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Gao X, Sun S, Meng P, Cai J, Pei S, Huang H, Zhang J. Carbon fluxes and water-use efficiency in a Pinus tabuliformis plantation in Northeast China and their relationship to drought. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174258. [PMID: 38925374 DOI: 10.1016/j.scitotenv.2024.174258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 06/13/2024] [Accepted: 06/22/2024] [Indexed: 06/28/2024]
Abstract
The impact of extreme weather events on carbon fluxes and water-use efficiency (WUE) in revegetated areas under water-limited conditions is poorly understood. We analyzed changes in carbon fluxes and WUE over three years of eddy-covariance measurements in a Pinus tabuliformis plantation in Northeast China to investigate carbon fluxes and WUE responses to drought events at different time scales. Mean annual net ecosystem exchange (NEE), gross primary production (GPP), and ecosystem respiration (Re) were -368.48, 1042.42, and 673.94 g C m-2, respectively. Drought events increased NEE, as GPP was more sensitive to water stress than Re at different growing stages. Mean annual WUE was 2.46 g C kg-1 H2O, and plant phenology played a key role in WUE responses to drought. Water stress had negative and positive effects on daily WUE at the early and late growing stages, respectively, and daily WUE was generally insensitive to drought at the mid growing stage. A lagged effect existed in the carbon fluxes and WUE dynamics after drought events at various time scales. Water stress at the early growing stage was more important than that at other growing stages on annual carbon sequestration and WUE, as it dominated canopy growth in the current year. The annual mean normalized difference vegetation index controlled interannual variations in carbon fluxes and WUE in the plantation. Our findings contribute to the prediction of possible changes in carbon and water fluxes under climate warming in the afforested areas of Northeast China.
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Affiliation(s)
- Xiang Gao
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, 100091 Beijing, China; Co-innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, 210037 Nanjing, Jiangsu, China; Henan Xiaolangdi Forest Ecosystem National Observation and Research Station, 454650 Jiyuan, Henan, China.
| | - Shoujia Sun
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, 100091 Beijing, China; Co-innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, 210037 Nanjing, Jiangsu, China; Henan Xiaolangdi Forest Ecosystem National Observation and Research Station, 454650 Jiyuan, Henan, China.
| | - Ping Meng
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, 100091 Beijing, China; Co-innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, 210037 Nanjing, Jiangsu, China; Henan Xiaolangdi Forest Ecosystem National Observation and Research Station, 454650 Jiyuan, Henan, China.
| | - Jinfeng Cai
- Co-innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, 210037 Nanjing, Jiangsu, China
| | - Songyi Pei
- State-owned Jianping County Heishui Mechanized Forest Farm, 122000 Chaoyang, Liaoning, China
| | - Hui Huang
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, 100091 Beijing, China; Co-innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, 210037 Nanjing, Jiangsu, China; Henan Xiaolangdi Forest Ecosystem National Observation and Research Station, 454650 Jiyuan, Henan, China.
| | - Jinsong Zhang
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, 100091 Beijing, China; Co-innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, 210037 Nanjing, Jiangsu, China; Henan Xiaolangdi Forest Ecosystem National Observation and Research Station, 454650 Jiyuan, Henan, China.
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Li X, Black TA, Zha T, Jassal RS, Nesic Z, Lee SC, Bourque CPA, Hao S, Jin C, Liu P, Jia X, Tian Y. Long-term trend and interannual variation in evapotranspiration of a young temperate Douglas-fir stand over 2002-2022 reveals the impacts of climate change. PLANT, CELL & ENVIRONMENT 2024. [PMID: 38863246 DOI: 10.1111/pce.15000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 05/27/2024] [Accepted: 05/31/2024] [Indexed: 06/13/2024]
Abstract
The shortage of decades-long continuous measurements of ecosystem processes limits our understanding of how changing climate impacts forest ecosystems. We used continuous eddy-covariance and hydrometeorological data over 2002-2022 from a young Douglas-fir stand on Vancouver Island, Canada to assess the long-term trend and interannual variability in evapotranspiration (ET) and transpiration (T). Collectively, annual T displayed a decreasing trend over the 21 years with a rate of 1% yr-1, which is attributed to the stomatal downregulation induced by rising atmospheric CO2 concentration. Similarly, annual ET also showed a decreasing trend since evaporation stayed relatively constant. Variability in detrended annual ET was mostly controlled by the average soil water storage during the growing season (May-October). Though the duration and intensity of the drought did not increase, the drought-induced decreases in T and ET showed an increasing trend. This pattern may reflect the changes in forest structure, related to the decline in the deciduous understory cover during the stand development. These results suggest that the water-saving effect of stomatal regulation and water-related factors mostly determined the trend and variability in ET, respectively. This may also imply an increase in the limitation of water availability on ET in young forests, associated with the structural and compositional changes related to forest growth.
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Affiliation(s)
- Xinhao Li
- State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing, China
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - T Andrew Black
- Biometeorology and Soil Physics Group, University of British Columbia, Vancouver, British Columbia, Canada
| | - Tianshan Zha
- State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing, China
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Rachhpal S Jassal
- Biometeorology and Soil Physics Group, University of British Columbia, Vancouver, British Columbia, Canada
| | - Zoran Nesic
- Biometeorology and Soil Physics Group, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sung-Ching Lee
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Charles P-A Bourque
- Faculty of Forestry and Environmental Management, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Shaorong Hao
- State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing, China
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Chuan Jin
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Hainan University, Haikou, China
| | - Peng Liu
- State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing, China
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Xin Jia
- State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing, China
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Yun Tian
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Beijing Engineering Research Center of Soil and Water Conservation, Beijing Forestry University, Beijing, China
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3
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Gessler A, Zweifel R. Beyond source and sink control - toward an integrated approach to understand the carbon balance in plants. THE NEW PHYTOLOGIST 2024; 242:858-869. [PMID: 38375596 DOI: 10.1111/nph.19611] [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: 10/10/2023] [Accepted: 02/03/2024] [Indexed: 02/21/2024]
Abstract
A conceptual understanding on how the vegetation's carbon (C) balance is determined by source activity and sink demand is important to predict its C uptake and sequestration potential now and in the future. We have gathered trajectories of photosynthesis and growth as a function of environmental conditions described in the literature and compared them with current concepts of source and sink control. There is no clear evidence for pure source or sink control of the C balance, which contradicts recent hypotheses. Using model scenarios, we show how legacy effects via structural and functional traits and antecedent environmental conditions can alter the plant's carbon balance. We, thus, combined the concept of short-term source-sink coordination with long-term environmentally driven legacy effects that dynamically acclimate structural and functional traits over time. These acclimated traits feedback on the sensitivity of source and sink activity and thus change the plant physiological responses to environmental conditions. We postulate a whole plant C-coordination system that is primarily driven by stomatal optimization of growth to avoid a C source-sink mismatch. Therefore, we anticipate that C sequestration of forest ecosystems under future climate conditions will largely follow optimality principles that balance water and carbon resources to maximize growth in the long term.
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Affiliation(s)
- Arthur Gessler
- Swiss Federal Research Institute WSL, 8903, Birmensdorf, Switzerland
- Institute of Terrestrial Ecosystems, ETH Zurich, 8092, Zurich, Switzerland
| | - Roman Zweifel
- Swiss Federal Research Institute WSL, 8903, Birmensdorf, Switzerland
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4
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Damasceno AR, Garcia S, Aleixo IF, Menezes JCG, Pereira IS, De Kauwe MG, Ferrer VR, Fleischer K, Grams TEE, Guedes AV, Hartley IP, Kruijt B, Lugli LF, Martins NP, Norby RJ, Pires-Santos JS, Portela BTT, Rammig A, de Oliveira LR, Santana FD, Santos YR, de Souza CCS, Ushida G, Lapola DM, Quesada CAN, Domingues TF. In situ short-term responses of Amazonian understory plants to elevated CO 2. PLANT, CELL & ENVIRONMENT 2024; 47:1865-1876. [PMID: 38334166 DOI: 10.1111/pce.14842] [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: 08/23/2023] [Revised: 01/16/2024] [Accepted: 01/23/2024] [Indexed: 02/10/2024]
Abstract
The response of plants to increasing atmospheric CO2 depends on the ecological context where the plants are found. Several experiments with elevated CO2 (eCO2) have been done worldwide, but the Amazonian forest understory has been neglected. As the central Amazon is limited by light and phosphorus, understanding how understory responds to eCO2 is important for foreseeing how the forest will function in the future. In the understory of a natural forest in the Central Amazon, we installed four open-top chambers as control replicates and another four under eCO2 (+250 ppm above ambient levels). Under eCO2, we observed increases in carbon assimilation rate (67%), maximum electron transport rate (19%), quantum yield (56%), and water use efficiency (78%). We also detected an increase in leaf area (51%) and stem diameter increment (65%). Central Amazon understory responded positively to eCO2 by increasing their ability to capture and use light and the extra primary productivity was allocated to supporting more leaf and conducting tissues. The increment in leaf area while maintaining transpiration rates suggests that the understory will increase its contribution to evapotranspiration. Therefore, this forest might be less resistant in the future to extreme drought, as no reduction in transpiration rates were detected.
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Affiliation(s)
- Amanda Rayane Damasceno
- Ecology Graduate Program, National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | - Sabrina Garcia
- Environmental Dynamics Coordination (CODAM), National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | - Izabela Fonseca Aleixo
- Environmental Dynamics Coordination (CODAM), National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | | | - Iokanam Sales Pereira
- Environmental Dynamics Coordination (CODAM), National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | | | - Vanessa Rodrigues Ferrer
- Ecology Graduate Program, National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | | | - Thorsten E E Grams
- School of Life Sciences, Technical University of Munich (TUM), Freising, Germany
| | - Alacimar V Guedes
- Environmental Dynamics Coordination (CODAM), National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | - Iain Paul Hartley
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, UK
| | - Bart Kruijt
- Wageningen University, Water Systems and Global Change, Wageningen, Netherlands
| | | | - Nathielly Pires Martins
- Tropical Forest Sciences Graduate Program, National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | - Richard J Norby
- School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, UK
| | | | - Bruno Takeshi Tanaka Portela
- Environmental Dynamics Coordination (CODAM), National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | - Anja Rammig
- School of Life Sciences, Technical University of Munich (TUM), Freising, Germany
| | - Leonardo Ramos de Oliveira
- Environmental Dynamics Coordination (CODAM), National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | - Flávia Delgado Santana
- Environmental Dynamics Coordination (CODAM), National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | - Yago Rodrigues Santos
- Environmental Dynamics Coordination (CODAM), National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | | | - Gabriela Ushida
- Ecology Graduate Program, National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | - David Montenegro Lapola
- Laboratório de Ciência do Sistema Terrestre - LabTerra, Centro de Pesquisas Meteorológicas e Climáticas Aplicadas à Agricultura - CEPAGRI, Universidade Estadual de Campinas - UNICAMP, Campinas, São Paulo, Brazil
| | - Carlos Alberto Nobre Quesada
- Environmental Dynamics Coordination (CODAM), National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | - Tomas Ferreira Domingues
- Faculdde de Filosofia, Ciências e Letras de Ribeirão Preto, Departamento de Biologia, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
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Zheng Y, Zhao W, Chen A, Chen Y, Chen J, Zhu Z. Vegetation canopy structure mediates the response of gross primary production to environmental drivers across multiple temporal scales. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170439. [PMID: 38281630 DOI: 10.1016/j.scitotenv.2024.170439] [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: 10/29/2023] [Revised: 01/10/2024] [Accepted: 01/23/2024] [Indexed: 01/30/2024]
Abstract
Gross primary production (GPP) is a critical component of the global carbon cycle and plays a significant role in the terrestrial carbon budget. The impact of environmental factors on GPP can occur through both direct (by influencing photosynthetic efficiency) and indirect (through the modulation of vegetation structure) pathways, but the extent to which these mechanisms contribute has been seldom quantified. In this study, we used structural equation modeling and observations from the FLUXNET network to investigate the direct and indirect effects of environmental factors on terrestrial ecosystem GPP at multiple temporal scales. We found that canopy structure, represented by leaf area index (LAI), is a crucial intermediate factor in the GPP response to environmental drivers. Environmental factors affect GPP indirectly by altering canopy structure, and the relative proportion of indirect effects decreased with increasing LAI. The study also identified different effects of environmental factors on GPP across time scales. At the half-hourly time scale, radiation was the primary driver of GPP. In contrast, the influences of temperature and vapor pressure deficit took on greater prominence at longer time scales. About half of the total effect of temperature on GPP was indirect through the regulation of canopy structure, and the indirect effect increased with increasing time scale (GPPNT-based models: 0.135 (half-hourly) vs. 0.171 (daily) vs. 0.189 (weekly) vs. 0.217 (monthly); GPPDT-based models: 0.139 vs. 0.170 vs. 0.187 vs. 0.215; all values were reported in gC m-2 d-1 °C-1, P < 0.001); while the indirect effect of radiation on GPP was comparatively lower, accounting for less than a quarter of the total effect. Furthermore, we observed a direct, negative-to-positive impact of precipitation on GPP across timescales. These findings provide crucial information on the interplay between environmental factors and LAI on GPP and enable a deeper understanding of the driving mechanisms of GPP.
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Affiliation(s)
- Yaoyao Zheng
- School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen 518055, China; Key Laboratory of Earth Surface System and Human-Earth Relations, Ministry of Natural Resources of China, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Weiqing Zhao
- School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen 518055, China; Key Laboratory of Earth Surface System and Human-Earth Relations, Ministry of Natural Resources of China, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Anping Chen
- Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO, USA
| | - Yue Chen
- School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen 518055, China; Key Laboratory of Earth Surface System and Human-Earth Relations, Ministry of Natural Resources of China, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Jiana Chen
- School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen 518055, China; Key Laboratory of Earth Surface System and Human-Earth Relations, Ministry of Natural Resources of China, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Zaichun Zhu
- School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen 518055, China; Key Laboratory of Earth Surface System and Human-Earth Relations, Ministry of Natural Resources of China, Shenzhen Graduate School, Peking University, Shenzhen 518055, China.
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Soldatova E, Krasilnikov S, Kuzyakov Y. Soil organic matter turnover: Global implications from δ 13C and δ 15N signatures. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169423. [PMID: 38128662 DOI: 10.1016/j.scitotenv.2023.169423] [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: 09/06/2023] [Revised: 12/13/2023] [Accepted: 12/14/2023] [Indexed: 12/23/2023]
Abstract
The turnover and residence time of carbon (C) and nitrogen (N) in soil is a fundamental parameter reflecting the rates of soil organic matter (SOM) transformation and the contribution of soils to greenhouse gases fluxes. Based on the global database of the stable isotope composition of C (δ13C) and N (δ15N) depending on soil depth (171 profiles), we assessed С and N turnover and related them to climate, biome types and soil properties. The 13C and 15N discrimination between the litter horizon and mineral soil was evaluated to explain the key processes of litter transformation. The 13C and 15N discrimination by microbial utilization of litter and SOM, as well as the continuous increase of δ13C and δ15N with depth, enabled to assess C and N turnover within SOM. N turnover was two times faster than that of C, which reflects i) repeated N recycling by microorganisms accelerating N turnover, ii) C loss as CO2 and input of new C atoms to cycling, which reduces the C turnover within soil, and iii) generally slower turnover of N free persistent organic compounds (e.g. lignin, suberin, cellulose) compared to the N containing compounds (e.g. amino acids, ribonucleic acids). An increase in temperature and precipitation accelerated C and N turnover because: i) higher microbial activity and SOM decomposition rate, ii) larger soil moisture and fast diffusion of dissolved organics towards exoenzymes, iii) downward transport of 13C-enriched organic matter (e.g. sugars, amino acids), and iii) leaching of 15N-depleted nitrates from the topsoil into subsoil and losses from the whole soil profile. Temperature accelerates SOM turnover stronger than precipitation. The temperature increase by 10 °C accelerates the C and N turnover for 40 %. SOM turnover is boosted by decreasing C/N ratio because: i) SOM with a high C/N ratio originated from litter is converted to microbially-derived SOM in mineral soil characterized by a low C/N ratio; ii) litter with a low C/N ratio is decomposed faster than litter with a high C/N; iii) microbial carbon-use efficiency increases with N availability. The biome type affects SOM decomposition by i) climate: slower turnover under wet and cold conditions, and ii) by litter quality: faster utilization of leaves than needles. Thus, the fastest C turnover is common under evergreen forests and the lowest under mixed and coniferous ones, whereas temperature and C/N ratio are the main factors controlling SOM turnover. Concluding, the assessment of SOM turnover by δ13C and δ15N approach showed two times faster N turnover compared to C, and specifics of SOM turnover depending on the biomes as well as climate conditions.
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Affiliation(s)
- Evgeniya Soldatova
- Center for Isotope Biogeochemistry, Institute of Environmental and Agricultural Biology (X-BIO), University of Tyumen, 6 Volodarskogo Street, 625003 Tyumen, Russia; Laboratory of Mass Transport, Geological Institute of the Russian Academy of Sciences, 7с1 Pyzhevskiy Pereulok, 119017 Moscow, Russia.
| | - Sergey Krasilnikov
- Department of Land Surveying & Geo-Informatics, Research Centre for Deep Space Explorations, The Hong Kong Polytechnic University, ZN601, 6/F, Phase 8, 181 Chatham Road South, Kowloon, Hong Kong.
| | - Yakov Kuzyakov
- Department of Soil Science of Temperate Ecosystems, Department of Agricultural Soil Science, University of Goettingen, 2 Büsgenweg, 37077 Göttingen, Germany; Peoples Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, 117198 Moscow, Russia; Institute of Environmental Sciences, Kazan Federal University, 420049 Kazan, Russia.
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7
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Xu X, van der Sleen P, Groenendijk P, Vlam M, Medvigy D, Moorcroft P, Petticord D, Ma Y, Zuidema PA. Constraining long-term model predictions for woody growth using tropical tree rings. GLOBAL CHANGE BIOLOGY 2024; 30:e17075. [PMID: 38273586 DOI: 10.1111/gcb.17075] [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: 08/18/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 01/27/2024]
Abstract
The strength and persistence of the tropical carbon sink hinges on the long-term responses of woody growth to climatic variations and increasing CO2 . However, the sensitivity of tropical woody growth to these environmental changes is poorly understood, leading to large uncertainties in growth predictions. Here, we used tree ring records from a Southeast Asian tropical forest to constrain ED2.2-hydro, a terrestrial biosphere model with explicit vegetation demography. Specifically, we assessed individual-level woody growth responses to historical climate variability and increases in atmospheric CO2 (Ca ). When forced with historical Ca , ED2.2-hydro reproduced the magnitude of increases in intercellular CO2 concentration (a major determinant of photosynthesis) estimated from tree ring carbon isotope records. In contrast, simulated growth trends were considerably larger than those obtained from tree rings, suggesting that woody biomass production efficiency (WBPE = woody biomass production:gross primary productivity) was overestimated by the model. The estimated WBPE decline under increasing Ca based on model-data discrepancy was comparable to or stronger than (depending on tree species and size) the observed WBPE changes from a multi-year mature-forest CO2 fertilization experiment. In addition, we found that ED2.2-hydro generally overestimated climatic sensitivity of woody growth, especially for late-successional plant functional types. The model-data discrepancy in growth sensitivity to climate was likely caused by underestimating WBPE in hot and dry years due to commonly used model assumptions on carbon use efficiency and allocation. To our knowledge, this is the first study to constrain model predictions of individual tree-level growth sensitivity to Ca and climate against tropical tree-ring data. Our results suggest that improving model processes related to WBPE is crucial to obtain better predictions of tropical forest responses to droughts and increasing Ca . More accurate parameterization of WBPE will likely reduce the stimulation of woody growth by Ca rise predicted by biosphere models.
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Affiliation(s)
- Xiangtao Xu
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Peter van der Sleen
- Forest Ecology & Forest Management Group, Wageningen University, Wageningen, The Netherlands
| | - Peter Groenendijk
- Department of Plant Biology, Institute of Biology, University of Campinas, UNICAMP, Campinas, SP, Brazil
| | - Mart Vlam
- Forest Ecology & Forest Management Group, Wageningen University, Wageningen, The Netherlands
| | - David Medvigy
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Paul Moorcroft
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Daniel Petticord
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Yixin Ma
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Pieter A Zuidema
- Forest Ecology & Forest Management Group, Wageningen University, Wageningen, The Netherlands
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8
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Das R, Chaturvedi RK, Roy A, Karmakar S, Ghosh S. Warming inhibits increases in vegetation net primary productivity despite greening in India. Sci Rep 2023; 13:21309. [PMID: 38042916 PMCID: PMC10693629 DOI: 10.1038/s41598-023-48614-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 11/28/2023] [Indexed: 12/04/2023] Open
Abstract
India is the second-highest contributor to the post-2000 global greening. However, with satellite data, here we show that this 18.51% increase in Leaf Area Index (LAI) during 2001-2019 fails to translate into increased carbon uptake due to warming constraints. Our analysis further shows 6.19% decrease in Net Primary Productivity (NPP) during 2001-2019 over the temporally consistent forests in India despite 6.75% increase in LAI. We identify hotspots of statistically significant decreasing trends in NPP over the key forested regions of Northeast India, Peninsular India, and the Western Ghats. Together, these areas contribute to more than 31% of the NPP of India (1274.8 TgC.year-1). These three regions are also the warming hotspots in India. Granger Causality analysis confirms that temperature causes the changes in net-photosynthesis of vegetation. Decreasing photosynthesis and stable respiration, above a threshold temperature, over these regions, as seen in observations, are the key reasons behind the declining NPP. Our analysis shows that warming has already started affecting carbon uptake in Indian forests and calls for improved climate resilient forest management practices in a warming world.
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Affiliation(s)
- Ripan Das
- Interdisciplinary Program in Climate Studies, Indian Institute of Technology Bombay, Powai, Mumbai, 400 076, India
| | - Rajiv Kumar Chaturvedi
- Department of Humanities and Social Sciences, Birla Institute of Technology and Science-Goa Campus, Zuarinagar, India
| | - Adrija Roy
- Department of Civil Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400 076, India
| | - Subhankar Karmakar
- Interdisciplinary Program in Climate Studies, Indian Institute of Technology Bombay, Powai, Mumbai, 400 076, India
- Environmental Science and Engineering Department, Indian Institute of Technology Bombay, Powai, Mumbai, 400 076, India
| | - Subimal Ghosh
- Interdisciplinary Program in Climate Studies, Indian Institute of Technology Bombay, Powai, Mumbai, 400 076, India.
- Department of Civil Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400 076, India.
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9
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Peng X, Jiang S, Liu S, Valbuena R, Smith A, Zhan Y, Shi Y, Ning Y, Feng S, Gao H, Wang Z. Long-term satellite observations show continuous increase of vegetation growth enhancement in urban environment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 898:165515. [PMID: 37451465 DOI: 10.1016/j.scitotenv.2023.165515] [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: 05/23/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Urbanization shows continuous expansion and development, ushering in the co-evolution of urban environments and vegetation over time. Recent remote sensing-based studies have discovered prevalent vegetation growth enhancement in urban environments. However, whether there is a temporal evolution of the growth enhancement remains unknown and unexplored. Here we expanded the existing framework for assessing the long-term impact of urbanization on vegetation greenness (enhanced vegetation index, EVI) using long time series of remote sensing images and applied it in Changsha, the capital city of Hunan province in China. Results showed that vegetation growth experienced widespread enhancement from 2000 to 2017, and increased 1.8 times from 2000 to 2017, suggesting strong continuous adaptive capability of vegetation to urban conditions. Although the overall impact of urbanization was negative due to the replacement of vegetated surfaces, the growth enhancement nevertheless offset or compensated the direct loss of vegetated cover during urbanization in the magnitude of 28 % in 2000 to 44 % in 2017. Our study also revealed large spatial heterogeneity in vegetation growth response among various districts at different urbanization levels and found an emergent trend under the observed spatial heterogeneity toward an asymptotic maximum with urbanization, showing EVI converges to 0.22 in highly urbanized areas. We further found that the positive effect of urbanization on vegetation growth is a function of urbanization intensity and time, which implies that the effect of the urban environment on vegetation can be simulated and predicted, and can be verified in more cities in the future. Our study is the first to successfully quantify long-term spatial patterns on the co-evolution of urbanization and vegetation, providing a new understanding of the continuous adaptive responses of vegetation growth to urbanization and shedding light on predicting biological responses to future environmental change.
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Affiliation(s)
- Xi Peng
- College of Life Science and Technology, National Engineering Laboratory for Applied Technology in Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China
| | - Shucheng Jiang
- College of Life Science and Technology, National Engineering Laboratory for Applied Technology in Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China
| | - Shuguang Liu
- College of Life Science and Technology, National Engineering Laboratory for Applied Technology in Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China.
| | - Rubén Valbuena
- School of Natural Sciences, Bangor University, Bangor, UK
| | - Andy Smith
- School of Natural Sciences, Bangor University, Bangor, UK
| | - Yang Zhan
- College of Life Science and Technology, National Engineering Laboratory for Applied Technology in Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China
| | - Yi Shi
- College of Life Science and Technology, National Engineering Laboratory for Applied Technology in Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China
| | - Ying Ning
- College of Life Science and Technology, National Engineering Laboratory for Applied Technology in Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China
| | - Shuailong Feng
- College of Life Science and Technology, National Engineering Laboratory for Applied Technology in Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China
| | - Haiqiang Gao
- College of Life Science and Technology, National Engineering Laboratory for Applied Technology in Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China
| | - Zhao Wang
- College of Life Science and Technology, National Engineering Laboratory for Applied Technology in Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China
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10
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Metze D, Schnecker J, Canarini A, Fuchslueger L, Koch BJ, Stone BW, Hungate BA, Hausmann B, Schmidt H, Schaumberger A, Bahn M, Kaiser C, Richter A. Microbial growth under drought is confined to distinct taxa and modified by potential future climate conditions. Nat Commun 2023; 14:5895. [PMID: 37736743 PMCID: PMC10516970 DOI: 10.1038/s41467-023-41524-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 09/07/2023] [Indexed: 09/23/2023] Open
Abstract
Climate change increases the frequency and intensity of drought events, affecting soil functions including carbon sequestration and nutrient cycling, which are driven by growing microorganisms. Yet we know little about microbial responses to drought due to methodological limitations. Here, we estimate microbial growth rates in montane grassland soils exposed to ambient conditions, drought, and potential future climate conditions (i.e., soils exposed to 6 years of elevated temperatures and elevated CO2 levels). For this purpose, we combined 18O-water vapor equilibration with quantitative stable isotope probing (termed 'vapor-qSIP') to measure taxon-specific microbial growth in dry soils. In our experiments, drought caused >90% of bacterial and archaeal taxa to stop dividing and reduced the growth rates of persisting ones. Under drought, growing taxa accounted for only 4% of the total community as compared to 35% in the controls. Drought-tolerant communities were dominated by specialized members of the Actinobacteriota, particularly the genus Streptomyces. Six years of pre-exposure to future climate conditions (3 °C warming and + 300 ppm atmospheric CO2) alleviated drought effects on microbial growth, through more drought-tolerant taxa across major phyla, accounting for 9% of the total community. Our results provide insights into the response of active microbes to drought today and in a future climate, and highlight the importance of studying drought in combination with future climate conditions to capture interactive effects and improve predictions of future soil-climate feedbacks.
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Affiliation(s)
- Dennis Metze
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Vienna, Austria.
| | - Jörg Schnecker
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Alberto Canarini
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Lucia Fuchslueger
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Benjamin J Koch
- Center for Ecosystem Science and Society and Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Bram W Stone
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Bruce A Hungate
- Center for Ecosystem Science and Society and Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Bela Hausmann
- Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna, Vienna, Austria
- Division of Clinical Microbiology, Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Hannes Schmidt
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Andreas Schaumberger
- Agricultural Research and Education Centre Raumberg-Gumpenstein, Irdning, Austria
| | - Michael Bahn
- Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - Christina Kaiser
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Andreas Richter
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
- International Institute for Applied Systems Analysis, Advancing Systems Analysis Program, Laxenburg, Austria.
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11
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Argles APK, Robertson E, Harper AB, Morison JIL, Xenakis G, Hastings A, Mccalmont J, Moore JR, Bateman IJ, Gannon K, Betts RA, Bathgate S, Thomas J, Heard M, Cox PM. Modelling the impact of forest management and CO 2-fertilisation on growth and demography in a Sitka spruce plantation. Sci Rep 2023; 13:13487. [PMID: 37596319 PMCID: PMC10439122 DOI: 10.1038/s41598-023-39810-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 07/31/2023] [Indexed: 08/20/2023] Open
Abstract
Afforestation and reforestation to meet 'Net Zero' emissions targets are considered a necessary policy by many countries. Their potential benefits are usually assessed through forest carbon and growth models. The implementation of vegetation demography gives scope to represent forest management and other size-dependent processes within land surface models (LSMs). In this paper, we evaluate the impact of including management within an LSM that represents demography, using both in-situ and reanalysis climate drivers at a mature, upland Sitka spruce plantation in Northumberland, UK. We compare historical simulations with fixed and variable CO2 concentrations, and with and without tree thinning implemented. Simulations are evaluated against the observed vegetation structure and carbon fluxes. Including thinning and the impact of increasing CO2 concentration ('CO2 fertilisation') gave more realistic estimates of stand-structure and physical characteristics. Historical CO2 fertilisation had a noticeable effect on the Gross Primary Productivity seasonal-diurnal cycle and contributed to approximately 7% higher stand biomass by 2018. The net effect of both processes resulted in a decrease of tree density and biomass, but an increase in tree height and leaf area index.
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Affiliation(s)
- Arthur P K Argles
- Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, Devon, UK.
- Department of Mathematics and Statistics, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4QE, UK.
| | - Eddy Robertson
- Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, Devon, UK
| | - Anna B Harper
- Department of Mathematics and Statistics, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4QE, UK
| | | | | | - Astley Hastings
- School of Biological Sciences, University of Aberdeen, King's College, Aberdeen, AB24 3FX, UK
| | - Jon Mccalmont
- School of Biological Sciences, University of Aberdeen, King's College, Aberdeen, AB24 3FX, UK
- Department of Biosciences, Faculty of Health and Life Sciences, University of Exeter, Streatham Campus, Rennes Drive, Exeter, EX4 4RJ, UK
| | - Jon R Moore
- Department of Mathematics and Statistics, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4QE, UK
| | - Ian J Bateman
- Land, Environment, Economics and Policy Institute (LEEP), Department of Economics, University of Exeter Business School, Exeter, UK
| | - Kate Gannon
- Land, Environment, Economics and Policy Institute (LEEP), Department of Economics, University of Exeter Business School, Exeter, UK
| | - Richard A Betts
- Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, Devon, UK
- University of Exeter Global Systems Institute, Exeter, EX4 4QE, UK
| | | | - Justin Thomas
- School of Biological Sciences, University of Aberdeen, King's College, Aberdeen, AB24 3FX, UK
| | - Matthew Heard
- The National Trust, Heelis, Kemble Drive, Swindon, SN2 2NA, UK
| | - Peter M Cox
- Department of Mathematics and Statistics, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4QE, UK
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12
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Mori AS, Suzuki KF, Hori M, Kadoya T, Okano K, Uraguchi A, Muraoka H, Sato T, Shibata H, Suzuki-Ohno Y, Koba K, Toda M, Nakano SI, Kondoh M, Kitajima K, Nakamura M. Perspective: sustainability challenges, opportunities and solutions for long-term ecosystem observations. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220192. [PMID: 37246388 DOI: 10.1098/rstb.2022.0192] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 04/11/2023] [Indexed: 05/30/2023] Open
Abstract
As interest in natural capital grows and society increasingly recognizes the value of biodiversity, we must discuss how ecosystem observations to detect changes in biodiversity can be sustained through collaboration across regions and sectors. However, there are many barriers to establishing and sustaining large-scale, fine-resolution ecosystem observations. First, comprehensive monitoring data on both biodiversity and possible anthropogenic factors are lacking. Second, some in situ ecosystem observations cannot be systematically established and maintained across locations. Third, equitable solutions across sectors and countries are needed to build a global network. Here, by examining individual cases and emerging frameworks, mainly from (but not limited to) Japan, we illustrate how ecological science relies on long-term data and how neglecting basic monitoring of our home planet further reduces our chances of overcoming the environmental crisis. We also discuss emerging techniques and opportunities, such as environmental DNA and citizen science as well as using the existing and forgotten sites of monitoring, that can help overcome some of the difficulties in establishing and sustaining ecosystem observations at a large scale with fine resolution. Overall, this paper presents a call to action for joint monitoring of biodiversity and anthropogenic factors, the systematic establishment and maintenance of in situ observations, and equitable solutions across sectors and countries to build a global network, beyond cultures, languages, and economic status. We hope that our proposed framework and the examples from Japan can serve as a starting point for further discussions and collaborations among stakeholders across multiple sectors of society. It is time to take the next step in detecting changes in socio-ecological systems, and if monitoring and observation can be made more equitable and feasible, they will play an even more important role in ensuring global sustainability for future generations. This article is part of the theme issue 'Detecting and attributing the causes of biodiversity change: needs, gaps and solutions'.
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Affiliation(s)
- Akira S Mori
- Research Center for Advanced Science and Technology, The University of Tokyo, Komaba 4-6-1, Meguro, Tokyo 153-8904, Japan
- Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya, Yokohama, Kanagawa 240-8501, Japan
| | - Kureha F Suzuki
- Research Center for Advanced Science and Technology, The University of Tokyo, Komaba 4-6-1, Meguro, Tokyo 153-8904, Japan
- Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya, Yokohama, Kanagawa 240-8501, Japan
| | - Masakazu Hori
- Japan Fisheries Research and Education Agency, 6F Technowave100, 1-1-25 Shin-urashima, Kanagawa-ku, Yokohama, Kanagawa 221-8529, Japan
| | - Taku Kadoya
- National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Kotaro Okano
- Research Center for Advanced Science and Technology, The University of Tokyo, Komaba 4-6-1, Meguro, Tokyo 153-8904, Japan
| | - Aya Uraguchi
- Conservation International Japan, 1-17 Yotsuya, Shinjuku, Tokyo 160-0014, Japan
| | - Hiroyuki Muraoka
- National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki 305-8506, Japan
- River Basin Research Center, Gifu University, 1-1 Yanagido, Gifu City 501-1193, Japan
| | - Tamotsu Sato
- International Strategy Division, Forestry and Forest Products Research Institute (FFPRI), 1 Matsunosato, Tsukuba, Ibaraki 305-8687, Japan
| | - Hideaki Shibata
- Field Science Center for Northern Biosphere, Hokkaido University, N9 W9, Kita-ku, Sapporo, Hokkaido 060-0809, Japan
| | - Yukari Suzuki-Ohno
- Graduate School of Life Sciences, Tohoku University, 6-3 Aoba, Aramaki-aza, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Keisuke Koba
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, Shiga 520-2113, Japan
| | - Mariko Toda
- Kokusai Kogyo Co., Ltd. Shinjuku Front Tower, 21-1, Kita-Shinjuku 2-chome, Shinjukuku, Tokyo 169-0074, Japan
| | - Shin-Ichi Nakano
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, Shiga 520-2113, Japan
| | - Michio Kondoh
- Graduate School of Life Sciences, Tohoku University, 6-3 Aoba, Aramaki-aza, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Kaoru Kitajima
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Masahiro Nakamura
- Tomakomai Experimental Forest, Field Science Center for Northern Biosphere, Hokkaido University, Takaoka, Tomakomai, Hokkaido 053-0035, Japan
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13
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Devi NB, Lepcha NT. Carbon sink and source function of Eastern Himalayan forests: implications of change in climate and biotic variables. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:843. [PMID: 37318600 DOI: 10.1007/s10661-023-11460-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 06/03/2023] [Indexed: 06/16/2023]
Abstract
Forests serve as a sink and source of carbon and play a substantial role in regional and global carbon cycling. The Himalayan forests act as climate regulators of the Hindukush region, which is experiencing climate change at a high pace, and a proper understanding of these systems is necessary to mitigate this problem. We hypothesize that the variance of abiotic factors and vegetation will influence the carbon sink and source function of the different forest types of the Himalayas. Carbon sequestration was computed from the increment of carbon stocks estimated allometrically using Forest Survey of India equations, and soil CO2 flux was determined by the alkali absorption method. The carbon sequestration rate and CO2 flux by the different forests exhibited a negative relation. The carbon sequestration rate was highest with minimum emission in the temperate forest, while the tropical forest recorded the least sequestration and maximum carbon flux rate. The Pearson correlation test between carbon sequestration and tree species richness and diversity revealed a positive-significant influence but negative relation with climatic factors. An analysis of variance indicated significant seasonal differences between the rate of soil carbon emissions due to variations in the forest. A multivariate regression analysis of the monthly soil CO2 emission rate shows high variability (85%) due to fluctuations of climatic variables in the Eastern Himalayan forests. Results of the present study revealed that the carbon sink and source function of forests respond to changes in forest types, climatic variables, and edaphic factors. Tree species and soil nutrient content influenced carbon sequestration, while shifts in climatic factors influenced soil CO2 emission rate. Increased temperature and rainfall may further change the soil quality by enhancing soil CO2 emission and reducing soil organic carbon, thereby impacting this region's carbon sink and source function. Enhancing tree diversity in the forests of this region may be beneficial for retarding this impact.
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Affiliation(s)
- N Bijayalaxmi Devi
- Department of Botany, Ecology Laboratory, Sikkim University, 6th Mile Gangtok-737102, Sikkim, India.
| | - Nima Tshering Lepcha
- Department of Botany, Ecology Laboratory, Sikkim University, 6th Mile Gangtok-737102, Sikkim, India
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14
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Férriz M, Martin-Benito D, Fernández-de-Simón MB, Conde M, García-Cervigón AI, Aranda I, Gea-Izquierdo G. Functional phenotypic plasticity mediated by water stress and [CO2] explains differences in drought tolerance of two phylogenetically close conifers. TREE PHYSIOLOGY 2023; 43:909-924. [PMID: 36809504 PMCID: PMC10255776 DOI: 10.1093/treephys/tpad021] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 02/15/2023] [Indexed: 06/11/2023]
Abstract
Forests are threatened globally by increased recurrence and intensity of hot droughts. Functionally close coexisting species may exhibit differences in drought vulnerability large enough to cause niche differentiation and affect forest dynamics. The effect of rising atmospheric [CO2], which could partly alleviate the negative effects of drought, may also differ between species. We analysed functional plasticity in seedlings of two taxonomically close pine species (Pinus pinaster Ait., Pinus pinea L.) under different [CO2] and water stress levels. The multidimensional functional trait variability was more influenced by water stress (preferentially xylem traits) and [CO2] (mostly leaf traits) than by differences between species. However, we observed differences between species in the strategies followed to coordinate their hydraulic and structural traits under stress. Leaf 13C discrimination decreased with water stress and increased under elevated [CO2]. Under water stress both species increased their sapwood area to leaf area ratios, tracheid density and xylem cavitation, whereas they reduced tracheid lumen area and xylem conductivity. Pinus pinea was more anisohydric than P. pinaster. Pinus pinaster produced larger conduits under well-watered conditions than P. pinea. Pinus pinea was more tolerant to water stress and more resistant to xylem cavitation under low water potentials. The higher xylem plasticity in P. pinea, particularly in tracheid lumen area, expressed a higher capacity of acclimation to water stress than P. pinaster. In contrast, P. pinaster coped with water stress comparatively more by increasing plasticity of leaf hydraulic traits. Despite the small differences observed in the functional response to water stress and drought tolerance between species, these interspecific differences agreed with ongoing substitution of P. pinaster by P. pinea in forests where both species co-occur. Increased [CO2] had little effect on the species-specific relative performance. Thus, a competitive advantage under moderate water stress of P. pinea compared with P. pinaster is expected to continue in the future.
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Affiliation(s)
- M Férriz
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| | - D Martin-Benito
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| | | | - M Conde
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| | - A I García-Cervigón
- Department of Biology and Geology, Physics and Inorganic Chemistry Rey Juan Carlos University, c/Tulipán s/n, 28933 Móstoles, Spain
| | - I Aranda
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| | - G Gea-Izquierdo
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
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15
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Wang Y, Tang Y, Xia N, Terrer C, Guo H, Du E. Urban CO 2 imprints on carbon isotope and growth of Chinese pine in the Beijing metropolitan region. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 866:161389. [PMID: 36610623 DOI: 10.1016/j.scitotenv.2023.161389] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 12/05/2022] [Accepted: 01/01/2023] [Indexed: 06/17/2023]
Abstract
Rapid urbanization has occurred globally and resulted in increasing CO2 emissions from urban areas. Compared to natural forests, urban forests are subject to higher atmospheric CO2 concentrations in view of strong urban-periurban-rural gradients of CO2 emissions. However, relevant insights in the CO2-associated urban imprints on the physiology and growth of regional forests remain lacking. By sampling foliage and tree rings of Chinese pine (Pinus tabuliformis) in the Beijing metropolitan region, China, we explored whether and how urban CO2 emissions affect stable carbon isotope ratios (δ13C) and tree growth spatially and/or temporally. The results indicate a significant decrease in foliar δ13C values towards the urban center and this pattern was mainly explained by the urban-periurban-rural gradients of CO2 emissions as surrogated by trunk road density. Tree-ring δ13C values showed a significant decrease over last four decades and this trend was mainly explained by rising levels of CO2 and secondarily mediated by the variations of aridity index during growing season. Moreover, annual basal area increment of Chinese pine was significantly accelerated during last two decades, being mainly driven by increasing CO2 emissions and secondarily mediated by climate variations. These findings reveal significant CO2-associated imprints of urbanization on plant growth and provide empirical evidences of significant CO2-induced alteration of carbon cycles in urban forests.
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Affiliation(s)
- Yang Wang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Yang Tang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Nan Xia
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - César Terrer
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, USA
| | - Hongbo Guo
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Enzai Du
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China.
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16
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Baldrian P, López-Mondéjar R, Kohout P. Forest microbiome and global change. Nat Rev Microbiol 2023:10.1038/s41579-023-00876-4. [PMID: 36941408 DOI: 10.1038/s41579-023-00876-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2023] [Indexed: 03/23/2023]
Abstract
Forests influence climate and mitigate global change through the storage of carbon in soils. In turn, these complex ecosystems face important challenges, including increases in carbon dioxide, warming, drought and fire, pest outbreaks and nitrogen deposition. The response of forests to these changes is largely mediated by microorganisms, especially fungi and bacteria. The effects of global change differ among boreal, temperate and tropical forests. The future of forests depends mostly on the performance and balance of fungal symbiotic guilds, saprotrophic fungi and bacteria, and fungal plant pathogens. Drought severely weakens forest resilience, as it triggers adverse processes such as pathogen outbreaks and fires that impact the microbial and forest performance for carbon storage and nutrient turnover. Nitrogen deposition also substantially affects forest microbial processes, with a pronounced effect in the temperate zone. Considering plant-microorganism interactions would help predict the future of forests and identify management strategies to increase ecosystem stability and alleviate climate change effects. In this Review, we describe the impact of global change on the forest ecosystem and its microbiome across different climatic zones. We propose potential approaches to control the adverse effects of global change on forest stability, and present future research directions to understand the changes ahead.
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Affiliation(s)
- Petr Baldrian
- Laboratory of Environmental Microbiology, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic.
| | - Rubén López-Mondéjar
- Laboratory of Environmental Microbiology, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
- Department of Soil and Water Conservation and Waste Management, CEBAS-CSIC, Campus Universitario de Espinardo, Murcia, Spain
| | - Petr Kohout
- Laboratory of Environmental Microbiology, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
- Faculty of Science, Charles University, Prague, Czech Republic
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17
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Oswald SW, Aubrey DP. Modeling starch dynamics from seasonal variations of photosynthesis, growth, and respiration. TREE PHYSIOLOGY 2023:tpad007. [PMID: 36708035 DOI: 10.1093/treephys/tpad007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 11/21/2022] [Indexed: 06/18/2023]
Abstract
Nonstructural carbohydrates (NSCs) buffer differences in plant carbon supply (photosynthesis) and demand (respiration, growth, etc.) but the regulation of their dynamics remains unresolved. Seasonal variations in NSCs are well-documented, but differences in the time-average, amplitude, phase, and other characteristics across ecosystems and functional types lack explanation; furthermore, observed dynamics do not always match expectations. The failure to match observed and expected dynamics has stimulated debate on whether carbon supply or demand drives NSC dynamics. To gain insight into how carbon supply and demand drive seasonal NSC dynamics, we derive a simple model of NSC dynamics based on carbon mass balance and linearizing the NSC demand to determine how supply-driven and demand-driven seasonal NSC dynamics differ. We find that supply-driven and demand-driven dynamics yield distinct timings of seasonal extrema, and supply overrides demand when carbon supply is low in winter (e.g., at high latitudes). Our results also suggest that NSC dynamics often lag changes carbon mass balance. We also predict differences in NSC dynamics across mass, suggesting saplings are more dynamics and respond faster to the environment than mature trees. Our findings suggest substrate-dependent regulation with environmental variation is sufficient to generate complex NSC dynamics.
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Affiliation(s)
- Scott W Oswald
- Savannah River Ecology Lab, Savannah River Site, Jackson, SC, USA
- Warnell School of Forestry, University of Georgia, Athens, GA, USA
| | - Doug P Aubrey
- Savannah River Ecology Lab, Savannah River Site, Jackson, SC, USA
- Warnell School of Forestry, University of Georgia, Athens, GA, USA
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18
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Zou J, Zhang W, Zhang Y, Wu J. Global patterns of plant and microbial biomass in response to CO 2 fumigation. Front Microbiol 2023; 14:1175854. [PMID: 37152733 PMCID: PMC10156983 DOI: 10.3389/fmicb.2023.1175854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/03/2023] [Indexed: 05/09/2023] Open
Abstract
Introduction The stimulation of plant and microbial growth has been widely observed as a result of elevated CO2 concentrations (eCO2), however, this stimulation could be influenced by various factors and their relative importance remains unclear. Methods A global meta-analysis was performed using 884 lines of observations collected from published papers, which analyzed the eCO2 impact on plant and microbial biomass. Results A significant positive impact of eCO2 was observed on various biomass measures, including aboveground biomass (20.5%), belowground biomass (42.6%), soil microbial biomass (10.4%), fungal biomass (11.0%), and bacterial biomass (9.2%). It was found that eCO2 levels above 200 ppm had a greater impact on plant biomass compared to concentrations at or below 200 ppm. On the other hand, studies showed that positive effects on microbial biomass were more prominent at lower eCO2 levels (≤200 ppm) than at higher levels (>200 ppm), which could be explained by soil nitrogen limitations. Importantly, our results indicated that aboveground biomass was controlled more by climatic and experimental conditions, while soil properties strongly impacted the stimulation of belowground and microbial biomass. Discussion Our results provided evidence of the eCO2 fertilization effect across various ecosystem types, experimental methods, and climates, and provided a quantitative estimate of plant and soil microbial biomass sensitivity to eCO2. The results obtained in this study suggest that ecosystem models should consider climatic and edaphic factors to more accurately predict the effects of global climate change and their impact on ecosystem functions.
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Ziegler C, Kulawska A, Kourmouli A, Hamilton L, Shi Z, MacKenzie AR, Dyson RJ, Johnston IG. Quantification and uncertainty of root growth stimulation by elevated CO 2 in a mature temperate deciduous forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 854:158661. [PMID: 36096230 DOI: 10.1016/j.scitotenv.2022.158661] [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: 07/26/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 06/15/2023]
Abstract
Increasing CO2 levels are a major global challenge, and the potential mitigation of anthropogenic CO2 emissions by natural carbon sinks remains poorly understood. The uptake of elevated CO2 (eCO2) by the terrestrial biosphere, and subsequent sequestration as biomass in ecosystems, remain hard to quantify in natural ecosystems. Here, we combine field observations of fine root stocks and flows, derived from belowground imaging and soil cores, with image analysis, stochastic modelling, and statistical inference, to elucidate belowground root dynamics in a mature temperate deciduous forest under free-air eCO2 to 150 ppm above ambient levels. eCO2 led to relatively faster root production (a peak volume fold change of 4.52 ± 0.44 eCO2 versus 2.58 ± 0.21 control), with increased root elongation relative to decay the likely causal mechanism for this acceleration. Physical analysis of 552 root systems from soil cores support this picture, with lengths and widths of fine roots significantly increasing under eCO2. Estimated fine root contributions to belowground net primary productivity increase under eCO2 (mean annual 204 ± 93 g dw m-2 yr-1 eCO2 versus 140 ± 60 g dw m-2 yr-1 control). This multi-faceted approach thus sheds quantitative light on the challenging characterisation of the eCO2 response of root biomass in mature temperate forests.
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Affiliation(s)
- Clare Ziegler
- Birmingham Institute of Forest Research, University of Birmingham, Birmingham, UK; School of Biosciences, University of Birmingham, Birmingham, UK
| | - Aleksandra Kulawska
- Birmingham Institute of Forest Research, University of Birmingham, Birmingham, UK; School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Angeliki Kourmouli
- Birmingham Institute of Forest Research, University of Birmingham, Birmingham, UK; School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Liz Hamilton
- Birmingham Institute of Forest Research, University of Birmingham, Birmingham, UK; School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Zongbo Shi
- Birmingham Institute of Forest Research, University of Birmingham, Birmingham, UK; School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - A Rob MacKenzie
- Birmingham Institute of Forest Research, University of Birmingham, Birmingham, UK; School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Rosemary J Dyson
- Birmingham Institute of Forest Research, University of Birmingham, Birmingham, UK; School of Mathematics, University of Birmingham, Birmingham, UK
| | - Iain G Johnston
- Department of Mathematics, University of Bergen, Bergen, Norway; Computational Biology Unit, University of Bergen, Bergen, Norway; Birmingham Institute of Forest Research, University of Birmingham, Birmingham, UK.
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20
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Maschler J, Bialic‐Murphy L, Wan J, Andresen LC, Zohner CM, Reich PB, Lüscher A, Schneider MK, Müller C, Moser G, Dukes JS, Schmidt IK, Bilton MC, Zhu K, Crowther TW. Links across ecological scales: Plant biomass responses to elevated CO 2. GLOBAL CHANGE BIOLOGY 2022; 28:6115-6134. [PMID: 36069191 PMCID: PMC9825951 DOI: 10.1111/gcb.16351] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 07/06/2022] [Indexed: 06/04/2023]
Abstract
The degree to which elevated CO2 concentrations (e[CO2 ]) increase the amount of carbon (C) assimilated by vegetation plays a key role in climate change. However, due to the short-term nature of CO2 enrichment experiments and the lack of reconciliation between different ecological scales, the effect of e[CO2 ] on plant biomass stocks remains a major uncertainty in future climate projections. Here, we review the effect of e[CO2 ] on plant biomass across multiple levels of ecological organization, scaling from physiological responses to changes in population-, community-, ecosystem-, and global-scale dynamics. We find that evidence for a sustained biomass response to e[CO2 ] varies across ecological scales, leading to diverging conclusions about the responses of individuals, populations, communities, and ecosystems. While the distinct focus of every scale reveals new mechanisms driving biomass accumulation under e[CO2 ], none of them provides a full picture of all relevant processes. For example, while physiological evidence suggests a possible long-term basis for increased biomass accumulation under e[CO2 ] through sustained photosynthetic stimulation, population-scale evidence indicates that a possible e[CO2 ]-induced increase in mortality rates might potentially outweigh the effect of increases in plant growth rates on biomass levels. Evidence at the global scale may indicate that e[CO2 ] has contributed to increased biomass cover over recent decades, but due to the difficulty to disentangle the effect of e[CO2 ] from a variety of climatic and land-use-related drivers of plant biomass stocks, it remains unclear whether nutrient limitations or other ecological mechanisms operating at finer scales will dampen the e[CO2 ] effect over time. By exploring these discrepancies, we identify key research gaps in our understanding of the effect of e[CO2 ] on plant biomass and highlight the need to integrate knowledge across scales of ecological organization so that large-scale modeling can represent the finer-scale mechanisms needed to constrain our understanding of future terrestrial C storage.
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Affiliation(s)
- Julia Maschler
- Institute of Integrative BiologyETH Zurich (Swiss Federal Institute of Technology)ZurichSwitzerland
| | - Lalasia Bialic‐Murphy
- Institute of Integrative BiologyETH Zurich (Swiss Federal Institute of Technology)ZurichSwitzerland
| | - Joe Wan
- Institute of Integrative BiologyETH Zurich (Swiss Federal Institute of Technology)ZurichSwitzerland
| | | | - Constantin M. Zohner
- Institute of Integrative BiologyETH Zurich (Swiss Federal Institute of Technology)ZurichSwitzerland
| | - Peter B. Reich
- Department of Forest ResourcesUniversity of MinnesotaSt. PaulMinnesotaUSA
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
- Institute for Global Change Biology, and School for the Environment and SustainabilityUniversity of MichiganAnn ArborMichiganUSA
| | - Andreas Lüscher
- ETH ZurichInstitute of Agricultural ScienceZurichSwitzerland
- Agroscope, Forage Production and Grassland SystemsZurichSwitzerland
| | - Manuel K. Schneider
- ETH ZurichInstitute of Agricultural ScienceZurichSwitzerland
- Agroscope, Forage Production and Grassland SystemsZurichSwitzerland
| | - Christoph Müller
- Institute of Plant EcologyJustus Liebig UniversityGiessenGermany
- School of Biology and Environmental Science and Earth InstituteUniversity College DublinDublinIreland
| | - Gerald Moser
- Institute of Plant EcologyJustus Liebig UniversityGiessenGermany
| | - Jeffrey S. Dukes
- Department of Forestry and Natural ResourcesPurdue UniversityWest LafayetteIndianaUSA
- Department of Biological SciencesPurdue UniversityWest LafayetteIndianaUSA
- Department of Global EcologyCarnegie Institution for ScienceStanfordCaliforniaUSA
| | - Inger Kappel Schmidt
- Geosciences and Natural Resource ManagementUniversity of CopenhagenCopenhagenDenmark
| | - Mark C. Bilton
- Department of Agriculture and Natural Resources SciencesNamibia University of Science and Technology (NUST)WindhoekNamibia
| | - Kai Zhu
- Department of Environmental StudiesUniversity of CaliforniaSanta CruzCaliforniaUSA
| | - Thomas W. Crowther
- Institute of Integrative BiologyETH Zurich (Swiss Federal Institute of Technology)ZurichSwitzerland
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21
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Laffitte B, Seyler BC, Wang W, Li P, Du J, Tang Y. Declining tree growth rates despite increasing water-use efficiency under elevated CO 2 reveals a possible global overestimation of CO 2 fertilization effect. Heliyon 2022; 8:e11219. [PMID: 36339991 PMCID: PMC9626951 DOI: 10.1016/j.heliyon.2022.e11219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/27/2022] [Accepted: 10/19/2022] [Indexed: 11/06/2022] Open
Abstract
Though rising atmospheric CO2 concentrations (Ca) harm the environment and society, they may also raise photosynthetic rates and enhance intrinsic water-use efficiency (iWUE). Numerous short-term studies have investigated tree growth under elevated CO2 (eCO2) conditions, but no long-duration study has investigated eCO2 impacts on tree growth and iWUE under natural conditions. Utilizing a new dendrochronological experimental design in a heavily-touristed nature preserve in Southwest China (Jiuzhaigou National Nature Reserve), we compared tree growth (e.g., basal area increment) and iWUE in two biophysically and environmentally similar valleys with contrasting anthropogenic activities. Trees in the control valley with ambient CO2 benefited from increasing Ca, possibly due to the CO2 fertilization effect and optimal environmental conditions. However, trees in the treatment valley with intensive tourism experienced comparatively higher localized eCO2 and growth rate declines. While iWUE increased (1959–2017) in the control (25.3%) and treatment sites (47.8%), declining tree growth rates in the treatment site was likely because comparatively extreme CO2 exposure levels encouraged stomatal closures. As the first long-term study investigating eCO2 impacts on tree growth and iWUE under natural conditions, we demonstrate that increased forest iWUE is unlikely to overcome negative drought stress and rising temperature impacts. Thus, forest potential for mitigating eCO2 and global climate change is likely overestimated, particularly under dry temperate conditions.
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Affiliation(s)
- Benjamin Laffitte
- Department of Environment, College of Architecture and Environment, Sichuan University, No. 24, South Section One, First Ring Road, Chengdu, Sichuan 610065, China
| | - Barnabas C. Seyler
- Department of Environment, College of Architecture and Environment, Sichuan University, No. 24, South Section One, First Ring Road, Chengdu, Sichuan 610065, China
| | - Wenzhi Wang
- The Key Laboratory of Mountain Environment Evolution and Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China
| | - Pengbo Li
- Department of Environment, College of Architecture and Environment, Sichuan University, No. 24, South Section One, First Ring Road, Chengdu, Sichuan 610065, China
| | - Jie Du
- Jiuzhaigou Administrative Bureau, Zhangzha, Jiuzhaigou, Sichuan 623402, China
| | - Ya Tang
- Department of Environment, College of Architecture and Environment, Sichuan University, No. 24, South Section One, First Ring Road, Chengdu, Sichuan 610065, China,Corresponding author.
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22
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McDowell NG, Ball M, Bond‐Lamberty B, Kirwan ML, Krauss KW, Megonigal JP, Mencuccini M, Ward ND, Weintraub MN, Bailey V. Processes and mechanisms of coastal woody-plant mortality. GLOBAL CHANGE BIOLOGY 2022; 28:5881-5900. [PMID: 35689431 PMCID: PMC9544010 DOI: 10.1111/gcb.16297] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 05/24/2022] [Indexed: 05/26/2023]
Abstract
Observations of woody plant mortality in coastal ecosystems are globally widespread, but the overarching processes and underlying mechanisms are poorly understood. This knowledge deficiency, combined with rapidly changing water levels, storm surges, atmospheric CO2 , and vapor pressure deficit, creates large predictive uncertainty regarding how coastal ecosystems will respond to global change. Here, we synthesize the literature on the mechanisms that underlie coastal woody-plant mortality, with the goal of producing a testable hypothesis framework. The key emergent mechanisms underlying mortality include hypoxic, osmotic, and ionic-driven reductions in whole-plant hydraulic conductance and photosynthesis that ultimately drive the coupled processes of hydraulic failure and carbon starvation. The relative importance of these processes in driving mortality, their order of progression, and their degree of coupling depends on the characteristics of the anomalous water exposure, on topographic effects, and on taxa-specific variation in traits and trait acclimation. Greater inundation exposure could accelerate mortality globally; however, the interaction of changing inundation exposure with elevated CO2 , drought, and rising vapor pressure deficit could influence mortality likelihood. Models of coastal forests that incorporate the frequency and duration of inundation, the role of climatic drivers, and the processes of hydraulic failure and carbon starvation can yield improved estimates of inundation-induced woody-plant mortality.
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Affiliation(s)
- Nate G. McDowell
- Atmospheric Sciences and Global Change DivisionPacific Northwest National LabRichlandWashingtonUSA
- School of Biological SciencesWashington State UniversityPullmanWashingtonUSA
| | - Marilyn Ball
- Plant Science Division, Research School of BiologyThe Australian National UniversityActonAustralian Capital TerritoryAustralia
| | - Ben Bond‐Lamberty
- Joint Global Change Research Institute, Pacific Northwest National LaboratoryCollege ParkMarylandUSA
| | - Matthew L. Kirwan
- Virginia Institute of Marine Science, William & MaryGloucester PointVirginiaUSA
| | - Ken W. Krauss
- U.S. Geological Survey, Wetland and Aquatic Research CenterLafayetteLouisianaUSA
| | | | - Maurizio Mencuccini
- ICREA, Passeig Lluís Companys 23BarcelonaSpain
- CREAFCampus UAB, BellaterraBarcelonaSpain
| | - Nicholas D. Ward
- Marine and Coastal Research LaboratoryPacific Northwest National LaboratorySequimWashingtonUSA
- School of OceanographyUniversity of WashingtonSeattleWashingtonUSA
| | - Michael N. Weintraub
- Department of Environmental SciencesUniversity of ToledoToledoOhioUSA
- Biological Sciences DivisionPacific Northwest National LaboratoryWashingtonUSA
| | - Vanessa Bailey
- Biological Sciences DivisionPacific Northwest National LaboratoryWashingtonUSA
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23
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Davis EC, Sohngen B, Lewis DJ. The effect of carbon fertilization on naturally regenerated and planted US forests. Nat Commun 2022; 13:5490. [PMID: 36123337 PMCID: PMC9485135 DOI: 10.1038/s41467-022-33196-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 09/08/2022] [Indexed: 11/24/2022] Open
Abstract
Over the last half century in the United States, the per-hectare volume of wood in trees has increased, but it is not clear whether this increase has been driven by forest management, forest recovery from past land uses, such as agriculture, or other environmental factors such as elevated carbon dioxide, nitrogen deposition, or climate change. This paper uses empirical analysis to estimate the effect of elevated carbon dioxide on aboveground wood volume in temperate forests of the United States. To accomplish this, we employ matching techniques that allow us to disentangle the effects of elevated carbon dioxide from other environmental factors affecting wood volume and to estimate the effects separately for planted and natural stands. We show that elevated carbon dioxide has had a strong and consistently positive effect on wood volume while other environmental factors yielded a mix of both positive and negative effects. This study, by enabling a better understanding of how elevated carbon dioxide and other anthropogenic factors are influencing forest stocks, can help policymakers and other stakeholders better account for the role of forests in Nationally Determined Contributions and global mitigation pathways to achieve a 1.5 degree Celsius target. The CO2 fertilisation effect in forests remains controversial. Here, the authors disentangle the effect of CO2 on forest wood volume from other environmental factors, showing that elevated CO2 had a positive effect on wood volume in planted and natural US temperate forests.
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Affiliation(s)
- Eric C Davis
- United States Department of Agriculture-Economic Research Service, Kansas City, MO, 64105, USA.
| | - Brent Sohngen
- Department of Agricultural, Environmental, and Development Economics, The Ohio State University, Columbus, OH, 43210, USA
| | - David J Lewis
- Department of Applied Economics, College of Agricultural Sciences, Oregon State University, Corvallis, OR, 97331, USA
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24
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Sun W, Berry JA, Yakir D, Seibt U. Leaf relative uptake of carbonyl sulfide to CO 2 seen through the lens of stomatal conductance-photosynthesis coupling. THE NEW PHYTOLOGIST 2022; 235:1729-1742. [PMID: 35478172 DOI: 10.1111/nph.18178] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/16/2022] [Indexed: 06/14/2023]
Abstract
Carbonyl sulfide (COS) has emerged as a multi-scale tracer for terrestrial photosynthesis. To infer ecosystem-scale photosynthesis from COS fluxes often requires knowledge of leaf relative uptake (LRU), the concentration-normalized ratio between leaf COS uptake and photosynthesis. However, current mechanistic understanding of LRU variability remains inadequate for deriving robust COS-based estimates of photosynthesis. We derive a set of closed-form equations to describe LRU responses to light, humidity and CO2 based on the Ball-Berry stomatal conductance model and the biochemical model of photosynthesis. This framework reproduces observed LRU responses: decreasing LRU with increasing light or decreasing humidity; it also predicts that LRU increases with ambient CO2 . By fitting the LRU equations to flux measurements on a C3 reed (Typha latifolia), we obtain physiological parameters that control LRU variability, including an estimate of the Ball-Berry slope of 7.1 without using transpiration measurements. Sensitivity tests reveal that LRU is more sensitive to photosynthetic capacity than to the Ball-Berry slope, indicating stomatal response to photosynthesis. This study presents a simple framework for interpreting observed LRU variability and upscaling LRU. The stoma-regulated LRU response to CO2 suggests that COS may offer a unique window into long-term stomatal acclimation to elevated CO2 .
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Affiliation(s)
- Wu Sun
- Department of Global Ecology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA, 94305, USA
| | - Joseph A Berry
- Department of Global Ecology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA, 94305, USA
| | - Dan Yakir
- Earth and Planetary Science, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Ulli Seibt
- Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, 520 Portola Plaza, Los Angeles, CA, 90095-1565, USA
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25
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Increasing sensitivity of dryland vegetation greenness to precipitation due to rising atmospheric CO2. Nat Commun 2022; 13:4875. [PMID: 35985990 PMCID: PMC9391480 DOI: 10.1038/s41467-022-32631-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 08/05/2022] [Indexed: 11/09/2022] Open
Abstract
Water availability plays a critical role in shaping terrestrial ecosystems, particularly in low- and mid-latitude regions. The sensitivity of vegetation growth to precipitation strongly regulates global vegetation dynamics and their responses to drought, yet sensitivity changes in response to climate change remain poorly understood. Here we use long-term satellite observations combined with a dynamic statistical learning approach to examine changes in the sensitivity of vegetation greenness to precipitation over the past four decades. We observe a robust increase in precipitation sensitivity (0.624% yr−1) for drylands, and a decrease (−0.618% yr−1) for wet regions. Using model simulations, we show that the contrasting trends between dry and wet regions are caused by elevated atmospheric CO2 (eCO2). eCO2 universally decreases the precipitation sensitivity by reducing leaf-level transpiration, particularly in wet regions. However, in drylands, this leaf-level transpiration reduction is overridden at the canopy scale by a large proportional increase in leaf area. The increased sensitivity for global drylands implies a potential decrease in ecosystem stability and greater impacts of droughts in these vulnerable ecosystems under continued global change. Changes in vegetation responses to precipitation may be hydroclimate dependent. Here the authors reveal contrasting trends of vegetation sensitivity to precipitation in drylands vs. wetter ecosystems over the last 4 decades and identify increased CO2 as a major contributing factor.
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26
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Gong XY, Ma WT, Yu YZ, Fang K, Yang Y, Tcherkez G, Adams MA. Overestimated gains in water-use efficiency by global forests. GLOBAL CHANGE BIOLOGY 2022; 28:4923-4934. [PMID: 35490304 DOI: 10.1111/gcb.16221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 05/09/2022] [Accepted: 04/20/2022] [Indexed: 06/14/2023]
Abstract
Increases in terrestrial water-use efficiency (WUE) have been reported in many studies, pointing to potential changes in physiological forcing of global carbon and hydrological cycles. However, gains in WUE are of uncertain magnitude over longer (i.e. >10 years) periods of time largely owing to difficulties in accounting for structural and physiological acclimation. 13 C signatures (i.e. δ13 C) of plant organic matter have long been used to estimate WUE at temporal scales ranging from days to centuries. Mesophyll conductance is a key uncertainty in estimated WUE owing to its influence on diffusion of CO2 to sites of carboxylation. Here we apply new knowledge of mesophyll conductance to 464 δ13 C chronologies in tree-rings of 143 species spanning global biomes. Adjusted for mesophyll conductance, gains in WUE during the 20th century (0.15 ppm year-1 ) were considerably smaller than those estimated from conventional modelling (0.26 ppm year-1 ). Across the globe, mean sensitivity of WUE to atmospheric CO2 was 0.15 ppm ppm-1 . Ratios of internal-to-atmospheric CO2 (on a mole fraction basis; ci /ca ) in leaves were mostly constant over time but differed among biomes and plant taxa-highlighting the significance of both plant structure and physiology. Together with synchronized responses in stomatal and mesophyll conductance, our results suggest that ratios of chloroplastic-to-atmospheric CO2 (cc /ca ) are constrained over time. We conclude that forest WUE may have not increased as much as previously suggested and that projections of future climate forcing via CO2 fertilization may need to be adjusted accordingly.
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Affiliation(s)
- Xiao Ying Gong
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Wei Ting Ma
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Yong Zhi Yu
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Keyan Fang
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Yusheng Yang
- Key Laboratory for Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province Funded), College of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Guillaume Tcherkez
- Research School of Biology, ANU College of Medicine, Biology and Environment, Australian National University, Canberra, Australia
- Institut de Recherche en Horticulture et Semences, INRAe, Université d'Angers, Beaucouzé, France
| | - Mark A Adams
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, Victoria, Australia
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27
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Enhanced leaf turnover and nitrogen recycling sustain CO 2 fertilization effect on tree-ring growth. Nat Ecol Evol 2022; 6:1271-1278. [PMID: 35817826 DOI: 10.1038/s41559-022-01811-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 05/24/2022] [Indexed: 11/08/2022]
Abstract
Whether increased photosynthates under elevated atmospheric CO2 could translate into sustained biomass accumulation in forest trees remains uncertain. Here we demonstrate how tree radial growth is closely linked to litterfall dynamics, which enhances nitrogen recycling to support a sustained effect of CO2 fertilization on tree-ring growth. Our ten-year observations in two alpine treeline forests indicated that annual (or seasonal) stem radial increments generally had a positive relationship with the previous year's (or season's) litterfall and its associated nitrogen return and resorption. Annual tree-ring width, annual litterfall and annual nitrogen return and resorption all showed an increasing trend during 2007-2017, and most of the variations were explained by elevated atmospheric CO2 rather than climate change. Similar patterns were found in the longer time series of tree-ring width index from 1986-2017. The regional representativeness of our observed patterns was confirmed by the literature data of six other tree species at 11 treeline sites over the Tibetan Plateau. Enhanced nitrogen recycling through increased litterfall under elevated atmospheric CO2 supports a general increasing trend of tree-ring growth in recent decades, especially in cold and nitrogen-poor environments.
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28
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Gea‐Izquierdo G, Sánchez‐González M. Forest disturbances and climate constrain carbon allocation dynamics in trees. GLOBAL CHANGE BIOLOGY 2022; 28:4342-4358. [PMID: 35322511 PMCID: PMC9541293 DOI: 10.1111/gcb.16172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/19/2022] [Indexed: 06/14/2023]
Abstract
Forest disturbances such as drought, fire, and logging affect the forest carbon dynamics and the terrestrial carbon sink. Forest mortality after disturbances creates uncertainties that need to be accounted for to understand forest dynamics and their associated C-sink. We combined data from permanent resampling plots and biomass oriented dendroecological plots to estimate time series of annual woody biomass growth (ABI) in several forests. ABI time series were used to benchmark a vegetation model to analyze dynamics in forest productivity and carbon allocation forced by environmental variability. The model implements source and sink limitations explicitly by dynamically constraining carbon allocation of assimilated photosynthates as a function of temperature and moisture. Bias in tree-ring reconstructed ABI increased back in time from data collection and with increasing disturbance intensity. ABI bias ranged from zero, in open stands without recorded mortality, to over 100% in stands with major disturbances such as thinning or snowstorms. Stand leaf area was still lower than in control plots decades after heavy thinning. Disturbances, species life-history strategy and climatic variability affected carbon-partitioning patterns in trees. Resprouting broadleaves reached maximum biomass growth at earlier ages than nonresprouting conifers. Environmental variability and leaf area explained much variability in woody biomass allocation. Effects of stand competition on C-allocation were mediated by changes in stand leaf area except after major disturbances. Divergence between tree-ring estimated and simulated ABI were caused by unaccounted changes in allocation or misrepresentation of some functional process independently of the model calibration approach. Higher disturbance intensity produced greater modifications of the C-allocation pattern, increasing error in reconstructed biomass dynamics. Legacy effects from disturbances decreased model performance and reduce the potential use of ABI as a proxy to net primary productivity. Trait-based dynamics of C-allocation in response to environmental variability need to be refined in vegetation models.
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29
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Effects of Elevated Atmospheric CO2 Concentration on Insect Herbivory and Nutrient Fluxes in a Mature Temperate Forest. FORESTS 2022. [DOI: 10.3390/f13070998] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Insect herbivory is one of the most important ecological processes affecting plant–soil feedbacks and overall forest ecosystem health. In this study, we assess how elevated carbon dioxide (eCO2) impacts (i) leaf level insect herbivory and (ii) the stand-level herbivore-mediated transfer of carbon (C) and nitrogen (N) from the canopy to the ground in a natural mature oak temperate forest community in central England at the Birmingham Institute of Forest Research Free Air CO2 Enrichment (BIFoR FACE) site. Recently abscised leaves were collected every two weeks through the growing season in August to December from 2017–2019, with the identification of four dominant species: Quercus robur (pedunculate oak), Acer pseudoplatanus (sycamore), Crataegus monogyna (common hawthorn) and Corylus avellana (hazel). The selected leaves were scanned and visually analyzed to quantify the leaf area loss from folivory monthly. Additionally, the herbivore-mediated transfer of C and N fluxes from the dominant tree species Q. robur was calculated from these leaf-level folivory estimates, the total foliar production and the foliar C and N contents. This study finds that the leaf-level herbivory at the BIFoR FACE has not changed significantly across the first 3 years of eCO2 treatment when assessed across all dominant tree species, although we detected significant changes under the eCO2 treatment for individual tree species and years. Despite the lack of any strong leaf-level herbivory response, the estimated stand-level foliar C and N transferred to the ground via herbivory was substantially higher under eCO2, mainly because there was a ~50% increase in the foliar production of Q. robur under eCO2. This result cautions against concluding much from either the presence or absence of leaf-level herbivory responses to any environmental effect, because their actual ecosystem effects are filtered through so many (usually unmeasured) factors.
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Changing Sensitivity of Diverse Tropical Biomes to Precipitation Consistent with the Expected Carbon Dioxide Fertilization Effect. JOURNAL OF LANDSCAPE ECOLOGY 2022. [DOI: 10.2478/jlecol-2022-0005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Global environmental changes have implications for the terrestrial ecosystem functioning, but disentangling individual effects remains elusive. The impact of vegetation responses to increasing atmospheric CO2 concentrations is particularly poorly understood. As the atmospheric CO2 concentration increases, the CO2 acts as a fertilizer for plant growth. An increase in atmospheric CO2 reduces the amount of water needed to produce an equivalent amount of biomass due to closing or a narrowing of the stomata that reduces the amount of water that is transpired by plants. To study the impacts of climate change and CO2 fertilization on plant growth, we analyzed the growing season sensitivity of plant growth to climatic forcing from alpine to semi-desert eco-climatic zones of Ethiopia for various plant functional types over the period of 1982–2011. Growing season 3rd generation Normalized Difference Vegetation Index of Global Inventory Modeling and Mapping Studies (NDVI) was used as a proxy of plant growth, while mean growing season precipitation (prec), temperature (temp), and solar radiation (sr) as the climate forcing. The sensitivities of plant growth are calculated as a partial correlation, and a derivative of NDVI with respect to prec, temp and sr for earliest and recent 15-year periods of the satellite records, and using a moving window of 15-year. Our results show increasing trends of plant growth that are not explained by any climate variables. We also find that an equivalent increase in prec leads to a larger increase in NDVI since the 1980s. This result implies a given amount of prec has sustained greater amounts of plant foliage materials over time due to decreasing transpiration with increasing CO2 concentration as expected from the CO2 fertilization effect on water use efficiency and plant growth. Increasing trends of growth in shallow-rooted vegetation tend to be associated with woody vegetation encroachment.
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Gosling WD, Miller CS, Shanahan TM, Holden PB, Overpeck JT, van Langevelde F. A stronger role for long-term moisture change than for CO 2 in determining tropical woody vegetation change. Science 2022; 376:653-656. [PMID: 35511966 DOI: 10.1126/science.abg4618] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Anthropogenically elevated CO2 (eCO2) concentrations have been suggested to increase woody cover within tropical ecosystems through fertilization. The effect of eCO2 is built into Earth system models, although testing the relationship over long periods remains challenging. Here, we explore the relative importance of six drivers of vegetation change in western Africa over the past ~500,000 years (moisture availability, fire activity, mammalian herbivore density, temperature, temperature seasonality, CO2) by coupling past environmental change data from Lake Bosumtwi (Ghana) with global data. We found that moisture availability and fire activity were the most important factors in determining woody cover, whereas the effect of CO2 was small. Our findings suggest that the role of eCO2 effects on tropical vegetation in predictive models must be reconsidered.
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Affiliation(s)
- William D Gosling
- Institute for Biodiversity & Ecosystem Dynamics, University of Amsterdam, Netherlands
| | | | - Timothy M Shanahan
- Department of Geological Sciences, University of Texas at Austin, Austin, TX, USA
| | - Philip B Holden
- School of Environment, Earth & Ecosystem Sciences, The Open University, Milton Keynes, UK
| | - Jonathan T Overpeck
- School for Environment & Sustainability, University of Michigan, Ann Arbor, MI, USA
| | - Frank van Langevelde
- Department of Environmental Sciences, Wageningen University & Research, Wageningen, Netherlands.,School of Life Sciences, University of KwaZulu-Natal, KwaZulu-Natal, South Africa
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CO 2 fertilization of terrestrial photosynthesis inferred from site to global scales. Proc Natl Acad Sci U S A 2022; 119:e2115627119. [PMID: 35238668 PMCID: PMC8915860 DOI: 10.1073/pnas.2115627119] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The magnitude of the CO2 fertilization effect on terrestrial photosynthesis is uncertain because it is not directly observed and is subject to confounding effects of climatic variability. We apply three well-established eco-evolutionary optimality theories of gas exchange and photosynthesis, constraining the main processes of CO2 fertilization using measurable variables. Using this framework, we provide robust observationally inferred evidence that a strong CO2 fertilization effect is detectable in globally distributed eddy covariance networks. Applying our method to upscale photosynthesis globally, we find that the magnitude of the CO2 fertilization effect is comparable to its in situ counterpart but highlight the potential for substantial underestimation of this effect in tropical forests for many reflectance-based satellite photosynthesis products. Global photosynthesis is increasing with elevated atmospheric CO2 concentrations, a response known as the CO2 fertilization effect (CFE), but the key processes of CFE are not constrained and therefore remain uncertain. Here, we quantify CFE by combining observations from a globally distributed network of eddy covariance measurements with an analytical framework based on three well-established photosynthetic optimization theories. We report a strong enhancement of photosynthesis across the observational network (9.1 gC m−2 year−2) and show that the CFE is responsible for 44% of the gross primary production (GPP) enhancement since the 2000s, with additional contributions primarily from warming (28%). Soil moisture and specific humidity are the two largest contributors to GPP interannual variation through their influences on plant hydraulics. Applying our framework to satellite observations and meteorological reanalysis data, we diagnose a global CO2-induced GPP trend of 4.4 gC m−2 year−2, which is at least one-third stronger than the median trends of 13 dynamic global vegetation models and eight satellite-derived GPP products, mainly because of their differences in the magnitude of CFE in evergreen broadleaf forests. These results highlight the critical role that CFE has played in the global carbon cycle in recent decades.
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de Wergifosse L, André F, Goosse H, Boczon A, Cecchini S, Ciceu A, Collalti A, Cools N, D'Andrea E, De Vos B, Hamdi R, Ingerslev M, Knudsen MA, Kowalska A, Leca S, Matteucci G, Nord-Larsen T, Sanders TG, Schmitz A, Termonia P, Vanguelova E, Van Schaeybroeck B, Verstraeten A, Vesterdal L, Jonard M. Simulating tree growth response to climate change in structurally diverse oak and beech forests. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150422. [PMID: 34852431 DOI: 10.1016/j.scitotenv.2021.150422] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/23/2021] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
Abstract
This study aimed to simulate oak and beech forest growth under various scenarios of climate change and to evaluate how the forest response depends on site properties and particularly on stand characteristics using the individual process-based model HETEROFOR. First, this model was evaluated on a wide range of site conditions. We used data from 36 long-term forest monitoring plots to initialize, calibrate, and evaluate HETEROFOR. This evaluation showed that HETEROFOR predicts individual tree radial growth and height increment reasonably well under different growing conditions when evaluated on independent sites. In our simulations under constant CO2 concentration ([CO2]cst) for the 2071-2100 period, climate change induced a moderate net primary production (NPP) gain in continental and mountainous zones and no change in the oceanic zone. The NPP changes were negatively affected by air temperature during the vegetation period and by the annual rainfall decrease. To a lower extent, they were influenced by soil extractable water reserve and stand characteristics. These NPP changes were positively affected by longer vegetation periods and negatively by drought for beech and larger autotrophic respiration costs for oak. For both species, the NPP gain was much larger with rising CO2 concentration ([CO2]var) mainly due to the CO2 fertilisation effect. Even if the species composition and structure had a limited influence on the forest response to climate change, they explained a large part of the NPP variability (44% and 34% for [CO2]cst and [CO2]var, respectively) compared to the climate change scenario (5% and 29%) and the inter-annual climate variability (20% and 16%). This gives the forester the possibility to act on the productivity of broadleaved forests and prepare them for possible adverse effects of climate change by reinforcing their resilience.
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Affiliation(s)
- Louis de Wergifosse
- Earth and Life Institute: Environmental Sciences, UCLouvain, 1, Croix du Sud, 1348 Louvain-la-Neuve, Belgium; Earth and Life Institute: Earth and Climate, UCLouvain, 3, Place Louis Pasteur, 1348 Louvain-la-Neuve, Belgium.
| | - Frédéric André
- Earth and Life Institute: Environmental Sciences, UCLouvain, 1, Croix du Sud, 1348 Louvain-la-Neuve, Belgium
| | - Hugues Goosse
- Earth and Life Institute: Earth and Climate, UCLouvain, 3, Place Louis Pasteur, 1348 Louvain-la-Neuve, Belgium
| | - Andrzej Boczon
- Forest Research Institute, Sekocin Stary, ul. Braci Lesnej 3, 05-090 Raszyn, Poland
| | - Sébastien Cecchini
- Office National des Forêts, Département Recherche-Développement-Innovation, Bâtiment B, Boulevard de Constance, 77300 Fontainebleau, France
| | - Albert Ciceu
- Forest Management Department, National Institute for Research and Development in Forestry INCDS Marin Drăcea, 128, Bulevardul Eroilor, 077190 Voluntari, Romania; Department of Forest Engineering, Forest Management Planning and Terrestrial Measurements, Faculty of Silviculture and Forest Engineering, "Transilvania" University, 1 Ludwig van Beethoven Str., 500123 Braşov, Romania
| | - Alessio Collalti
- Forest Modelling Lab., Institute for Agriculture and Forestry Systems in the Mediterranean, National Research Council of Italy (CNR-ISAFOM), Via Madonna Alta 128, 06128 Perugia, PG, Italy; Department of Innovation in Biological, Agro-food and Forest Systems (DIBAF), University of Tuscia, via San Camillo de Lellis, 01100 Viterbo, VT, Italy
| | - Nathalie Cools
- Research Institute for Nature and Forest (INBO), 4, Gaverstraat, 9500 Geraardsbergen, Belgium
| | - Ettore D'Andrea
- Institute for Agriculture and Forestry Systems in the Mediterranean, National Research Council of Italy 8 (CNR-ISAFOM), P. le Enrico Fermi 1 Loc. Porto del Granatello, 80055 Portici, NA, Italy
| | - Bruno De Vos
- Research Institute for Nature and Forest (INBO), 4, Gaverstraat, 9500 Geraardsbergen, Belgium
| | - Rafiq Hamdi
- Royal Meteorological Institute of Belgium, 3, Avenue circulaire, 1180 Brussels, Belgium
| | - Morten Ingerslev
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, DK-1958 Frederiksberg C, Denmark
| | - Morten Alban Knudsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, DK-1958 Frederiksberg C, Denmark
| | - Anna Kowalska
- Forest Research Institute, Sekocin Stary, ul. Braci Lesnej 3, 05-090 Raszyn, Poland
| | - Stefan Leca
- Forest Management Department, National Institute for Research and Development in Forestry INCDS Marin Drăcea, 128, Bulevardul Eroilor, 077190 Voluntari, Romania
| | - Giorgio Matteucci
- Institute for BioEconomy, National Research Council of Italy (CNR-IBE), via Madonna del Piano, 10 50019 Sesto Fiorentino, FI, Italy
| | - Thomas Nord-Larsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, DK-1958 Frederiksberg C, Denmark
| | - Tanja Gm Sanders
- Thünen Institute of Forest Ecosystems, Alfred-Moeller-Str. 1, Haus 41/42, 16225 Eberswalde, Germany
| | - Andreas Schmitz
- Department of Silviculture and Forest Ecology of the Temperate Zones, University of Göttingen, 1, Büsgenweg, 37077 Göttingen, Germany; State Agency for Nature, Environment and Consumer Protection of North Rhine-Westphalia, 10, Leibnizstraße, 45659 Recklinghausen, Germany; Department of Silviculture and Forest Ecology of the Temperate Zones, University of Göttingen, 1, Büsgenweg, 37077 Göttingen, Germany
| | - Piet Termonia
- Royal Meteorological Institute of Belgium, 3, Avenue circulaire, 1180 Brussels, Belgium; Department of Physics and Astronomy, Ghent University, 86, Proeftuinstraat, 9000 Ghent, Belgium
| | - Elena Vanguelova
- Centre of Ecosystem, Society and Biosecurity, Forest Research, Alice Holt Lodge, Farnham, Surrey GU10 4LH, UK
| | - Bert Van Schaeybroeck
- Royal Meteorological Institute of Belgium, 3, Avenue circulaire, 1180 Brussels, Belgium
| | - Arne Verstraeten
- Research Institute for Nature and Forest (INBO), 4, Gaverstraat, 9500 Geraardsbergen, Belgium
| | - Lars Vesterdal
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, DK-1958 Frederiksberg C, Denmark
| | - Mathieu Jonard
- Earth and Life Institute: Environmental Sciences, UCLouvain, 1, Croix du Sud, 1348 Louvain-la-Neuve, Belgium
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Wang B, Waters C, Anwar MR, Cowie A, Liu DL, Summers D, Paul K, Feng P. Future climate impacts on forest growth and implications for carbon sequestration through reforestation in southeast Australia. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 302:113964. [PMID: 34678538 DOI: 10.1016/j.jenvman.2021.113964] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 10/05/2021] [Accepted: 10/16/2021] [Indexed: 06/13/2023]
Abstract
Reforestation is identified as one of the key nature-based solutions to deliver carbon dioxide removal, which will be required to achieve the net zero ambition of the Paris Agreement. However, the potential for sequestration through reforestation is uncertain because climate change is expected to affect the drivers of forest growth. This study used the process-based 3-PG model to investigate the effects of climate change on development of above-ground biomass (AGB), as an indicator of forest growth, in regenerating native forests in southeast Australia. We investigated how changing climate affects AGB, by combining historical data and future climate projections based on 25 global climate models (GCMs) for the Coupled Model Intercomparison Project Phase 6 (CMIP6) under two Shared Socioeconomic Pathways. We found that the ensemble means of 25 GCMs indicated an increase in temperature with large variations in projected rainfall. When these changes were applied in 3-PG, we found an increase in the simulated AGB by as much as 25% under a moderate emission scenario. This estimate rose to 51% under a high emission scenario by the end of the 21st century across nine selected sites in southeast Australia. However, when CO2 response was excluded, we found a large decrease in AGB at the nine sites. Our modelling results showed that the modelled response to elevated atmospheric CO2 (the CO2 fertilization effect) was largely responsible for the simulated increase of AGB (%). We found that the estimates of future changes in the AGB were subject to uncertainties originating from climate projections, future emission scenarios, and the assumed response to CO2 fertilization. Such modelling simulation improves understanding of possible climate change impacts on forest growth and the inherent uncertainties in estimating mitigation potential through reforestation, with implications for climate policy in Australia.
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Affiliation(s)
- Bin Wang
- NSW Department of Primary Industries, Wagga Wagga Agricultural Institute, Pine Gully Road Wagga Wagga, NSW, 2650, Australia.
| | - Cathy Waters
- NSW Department of Primary Industries, Dubbo, NSW, 2830, Australia
| | - Muhuddin Rajin Anwar
- NSW Department of Primary Industries, Wagga Wagga Agricultural Institute, Pine Gully Road Wagga Wagga, NSW, 2650, Australia; Graham Centre for Agricultural Innovation (an Alliance Between NSW Department of Primary Industries and Charles Sturt University), Pine Gully Road Wagga Wagga, NSW, 2650, Australia
| | - Annette Cowie
- NSW Department of Primary Industries, Trevenna Rd, Armidale, NSW, 2351, Australia; School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia
| | - De Li Liu
- NSW Department of Primary Industries, Wagga Wagga Agricultural Institute, Pine Gully Road Wagga Wagga, NSW, 2650, Australia; Climate Change Research Centre, University of New South Wales, Sydney, NSW, 2052, Australia
| | - David Summers
- UniSA Business, The University of South Australia, GPO Box 2471, Adelaide, SA, 5001, Australia
| | - Keryn Paul
- CSIRO Land and Water, GPO Box 1700, ACT, 2601, Australia
| | - Puyu Feng
- College of Land Science and Technology, China Agricultural University, Beijing, 100193, China
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Contrasting responses of woody and grassland ecosystems to increased CO 2 as water supply varies. Nat Ecol Evol 2022; 6:315-323. [PMID: 35027723 DOI: 10.1038/s41559-021-01642-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 11/30/2021] [Indexed: 11/08/2022]
Abstract
Experiments show that elevated atmospheric CO2 (eCO2) often enhances plant photosynthesis and productivity, yet this effect varies substantially and may be climate sensitive. Understanding if, where and how water supply regulates CO2 enhancement is critical for projecting terrestrial responses to increasing atmospheric CO2 and climate change. Here, using data from 14 long-term ecosystem-scale CO2 experiments, we show that the eCO2 enhancement of annual aboveground net primary productivity is sensitive to annual precipitation and that this sensitivity differs between woody and grassland ecosystems. During wetter years, CO2 enhancement increases in woody ecosystems but declines in grass-dominated systems. Consistent with this difference, woody ecosystems can increase leaf area index in wetter years more effectively under eCO2 than can grassland ecosystems. Overall, and across different precipitation regimes, woody systems had markedly stronger CO2 enhancement (24%) than grasslands (13%). We developed an empirical relationship to quantify aboveground net primary productivity enhancement on the basis of changes in leaf area index, providing a new approach for evaluating eCO2 impacts on the productivity of terrestrial ecosystems.
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Gardner A, Ellsworth DS, Crous KY, Pritchard J, MacKenzie AR. Is photosynthetic enhancement sustained through three years of elevated CO2 exposure in 175-year-old Quercus robur? TREE PHYSIOLOGY 2022; 42:130-144. [PMID: 34302175 PMCID: PMC8754963 DOI: 10.1093/treephys/tpab090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 07/07/2021] [Indexed: 05/15/2023]
Abstract
Current carbon cycle models attribute rising atmospheric CO2 as the major driver of the increased terrestrial carbon sink, but with substantial uncertainties. The photosynthetic response of trees to elevated atmospheric CO2 is a necessary step, but not the only one, for sustaining the terrestrial carbon uptake, but can vary diurnally, seasonally and with duration of CO2 exposure. Hence, we sought to quantify the photosynthetic response of the canopy-dominant species, Quercus robur, in a mature deciduous forest to elevated CO2 (eCO2) (+150 μmol mol-1 CO2) over the first 3 years of a long-term free air CO2 enrichment facility at the Birmingham Institute of Forest Research in central England (BIFoR FACE). Over 3000 measurements of leaf gas exchange and related biochemical parameters were conducted in the upper canopy to assess the diurnal and seasonal responses of photosynthesis during the 2nd and 3rd year of eCO2 exposure. Measurements of photosynthetic capacity via biochemical parameters, derived from CO2 response curves, (Vcmax and Jmax) together with leaf nitrogen concentrations from the pre-treatment year to the 3rd year of eCO2 exposure, were examined. We hypothesized an initial enhancement in light-saturated net photosynthetic rates (Asat) with CO2 enrichment of ≈37% based on theory but also expected photosynthetic capacity would fall over the duration of the study. Over the 3-year period, Asat of upper-canopy leaves was 33 ± 8% higher (mean and standard error) in trees grown in eCO2 compared with ambient CO2 (aCO2), and photosynthetic enhancement decreased with decreasing light. There were no significant effects of CO2 treatment on Vcmax or Jmax, nor leaf nitrogen. Our results suggest that mature Q. robur may exhibit a sustained, positive response to eCO2 without photosynthetic downregulation, suggesting that, with adequate nutrients, there will be sustained enhancement in C assimilated by these mature trees. Further research will be required to understand the location and role of the additionally assimilated carbon.
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Affiliation(s)
- A Gardner
- Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, B15 2TT, UK
- School of Biological Sciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - D S Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia
| | - K Y Crous
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia
| | - J Pritchard
- Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, B15 2TT, UK
- School of Biological Sciences, University of Birmingham, Edgbaston, B15 2TT, UK
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O'Brien AM, Lins TF, Yang Y, Frederickson ME, Sinton D, Rochman CM. Microplastics shift impacts of climate change on a plant-microbe mutualism: Temperature, CO 2, and tire wear particles. ENVIRONMENTAL RESEARCH 2022; 203:111727. [PMID: 34339696 DOI: 10.1016/j.envres.2021.111727] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/12/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
Anthropogenic stressors can affect individual species and alter species interactions. Moreover, species interactions or the presence of multiple stressors can modify the stressor effects, yet most work focuses on single stressors and single species. Plant-microbe interactions are a class of species interactions on which ecosystems and agricultural systems depend, yet may be affected by multiple global change stressors. Here, we use duckweed and microbes from its microbiome to model responses of interacting plants and microbes to multiple stressors: climate change and tire wear particles. Climate change is occurring globally, and microplastic tire wear particles from roads now reach many ecosystems. We paired perpendicular gradients of temperature and carbon dioxide (CO2) treatments with factorial manipulation of leachate from tire wear particles and duckweed microbiomes. We found that tire leachate and warmer temperatures enhanced duckweed and microbial growth, but caused effects of microbes on duckweed to become negative. However, induced negative effects of microbes were less than additive with warming and leachate. Without tire leachate, we observed that higher CO2 and temperature induced positive correlations between duckweed and microbial growth, which can strengthen mutualisms. In contrast, with tire leachate, growth correlations were never positive, and shifted negative at lower CO2, again suggesting leachate disrupts this plant-microbiome mutualism. In summary, our results demonstrate that multiple interacting stressors can affect multiple interacting species, and that leachate from tire wear particles could potentially disrupt plant-microbe mutualisms.
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Affiliation(s)
- Anna M O'Brien
- Dept. of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks St, Toronto, M5S 3B2, Ontario, Canada; Dept. of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, M5S 3G8, Ontario, Canada.
| | - Tiago F Lins
- Dept. of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, M5S 3G8, Ontario, Canada
| | - Yamin Yang
- Dept. of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, M5S 3G8, Ontario, Canada
| | - Megan E Frederickson
- Dept. of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks St, Toronto, M5S 3B2, Ontario, Canada
| | - David Sinton
- Dept. of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, M5S 3G8, Ontario, Canada
| | - Chelsea M Rochman
- Dept. of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks St, Toronto, M5S 3B2, Ontario, Canada
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Byeon S, Song W, Park M, Kim S, Kim S, Lee H, Jeon J, Kim K, Lee M, Lim H, Han SH, Oh C, Kim HS. Canopy height affects the allocation of photosynthetic carbon and nitrogen in two deciduous tree species under elevated CO 2. JOURNAL OF PLANT PHYSIOLOGY 2022; 268:153584. [PMID: 34890847 DOI: 10.1016/j.jplph.2021.153584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 11/15/2021] [Accepted: 11/29/2021] [Indexed: 06/13/2023]
Abstract
Down-regulation of leaf N and Rubisco under elevated CO2 (eCO2) are accompanied by increased non-structural carbohydrates (NSC) due to the sink-source imbalance. Here, to investigate whether the canopy position affects the down-regulation of Rubisco, we measured leaf N, NSC and N allocation in two species with different heights at maturity [Fraxinus rhynchophylla (6.8 ± 0.3 m) and Sorbus alnifolia (3.6 ± 0.2 m)] from 2017 to 2019. Since 2009, both species were grown at three different CO2 concentrations in open-top chambers: ambient CO2 (400 ppm; aCO2); ambient CO2 × 1.4 (560 ppm; eCO21.4); and ambient CO2 × 1.8 (720 ppm; eCO21.8). Leaf N per unit mass (Nmass) decreased under eCO2, except under eCO21.8 in S. alnifolia and coincided with increased NSC. NSC increased under eCO2 in F. rhynchophylla, but the increment of NSC was greater in the upper canopy of S. alnifolia. Conversely, Rubisco content per unit area was reduced under eCO2 in S. alnifolia and there was no interaction between CO2 and canopy position. In contrast, the reduction of Rubisco content per unit area was greater in the upper canopy of F. rhynchophylla, with a significant interaction between CO2 and canopy position. Rubisco was negatively correlated with NSC only in the upper canopy of F. rhynchophylla, and at the same NSC, Rubisco was lower under eCO2 than under aCO2. Contrary to Rubisco, chlorophyll increased under eCO2 in both species, although there was no interaction between CO2 and canopy position. Finally, photosynthetic N content (Rubisco + chlorophyll + PSII) was reduced and consistent with down-regulation of Rubisco. Therefore, the observed Nmass reduction under eCO2 was associated with dilution due to NSC accumulation. Moreover, down-regulation of Rubisco under eCO2 was more sensitive to NSC accumulation in the upper canopy. Our findings emphasize the need for the modification of the canopy level model in the context of climate change.
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Affiliation(s)
- Siyeon Byeon
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Wookyung Song
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Minjee Park
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea; Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, 47907, USA; Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Sukyung Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Seohyun Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - HoonTaek Lee
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea; Department of Biogeochemical Integration, Max-Planck-Institute for Biogeochemistry, 07745, Jena, Germany; Technische Universität Dresden, Institute of Photogrammetry and Remote Sensing, 01069, Dresden, Germany
| | - Jihyeon Jeon
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Kunhyo Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Minsu Lee
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Hyemin Lim
- Department of Forest Bioresources, National Institute of Forest Science, Suwon, 16631, Republic of Korea
| | - Sim-Hee Han
- Department of Forest Bioresources, National Institute of Forest Science, Suwon, 16631, Republic of Korea
| | - Changyoung Oh
- Department of Forest Bioresources, National Institute of Forest Science, Suwon, 16631, Republic of Korea
| | - Hyun Seok Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea; Interdisciplinary Program in Agricultural and Forest Meteorology, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea; National Center for Agro Meteorology, Seoul, 08826, Republic of Korea; Research Institute of Agriculture and Life Sciences, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea.
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Byeon S, Song W, Park M, Kim S, Kim S, Lee H, Jeon J, Kim K, Lee M, Lim H, Han SH, Oh C, Kim HS. Down-regulation of photosynthesis and its relationship with changes in leaf N allocation and N availability after long-term exposure to elevated CO 2 concentration. JOURNAL OF PLANT PHYSIOLOGY 2021; 265:153489. [PMID: 34416600 DOI: 10.1016/j.jplph.2021.153489] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 08/02/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
Down-regulation of photosynthesis under elevated CO2 (eCO2) concentrations could be attributed to the depletion of nitrogen (N) availability after long-term exposure to eCO2 (progressive nitrogen limitation, PNL) or leaf N dilutions due to excessive accumulation of nonstructural carbohydrates. To determine the mechanism underlying this down-regulation, we investigated N availability, photosynthetic characteristics, and N allocation in leaves of Pinus densiflora (shade-intolerant species, evergreen tree), Fraxinus rhynchophylla (intermediate shade-tolerant species, deciduous tree), and Sorbus alnifolia (shade-tolerant species, deciduous tree). The three species were grown under three different CO2 concentrations in open-top chambers, i.e., ambient 400 ppm (aCO2); ambient × 1.4, 560 ppm (eCO21.4); and ambient × 1.8, 720 ppm (eCO21.8), for 11 years. Unlike previous studies that addressed PNL, after 11 years of eCO2 exposure, N availability remained higher under eCO21.8, and chlorophyll and photosynthetic N use efficiency increased under eCO2. In the case of nonstructural carbohydrates, starch and soluble sugar showed significant increases under eCO2. The maximum carboxylation rate, leaf N per mass (Nmass), and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) were low under eCO21.8. The ratio of RuBP regeneration to the carboxylation rate as well as that of chlorophyll N to Rubisco N increased with CO2 concentrations. Based on the reduction in Nmass (not in Narea) that was diluted by increase in nonstructural carbohydrate, down-regulation of photosynthesis was found to be caused by the dilution rather than PNL. The greatest increases in chlorophyll under eCO2 were observed in S. alnifolia, which was the most shade-tolerant species. This study could help provide more detailed, mechanistically based processes to explain the down-regulation of photosynthesis by considering two hypotheses together and showed N allocation seems to be flexible against changes in CO2 concentration.
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Affiliation(s)
- Siyeon Byeon
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Wookyung Song
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Minjee Park
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea; Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, 47907, USA; Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Sukyung Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Seohyun Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - HoonTaek Lee
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea; Department of Biogeochemical Integration, Max-Planck-Institute for Biogeochemistry, 07745, Jena, Germany; Technische Universität Dresden, Institute of Photogrammetry and Remote Sensing, 01069, Dresden, Germany
| | - Jihyeon Jeon
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Kunhyo Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Minsu Lee
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Hyemin Lim
- Department of Forest Bioresources, National Institute of Forest Science, Gyeonggi, 16631, Republic of Korea
| | - Sim-Hee Han
- Department of Forest Bioresources, National Institute of Forest Science, Gyeonggi, 16631, Republic of Korea
| | - ChangYoung Oh
- Department of Forest Bioresources, National Institute of Forest Science, Gyeonggi, 16631, Republic of Korea
| | - Hyun Seok Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea; Interdisciplinary Program in Agricultural and Forest Meteorology, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea; National Center for Agro Meteorology, Seoul, 08826, Republic of Korea; Research Institute of Agriculture and Life Sciences, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea.
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Pellitier PT, Ibáñez I, Zak DR, Argiroff WA, Acharya K. Ectomycorrhizal access to organic nitrogen mediates CO 2 fertilization response in a dominant temperate tree. Nat Commun 2021; 12:5403. [PMID: 34518539 PMCID: PMC8438073 DOI: 10.1038/s41467-021-25652-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 08/19/2021] [Indexed: 01/04/2023] Open
Abstract
Plant–mycorrhizal interactions mediate plant nitrogen (N) limitation and can inform model projections of the duration and strength of the effect of increasing CO2 on plant growth. We present dendrochronological evidence of a positive, but context-dependent fertilization response of Quercus rubra L. to increasing ambient CO2 (iCO2) along a natural soil nutrient gradient in a mature temperate forest. We investigated this heterogeneous response by linking metagenomic measurements of ectomycorrhizal (ECM) fungal N-foraging traits and dendrochronological models of plant uptake of inorganic N and N bound in soil organic matter (N-SOM). N-SOM putatively enhanced tree growth under conditions of low inorganic N availability, soil conditions where ECM fungal communities possessed greater genomic potential to decay SOM and obtain N-SOM. These trees were fertilized by 38 years of iCO2. In contrast, trees occupying inorganic N rich soils hosted ECM fungal communities with reduced SOM decay capacity and exhibited neutral growth responses to iCO2. This study elucidates how the distribution of N-foraging traits among ECM fungal communities govern tree access to N-SOM and subsequent growth responses to iCO2. Root-mycorrhizal interactions could help explain the heterogeneity of plant responses to CO2 fertilisation and nutrient availability. Here the authors combine tree-ring and metagenomic data to reveal that tree growth responses to increasing CO2 along a soil nutrient gradient depend on the nitrogen foraging traits of ectomycorrhizal fungi.
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Affiliation(s)
- Peter T Pellitier
- School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, USA. .,Department of Biology, Stanford University, Stanford, CA, USA.
| | - Inés Ibáñez
- School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, USA
| | - Donald R Zak
- School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, USA.
| | - William A Argiroff
- School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, USA
| | - Kirk Acharya
- School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, USA
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41
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De Kauwe MG, Medlyn BE, Tissue DT. To what extent can rising [CO 2 ] ameliorate plant drought stress? THE NEW PHYTOLOGIST 2021; 231:2118-2124. [PMID: 34101183 DOI: 10.1111/nph.17540] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 06/01/2021] [Indexed: 06/12/2023]
Abstract
Plant responses to elevated atmospheric carbon dioxide (eCO2 ) have been hypothesized as a key mechanism that may ameliorate the impact of future drought. Yet, despite decades of experiments, the question of whether eCO2 reduces plant water use, yielding 'water savings' that can be used to maintain plant function during periods of water stress, remains unresolved. In this Viewpoint, we identify the experimental challenges and limitations to our understanding of plant responses to drought under eCO2 . In particular, we argue that future studies need to move beyond exploring whether eCO2 played 'a role' or 'no role' in responses to drought, but instead more carefully consider the timescales and conditions that would induce an influence. We also argue that considering emergent differences in soil water content may be an insufficient means of assessing the impact of eCO2 . We identify eCO2 impact during severe drought (e.g. to the point of mortality), interactions with future changes in vapour pressure deficit and uncertainty about changes in leaf area as key gaps in our current understanding. New insights into CO2 × drought interactions are essential to better constrain model theory that governs future climate model projections of land-atmosphere interactions during periods of water stress.
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Affiliation(s)
- Martin G De Kauwe
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, 2052, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
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Adams MA, Buckley TN, Binkley D, Neumann M, Turnbull TL. CO 2, nitrogen deposition and a discontinuous climate response drive water use efficiency in global forests. Nat Commun 2021; 12:5194. [PMID: 34465788 PMCID: PMC8408268 DOI: 10.1038/s41467-021-25365-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/28/2021] [Indexed: 02/07/2023] Open
Abstract
Reduced stomatal conductance is a common plant response to rising atmospheric CO2 and increases water use efficiency (W). At the leaf-scale, W depends on water and nitrogen availability in addition to atmospheric CO2. In hydroclimate models W is a key driver of rainfall, droughts, and streamflow extremes. We used global climate data to derive Aridity Indices (AI) for forests over the period 1965-2015 and synthesised those with data for nitrogen deposition and W derived from stable isotopes in tree rings. AI and atmospheric CO2 account for most of the variance in W of trees across the globe, while cumulative nitrogen deposition has a significant effect only in regions without strong legacies of atmospheric pollution. The relation of aridity and W displays a clear discontinuity. W and AI are strongly related below a threshold value of AI ≈ 1 but are not related where AI > 1. Tree ring data emphasise that effective demarcation of water-limited from non-water-limited behaviour of stomata is critical to improving hydrological models that operate at regional to global scales.
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Affiliation(s)
- Mark A. Adams
- grid.1027.40000 0004 0409 2862Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, VIC Australia ,grid.1013.30000 0004 1936 834XSchool of Life and Environmental Sciences, University of Sydney, Sydney, NSW Australia
| | - Thomas N. Buckley
- grid.27860.3b0000 0004 1936 9684Department of Plant Sciences, College of Agricultural and Environmental Sciences, University of California, Davis, CA USA
| | - Dan Binkley
- grid.261120.60000 0004 1936 8040School of Forestry, Northern Arizona University, Flagstaff, AZ USA
| | - Mathias Neumann
- grid.5173.00000 0001 2298 5320Institute of Silviculture, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Tarryn L. Turnbull
- grid.1027.40000 0004 0409 2862Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, VIC Australia ,grid.1013.30000 0004 1936 834XSchool of Life and Environmental Sciences, University of Sydney, Sydney, NSW Australia
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West TAP, Salekin S, Melia N, Wakelin SJ, Yao RT, Meason D. Diversification of forestry portfolios for climate change and market risk mitigation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 289:112482. [PMID: 33813299 DOI: 10.1016/j.jenvman.2021.112482] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/08/2021] [Accepted: 03/24/2021] [Indexed: 06/12/2023]
Abstract
Investments in forestry are long-term and thus subject to numerous sources of risk. In addition to the volatility from markets, forestry investments are directly exposed to future impacts from climate change. We examined how diversification of forest management regimes can mitigate the expected risks associated with forestry activities in New Zealand based on an application of Modern Portfolio Theory. Uncertainties in the responses of Pinus radiata (D. Don) productivity to climate change, from 2050 to 2090, were simulated with 3-PG, a process-based forest growth model, based on future climate scenarios and Representative Concentration Pathways (RCPs). Future timber market scenarios were based on RCP-specific projections from the Global Timber Model and historical log grade prices. Outputs from 3-PG and the market scenarios were combined to compute annualized forestry returns for four P. radiata regimes for 2050-2090. This information was then used to construct optimal forestry portfolios that minimize investment risk for a given target return under different RCPs, forest productivity and market scenarios. While current P. radiata regimes in New Zealand are largely homogenous, our results suggest that regime diversification can mitigate future risks imposed by climate change and market uncertainty. Nevertheless, optimal portfolio compositions varied substantially across our range of scenarios and portfolio objectives. The application of this framework can help forest managers to better account for future risks in their management decisions.
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Affiliation(s)
- Thales A P West
- Scion-New Zealand Forest Research Institute, Rotorua, New Zealand; Environmental Geography Group, Institute for Environmental Studies (IVM), VU University Amsterdam, Amsterdam, The Netherlands; Centre for Environment, Energy and Natural Resource Governance, University of Cambridge, Cambridge, United Kingdom.
| | - Serajis Salekin
- Scion-New Zealand Forest Research Institute, Rotorua, New Zealand
| | - Nathanael Melia
- School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Steve J Wakelin
- Scion-New Zealand Forest Research Institute, Rotorua, New Zealand
| | - Richard T Yao
- Scion-New Zealand Forest Research Institute, Rotorua, New Zealand
| | - Dean Meason
- Scion-New Zealand Forest Research Institute, Rotorua, New Zealand
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Gonsamo A, Ciais P, Miralles DG, Sitch S, Dorigo W, Lombardozzi D, Friedlingstein P, Nabel JEMS, Goll DS, O'Sullivan M, Arneth A, Anthoni P, Jain AK, Wiltshire A, Peylin P, Cescatti A. Greening drylands despite warming consistent with carbon dioxide fertilization effect. GLOBAL CHANGE BIOLOGY 2021; 27:3336-3349. [PMID: 33910268 DOI: 10.1111/gcb.15658] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 04/16/2021] [Accepted: 04/23/2021] [Indexed: 06/12/2023]
Abstract
The rising atmospheric CO2 concentration leads to a CO2 fertilization effect on plants-that is, increased photosynthetic uptake of CO2 by leaves and enhanced water-use efficiency (WUE). Yet, the resulting net impact of CO2 fertilization on plant growth and soil moisture (SM) savings at large scale is poorly understood. Drylands provide a natural experimental setting to detect the CO2 fertilization effect on plant growth since foliage amount, plant water-use and photosynthesis are all tightly coupled in water-limited ecosystems. A long-term change in the response of leaf area index (LAI, a measure of foliage amount) to changes in SM is likely to stem from changing water demand of primary productivity in water-limited ecosystems and is a proxy for changes in WUE. Using 34-year satellite observations of LAI and SM over tropical and subtropical drylands, we identify that a 1% increment in SM leads to 0.15% (±0.008, 95% confidence interval) and 0.51% (±0.01, 95% confidence interval) increments in LAI during 1982-1998 and 1999-2015, respectively. The increasing response of LAI to SM has contributed 7.2% (±3.0%, 95% confidence interval) to total dryland greening during 1999-2015 compared to 1982-1998. The increasing response of LAI to SM is consistent with the CO2 fertilization effect on WUE in water-limited ecosystems, indicating that a given amount of SM has sustained greater amounts of photosynthetic foliage over time. The LAI responses to changes in SM from seven dynamic global vegetation models are not always consistent with observations, highlighting the need for improved process knowledge of terrestrial ecosystem responses to rising atmospheric CO2 concentration.
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Affiliation(s)
- Alemu Gonsamo
- School of Earth, Environment and Society, McMaster University, Hamilton, ON, Canada
| | - Philippe Ciais
- Laboratoire des Sciences du Climat et de l'Environnement, CEA CNRS UPSACLAY, Gif sur Yvette, France
| | - Diego G Miralles
- Hydro-Climate Extremes Lab (H-CEL), Ghent University, Ghent, Belgium
| | - Stephen Sitch
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Wouter Dorigo
- Department of Geodesy and Geoinformation, Vienna University of Technology, Vienna, Austria
| | | | - Pierre Friedlingstein
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
| | | | - Daniel S Goll
- Department of Geography, University of Augsburg, Augsburg, Germany
| | - Michael O'Sullivan
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Almut Arneth
- Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Garmisch-Partenkirchen, Germany
| | - Peter Anthoni
- Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Garmisch-Partenkirchen, Germany
| | - Atul K Jain
- Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | | | - Philippe Peylin
- Laboratoire des Sciences du Climat et de l'Environnement, CEA CNRS UPSACLAY, Gif sur Yvette, France
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Nadal-Sala D, Medlyn BE, Ruehr NK, Barton CVM, Ellsworth DS, Gracia C, Tissue DT, Tjoelker MG, Sabaté S. Increasing aridity will not offset CO 2 fertilization in fast-growing eucalypts with access to deep soil water. GLOBAL CHANGE BIOLOGY 2021; 27:2970-2990. [PMID: 33694242 DOI: 10.1111/gcb.15590] [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: 12/03/2020] [Accepted: 03/07/2021] [Indexed: 06/12/2023]
Abstract
Rising atmospheric [CO2 ] (Ca ) generally enhances tree growth if nutrients are not limiting. However, reduced water availability and elevated evaporative demand may offset such fertilization. Trees with access to deep soil water may be able to mitigate such stresses and respond more positively to Ca . Here, we sought to evaluate how increased vapor pressure deficit and reduced precipitation are likely to modify the impact of elevated Ca (eCa ) on tree productivity in an Australian Eucalyptus saligna Sm. plantation with access to deep soil water. We parameterized a forest growth simulation model (GOTILWA+) using data from two field experiments on E. saligna: a 2-year whole-tree chamber experiment with factorial Ca (ambient =380, elevated =620 μmol mol-1 ) and watering treatments, and a 10-year stand-scale irrigation experiment. Model evaluation showed that GOTILWA+ can capture the responses of canopy C uptake to (1) rising vapor pressure deficit (D) under both Ca treatments; (2) alterations in tree water uptake from shallow and deep soil layers during soil dry-down; and (3) the impact of irrigation on tree growth. Simulations suggest that increasing Ca up to 700 μmol mol-1 alone would result in a 33% increase in annual gross primary production (GPP) and a 62% increase in biomass over 10 years. However, a combined 48% increase in D and a 20% reduction in precipitation would halve these values. Our simulations identify high D conditions as a key limiting factor for GPP. They also suggest that rising Ca will compensate for increasing aridity limitations in E. saligna trees with access to deep soil water under non-nutrient limiting conditions, thereby reducing the negative impacts of global warming upon this eucalypt species. Simulation models not accounting for water sources available to deep-rooting trees are likely to overestimate aridity impacts on forest productivity and C stocks.
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Affiliation(s)
- Daniel Nadal-Sala
- Ecology Section, Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona (UB), Barcelona, Spain
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Nadine K Ruehr
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Craig V M Barton
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - David S Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Carles Gracia
- Ecology Section, Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona (UB), Barcelona, Spain
- CREAF (Center for Ecological Research and Forestry Applications, Cerdanyola del Vallès, Spain
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Mark G Tjoelker
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Santi Sabaté
- Ecology Section, Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona (UB), Barcelona, Spain
- CREAF (Center for Ecological Research and Forestry Applications, Cerdanyola del Vallès, Spain
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Growth and Photosynthetic Responses of Seedlings of Japanese White Birch, a Fast-Growing Pioneer Species, to Free-Air Elevated O3 and CO2. FORESTS 2021. [DOI: 10.3390/f12060675] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Plant growth is not solely determined by the net photosynthetic rate (A), but also influenced by the amount of leaves as a photosynthetic apparatus. To evaluate growth responses to CO2 and O3, we investigated the effects of elevated CO2 (550–560 µmol mol−1) and O3 (52 nmol mol−1; 1.7 × ambient O3) on photosynthesis and biomass allocation in seedlings of Japanese white birch (Betula platyphylla var. japonica) grown in a free-air CO2 and O3 exposure system without any limitation of root growth. Total biomass was enhanced by elevated CO2 but decreased by elevated O3. The ratio of root to shoot (R:S ratio) showed no difference among the treatment combinations, suggesting that neither elevated CO2 nor elevated O3 affected biomass allocation in the leaf. Accordingly, photosynthetic responses to CO2 and O3 might be more important for the growth response of Japanese white birch. Based on A measured under respective growth CO2 conditions, light-saturated A at a light intensity of 1500 µmol m−2 s−1 (A1500) in young leaves (ca. 30 days old) exhibited no enhancement by elevated CO2 in August, suggesting photosynthetic acclimation to elevated CO2. However, lower A1500 was observed in old leaves (ca. 60 days old) of plants grown under elevated O3 (regulated to be twice ambient O3). Conversely, light-limited A measured under a light intensity of 200 µmol m−2 s−1 (A200) was significantly enhanced by elevated CO2 in young leaves, but suppressed by elevated O3 in old leaves. Decreases in total biomass under elevated O3 might be attributed to accelerated leaf senescence by O3, indicated by the reduced A1500 and A200 in old leaves. Increases in total biomass under elevated CO2 might be attributed to enhanced A under high light intensities, which possibly occurred before the photosynthetic acclimation observed in August, and/or enhanced A under limiting light intensities.
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Lauriks F, Salomón RL, Steppe K. Temporal variability in tree responses to elevated atmospheric CO 2. PLANT, CELL & ENVIRONMENT 2021; 44:1292-1310. [PMID: 33368341 DOI: 10.1111/pce.13986] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 12/18/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
At leaf level, elevated atmospheric CO2 concentration (eCO2 ) results in stimulation of carbon net assimilation and reduction of stomatal conductance. However, a comprehensive understanding of the impact of eCO2 at larger temporal (seasonal and annual) and spatial (from leaf to whole-tree) scales is still lacking. Here, we review overall trends, magnitude and drivers of dynamic tree responses to eCO2 , including carbon and water relations at the leaf and the whole-tree level. Spring and early season leaf responses are most susceptible to eCO2 and are followed by a down-regulation towards the onset of autumn. At the whole-tree level, CO2 fertilization causes consistent biomass increments in young seedlings only, whereas mature trees show a variable response. Elevated CO2 -induced reductions in leaf stomatal conductance do not systematically translate into limitation of whole-tree transpiration due to the unpredictable response of canopy area. Reduction in the end-of-season carbon sink demand and water-limiting strategies are considered the main drivers of seasonal tree responses to eCO2 . These large temporal and spatial variabilities in tree responses to eCO2 highlight the risk of predicting tree behavior to eCO2 based on single leaf-level point measurements as they only reveal snapshots of the dynamic responses to eCO2 .
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Affiliation(s)
- Fran Lauriks
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Roberto Luis Salomón
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Department of Natural Resources and Systems, Universidad Politécnica de Madrid (UPM), Madrid, Spain
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Sreeharsha RV, Venkata Mohan S. Symbiotic integration of bioprocesses to design a self-sustainable life supporting ecosystem in a circular economy framework. BIORESOURCE TECHNOLOGY 2021; 326:124712. [PMID: 33517050 DOI: 10.1016/j.biortech.2021.124712] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
Climate change, resource depletion and unsustainable crop productivity are major challenges that mankind is currently facing. Natural ecosystems of earth's biosphere are becoming vulnerable and there is a need to design Bioregenerative Life Support Systems (BLSS) which are ecologically engineered microcosms that could effectively deal with problems associated with urbanization and industrialization in a sustainable manner. The principles of BLSS could be integrated with waste fed biorefineries and solar energy to create a self-sustainable bioregenerative ecosystem (SSBE). Such engineered ecosystems will have potential to fulfil urban life essentials and climate change mitigation thus generating ecologically smart and resilient communities which can strengthen the global economy. This article provides a detailed overview on SSBE framework and its improvement in the contemporary era to achieve circular bioeconomy by means of effective resource recycling.
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Affiliation(s)
- Rachapudi Venkata Sreeharsha
- Bioengineering and Environmental Science Laboratory, Department of Energy and Environmental, Engineering, CSIR- Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India
| | - S Venkata Mohan
- Bioengineering and Environmental Science Laboratory, Department of Energy and Environmental, Engineering, CSIR- Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India.
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Increased water use efficiency leads to decreased precipitation sensitivity of tree growth, but is offset by high temperatures. Oecologia 2021; 197:1095-1110. [PMID: 33743068 PMCID: PMC8591026 DOI: 10.1007/s00442-021-04892-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 03/02/2021] [Indexed: 11/30/2022]
Abstract
Both increases in temperature and changes in precipitation may limit future tree growth, but rising atmospheric CO2 could offset some of these stressors through increased plant Water Use Efficiency (WUE). The net balance between the negative impacts of climate change and positive effects of CO2 on tree growth is crucial for ecotones, where increased climate stress could drive mortality and shifts in range. Here, we quantify the effects of climate, stand structure, and rising CO2 on both annual tree-ring growth increment and intrinsic WUE (iWUE) at a savanna-forest boundary in the Upper Midwest United States. Taking a Bayesian hierarchical modelling approach, we find that plant iWUE increased by ~ 16–23% over the course of the twentieth century, but on average, tree-ring growth increments do not significantly increase. Consistent with higher iWUE under increased CO2 and recent wetting, we observe a decrease in sensitivity of tree growth to annual precipitation, leading to ~ 35–41% higher growth under dry conditions compared to trees of similar size in the past. However, an emerging interaction between summer maximum temperatures and annual precipitation diminishes the water-savings benefit under hot and dry conditions. This decrease in precipitation sensitivity, and the interaction between temperature and precipitation are strongest in open canopy microclimates, suggesting that stand structure may modulate response to future changes. Overall, while higher iWUE may provide some water savings benefits to growth under normal drought conditions, near-term future temperature increases combined with drought events could drive growth declines of about 50%.
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50
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McDermid SS, Cook BI, De Kauwe MG, Mankin J, Smerdon JE, Williams AP, Seager R, Puma MJ, Aleinov I, Kelley M, Nazarenko L. Disentangling the Regional Climate Impacts of Competing Vegetation Responses to Elevated Atmospheric CO 2. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2021; 126:e2020JD034108. [PMID: 34513547 PMCID: PMC8409678 DOI: 10.1029/2020jd034108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/16/2020] [Accepted: 01/24/2021] [Indexed: 05/05/2023]
Abstract
Biophysical vegetation responses to elevated atmospheric carbon dioxide (CO2) affect regional hydroclimate through two competing mechanisms. Higher CO2 increases leaf area (LAI), thereby increasing transpiration and water losses. Simultaneously, elevated CO2 reduces stomatal conductance and transpiration, thereby increasing rootzone soil moisture. Which mechanism dominates in the future is highly uncertain, partly because these two processes are difficult to explicitly separate within dynamic vegetation models. We address this challenge by using the GISS ModelE global climate model to conduct a novel set of idealized 2×CO2 sensitivity experiments to: evaluate the total vegetation biophysical contribution to regional climate change under high CO2; and quantify the separate contributions of enhanced LAI and reduced stomatal conductance to regional hydroclimate responses. We find that increased LAI exacerbates soil moisture deficits across the sub-tropics and more water-limited regions, but also attenuates warming by ∼0.5-1°C in the US Southwest, Central Asia, Southeast Asia, and northern South America. Reduced stomatal conductance effects contribute ∼1°C of summertime warming. For some regions, enhanced LAI and reduced stomatal conductance produce nonlinear and either competing or mutually amplifying hydroclimate responses. In northeastern Australia, these effects combine to exacerbate radiation-forced warming and contribute to year-round water limitation. Conversely, at higher latitudes these combined effects result in less warming than would otherwise be predicted due to nonlinear responses. These results highlight substantial regional variation in CO2-driven vegetation responses and the importance of improving model representations of these processes to better quantify regional hydroclimate impacts.
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Affiliation(s)
- Sonali Shukla McDermid
- Department of Environmental
StudiesNew York UniversityNew YorkNYUSA
- NASA Goddard Institute for Space StudiesNew YorkNYUSA
| | - Benjamin I. Cook
- NASA Goddard Institute for Space StudiesNew YorkNYUSA
- Lamont‐Doherty Earth Observatory of Columbia UniversityPalisadesNYUSA
| | - Martin G. De Kauwe
- ARC Centre of Excellence for Climate ExtremesSydneyNSWAustralia
- Change Research CentreUniversity of New South WalesSydneyNSWAustralia
- Evolution & Ecology Research CentreUniversity of New South WalesSydneyNSWAustralia
| | - Justin Mankin
- Lamont‐Doherty Earth Observatory of Columbia UniversityPalisadesNYUSA
- Department of
GeographyDartmouth CollegeHanoverNHUSA
| | - Jason E. Smerdon
- Lamont‐Doherty Earth Observatory of Columbia UniversityPalisadesNYUSA
| | - A. Park Williams
- Lamont‐Doherty Earth Observatory of Columbia UniversityPalisadesNYUSA
| | - Richard Seager
- Lamont‐Doherty Earth Observatory of Columbia UniversityPalisadesNYUSA
| | - Michael J. Puma
- NASA Goddard Institute for Space StudiesNew YorkNYUSA
- Center for Climate Systems
ResearchColumbia UniversityNew YorkNYUSA
| | - Igor Aleinov
- NASA Goddard Institute for Space StudiesNew YorkNYUSA
- Center for Climate Systems
ResearchColumbia UniversityNew YorkNYUSA
| | | | - Larissa Nazarenko
- NASA Goddard Institute for Space StudiesNew YorkNYUSA
- Center for Climate Systems
ResearchColumbia UniversityNew YorkNYUSA
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