J, Querejeta JI, Prieto I, Frey B, Alguacil MM. Warming and rainfall reduction alter soil microbial diversity and co-occurrence networks and enhance pathogenic fungi in dryland soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175006. [PMID: 39069184 DOI: 10.1016/j.scitotenv.2024.175006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 07/10/2024] [Accepted: 07/22/2024] [Indexed: 07/30/2024]
Abstract
In this 9-year manipulative field experiment, we examined the impacts of experimental warming (2 °C, W), rainfall reduction (30 % decrease in annual rainfall, RR), and their combination (W + RR) on soil microbial communities and native vegetation in a semi-arid shrubland in south-eastern Spain. Warming had strong negative effects on plant performance across five coexisting native shrub species, consistently reducing their aboveground biomass growth and long-term survival. The impacts of rainfall reduction on plant growth and survival were species-specific and more variable. Warming strongly altered the soil microbial community alpha-diversity and changed the co-occurrence network structure. The relative abundance of symbiotic arbuscular mycorrhizal fungi (AMF) increased under W and W + RR, which could help buffer the direct negative impacts of climate change on their host plants nutrition and enhance their resistance to heat and drought stress. Indicator microbial taxa analyses evidenced that the marked sequence abundance of many plant pathogenic fungi, such as Phaeoacremonium, Cyberlindnera, Acremonium, Occultifur, Neodevriesia and Stagonosporopsis, increased significantly in the W and W + RR treatments. Moreover, the relative abundance of fungal animal pathogens and mycoparasites in soil also increased significantly under climate warming. Our findings indicate that warmer and drier conditions sustained over several years can alter the soil microbial community structure, composition, and network topology. The projected warmer and drier climate favours pathogenic fungi, which could offset the benefits of increased AMF abundance under warming and further aggravate the severe detrimental impacts of increased abiotic stress on native vegetation performance and ecosystem services in drylands.
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Affiliation(s)
- J Cuartero
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland.
| | - J I Querejeta
- Departamento de Conservación de Suelos y Agua, Centro de Edafología y Biología Aplicada del Segura - Consejo Superior de Investigaciones Científicas, Murcia, Spain
| | - I Prieto
- Departamento de Conservación de Suelos y Agua, Centro de Edafología y Biología Aplicada del Segura - Consejo Superior de Investigaciones Científicas, Murcia, Spain; Area de Ecología, Facultad de Ciencias Biológicas y Ambientales, Departamento de Biodiversidad y Gestión Ambiental, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - B Frey
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - M M Alguacil
- Departamento de Conservación de Suelos y Agua, Centro de Edafología y Biología Aplicada del Segura - Consejo Superior de Investigaciones Científicas, Murcia, Spain
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81
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Su S, Zhang Z, Lin J, Owens G, Chen Z. How nitrate and ammonium impact soil organic carbon transformation with reference to aggregate size. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175213. [PMID: 39111442 DOI: 10.1016/j.scitotenv.2024.175213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 07/08/2024] [Accepted: 07/31/2024] [Indexed: 08/17/2024]
Abstract
While nitrogen (N) deposition and over-fertilization enrich N in soil, it is unclear how it impacts soil organic carbon (SOC) transformation at the aggregate scale. Herein, a 90-day study reveals the transformation mechanisms of SOC in soil aggregates under nitrate and ammonium enrichment conditions. Results showed that nitrate treatment (NT) and ammonium treatment (AT) significantly increased SOC content by 15.6 % and 18.9 %, respectively. In addition, NT increased SOC accrual in large macro-aggregates (LMA), while AT increased SOC accrual in small macro-aggregates (SMA) and micro-aggregates (MA). Further analysis of pyrolysis products showed that N enrichment drove the transformation of labile soil organic matter (SOM) composition into recalcitrant SOM, with polysaccharides declining from 19-30 % to 2-13 %, while lipids rose from 18-27 % to 33-45 %. LMA and SMA contained more aromatic compounds than MA. This is linked to the inhibition of the expression of C degradation function genes, while almost all genes encoding SOC degradation are down-regulated under N enrichment. In the meantime, NT increased the abundance of genes encoding the degradation of N-containing compounds in LMA. Moreover, NO3- enrichment exerted a higher inhibitory effect on labile SOC degradation while NH4+ enrichment substantially inhibited recalcitrant SOC. Finally, Random Forest analysis confirmed that N enrichment elevated the importance of N-containing compounds' metabolism, which diminished when the size of soil aggregates decreased. In contrast, the importance of genes encoding saccharides and cellulose metabolism increased in smaller aggregates. This study highlights that both N type and aggregate size were determining factors in shaping SOC transformation in the N enrichment process.
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Affiliation(s)
- Shixun Su
- Fujian Key Laboratory of Pollution Control and Resource Reuse, College of Environmental and Resource Sciences, Fujian Normal University, Fuzhou 350117, Fujian Province, China
| | - Zhenjun Zhang
- Fujian Key Laboratory of Pollution Control and Resource Reuse, College of Environmental and Resource Sciences, Fujian Normal University, Fuzhou 350117, Fujian Province, China
| | - Jiajiang Lin
- Fujian Key Laboratory of Pollution Control and Resource Reuse, College of Environmental and Resource Sciences, Fujian Normal University, Fuzhou 350117, Fujian Province, China.
| | - Gary Owens
- Environmental Contaminants Group, Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia
| | - Zuliang Chen
- Fujian Key Laboratory of Pollution Control and Resource Reuse, College of Environmental and Resource Sciences, Fujian Normal University, Fuzhou 350117, Fujian Province, China; Environmental Contaminants Group, Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia.
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82
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Dong S, Li L, Shi X, Ma M, Liu F, Lei J. Inorganic carbon migration and transformation in groundwater evaporation discharge area. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:174994. [PMID: 39069180 DOI: 10.1016/j.scitotenv.2024.174994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 07/11/2024] [Accepted: 07/21/2024] [Indexed: 07/30/2024]
Abstract
During groundwater evaporation discharge, a series of carbon-related water-rock interactions potentially impact the terrestrial carbon cycle significantly. However, the migration and transformation of carbon in groundwater evaporation discharge area remain inadequately understood. Using the Tumochuan Plain in Inner Mongolia as a case study, this paper constructs a carbon balance equation for groundwater evaporation discharge area by employing mass balance principles and hydrogeochemical simulation methods, thereby analyzing the mechanisms of carbon diversion during groundwater evaporation. The result showed that evaporation discharge area of Tumochuan Plain was a 'carbon sink'. Carbon emission rate to atmosphere in study area was 7.35 g/(m2·a), while carbon fixation rate by calcite precipitation and dissolved inorganic carbon (DIC) into groundwater was 37.15 g/(m2·a). The precipitation of calcite and the dissolution of dolomite were the main water-rock interactions controlling the migration and transformation of DIC. The carbon absorbed by dolomite dissolution reached 21,698.02 t/a (30.56 g/(m2·a)), offsetting a significant portion of the CO2 emitted during calcite precipitation. In addition, the calcium released by the dissolution of dolomite and anorthite effectively promoted the precipitation of calcite, which was the primary factor for groundwater to become a carbon sink in this area.
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Affiliation(s)
- Shaogang Dong
- School of Ecology and Environment, Inner Mongolia University, Hohhot, Inner Mongolia, 010021, China.
| | - Lu Li
- School of Ecology and Environment, Inner Mongolia University, Hohhot, Inner Mongolia, 010021, China
| | - Xiaolong Shi
- Inner Mongolia Autonomous Region Environmental Monitoring Station Hohhot Sub-station, Hohhot, Inner Mongolia, 010030, China
| | - Mingyan Ma
- School of Ecology and Environment, Inner Mongolia University, Hohhot, Inner Mongolia, 010021, China
| | - Fanyao Liu
- School of Ecology and Environment, Inner Mongolia University, Hohhot, Inner Mongolia, 010021, China
| | - Junhao Lei
- School of Ecology and Environment, Inner Mongolia University, Hohhot, Inner Mongolia, 010021, China
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83
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Pan F, Yang Q, Liang Y, Yu X, Hu P, Zhang W, Pang Y. Lithology and elevated temperature impact phoD-harboring bacteria on soil available P enhancing in subtropical forests. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174815. [PMID: 39019286 DOI: 10.1016/j.scitotenv.2024.174815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 07/13/2024] [Accepted: 07/13/2024] [Indexed: 07/19/2024]
Abstract
Plants are generally limited by soil phosphorus (P) deficiency in forest ecosystems. Soil available P is influenced by lithology, temperature, and soil microbes. However, the interactive effects of these factors on soil P availability in subtropical forests remain unclear. To assess their impacts, we measured soil inorganic and available P fractions and the diversity, composition, and co-occurrence network of phoD-harboring bacteria in two contrasting forest soils (lithosols in karst forests and ferralsols in non-karst forests) in the subtropical regions of southwestern China across six temperature gradients. The present results showed that the complexities in composition and network and the diversity indices of phoD-harboring bacteria were higher in the karst forest soils than those in the non-karst forest soils, with marked differences in composition. In both types of forest soils, the complexities of composition and networks and the diversity indices were higher in the high-temperature regions (mean annual temperature (MAT) > 16 °C) compared to the low-temperature regions (MAT <16 °C). Soil total inorganic and available P contents were lower in the karst forest soils compared to the non-karst forest soils. Soil total available P contents were lower in the high temperature regions than those in the low temperature regions in both forest soils, whereas soil total inorganic P contents were contrary. Variance partitioning analysis showed that soil inorganic and available P fractions were predominantly explained by lithology and its interaction with soil microbes and climate. The present findings demonstrate that soil P availability in subtropical forests of southwestern China is influenced by lithology and temperature, which regulate the diversity, composition, and network connectivity of phoD-harboring bacteria. Furthermore, this study highlights the significance of controlling the composition of phoD-harboring bacteria for mitigating plant P deficiency in karst ecosystems.
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Affiliation(s)
- Fujing Pan
- College of Environmental and Engineering, Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control, Guilin University of Technology, Guilin 541006, Guangxi, China; Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin 541006, Guangxi, China
| | - Qian Yang
- College of Environmental and Engineering, Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control, Guilin University of Technology, Guilin 541006, Guangxi, China; Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin 541006, Guangxi, China
| | - Yueming Liang
- Karst Dynamics Laboratory, Ministry of natural Resources, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004, Guangxi, China.
| | - Xuan Yu
- College of Environmental and Engineering, Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control, Guilin University of Technology, Guilin 541006, Guangxi, China; Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin 541006, Guangxi, China
| | - Peilei Hu
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China; Huanjiang Agriculture Ecosystem Observation and Research Station of Guangxi, Guangxi Key Laboratory of Karst Ecological Process and Services, Huanjiang Observation and Research of karst Ecosystems, Chinese Academy of Sciences, Huanjiang 547100, Guangxi, China
| | - Wei Zhang
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China; Huanjiang Agriculture Ecosystem Observation and Research Station of Guangxi, Guangxi Key Laboratory of Karst Ecological Process and Services, Huanjiang Observation and Research of karst Ecosystems, Chinese Academy of Sciences, Huanjiang 547100, Guangxi, China.
| | - Yuelan Pang
- Guangxi Field Scientific Observation and Research Station for Tea Resources, Institute of Tea Science Research, Guangxi Zhuang Autonomous Region, Guilin 541000, Guangxi, China
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84
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Senarathne S, van Geldern R, Chandrajith R, Barth JAC. Unexpected contributions by carbonates and organic matter in a silicate-dominated tropical catchment: An isotope approach. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174651. [PMID: 38992376 DOI: 10.1016/j.scitotenv.2024.174651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 07/07/2024] [Accepted: 07/07/2024] [Indexed: 07/13/2024]
Abstract
The understanding of global carbon has rarely extended to small-scale tropical river basins. To address these uncertainties, this study aims to investigate the importance of rock weathering and organic matter turnover in the carbon cycle in a terrain dominated by crystalline silicate rocks. The geochemical composition of the dissolved and particulate carbon phases (DIC, DOC and POC) and their stable carbon isotopes were studied in the Deduru Oya River in Sri Lanka. Dissolved inorganic carbon (DIC) was the most dominant carbon phase and its contribution to the total carbon pool varied between 67 and 89 %. Furthermore, the δ13CDIC values in the river varied between -1.1 and -16.5 ‰. The lithological characteristics and molar ratios between Ca2+, Mg2+ and HCO3- indicated rock weathering mainly by CO2 and carbonic acid. The δ13CDIC values for groundwater input were -15.9 ‰, while for carbonate weathering, mainly due to fertiliser input, they reached a value of -12.7 ‰. This input was fed into an isotope mass balance to determine the relative contributions. However, the isotope mass balance was only plausible after correcting for the effects on δ13CDIC caused by degassing and photosynthesis. Our study demonstrated that carbonate weathering and organic matter turnover are essential components of the river carbon cycle even in a silicate dominated catchment. They can represent up to 60 % of the DIC pool. Combined with the higher organic matter turnover and high pCO2 in the river water, it can be suggested that the Deduru Oya River acts as a net source of CO2 in the atmosphere. Our study shows that CO2 degassing and in-stream photosynthesis in tropical river systems need to be considered along with chemical weathering to account for carbon transport and turnover in tropical rivers.
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Affiliation(s)
- Sachintha Senarathne
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Department Geographie und Geowissenschaften, 91054 Erlangen, GeoZentrum Nordbayern, Schlossgarten 5, Germany.
| | - Robert van Geldern
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Department Geographie und Geowissenschaften, 91054 Erlangen, GeoZentrum Nordbayern, Schlossgarten 5, Germany
| | - Rohana Chandrajith
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Department Geographie und Geowissenschaften, 91054 Erlangen, GeoZentrum Nordbayern, Schlossgarten 5, Germany; Department of Geology, Faculty of Science, University of Peradeniya, Peradeniya, Sri Lanka
| | - Johannes A C Barth
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Department Geographie und Geowissenschaften, 91054 Erlangen, GeoZentrum Nordbayern, Schlossgarten 5, Germany
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85
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Sun X, Hu S, He R, Zeng J, Zhao D. Ecological restoration enhanced the stability of epiphytic microbial food webs of submerged macrophytes: Insights from predation characteristics of epiphytic predators. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174547. [PMID: 38992355 DOI: 10.1016/j.scitotenv.2024.174547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 07/03/2024] [Accepted: 07/04/2024] [Indexed: 07/13/2024]
Abstract
The application of various submerged macrophytes for ecological restoration has gained increasing attention in urban lake ecosystems. The multitrophic microbial communities that colonized in various submerged macrophytes constitute microbial food webs through trophic cascade effects, which affect the biogeochemical cycles of the lake ecosystem and directly determine the effects of ecological restoration. Therefore, it is essential to reveal the diversity, composition, assembly processes, and stability of the microbial communities within epiphytic food webs of diverse submerged macrophytes under eutrophication and ecological restoration scenarios. In this study, we explored the epiphytic microbial food webs of Vallisneria natans and Hydrilla verticillata in both eutrophic and ecological restoration regions. The obtained results indicated that the two regions with different nutrient levels remarkably affected the diversity and composition of epiphytic multitrophic microbial communities of submerged macrophytes, among them, the community composition of epiphytic predators were more prone to change. Secondly, environmental filtering effects played a more important role in driving the community assembly of epiphytic predators than that of prey. Furthermore, the generality and intraguild predation of epiphytic predators were significantly improved within ecological restoration regions, which increased the stability of epiphytic microbial food webs. Additionally, compared with Hydrilla verticillata, the epiphytic microbial food webs of Vallisneria natans exhibited higher multitrophic diversity and higher network stability regardless of regions. Overall, this study focused on the role of the epiphytic microbial food webs of submerged macrophytes in ecological restoration and uncovered the potential of epiphytic predators to enhance the stability of microbial food webs, which may provide new insights into the development of ecological restoration strategies.
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Affiliation(s)
- Xiaojian Sun
- Joint International Research Laboratory of Global Change and Water Cycle, the National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Siwen Hu
- Joint International Research Laboratory of Global Change and Water Cycle, the National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Rujia He
- Joint International Research Laboratory of Global Change and Water Cycle, the National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Jin Zeng
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; Sino-Danish Centre for Education and Research, University of Chinese Academy of Sciences, Beijing 100039, China; Poyang Lake Wetland Research Station, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Jiujiang 332899, China
| | - Dayong Zhao
- Joint International Research Laboratory of Global Change and Water Cycle, the National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China; College of Geography and Remote Sensing, Hohai University, Nanjing 210098, China.
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86
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Zhong Z, Wang X, Yang C, Wang Y, Yang G, Xu Y, Li C. Contrasting carbon cycle responses of semiarid abandoned farmland to simulated warmer-drier and warmer-wetter climates. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174693. [PMID: 38992364 DOI: 10.1016/j.scitotenv.2024.174693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 07/13/2024]
Abstract
Rewilding abandoned farmlands provides a nature-based climate solution via carbon (C) offsetting; however, the C-cycle-climate feedback in such restored ecosystems is poorly understood. Therefore, we conducted a 2-year field experiment in Loess Plateau, China, to determine the impacts of warming (∼1.4 °C) and altered precipitation (±25 %, ±50 %, and ambient), alone or in concert on soil C pools and associated C fluxes. Experimental warming significantly enhanced soil respiration without affecting the ecosystem net C uptake and soil C storage; these variables tended to increase along the manipulated precipitation gradient. Their interactions increased ecosystem net C uptake (synergism) but decreased soil respiration and soil C accumulation (antagonism) compared with a single warming or altered precipitation. Additionally, most variables related to the C cycle tended to be more responsive to increased precipitation, but the ecosystem net C uptake responded intensely to warming and decreased precipitation. Overall, ecosystem net C uptake and soil C storage increased by 94.4 % and 8.2 %, respectively, under the warmer-wetter scenario; however, phosphorus deficiency restricted soil C accumulation under these climatic conditions. By contrast, ecosystem net C uptake and soil C storage decreased by 56.6 % and 13.6 %, respectively, when exposed to the warmer-drier climate, intensifying its tendency toward a C source. Therefore, the C sink function of semiarid abandoned farmland was unsustainable. Our findings emphasize the need for management of post-abandonment regeneration to sustain ecosystem C sequestration in the context of climate change, aiding policymakers in the development of C-neutral routes in abandoned regions.
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Affiliation(s)
- Zekun Zhong
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Eco-meteorology Joint Laboratory of Dingbian County, Yulin 719000, Shaanxi, PR China
| | - Xing Wang
- College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Shaanxi Engineering Research Center of Circular Agriculture, Yangling 712100, Shaanxi, PR China
| | - Chenghui Yang
- Division of Laboratory Safety and Services, Northwest A&F University, Yangling 712100, Shaanxi, PR China
| | - Yanbo Wang
- School of Science, Western Sydney University, Penrith, NSW 2751, Australia
| | - Gaihe Yang
- College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Shaanxi Engineering Research Center of Circular Agriculture, Yangling 712100, Shaanxi, PR China
| | - Yadong Xu
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, Henan, PR China.
| | - Chao Li
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Eco-meteorology Joint Laboratory of Dingbian County, Yulin 719000, Shaanxi, PR China.
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87
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Kumblad L, E Wiklund AK, Rydin E. Long-term evaluation of potential Al toxicity after an Al treatment in a coastal bay. WATER RESEARCH 2024; 264:122242. [PMID: 39154535 DOI: 10.1016/j.watres.2024.122242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 08/06/2024] [Accepted: 08/08/2024] [Indexed: 08/20/2024]
Abstract
Coastal areas often suffer from eutrophication, causing ecosystem degradation and oxygen deficiencies. In hundreds of lakes, aluminium (Al) treatment has been a successful method to bind phosphorous in the sediments, reducing lake productivity. In this study we follow up a successful Al treatment of the sediment of Björnöfjärden, which was the first full-scale coastal remediation project using a geo-engineering method, that substantially reduced P concentrations in the water column. We evaluate the long-term development of Al in the water and aquatic life using 10 years data from before, during and after the aluminium treatment. Still after ten years, the treatment is successful with low P concentrations in the Bay. After a temporal increase of Al in water and biota (fish and algae) in connection with the Al treatment, the concentration decreased rapidly to pre-treatment levels. A risk assessment for biota and humans consuming fish and water from the bay showed that the risk for negative effects were negligible, also during the treatment year.
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Affiliation(s)
- Linda Kumblad
- Baltic Sea Centre, Stockholm University, SE-106 91 Stockholm, Sweden.
| | - Ann-Kristin E Wiklund
- Department of Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Emil Rydin
- Baltic Sea Centre, Stockholm University, SE-106 91 Stockholm, Sweden
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88
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Ni M, Liu R, Luo W, Pu J, Wu S, Wang Z, Zhang J, Wang X, Ma Y. A comprehensive conceptual framework for signaling in-lake CO 2 through dissolved organic matter. WATER RESEARCH 2024; 264:122228. [PMID: 39142047 DOI: 10.1016/j.watres.2024.122228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 08/04/2024] [Accepted: 08/06/2024] [Indexed: 08/16/2024]
Abstract
Organic carbon (C) and CO2 pools are closely interactive in aquatic environments. While there are strong indications linking freshwater CO2 to dissolved organic matter (DOM), the specific mechanisms underlying their common pathways remain unclear. Here, we present an extensive investigation from 20 subtropical lakes in China, establishing a comprehensive conceptual framework for identifying CO2 drivers and retrieving CO2 magnitude through co-trajectories of DOM evolution. Based on this framework, we show that lake CO2 during wet period is constrained by a combination of biogeochemical processes, while photo-mineralization of activated aromatic compounds fuels CO2 during dry period. We clearly determine that biological degradation of DOM governs temporal variations in CO2 rather than terrestrial C inputs within the subtropical lakes. Specifically, our results identify a shared route for the uptake of atmospheric polycyclic aromatic compounds and CO2 by lakes. Using machine learning, in-lake CO2 levels are well modelled through DOM signaling regardless of varying CO2 mechanisms. This study unravels the mechanistic underpinnings of causal links between lake CO2 and DOM, with important implications for understanding obscure aquatic CO2 drivers amidst the ongoing impacts of global climate change.
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Affiliation(s)
- Maofei Ni
- College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang 550025, China
| | - Rui Liu
- School of Geography and Tourism, Chongqing Normal University, University Town, Shapingba District, Chongqing 401331, China; The Key Laboratory of GIS Application Research, Chongqing Normal University, Chongqing 401331, China
| | - Weijun Luo
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Junbing Pu
- School of Geography and Tourism, Chongqing Normal University, University Town, Shapingba District, Chongqing 401331, China; Karst Research Team, Chongqing Key Laboratory of Carbon Cycle and Carbon Regulation of Mountain Ecosystem, School of Geography and Tourism, Chongqing Normal University, Chongqing 40133, China
| | - Shengjun Wu
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, 266, Fangzheng Avenue, Shuitu High-tech Park, Beibei, Chongqing 400714, China
| | - Zhikang Wang
- College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang 550025, China
| | - Jing Zhang
- School of Geography and Tourism, Chongqing Normal University, University Town, Shapingba District, Chongqing 401331, China.
| | - Xiaodan Wang
- College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang 550025, China
| | - Yongmei Ma
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, 266, Fangzheng Avenue, Shuitu High-tech Park, Beibei, Chongqing 400714, China.
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89
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Tang W, Ni R, Wang X, Song L. Different effects of seasonal impoundment and land use change on microbiome in a tributary sediment of the three gorgers reservoir. ENVIRONMENTAL RESEARCH 2024; 259:119559. [PMID: 38969316 DOI: 10.1016/j.envres.2024.119559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 06/27/2024] [Accepted: 07/03/2024] [Indexed: 07/07/2024]
Abstract
Anthropogenic activities significantly impact river ecosystem nutrient fluxes and microbial metabolism. Here, we examined the seasonal and spatial variation of sediments physicochemical parameters and the associated microbiome in the Pengxi river, a representative tributary of Three Gorges Reservoir, in response to seasonal impoundment and land use change by human activities. Results revealed that seasonal impoundment and land use change enhanced total organic carbon (TOC), total nitrogen (TN) and ammonium nitrogen (NH4+-N) concentration in the sediment, but have different effects on sediment microbiome. Sediment microbiota showed higher similarity during the seasonal high-water level (HWL) in consecutive two years. The abundant phyla Acidobacteria, Gemmatimonadetes, Cyanobacteria, Actinobacteria and Planctomycetes significantly increased as water level increased. Along the changes in bacterial taxa, we also observed changes in predicted carbon fixation functions and nitrogen-related functions, including the significantly higher levels of Calvin cycle, 4HB/3HP cycle, 3HP cycle and assimilatory nitrate reduction, while significantly lower level of denitrification. Though land use change significantly increased TOC, TN and NH4+-N concentration, its effects on spatial variation of bacterial community composition and predicted functions was not significant. The finding indicates that TGR hydrologic changes and land use change have different influences on the carbon and nitrogen fluxes and their associated microbiome in TGR sediments. A focus of future research will be on assessing on carbon and nitrogen flux balance and the associated carbon and nitrogen microbial cycling in TGR sediment.
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Affiliation(s)
- Wei Tang
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
| | - Renjie Ni
- School of Resources and Environmental Engineering, Anhui University, Hefei, 230601, China
| | - Xingzu Wang
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China.
| | - Liyan Song
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; School of Resources and Environmental Engineering, Anhui University, Hefei, 230601, China.
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90
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Magyari EK, Szabó Z, Falus G, Móra A, Szalai Z, Hamerlik L, Tóth M, Farkas Á, Pomogyi P, Somogyi B, Vörös L, Korponai J. Large shallow lake response to anthropogenic stressors and climate change: Missing macroinvertebrate recovery after oligotrophication (Lake Balaton, East-Central Europe). THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174191. [PMID: 38945249 DOI: 10.1016/j.scitotenv.2024.174191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 06/20/2024] [Accepted: 06/20/2024] [Indexed: 07/02/2024]
Abstract
East-Central Europe's largest shallow lake, Balaton, experienced strong eutrophication in the 1970-80s, followed by water quality improvement and oligotrophication by 2010 CE. Recently however, repeated cyanobacterial blooms occurred and warned that internal P-recycling can act similarly to external P load, therefore we need a better understanding of past water level (WL) and trophic changes in the lake. In this study we discuss the last 500-yr trophic, WL and habitat changes of the lake using paleoecological (chironomids, pollen) and geochemical (sediment chlorophyll, TOC, TS, TN, C/H ratio, major and trace element) methods. We demonstrate that the most intensive and irreversible change in the macroinvertebrate fauna occurred during the period of economic boom between the First and Second World War (∼1925-1940 CE), when large-scale built-in and leisure use of the lake has intensified. At that time, the Procladius-Microchironomus-Stempellina dominated community transformed to Procladius-Chironomus plumosus-type-Microchironomus community that coincided with land use changes, intensified erosion and water-level regulation in the lake with the maintenance of year-round high WL. This was followed by the impoverishment and population size decrease of the chironomid fauna and Procladius dominance since 1940 CE, without any recovery after 1994 CE despite the ongoing oligotrophication. Accelerated rate of change and turnover of the fauna was connected to an increase in the benthivorous fish biomass and eutrophication. The basin lost almost completely its once characteristic Stempellina species between 1927 and 1940 CE due to trophic level increase and seasonal anoxia in the Szemes Basin. Reference conditions for ecosystem improvement were assigned to 1740-1900 CE. We conclude that in spite of the ongoing oligotrophication, the re-establishment of the Procladius-Microchironomus-Stempellina assemblage is hampered, and requires fish population regulation.
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Affiliation(s)
- E K Magyari
- Department of Environmental and Landscape Geography, Eötvös Loránd University, Pázmány Péter str. 1/C, Budapest H-1117, Hungary; HUN-REN-MTM-ELTE Research group for Palaeontology, Pázmány Péter str. 1/C, Budapest H-1117, Hungary.
| | - Z Szabó
- Department of Environmental and Landscape Geography, Eötvös Loránd University, Pázmány Péter str. 1/C, Budapest H-1117, Hungary
| | - Gy Falus
- Mining and Geological Survey of Hungary, Columbus str. 17-23., Budapest H-1145, Hungary
| | - A Móra
- University of Pécs, Department of Hydrobiology, Ifjúság útja 6, Pécs H-7624, Hungary
| | - Z Szalai
- Department of Environmental and Landscape Geography, Eötvös Loránd University, Pázmány Péter str. 1/C, Budapest H-1117, Hungary; Geographical Institute, Research Centre for Astronomy and Earth Sciences, Budaörsi út 45, Budapest H-1112, Hungary
| | - L Hamerlik
- Matej Bel University, Faculty of Natural Sciences, Tajovskeho 40, 97401 Banská Bystrica, Slovakia; Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava, Slovakia
| | - M Tóth
- Balaton Limnological Research Institute, Klebelsberg Kuno utca 3., Tihany H-8237, Hungary
| | - Á Farkas
- HUN-REN ATOMKI, Bem tér 18/c, Debrecen H-4026, Hungary
| | - P Pomogyi
- Mid-Transdanubian Water Directorate, Balatoni út 6, Székesfehérvár H-8000, Hungary
| | - B Somogyi
- HUN-REN Balaton Limnological Research Institute, Klebelsberg Kuno utca 3, Tihany H-8237, Hungary
| | - L Vörös
- HUN-REN Balaton Limnological Research Institute, Klebelsberg Kuno utca 3, Tihany H-8237, Hungary
| | - J Korponai
- Department of Environmental and Landscape Geography, Eötvös Loránd University, Pázmány Péter str. 1/C, Budapest H-1117, Hungary; University of Public Service, Faculty of Water Sciences, Department of Water Supply and Sewerage, Bajcsy-Zsilinszky utca 12-14, Baja H-6500, Hungary; Department of Environmental Science, Sapientia Hungarian University of Transylvania, Calea Turzii 4, 400193 Cluj-Napoca, Romania
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91
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Hůnová I. Challenges in moving towards fog's contribution to spatial patterns of atmospheric deposition fluxes on a national scale. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174208. [PMID: 38909791 DOI: 10.1016/j.scitotenv.2024.174208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 06/18/2024] [Accepted: 06/21/2024] [Indexed: 06/25/2024]
Abstract
Fog is an important environmental phenomenon affecting, among other things, geochemical cycles via atmospheric deposition pathways. It is generally accepted that fog contributes substantially to atmospheric deposition fluxes especially in mountain forests. Nevertheless, due to intrinsic constraints, fog pathway has thus far been neglected in the quantification of atmospheric deposition and fog pathway has not been accounted for in nation-wide spatial patterns of atmospheric deposition of air pollutants. In this review we explore the causes as to why it is so complex to create a spatial pattern of fog contribution to atmospheric ion deposition fluxes on a national scale. Physical and chemical principles of fog formation are presented and factors influencing the abrupt temporal and spatial changes in both fog occurrence and fog chemistry are elucidated. The focus is on both constituents essential for fog deposition flux quantification, i.e. (i) hydrological input on fog water and (ii) chemistry of fog water.
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Affiliation(s)
- Iva Hůnová
- Czech Hydrometeorological Institute, Na Sabatce 17, 143 06 Prague 4 - Komorany, Czech Republic; Institute for Environmental Studies, Faculty of Science, Charles University in Prague, Benatska 2, 12800 Prague 2, Czech Republic.
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92
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Walthert L, Etzold S, Carminati A, Saurer M, Köchli R, Zweifel R. Coordination between degree of isohydricity and depth of root water uptake in temperate tree species. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174346. [PMID: 38944298 DOI: 10.1016/j.scitotenv.2024.174346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 06/26/2024] [Accepted: 06/26/2024] [Indexed: 07/01/2024]
Abstract
In an increasingly dry environment, it is crucial to understand how tree species use soil water and cope with drought. However, there is still a knowledge gap regarding the relationships between species-specific stomatal behaviour, spatial root distribution, and root water uptake (RWU) dynamics. Our study aimed to investigate above- and below-ground aspects of water use during soil drying periods in four temperate tree species that differ in stomatal behaviour: two isohydric tracheid-bearing conifers, Scots pine and Norway spruce, and two more anisohydric deciduous species, the diffuse-porous European beech, and the ring-porous Downy oak. From 2015 to 2020, soil-tree-atmosphere-continuum parameters were measured for each species in monospecific forests where trees had no access to groundwater. The hourly time series included data on air temperature, vapor pressure deficit, soil water potential, soil hydraulic conductivity, and RWU to a depth of 2 m. Analysis of drought responses included data on stem radius, leaf water potential, estimated osmotically active compounds, and drought damage. Our study reveals an inherent coordination between stomatal regulation, fine root distribution and water uptake. Compared to conifers, the more anisohydric water use of oak and beech was associated with less strict stomatal closure, greater investment in deep roots, four times higher maximum RWU, a shift of RWU to deeper soil layers as the topsoil dried, and a more pronounced soil drying below 1 m depth. Soil hydraulic conductivity started to limit RWU when values fell below 10-3 to 10-5 cm/d, depending on the soil. As drought progressed, oak and beech may also have benefited from their leaf osmoregulatory capacity, but at the cost of xylem embolism with around 50 % loss of hydraulic conductivity when soil water potential dropped below -1.25 MPa. Consideration of species-specific water use is crucial for forest management and vegetation modelling to improve forest resilience to drought.
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Affiliation(s)
- Lorenz Walthert
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland.
| | - Sophia Etzold
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Andrea Carminati
- Physics of Soils and Terrestrial Ecosystems, Department of Environmental Systems Science, ETH Zürich, Universitätsstrasse 16, 8092 Zürich, Switzerland
| | - Matthias Saurer
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Roger Köchli
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Roman Zweifel
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
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93
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Huang L, Bao W, Kuzyakov Y, Hu H, Zhang H, Li F. Enzyme stoichiometry reveals microbial nitrogen limitation in stony soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174124. [PMID: 38909790 DOI: 10.1016/j.scitotenv.2024.174124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 04/19/2024] [Accepted: 06/16/2024] [Indexed: 06/25/2024]
Abstract
Resource limitation for soil microorganisms is the crucial factor in nutrient cycling and vegetation development, which are especially important in arid climate. Given that rock fragments strongly impact hydrologic and geochemical processes in arid areas, we hypothesized that microbial resource (C and N) limitation will increase along the rock fragment content (RFC) gradient. We conducted a field experiment in Minjiang river arid valleys with four RFC content (0 %, 25 %, 50 %, and 75 %, V V-1) and four vegetation types (Artemisia vestita, Bauhinia brachycarpa, Sophora davidii, and the soil without plants). Activities of C (β-1,4-glucosidase, BG), N (β-1,4-N-acetyl-glucosaminidase, NAG; L-leucine aminopeptidase, LAP), and P (acid phosphatase, ACP) acquiring enzymes were investigated to assess the limitations by C, N or P. In unplanted soil, the C acquiring enzyme activity decreased by 43 %, but N acquiring enzyme activity increased by 72 % in 75 % RFC than those in rock-free soils (0 % RFC). Increasing RFC reduced C:N and C:P enzymatic ratios, as well as vector length and vector angle (< 45°). Plants increased the activities of C and N acquiring enzymes in soils, as well as C:P and N:P enzyme activities, as well as vector length (by 5.6 %-25 %), but decreased vector angle (by 13 %-21 %). Enzyme stoichiometry was dependent on biotic and abiotic factors, such as soil water content, soil C:N, and total content of phospholipid fatty acids, reflecting microbial biomass content. Increased RFC shifted enzymatic stoichiometry toward lower C but stronger N limitation for microorganisms. Vegetation increased microbial C and N limitation, and impacted the enzymatic activities and stoichiometry depending on shrub functional groups. Consequently, the direct effects of vegetation, nutrient availability and microbial biomass content, as well as indirect effects of soil properties collectively increased microbial resource limitations along the RFC gradient.
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Affiliation(s)
- Long Huang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization& Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weikai Bao
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization& Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China
| | - Yakov Kuzyakov
- Department of Soil Science of Temperate Ecosystems, Department of Agricultural Soil Science, University of Goettingen, 37077 Göttingen, Germany; Peoples Friendship University of Russia (RUDN University), 117198 Moscow, Russia; Institute of Environmental Sciences, Kazan Federal University, 420049 Kazan, Russia
| | - Hui Hu
- Henan Key Laboratory of Water Pollution Control and Rehabilitation, Henan University of Urban Construction, Pingdingshan 467000, China
| | - Hanyue Zhang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization& Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fanglan Li
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization& Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China.
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94
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Yin S, Liu Y, Wei C, Zhu D. Comparing molecular signatures of dissolved organic matter (DOM) in four large freshwater lakes differing in hydrological connectivity to the Changjiang River. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174401. [PMID: 38964414 DOI: 10.1016/j.scitotenv.2024.174401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 06/28/2024] [Accepted: 06/29/2024] [Indexed: 07/06/2024]
Abstract
Freshwater lakes serve as active conduits for processing terrestrial dissolved organic matter (DOM), playing a crucial role in global carbon cycle. Little attention has been paid to how hydrological connectivity to a large river would affect the molecular signatures of DOM in lakes. Here, we systematically characterized and compared the molecular signatures of DOM in surface waters of four large freshwater lakes in the middle and lower Changjiang River basin that are directly connected to the river (Lake Dongting and Lake Poyang, referred to as Lakeconnected) or indirectly connected to the river (Lake Chao and Lake Tai, referred to as Lakenonconnected). The DOM in Lakeconnected was found to have similar total organic carbon (TOC)-normalized contents and characteristics of lignin phenols to the DOM in surface waters from the upstream Changjiang river, indicating allochthonous/terrestrial sources from riverine inputs. As indicated by the UV-vis and fluorescence analyses, the DOM in Lakeconnected overall had higher aromaticity and larger average molecular weight as well as stronger allochthonous feature compared to the DOM in Lakenonconnected. Consistently, the FT-ICR MS analysis revealed that the DOM in Lakeconnected had higher molecular diversity, higher unsaturation degree, and larger proportions of highly aromatic compounds. In contrast, the DOM in Lakenonconnected had larger proportions of lipids and peptide-like structures, but lower proportions of aromatic compounds, which could be ascribed to the enhanced autochthonous production and photodegradation due to pollution and eutrophication as well as longer water residence time. The results highlight the strong impacts of the hydrological connectivity to a large river on the molecular signatures of lake DOM. CAPSULE: The hydrological connectivity of the lakes to the Changjiang River has strong impacts on the molecular signatures of lake DOM.
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Affiliation(s)
- Shujun Yin
- School of Urban and Environmental Sciences, Key Laboratory of the Ministry of Education for Earth Surface Processes, Peking University, Beijing 100871, China
| | - Yafang Liu
- School of Urban and Environmental Sciences, Key Laboratory of the Ministry of Education for Earth Surface Processes, Peking University, Beijing 100871, China
| | - Chenhui Wei
- School of Urban and Environmental Sciences, Key Laboratory of the Ministry of Education for Earth Surface Processes, Peking University, Beijing 100871, China
| | - Dongqiang Zhu
- School of Urban and Environmental Sciences, Key Laboratory of the Ministry of Education for Earth Surface Processes, Peking University, Beijing 100871, China.
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95
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Borrull E, Mestre M, Marrasé C, Gasol JM, Sala MM. Patterns of prokaryotic activity along the marine planktonic matter continuum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:173921. [PMID: 38906291 DOI: 10.1016/j.scitotenv.2024.173921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 05/17/2024] [Accepted: 06/09/2024] [Indexed: 06/23/2024]
Abstract
Prokaryotic abundance and activity are commonly assessed by dividing them into two size-fractions: free-living and attached to particles. Nevertheless, organic matter, essential for the growth of heterotrophic prokaryotes, is present in the environment in a continuum of sizes, from purely dissolved to large particles. Therefore, defining the activity of the prokaryotic community would be more accurate by considering all the distinct size fractions. To achieve this, we measured prokaryotic abundance (PA), heterotrophic prokaryotic activity (as leucine incorporation) and extracellular enzyme activities at a coastal site in the NW Mediterranean Sea. We conducted measurements in both bulk seawater and size fractionated samples sequentially passing through 5 different filter types: 0.2-0.8-3-5-10 μm pore size. Our results indicate that the fraction <0.8 μm contained the highest percentage of cells (91.6 ± 1.1 %) and leucine incorporation rates (72.2 ± 3.5 %). Most of the extracellular enzyme activity appeared in the dissolved fraction (<0.2 μm; 19.8-79.4 %), yet the specific activity of the enzymes (per cell activity) was 100-1000 times higher in the particulate (>0.8 μm) than in the free-living (0.2-0.8 μm) fraction. The size fraction with highest specific activities for leucine incorporation and most of the enzyme activities (β-glucosidase, esterase, Leu-aminopeptidase and alkaline phosphatase) was the 5-10 μm fraction. In contrast, the higher specific chitobiase activity in the >10 μm fraction, suggests that the prokaryotic community colonizing large particles might be more specialized in the hydrolysis of organic matter of zooplanktonic origin than the community colonizing smaller particles.
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Affiliation(s)
- Encarna Borrull
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSIC. Pg Marítim de la Barceloneta 37-49, E08003 Barcelona, Catalunya, Spain
| | - Mireia Mestre
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSIC. Pg Marítim de la Barceloneta 37-49, E08003 Barcelona, Catalunya, Spain
| | - Cèlia Marrasé
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSIC. Pg Marítim de la Barceloneta 37-49, E08003 Barcelona, Catalunya, Spain
| | - Josep M Gasol
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSIC. Pg Marítim de la Barceloneta 37-49, E08003 Barcelona, Catalunya, Spain
| | - M Montserrat Sala
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSIC. Pg Marítim de la Barceloneta 37-49, E08003 Barcelona, Catalunya, Spain.
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96
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de Araújo KR, Sawakuchi HO, Bertassoli DJ, Bastviken D, Pereira TS, Sawakuchi AO. Operational effects on aquatic carbon dioxide and methane emissions from the Belo Monte hydropower plant in the Xingu River, eastern Amazonia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174100. [PMID: 38908589 DOI: 10.1016/j.scitotenv.2024.174100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 05/25/2024] [Accepted: 06/16/2024] [Indexed: 06/24/2024]
Abstract
Operational demands and the natural inflow of water actively drive biweekly fluctuations in water levels in hydropower reservoirs. These daily to weekly fluctuations could have major effects on methane (CH4) and carbon dioxide (CO2) emissions via release of bubbles from reservoir bottom sediments (ebullition) or organic matter inputs, respectively. The impact of transient fluctuations in water levels on GHG emissions is poorly understood and particularly so in tropical run-of-the-river reservoirs. These reservoirs, characterized by high temperatures and availability of labile organic matter, are usually associated with extensive CH4 generation within bottom sediments. The aim of this study is to determine how water level fluctuations resulting from the operation of the Belo Monte hydropower plant on the Xingu River, eastern Amazon River Basin, affect local CO2 and CH4 emissions. Between February and December 2022, we monitored weekly fluxes and water concentrations of CO2 and CH4 in a site on the margin of the Xingu reservoir. Throughout the study period, fluxes of CO2 and CH4 were 118 ± 137 and 3.62 ± 8.47 mmol m-2 d-1 (average ± 1SD) while concentrations were 59 ± 29.77 and 0.30 ± 0.12 μM, respectively. The fluxes and water concentrations of CO2 were clearly correlated with the upstream discharge, and the variation observed was more closely associated with a seasonal pattern than with biweekly fluctuations in water level. However, CH4 fluxes were significantly correlated with biweekly water level fluctuations. The variations observed in CH4 fluxes occurred especially during the high-water season (February-April), when biweekly water level fluctuations were frequent and had higher amplitude, which increased CH4 ebullition. Reducing water level fluctuations during the high-water season could decrease ebullitive pulses and, consequently, total flux of CH4 (TFCH4) in the reservoir margins. This study underscores the critical role of water level fluctuations in near-shore CH4 emissions within tropical reservoirs and highlights significant temporal variability. However, additional research is necessary to understand how these findings can be applied across different spatial scales.
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Affiliation(s)
- Kleiton R de Araújo
- Programa de Pós Graduação em Geoquímica e Geotectônica, Instituto de Geociências, Universidade de São Paulo, São Paulo 05508-080, Brazil.
| | - Henrique O Sawakuchi
- Department of Thematic Studies, Environmental Change, Linköping University, Linköping 581 83, Sweden
| | - Dailson J Bertassoli
- Departamento de Geologia Sedimentar e Ambiental, Instituto de Geociências, Universidade de São Paulo, São Paulo 05508-080, Brazil
| | - David Bastviken
- Department of Thematic Studies, Environmental Change, Linköping University, Linköping 581 83, Sweden
| | - Tatiana S Pereira
- Faculdade de Ciências Biológicas, Universidade Federal do Pará, Altamira 68372 - 040, Brazil
| | - André O Sawakuchi
- Programa de Pós Graduação em Geoquímica e Geotectônica, Instituto de Geociências, Universidade de São Paulo, São Paulo 05508-080, Brazil; Departamento de Geologia Sedimentar e Ambiental, Instituto de Geociências, Universidade de São Paulo, São Paulo 05508-080, Brazil
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97
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Yáñez-Serrano AM, Corbera J, Portillo-Estrada M, Janssens IA, Llusià J, Filella I, Peñuelas J, Preece C, Sabater F, Fernández-Martínez M. Drivers of biogenic volatile organic compound emissions in hygrophytic bryophytes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174293. [PMID: 38936717 DOI: 10.1016/j.scitotenv.2024.174293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 05/16/2024] [Accepted: 06/23/2024] [Indexed: 06/29/2024]
Abstract
Bryophytes can both emit and take up biogenic volatile organic compounds (BVOCs) to and from the environment. Despite the scarce study of these exchanges, BVOCs have been shown to be important for a wide range of ecological roles. Bryophytes are the most ancient clade of land plants and preserve very similar traits to those first land colonisers. Therefore, the study of these plants can help understand the early processes of BVOC emissions as an adaptation to terrestrial life. Here, we determine the emission rates of BVOCs from different bryophyte species to understand what drives such emissions. We studied 26 bryophyte species from temperate regions that can be found in mountain springs located in NE Spain. Bryophyte BVOC emission presented no significant phylogenetic signal for any of the compounds analysed. Hence, we used mixed linear models to investigate the species-specific differences and eco-physiological and environmental drivers of bryophyte BVOC emission. In general, species-specific variability was the main factor explaining bryophyte BVOC emissions; but additionally, photosynthetic rates and light intensity increased BVOC emissions. Despite emission measurements reported here were conducted at 30°, and may not directly correspond to emission rates in natural conditions, most of the screened species have never been measured before for BVOC emissions and therefore this information can help understand the drivers of the emissions of BVOCs in bryophytes.
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Affiliation(s)
- A M Yáñez-Serrano
- IDAEA-CSIC, 08034 Barcelona, Spain; CREAF, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain; CSIC, Global Ecology Unit, CREAF-CSIC-UAB, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain.
| | - J Corbera
- Delegació de la Serralada Litoral Central, ICHN, Barcelona, Catalonia, Spain
| | - M Portillo-Estrada
- PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - I A Janssens
- PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - J Llusià
- CREAF, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain; CSIC, Global Ecology Unit, CREAF-CSIC-UAB, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - I Filella
- CREAF, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain; CSIC, Global Ecology Unit, CREAF-CSIC-UAB, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - J Peñuelas
- CREAF, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain; CSIC, Global Ecology Unit, CREAF-CSIC-UAB, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - C Preece
- IRTA, Torre Marimón, Caldes de Montbui, Catalonia, Spain
| | - F Sabater
- BEECA-UB, Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, E08028 Barcelona, Catalonia, Spain
| | - M Fernández-Martínez
- CREAF, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain; CSIC, Global Ecology Unit, CREAF-CSIC-UAB, E08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain; Delegació de la Serralada Litoral Central, ICHN, Barcelona, Catalonia, Spain; BEECA-UB, Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, E08028 Barcelona, Catalonia, Spain
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98
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Martinez Del Castillo E, Torbenson MCA, Reinig F, Konter O, Ziaco E, Büntgen U, Esper J. Diverging growth trends and climate sensitivities of individual pine trees after the 1976 extreme drought. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174370. [PMID: 38945248 DOI: 10.1016/j.scitotenv.2024.174370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 06/27/2024] [Accepted: 06/27/2024] [Indexed: 07/02/2024]
Abstract
Summer droughts are affecting the productivity and functioning of central European forests, with potentially lasting consequences for species composition and carbon sequestration. Long-term recovery rates and individual growth responses that may diverge from species-specific and population-wide behaviour are, however, poorly understood. Here, we present 2052 pine (Pinus sylvestris) ring width series from 19 forest sites in south-west Germany to investigate growth responses of individual trees to the exceptionally hot and dry summer of 1976. This outstanding drought event presents a distinctive test case to examine long-term post-drought recovery dynamics. We have proposed a new classification approach to identify a distinct sub-population of trees, referred to as "temporarily affected trees", with a prevalence ranging from 9 to 33 % across the forest stands. These trees exhibited an exceptionally prolonged growth suppression, lasting over a decade, indicating significantly lower resilience to the 1976 drought and a 50 % reduced capacity to recover to pre-drought states. Furthermore, shifts in resilience and recovery dynamics are accompanied by changing climate sensitivities, notably an increased response to maximum temperatures and summer droughts in post-1976 affected pines. Our findings underscore the likely interplay between individual factors and micro-site conditions that contribute to divergent tree responses to droughts. Assessing these factors at the individual tree level is recommended to advancing our understanding of forest responses to extreme drought events. By analyzing sub-population growth patterns, our study provides valuable insights into the impacts of summer droughts on central European forests in context of increasing drought events.
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Affiliation(s)
| | - Max C A Torbenson
- Department of Geography, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Frederick Reinig
- Department of Geography, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Oliver Konter
- Department of Geography, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Emanuele Ziaco
- Department of Geography, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Ulf Büntgen
- Department of Geography, University of Cambridge, Cambridge, United Kingdom; Global Change Research Institute of the Czech Academy of Sciences (CzechGlobe), Brno, Czech Republic; Department of Geography, Faculty of Science, Masaryk University, Brno, Czech Republic; Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
| | - Jan Esper
- Department of Geography, Johannes Gutenberg-University Mainz, Mainz, Germany; Global Change Research Institute of the Czech Academy of Sciences (CzechGlobe), Brno, Czech Republic
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99
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Xin X, Lan X, Li L, Tang H, Guo H, Li H, Jiang C, Liu F, Shao C, Qin Y, Liu Z, Qing G, Yan R, Hou L, Qi J. Anthropogenic and climate impacts on carbon stocks of grassland ecosystems in Inner Mongolia and adjacent region. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174054. [PMID: 38897466 DOI: 10.1016/j.scitotenv.2024.174054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 06/09/2024] [Accepted: 06/14/2024] [Indexed: 06/21/2024]
Abstract
Up to date, most studies reported that degradation is worsened in the grassland ecosystems of Inner Mongolia and adjacent regions as a result of intensified grazing. This seems to be scientific when considering the total forage or total above-ground biomass as a degradation indicator, but it does not hold true in terms of soil organic carbon density (SOCD). In this study, we quantified the changes of grassland ecosystem carbon stock in Inner Mongolia and adjacent regions from the 1980s to 2000s and identified the major drivers influencing these variations, using the National Grassland Resource Inventory and Soil Survey Dataset in 1980s and the Inventory data during 2002 to 2009 covering 624 sampling plots concerned vegetal traits and edaphic properties across the study region. The result indicated that the above-, below-ground and total vegetation biomass declined from the 1980s to 2000s by ∼ 10 %. However, total forage production increased by 6.72 % when considering livestock intake. SOCD remained stable despite a 67 % increase in grazing intensity. A generalized linear model (GLIM) analysis suggested that an increase in grazing intensity from the 1980s to 2000s could only explain 1.04 % of the total biomass change, while changes in precipitation and temperature explained 17.7 % (p < 0.05) of total vegetation biomass (TVB) change. Meanwhile, SOCD change during 1980s - 2000s could be explained 10.08 % by the soil texture (p < 0.05) and <1.6 % by changes in climate and livestock. This implies that the impacts of climate change on grassland biomass are more significant than those of grazing utilization, and SOCD was resistant to both climate change and intensified grazing. Overall, intensified grazing did not result in significant negative impacts on the grassland carbon stocks in the study region during the 1980s and 2000s. The grassland ecosystems possess a mechanism to adjust their root-shoot ratio, enabling them to maintain resilience against grazing utilization.
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Affiliation(s)
- Xiaoping Xin
- Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xueqi Lan
- Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Linghao Li
- Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - HuaJun Tang
- Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Haonan Guo
- College of Ecology, Lanzou University, Lanzhou 730000, China
| | - Hui Li
- College of Ecology, Lanzou University, Lanzhou 730000, China
| | - Cuixia Jiang
- College of Ecology, Lanzou University, Lanzhou 730000, China
| | - Feng Liu
- College of Ecology, Lanzou University, Lanzhou 730000, China
| | - Changliang Shao
- Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yifei Qin
- Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zhonglin Liu
- Department of Environmental Sciences, Inner Mongolia University, Huhhot 010021, China
| | - Gele Qing
- Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Ruirui Yan
- Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Lulu Hou
- Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Jiaguo Qi
- Center for Global Change & Earth Observations, Michigan State University, East Lansing, MI 48823, USA.
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100
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Clifton B, Ghezzehei TA, Viers JH. Carbon stock quantification in a floodplain restoration chronosequence along a Mediterranean-montane riparian corridor. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:173829. [PMID: 38857806 DOI: 10.1016/j.scitotenv.2024.173829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 05/14/2024] [Accepted: 06/05/2024] [Indexed: 06/12/2024]
Abstract
Uncertainty in the global carbon (C) budget has been reduced for most stocks, though it remains incomplete by not considering aquatic and transitional zone carbon stocks. A key issue preventing such complete accounting is a lack of available C data within these aquatic and aquatic-terrestrial transitional ecosystems. Concurrently, quantifiable results produced by restoration practices that explicitly target C stock accumulation and sequestration remain inconsistent or undocumented. To support a more complete carbon budget and identify impacts on C stock accumulation from restoration treatment actions, we investigated C stock values in a Mediterranean-montane riparian floodplain system in California, USA. We quantified the C stock in aboveground biomass, large wood, and litter in addition to the C and total nitrogen in the upper soil profile (5 cm) across 23 unique restoration treatments and remnant old-growth forests. Treatments span 40 years of restoration actions along seven river kilometers of the Cosumnes River, and include process-based (limited intervention), assisted (horticultural planting and other intensive restoration activities), hybrid (a combination of process and assisted actions), and remnant (old-growth forests that were not created with restoration actions) sites. Total C values measured up to 1100 Mg ha-1 and averaged 129 Mg ha-1 with biomass contributing the most to individual plot measurements. From 2012 to 2020, biomass C stock measurements showed an average 32 Mg ha-1 increase across all treatments, though treatment specific values varied. While remnant forest plots held the highest average C values across all stocks (336 Mg ha-1), C values of different stocks varied across treatment type. Process-based restoration treatments held more average biomass C (120 Mg ha-1) than hybrid (23 Mg ha-1) or assisted restoration treatments (50 Mg ha-1), while assisted restoration treatments held more average total C in soil and litter (58 Mg ha-1) than hybrid (35 Mg ha-1) and process-based restoration treatments (37 Mg ha-1). Regardless of treatment type, time was a significant factor for all C stock values. These findings support a more inclusive global carbon budget and provide valuable insight into restoration treatment actions that support C stock accumulation.
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Affiliation(s)
- Britne Clifton
- Environmental Systems, UC Merced, 5200 Lake Rd Merced, CA 95343.
| | - Teamrat A Ghezzehei
- Environmental Systems, UC Merced, 5200 Lake Rd Merced, CA 95343; School of Natural Sciences, UC Merced, 5200 Lake Rd Merced, CA 95343
| | - Joshua H Viers
- Environmental Systems, UC Merced, 5200 Lake Rd Merced, CA 95343; School of Engineering, UC Merced, 5200 Lake Rd Merced, CA 95343
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