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Wu N, Liu G, Qi X, Lin Z, Wang Y, Wang Y, Li Y, Oduro C, Khan S, Zhou S, Chu T. Different facets of alpha and beta diversity of benthic diatoms along stream watercourse in a large near-natural catchment. Ecol Evol 2024; 14:e11577. [PMID: 38873020 PMCID: PMC11169757 DOI: 10.1002/ece3.11577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 05/30/2024] [Indexed: 06/15/2024] Open
Abstract
Understanding the processes and mechanisms that shape the distribution patterns and variations of biodiversity along spatial gradients continues to be a priority for ecological research. We focused on the biodiversity of benthic diatom communities within a large near-natural watershed. The objectives are: (1) to explore the overall spatial patterns of benthic diatom biodiversity; (2) to investigate the effects associated with watercourse position and environmental variables, as well as both common and rare species on two facets (i.e., taxonomic and functional) of alpha and beta diversity; and (3) to unveil the mechanisms underlying their spatial variations. Alpha diversity indices along the stream watercourse showed a clear increasing trend from upstream to downstream sites. Results of random forest regression identified conductivity as the primary factor influencing functional alpha diversity, while elevation emerged as the predominant factor for taxonomic alpha diversity. Beta diversity partitioning revealed that taxonomic beta diversity generally exceeded functional beta diversity. These diversity measures exhibited different patterns along the watercourse position: taxonomic beta diversity remained relatively consistent along the watercourse, whereas functional total beta diversity and its two components of middle stream sites were lower than those of upstream and downstream sites. Functional beta diversity was sustained by dominant and common species, while rare species made significant contributions to taxonomic beta diversity. Both taxonomic and functional beta diversity and its components displayed a stronger influence from spatial factors than from local environmental, geo-climatic, and nutrient variables. Collectively, taxonomic and functional alpha and beta diversity demonstrated distinct responses to the main environmental gradients and spatial factors within our catchment, highlighting their different insights into diatom diversity. Furthermore, research is required to assess the generalizability of our findings to similar ecosystems. In addition, this study presents opportunities for expansion to include other taxa (e.g., macroinvertebrates and fish) to gain a comprehensive understanding of the driving mechanisms behind stream biodiversity.
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Affiliation(s)
- Naicheng Wu
- Department of Geography and Spatial Information TechniquesNingbo UniversityNingboChina
| | - Guohao Liu
- Department of Geography and Spatial Information TechniquesNingbo UniversityNingboChina
| | - Xinxin Qi
- Department of Geography and Spatial Information TechniquesNingbo UniversityNingboChina
| | - Zongwei Lin
- Department of Geography and Spatial Information TechniquesNingbo UniversityNingboChina
| | - Yixia Wang
- Department of Geography and Spatial Information TechniquesNingbo UniversityNingboChina
| | - Yaochun Wang
- Department of Geography and Spatial Information TechniquesNingbo UniversityNingboChina
| | - Yuying Li
- Henan International Joint Laboratory of Watershed Ecological Security in the Water Source Area of the Middle Route of South‐to‐North Water Diversion Project, College of Water Resource and Modern AgricultureNanyang Normal UniversityNanyangChina
| | - Collins Oduro
- Department of Geography and Spatial Information TechniquesNingbo UniversityNingboChina
- Ningbo University Donghai InstituteNingbo UniversityNingboChina
| | - Sangar Khan
- Department of Geography and Spatial Information TechniquesNingbo UniversityNingboChina
- Ningbo University Donghai InstituteNingbo UniversityNingboChina
| | - Shuchan Zhou
- Ningbo University Library (Journal Editorial Department)Ningbo UniversityNingboChina
| | - Tianjiang Chu
- Hangzhou Academy of Agricultural SciencesHangzhouChina
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2
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Lorenz AW, Kaijser W, Acuña V, Austnes K, Bonada N, Dörflinger G, Ferreira T, Karaouzas I, Rico A, Hering D. Stressors affecting the ecological status of temporary rivers in the Mediterranean region. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166254. [PMID: 37574055 DOI: 10.1016/j.scitotenv.2023.166254] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 07/13/2023] [Accepted: 08/10/2023] [Indexed: 08/15/2023]
Abstract
Temporary rivers are widespread in the Mediterranean region and impose a challenge for the implementation of the Water Framework Directive (WFD) and other environmental regulations. Surprisingly, an overarching analysis of their ecological status and the stressors affecting them is yet missing. We compiled data on the ecological status of 1504 temporary rivers in seven European Mediterranean region countries and related their ecological status (1) to publicly available data on pressures from the European WISE-WFD dataset, and (2) to seven more specific stressors modelled on a sub-catchment scale. More than 50 % of the temporary water bodies in the Mediterranean countries reached good or even high ecological status. In general, status classes derived from phytobenthos and macrophyte assessment were higher than those derived from the assessment of benthic invertebrates or fish. Of the more generally defined pressures reported to the WISE-WFD database, the most relevant for temporary rivers were 'diffuse agricultural' and 'point urban waste water'. Of the modelled more specific stressors, agricultural land use best explained overall ecological status, followed by total nitrogen load, and urban land use, while toxic substances, total phosphorus load and hydrological stressors were less relevant. However, stressors differed in relevance, with total nitrogen being most important for macrophytes, and agricultural land use for phytobenthos, benthic invertebrates and fish. For macrophytes, ecological quality increased with stressor intensity. The results underline the overarching effect of land use intensity for the ecological status of temporary water bodies. However, assessment results do not sufficiently reflect hydrological stress, most likely as the biological indicators used to evaluate these systems were designed for perennial water bodies and thus mainly target land use and nutrient impacts. We conclude that biomonitoring systems need to be updated or newly developed to better account for the specific situation of temporary water bodies.
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Affiliation(s)
- Armin W Lorenz
- Department of Aquatic Ecology, Faculty for Biology, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany; Center for Water and Environment, University of Duisburg-Essen, Universitätsstr. 2, 45141 Essen, Germany.
| | - Willem Kaijser
- Department of Aquatic Ecology, Faculty for Biology, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany
| | - Vicenç Acuña
- Catalan Institute for Water Research (ICRA - CERCA), Carrer Emili Grahit 101, 17003 Girona, Spain; Universitat de Girona, Plaça de Sant Domènec 3, 17004 Girona, Spain.
| | | | - Nuria Bonada
- FEHM-Lab (Freshwater Ecology, Hydrology and Management), Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Facultat de Biologia, Universitat de Barcelona (UB), Diagonal 643, 08028 Barcelona, Catalonia, Spain; Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Diagonal 643, 08028 Barcelona, Catalonia, Spain.
| | | | - Teresa Ferreira
- Forest Research Centre, Associate Laboratory TERRA, University of Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal.
| | - Ioannis Karaouzas
- Institute of Marine Biological Resources and Inland Waters, Hellenic Center for Marine Research, 46.7km Athens-Sounio Av., Anavyssos 19013, Greece.
| | - Andreu Rico
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, c/ Catedrático José Beltrán 2, 46980 Paterna, Valencia, Spain; IMDEA Water Institute, Science and Technology Campus of the University of Alcalá, Av. Punto Com 2, Alcalá de Henares 28805, Madrid, Spain.
| | - Daniel Hering
- Department of Aquatic Ecology, Faculty for Biology, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany; Center for Water and Environment, University of Duisburg-Essen, Universitätsstr. 2, 45141 Essen, Germany.
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3
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Jiménez L, Freixa A, Besolí N, Sabater S. Resistance but not recovery is related to the role of specialist taxa in river communities submitted to hydric stress. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 871:161952. [PMID: 36740050 DOI: 10.1016/j.scitotenv.2023.161952] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 01/24/2023] [Accepted: 01/28/2023] [Indexed: 06/18/2023]
Abstract
One of the main effects of global change is the human interference in the global water cycle, which alters river hydrological dynamics and submits their biological communities to hydric stress. Hydric stress is a pulse disturbance with potential multiple effects on biodiversity and functions in river ecosystems. The presence of habitat specialists may support the response of biological communities to pulse disturbances, maintaining ecological functions more consistently than other communities only having generalists. We tested this general hypothesis in stream communities submitted to increasing hydric stress (normal conditions vs humidity vs desiccation). We used communities with variable proportion of specialist algal and cyanobacterial taxa and tested their resistance to hydric stress by analyzing potential changes on their number of species, biovolume, proportion of intact cells, and photosynthetic variables (basal fluorescence, photosynthetic yield). We also evaluated the recovery of ecological functions (net community primary production, community respiration, phosphorus uptake) once hydric stress conditions ended. Hydric stress caused a slight decrease in the number of species and biovolume of assemblages, but the proportion of intact cells did not significantly change because of the disturbance. Basal fluorescence and photosynthetic yield under hydric stress decreased more markedly in communities without specialist taxa, while communities with habitat specialists resisted better. Metabolism did not remarkably decrease under moderate hydric stress, but dropped by half under desiccation in all communities, having or not specialist taxa. Overall, specialist taxa did provide higher resistance to stress but did not support a distinct recovery of ecological functions. We suggest that this characteristic response is related to the high plasticity of biofilm structures.
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Affiliation(s)
- Laura Jiménez
- Catalan Institute for Water Research (ICRA-CERCA), Girona, Spain
| | - Anna Freixa
- Catalan Institute for Water Research (ICRA-CERCA), Girona, Spain; Institute of Aquatic Ecology, University of Girona, Girona, Spain
| | - Neus Besolí
- Catalan Institute for Water Research (ICRA-CERCA), Girona, Spain
| | - Sergi Sabater
- Catalan Institute for Water Research (ICRA-CERCA), Girona, Spain; Institute of Aquatic Ecology, University of Girona, Girona, Spain.
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Li C, Miao L, Adyel TM, Huang W, Wang J, Wu J, Hou J, Wang Z. Eukaryotes contribute more than bacteria to the recovery of freshwater ecosystem functions under different drought durations. Environ Microbiol 2023. [PMID: 36916068 DOI: 10.1111/1462-2920.16370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 03/10/2023] [Indexed: 03/16/2023]
Abstract
Global climate change mostly impacts river ecosystems by affecting microbial biodiversity and ecological functions. Considering the high functional redundancy of microorganisms, the unknown relationship between biodiversity and ecosystem functions obstructs river ecological research, especially under the influence of increasing weather extremes, such as in intermittent rivers and ephemeral streams (IRES). Herein, dry-wet alternation experiments were conducted in artificial stream channels for 25 and 90 days of drought, both followed by 20 days of rewetting. The dynamic recovery of microbial biodiversity and ecosystem functions (represented by ecosystem metabolism and denitrification rate) were determined to analyse biodiversity-ecosystem-function (BEF) relationships after different drought durations. There was a significant difference between bacterial and eukaryotic biodiversity recovery after drought. Eukaryotic biodiversity was more sensitive to drought duration than bacterial, and the eukaryotic network was more stable under dry-wet alternations. Based on the establishment of partial least squares path models, we found that eukaryotic biodiversity has a stronger effect on ecosystem functions than bacteria after long-term drought. Indeed, this work represents a significant step forward for further research on the ecosystem functions of IRES, especially emphasizing the importance of eukaryotic biodiversity in the BEF relationship.
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Affiliation(s)
- Chaoran Li
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 210098, Nanjing, People's Republic of China
| | - Lingzhan Miao
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 210098, Nanjing, People's Republic of China
| | - Tanveer M Adyel
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Melbourne, Victoria, Australia
- STEM, University of South Australia, Mawson Lakes Campus, 5095, Mawson, Australia
| | - Wei Huang
- China Institute of Water Resources and Hydropower Research, 100038, Beijing, People's Republic of China
| | - Jianjun Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, China
| | - Jun Wu
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 210098, Nanjing, People's Republic of China
| | - Jun Hou
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 210098, Nanjing, People's Republic of China
| | - Zhiyuan Wang
- Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, National Energy Administration, Ministry of Transport, Ministry of Water Resources, 210029, Nanjing, China
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Wu N, Guo K, Zou Y, He F, Riis T. SER: An R package to characterize environmental regimes. Ecol Evol 2023; 13:e9882. [PMID: 36919015 PMCID: PMC10008288 DOI: 10.1002/ece3.9882] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 02/12/2023] [Accepted: 02/20/2023] [Indexed: 03/13/2023] Open
Abstract
Environmental regimes (or environmental legacy or historical legacy) are the dynamics of environmental characteristics over a given (either long or short) time period, such as frequency of mean or extreme events and rate of change, which might be absent by using only contemporary variables. We present SER, an R package for estimating environmental regimes for different environmental variables. Using the data included in the package, several examples are shown. SER is suitable for any type of environmental or biotic variables, including nutrient concentration, light, and dissolved oxygen. In addition, by changing the argument "days_bf," it is possible to compute environmental regimes over any time period, such as days, months, or years. Our case study showed that the inclusion of environmental regimes increased the explained variation of temporal β-diversity and its components. Environmental regimes are expected to advance the "environment-community" relationships in ecological studies. They can further be implemented in other subjects such as social science, socioeconomics, and epidemiology.
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Affiliation(s)
- Naicheng Wu
- Department of Geography and Spatial Information TechniquesNingbo UniversityNingboChina
| | - Kun Guo
- School of Ecological and Environmental SciencesEast China Normal UniversityShanghaiChina
| | - Yi Zou
- Department of Health and Environmental SciencesXi'an Jiaotong‐Liverpool UniversitySuzhouChina
| | - Fengzhi He
- Leibniz Institute of Freshwater Ecology and Inland FisheriesBerlinGermany
| | - Tenna Riis
- Department of BiologyAarhus UniversityAarhus CDenmark
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Sun L, Wu L, Liu X, Huang W, Zhu D, Wang Z, Guan R, Liu X. Reducing the Risk of Benthic Algae Outbreaks by Regulating the Flow Velocity in a Simulated South-North Water Diversion Open Channel. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:3564. [PMID: 36834257 PMCID: PMC9966353 DOI: 10.3390/ijerph20043564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/11/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
The reduction in open-channel flow velocity due to China's South-to-North Water Diversion Project (SNP) increases the risk of benthic algal community blooms resulting in drinking water safety issues. Consequently, it has attracted attention from all walks of life. However, regulatory measures to mitigate the risk of algal blooms and the main risk-causing factors are unclear. This study simulated the river ecosystem of the SNP channel through water diversion. Simulated gradient-increasing river flow velocity affects environmental factors and benthic algal alterations, and can be used to explore the feasibility of regulating the flow velocity to reduce the risk of algal blooms. We found that the algal biomasses in the velocity environments of 0.211 and 0.418 m/s decreased by 30.19% and 39.88%, respectively. Community structure alterations from diatoms to filamentous green algae were 75.56% and 87.53%, respectively. We observed significant differences in biodiversity, especially in terms of richness and evenness. The α diversity index of a species is influenced by physical and chemical environmental factors (especially flow velocity). Our study revealed that flow velocity is the main factor affecting the growth and outbreak of benthic algae. The risk of algal blooms in open channels can be effectively mitigated by regulating the flow velocity. This provides a theoretical basis for ensuring the water safety of large-scale water conservancy projects.
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Affiliation(s)
- Longfei Sun
- Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
| | - Leixiang Wu
- Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
| | - Xiaobo Liu
- Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
| | - Wei Huang
- Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
| | - Dayu Zhu
- Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
| | - Zhuowei Wang
- Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
| | - Ronghao Guan
- Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
| | - Xingchen Liu
- Department of Water Ecology and Environment, China Institute of Water Resources and Hydropower Research, Beijing 100038, China
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7
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B-Béres V, Kókai Z, Várbíró G, Mustazhapova G, Csabai Z, Pernecker B, Borics G, Bácsi I, Boda P. Flow Intermittence Drives the Benthic Algal Composition, Biodiversity and Diatom-Based Quality of Small Hilly Streams in the Pannonian Ecoregion, Hungary. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.834548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Climate change is putting increasing pressure on flowing waters. Drastic water level fluctuations in rivers or drying up of small and medium-sized streams all contribute to the biodiversity crisis threatening freshwater ecosystems. Benthic diatoms are important elements of biofilm in small streams. However, knowledge on the relationship between benthic diatoms and flow intermittence is incomplete, especially in regions recently impacted by recurrent drying. Thus, we investigated benthic diatom flora of small intermittent, hilly streams in the warm temperate region of Europe (the Pannonian Ecoregion). Our hypotheses were addressed to compositional changes, biodiversity loss and diatom-based ecological assessment. The results revealed clear flow intermittence-induced differences in taxa and trait composition of diatoms. Altogether six species for the dry phase and three species in the aquatic phase were identified as indicative ones by using indicator value analyses. In contrast to water regime induced changes in assemblages, there was a seasonal overlap in taxa and trait composition. During the study period, the drying up of streams did not result in significant biodiversity loss either at taxa or trait levels. Functional dispersion, however, reduced significantly by summer. Overall, neither the hydrological regime nor seasonal changes had a significant effect on diatom-based quality indices, except for the Rott trophic index (TID index). The TID index values were significantly lower in dry phases than in aquatic ones. These results suggested that the drying up of streams has a very complex influence on benthic diatoms. It seems that taxonomical and functional redundancy can reduce the negative impact of short-time flow intermittence on assemblages. As a practical benefit, the results are the first to support the use of diatom-based quality indices in the assessment of flow intermittence in the temperate region.
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