1
|
Yang J, Lu X, Liu Z, Tang X, Yu Q, Wang Y. Atmospheric drought dominates changes in global water use efficiency. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 934:173084. [PMID: 38735314 DOI: 10.1016/j.scitotenv.2024.173084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 05/06/2024] [Accepted: 05/07/2024] [Indexed: 05/14/2024]
Abstract
Water use efficiency (defined as the ratio of gross primary productivity to plant transpiration, WUET) describes the tradeoff between ecosystem carbon uptake and water loss. However, a comprehensive understanding of the impact of soil and atmospheric moisture deficits on WUET across large regions remains incomplete. Solar-induced chlorophyll fluorescence (SIF) serves as an effective signal for measuring both terrestrial vegetation photosynthesis and transpiration, thereby enabling a rapid response to changes in the physiological status of plants under water stress. The objectives of this study were to: 1) mechanistically calculate WUET using top-of-canopy SIF data and meteorological information by using the revised mechanistic light response model and the Penman-Monteith equation; 2) analyze the effects of atmospheric and soil water deficits on SIF-based WUET by using decoupled soil water content (SWC) and vapor pressure deficit (VPD); 3) evaluate estimated SIF-based WUET against data from 28 eddy covariance (EC) flux sites representing eight different vegetation types. Results indicated that the model performed well in ecosystems with dense canopies, explaining 56 % of the daily variability in EC tower-based WUET. For the years 2019-2020, the global average WUET derived from SIF was 3.49 g C/kg H2O. Notably, this value exceeded 4 g C/kg H2O in tropical rainforest regions near the equator and went beyond 5 g C/kg H2O in the high-latitude regions of the Northern Hemisphere. We found that SIF-based WUET was primarily influenced by VPD rather than SWC in over 90 % of the global vegetated area. The model used in this study increased our ability to mechanistically estimate WUET with SIF at the global scale, thereby highlighting the significance of the global response of SIF-based WUET to water stress, and also enhancing our understanding of the water‑carbon cycle in terrestrial ecosystems.
Collapse
Affiliation(s)
- Jingjing Yang
- The Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling, Shaanxi 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoliang Lu
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Zhunqiao Liu
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xianhui Tang
- The Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling, Shaanxi 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiang Yu
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China.
| | - Yunfei Wang
- School of Water Conservancy and Transportation, Zhengzhou University, Zhengzhou, Henan 450001, China.
| |
Collapse
|
2
|
Zhao Y, Xiong L, Yin J, Zha X, Li W, Han Y. Understanding the effects of flash drought on vegetation photosynthesis and potential drivers over China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 931:172926. [PMID: 38697519 DOI: 10.1016/j.scitotenv.2024.172926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/26/2024] [Accepted: 04/29/2024] [Indexed: 05/05/2024]
Abstract
Flash droughts characterized by rapid onset and intensification are expected to be a new normal under climate change and potentially affect vegetation photosynthesis and terrestrial carbon sink. However, the effects of flash drought on vegetation photosynthesis and their potential dominant driving factors remain uncertain. Here, we quantify the susceptibility and response magnitude of vegetation photosynthesis to flash drought across different ecosystems (i.e., forest, shrubland, grassland, and cropland) in China based on reanalysis and satellite observations. By employing the extreme gradient boosting model, we also identify the dominant factors that influence these flash drought-photosynthesis relationships. We show that over 51.46 % of ecosystems across China are susceptible to flash drought, and grasslands are substantially suppressed, as reflected in both sensitivity and response magnitude (with median gross primary productivity anomalies of -0.13). We further demonstrate that background climate differences (e.g., mean annual temperature and aridity) predominantly regulate the response variation in forest and shrubland, with hotter/colder or drier ecosystems being more severely suppressed by flash drought. However, in grasslands and croplands, the differential vegetation responses are attributed to the intensity of abnormal hydro-meteorological conditions during flash drought (e.g., vapor pressure deficit (VPD) and temperature anomalies). The effects of flash droughts intensify with increasing VPD and nonmonotonically relate to temperature, with colder or hotter temperatures leading to more severe vegetation loss. Our results identify the vulnerable ecological regions under flash drought and enable a better understanding of vegetation photosynthesis response to climate extremes, which may be useful for developing effective management strategies.
Collapse
Affiliation(s)
- Yue Zhao
- State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan 430072, PR China.
| | - Lihua Xiong
- State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan 430072, PR China.
| | - Jiabo Yin
- State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan 430072, PR China.
| | - Xini Zha
- Changjiang Water Resources Protection Institute, Wuhan 430051, PR China; Key Laboratory of Ecological Regulation of Non-point Source Pollution in Lake and Reservoir Water Sources, Changjiang Water Resources Commission, Wuhan 430051, PR China.
| | - Wenbin Li
- State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan 430072, PR China.
| | - Yajing Han
- State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan 430072, PR China.
| |
Collapse
|
3
|
Zhang Y, Gou X, Wang T, Zhang F, Wang K, Yang H, Yang K. Response of tree growth to drought variability in arid areas: Local hydroclimate and large-scale precipitation. ENVIRONMENTAL RESEARCH 2024; 249:118417. [PMID: 38316385 DOI: 10.1016/j.envres.2024.118417] [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: 10/06/2023] [Revised: 01/21/2024] [Accepted: 02/02/2024] [Indexed: 02/07/2024]
Abstract
The impact of drought on terrestrial ecosystems is increasing, and the spatiotemporal heterogeneity of drought changes exacerbates the difficulty of determining ecosystem responses, especially in arid regions far from oceans. Tree rings have been widely used to understand how forest ecosystems respond to drought. However, the link between local hydroclimate variations related to tree rings and large-scale climate changes is not clear in the Qilian Mountains. Here, we used the tree ring width index to analyze the trend of Picea crassifolia growth and its relationship with climate in the middle Qilian Mountains. The results showed that the radial growth trend of Picea crassifolia is synchronized in the middle Qilian Mountains by calculating the Gleichläufigkeit index (GLK). Our analyses indicated that tree radial growth is positively correlated with drought during the growing season. Tree growth responds stably to drought (scPDSI and SPEI) and precipitation but unstably to temperature during 1950-2019. We further traced the meteorological factors that cause regional drought changes associated with radial growth. An increased total precipitation and decreased evaporation contribute to drought alleviation, favoring an increased tree radial growth. The increased total precipitation is mainly due to increased large-scale precipitation, which is related to water vapor transport changes. This study attempts to explore the influence of large-scale meteorology on regional drought change and its related tree radial growth response, which helps us to better understand the changes in forest ecosystems under climate change.
Collapse
Affiliation(s)
- Yiran Zhang
- MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou, China
| | - Xiaohua Gou
- MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou, China.
| | - Tao Wang
- MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou, China
| | - Fen Zhang
- MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou, China
| | - Kai Wang
- MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou, China
| | - Haijiang Yang
- MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou, China
| | - Kaixuan Yang
- College of Geographic Sciences, Qinghai Normal University, Xining, 810016, China; Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Xining, 810016, China
| |
Collapse
|
4
|
Huang C, Huang J, Xiao J, Li X, He HS, Liang Y, Chen F, Tian H. Global convergence in terrestrial gross primary production response to atmospheric vapor pressure deficit. SCIENCE CHINA. LIFE SCIENCES 2024:10.1007/s11427-023-2475-9. [PMID: 38733513 DOI: 10.1007/s11427-023-2475-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 10/23/2023] [Indexed: 05/13/2024]
Abstract
Atmospheric vapor pressure deficit (VPD) increases with climate warming and may limit plant growth. However, gross primary production (GPP) responses to VPD remain a mystery, offering a significant source of uncertainty in the estimation of global terrestrial ecosystems carbon dynamics. In this study, in-situ measurements, satellite-derived data, and Earth System Models (ESMs) simulations were analysed to show that the GPP of most ecosystems has a similar threshold in response to VPD: first increasing and then declining. When VPD exceeds these thresholds, atmospheric drought stress reduces soil moisture and stomatal conductance, thereby decreasing the productivity of terrestrial ecosystems. Current ESMs underscore CO2 fertilization effects but predict significant GPP decline in low-latitude ecosystems when VPD exceeds the thresholds. These results emphasize the impacts of climate warming on VPD and propose limitations to future ecosystems productivity caused by increased atmospheric water demand. Incorporating VPD, soil moisture, and canopy conductance interactions into ESMs enhances the prediction of terrestrial ecosystem responses to climate change.
Collapse
Affiliation(s)
- Chao Huang
- Key Laboratory of National Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed, College of Forestry, Jiangxi Agricultural University, Nanchang, 330045, China
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Jingfeng Huang
- Institute of Applied Remote Sensing & Information Technology, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
- Key Laboratory of Agricultural Remote Sensing and Information Systems, Zhejiang Province, Zhejiang University, Hangzhou, 310058, China.
| | - Jingfeng Xiao
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, 03824, USA
| | - Xing Li
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, South Korea
| | - Hong S He
- School of Natural Resources, University of Missouri, 203 ABNR Building, Columbia, MO, 65211, USA
| | - Yu Liang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Fusheng Chen
- Key Laboratory of National Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed, College of Forestry, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Hanqin Tian
- Schiller Institute for Integrated Science and Society, Department of Earth and Environmental Sciences, Boston College, Chestnut Hill, MA, 02467, USA
| |
Collapse
|
5
|
Wang Y, Hu W, Sun H, Zhao Y, Zhang P, Li Z, Zhou Z, Tong Y, Liu S, Zhou J, Huang M, Jia X, Clothier B, Shao M, Zhou W, An Z. Soil moisture decline in China's monsoon loess critical zone: More a result of land-use conversion than climate change. Proc Natl Acad Sci U S A 2024; 121:e2322127121. [PMID: 38568978 PMCID: PMC11009674 DOI: 10.1073/pnas.2322127121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 03/06/2024] [Indexed: 04/05/2024] Open
Abstract
Soil moisture (SM) is essential for sustaining services from Earth's critical zone, a thin-living skin spanning from the canopy to groundwater. In the Anthropocene epoch, intensive afforestation has remarkably contributed to global greening and certain service improvements, often at the cost of reduced SM. However, attributing the response of SM in deep soil to such human activities is a great challenge because of the scarcity of long-term observations. Here, we present a 37 y (1985 to 2021) analysis of SM dynamics at two scales across China's monsoon loess critical zone. Site-scale data indicate that land-use conversion from arable cropland to forest/grassland caused an 18% increase in SM deficit over 0 to 18 m depth (P < 0.01). Importantly, this SM deficit intensified over time, despite limited climate change influence. Across the Loess Plateau, SM storage in 0 to 10 m layer exhibited a significant decreasing trend from 1985 to 2021, with a turning point in 1999 when starting afforestation. Compared with SM storage before 1999, the relative contributions of climate change and afforestation to SM decline after 1999 were -8% and 108%, respectively. This emphasizes the pronounced impacts of intensifying land-use conversions as the principal catalyst of SM decline. Such a decline shifts 18% of total area into an at-risk status, mainly in the semiarid region, thereby threatening SM security. To mitigate this risk, future land management policies should acknowledge the crucial role of intensifying land-use conversions and their interplay with climate change. This is imperative to ensure SM security and sustain critical zone services.
Collapse
Affiliation(s)
- Yunqiang Wang
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi710061, People’s Republic of China
- National Observation and Research Station of Earth Critical Zone on the Loess Plateau, Xi’an, Shaanxi710061, People’s Republic of China
- Department of Earth and Environmental Sciences, Xi’an Jiaotong University, Xi’an710049, People’s Republic of China
| | - Wei Hu
- The New Zealand Institute for Plant and Food Research Limited, Christchurch8140, New Zealand
| | - Hui Sun
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi710061, People’s Republic of China
- Xi’an Institute for Innovative Earth Environment Research, Xi’an710061, People’s Republic of China
| | - Yali Zhao
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi710061, People’s Republic of China
- National Observation and Research Station of Earth Critical Zone on the Loess Plateau, Xi’an, Shaanxi710061, People’s Republic of China
| | - Pingping Zhang
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi710061, People’s Republic of China
- National Observation and Research Station of Earth Critical Zone on the Loess Plateau, Xi’an, Shaanxi710061, People’s Republic of China
| | - Zimin Li
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi710061, People’s Republic of China
- National Observation and Research Station of Earth Critical Zone on the Loess Plateau, Xi’an, Shaanxi710061, People’s Republic of China
| | - Zixuan Zhou
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi710061, People’s Republic of China
- National Observation and Research Station of Earth Critical Zone on the Loess Plateau, Xi’an, Shaanxi710061, People’s Republic of China
| | - Yongping Tong
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi710061, People’s Republic of China
- National Observation and Research Station of Earth Critical Zone on the Loess Plateau, Xi’an, Shaanxi710061, People’s Republic of China
- Graduate University of Chinese Academy of Sciences, Beijing100049, People’s Republic of China
| | - Shaozhen Liu
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi710061, People’s Republic of China
- National Observation and Research Station of Earth Critical Zone on the Loess Plateau, Xi’an, Shaanxi710061, People’s Republic of China
| | - Jingxiong Zhou
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi710061, People’s Republic of China
- National Observation and Research Station of Earth Critical Zone on the Loess Plateau, Xi’an, Shaanxi710061, People’s Republic of China
- Graduate University of Chinese Academy of Sciences, Beijing100049, People’s Republic of China
| | - Mingbin Huang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Xianyang712100, People’s Republic of China
| | - Xiaoxu Jia
- Graduate University of Chinese Academy of Sciences, Beijing100049, People’s Republic of China
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing100101, People’s Republic of China
| | - Brent Clothier
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North4474, New Zealand
| | - Ming’an Shao
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing100101, People’s Republic of China
| | - Weijian Zhou
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi710061, People’s Republic of China
- Department of Earth and Environmental Sciences, Xi’an Jiaotong University, Xi’an710049, People’s Republic of China
- Interdisciplinary Research Center of Earth Science Frontier, Beijing Normal University, Beijing100875, People’s Republic of China
| | - Zhisheng An
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi710061, People’s Republic of China
- National Observation and Research Station of Earth Critical Zone on the Loess Plateau, Xi’an, Shaanxi710061, People’s Republic of China
- Department of Earth and Environmental Sciences, Xi’an Jiaotong University, Xi’an710049, People’s Republic of China
- Interdisciplinary Research Center of Earth Science Frontier, Beijing Normal University, Beijing100875, People’s Republic of China
| |
Collapse
|
6
|
Wang A, Gao X, Zhou Z, Siddique KHM, Yang H, Wang J, Zhang S, Zhao X. A novel index for vegetation drought assessment based on plant water metabolism and balance under vegetation restoration on the Loess Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170549. [PMID: 38309335 DOI: 10.1016/j.scitotenv.2024.170549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 01/15/2024] [Accepted: 01/27/2024] [Indexed: 02/05/2024]
Abstract
Vegetation is vital to the ecosystem, contributing to the global carbon balance, but susceptible to the impacts of climate change. Monitoring vegetation drought remains challenging due to the lack of widely accepted drought indices. This study focused on vegetation, and simulated the vegetation suitable water demand and soil available water supply (calculated by Remote-sensing-based Water Balance Assessment Tool model). The standardized Vegetation Water deficit Index (SVWDI) was established by calculating the vegetation water deficit, which reflects the response of vegetation to drought. We examined the spatiotemporal evolution of vegetation drought on the Loess Plateau and evaluated the applicability of standardized vegetation water deficit index. Our findings revealed that the standardized vegetation water deficit index demonstrated an overall upward trend across different time scales from 1991 to 2020. Drought conditions were concentrated in the first 20 years of the study period, but vegetation drought on the Loess Plateau has been alleviated in the past decade. Moreover, as the time scale extended, the trend of SVWDI generally decreased, with approximately 49.50 % (1-month scale), 46.66 % (3-month scale), 47.08 % (12-month scale), and 32.16 % (24-month scale) of the grid areas experiencing increased SVWDI. The correlation between SVWDI and tree-ring width index (TRWI) performed well under all precipitation gradients, but the Palmer drought severity index (PDSI) was only highly correlated with TRWI in regions with low precipitation. In terms of the relationship with vegetation health, SVWDI demonstrated the highest correlation with the normalized difference vegetation index (NDVI) across different time scales, followed by PDSI and standardized precipitation evapotranspiration index (SPEI). This study provides insights into the evolution of vegetation drought in response to climate change. The findings can guide initiatives such as returning farmland to forest and grassland on the Loess Plateau to aid climate change adaptation strategies.
Collapse
Affiliation(s)
- Ai Wang
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling 712100, Shaanxi Province, China
| | - Xuerui Gao
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China.
| | - Zeyu Zhou
- China Water Resources Beifang Investigation, Design and Research Co. Ltd, Tianjin 300222, China
| | - Kadambot H M Siddique
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, Australia
| | - Hao Yang
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling 712100, Shaanxi Province, China
| | - Jichao Wang
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling 712100, Shaanxi Province, China
| | - Shuyu Zhang
- School of Environmental Science and Engineering, Southern University of Science and Technology, China
| | - Xining Zhao
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China.
| |
Collapse
|
7
|
Mu Y, Jia X, Ye Z, Zha T, Guo X, Black TA, Zhang Y, Hao S, Han C, Gao S, Qin S, Liu P, Tian Y. Dry-season length affects the annual ecosystem carbon balance of a temperate semi-arid shrubland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170532. [PMID: 38296104 DOI: 10.1016/j.scitotenv.2024.170532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/25/2023] [Accepted: 01/26/2024] [Indexed: 02/03/2024]
Abstract
Semi-arid ecosystems have been shown to dominate over tropical forests in determining the trend and interannual variability of land carbon (C) sink. However, the magnitude and variability of ecosystem C balance remain largely uncertain for temperate semi-arid shrublands at the decadal scale. Using eddy-covariance and micro-meteorological measurements, we quantified the interannual variation in net ecosystem production (NEP) and its components, gross primary production (GPP) and ecosystem respiration (Reco, i.e., the sum of autotrophic and heterotrophic respiration), in a semi-arid shrubland of the Mu Us Desert, northern China during 2012-2022. This shrubland was an overall weak C sink over the 11 years (NEP = 12 ± 46 g C m-2 yr-1, mean ± SD). Annual NEP ranged from -66 to 77 g C m-2 yr-1, with the ecosystem frequently switching between being an annual C sink and a C source. GPP was twice as sensitive as Reco to prolonged dry seasons, leading to a close negative relationship between annual NEP and dry-season length (R2 = 0.80, P < 0.01). Annual GPP (R2 = 0.51, P = 0.01) and NEP (R2 = 0.58, P < 0.01) were positively correlated with annual rainfall. Negative annual NEP (the ecosystem being a C source) tended to occur when the dry season exceeded 50 d yr-1 or rainfall dropped below 280 mm yr-1. Increases in dry-season length strengthened the effects of low soil moisture relative to high vapor pressure deficit in constraining NEP. Both GPP and NEP were more closely correlated with C uptake amplitude (annual maximum daily values) than with C uptake period. These findings indicate that dry-season extension under climate change may reduce the long-term C sequestration in semi-arid shrublands. Plant species adapted to prolonged dry seasons should be used in ecosystem restoration in the studied area to enhance ecosystem functions.
Collapse
Affiliation(s)
- Yanmei Mu
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| | - Xin Jia
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China; Key Laboratory for Soil and Water Conservation, National Forestry and Grassland Administration, Beijing Forestry University, Beijing 100083, China.
| | - Ziqi Ye
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada
| | - Tianshan Zha
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China; Key Laboratory for Soil and Water Conservation, National Forestry and Grassland Administration, Beijing Forestry University, Beijing 100083, China
| | - Xulin Guo
- Department of Geography and Planning, University of Saskatchewan, Saskatoon, SK S7N 5C8, Canada
| | - T Andrew Black
- Biometeorology and Soil Physics Group, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Yuqing Zhang
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China; Key Laboratory for Soil and Water Conservation, National Forestry and Grassland Administration, Beijing Forestry University, Beijing 100083, China
| | - Shaorong Hao
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| | - Cong Han
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| | - Shengjie Gao
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| | - Shugao Qin
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; Key Laboratory for Soil and Water Conservation, National Forestry and Grassland Administration, Beijing Forestry University, Beijing 100083, China
| | - Peng Liu
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China; Key Laboratory for Soil and Water Conservation, National Forestry and Grassland Administration, Beijing Forestry University, Beijing 100083, China
| | - Yun Tian
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China
| |
Collapse
|
8
|
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.
Collapse
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.
| |
Collapse
|
9
|
Williams E, Funk C, Peterson P, Tuholske C. High resolution climate change observations and projections for the evaluation of heat-related extremes. Sci Data 2024; 11:261. [PMID: 38429277 DOI: 10.1038/s41597-024-03074-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 02/14/2024] [Indexed: 03/03/2024] Open
Abstract
The Climate Hazards Center Coupled Model Intercomparison Project Phase 6 climate projection dataset (CHC-CMIP6) was developed to support the analysis of climate-related hazards, including extreme humid heat and drought conditions, over the recent past and in the near-future. Global daily high resolution (0.05°) grids of the Climate Hazards InfraRed Temperature with Stations temperature product, the Climate Hazards InfraRed Precipitation with Stations precipitation product, and ERA5-derived relative humidity form the basis of the 1983-2016 historical record, from which daily Vapor Pressure Deficits (VPD) and maximum Wet Bulb Globe Temperatures (WBGTmax) were derived. Large CMIP6 ensembles from the Shared Socioeconomic Pathway 2-4.5 and SSP 5-8.5 scenarios were then used to develop high resolution daily 2030 and 2050 'delta' fields. These deltas were used to perturb the historical observations, thereby generating 0.05° 2030 and 2050 projections of daily precipitation, temperature, relative humidity, and derived VPD and WBGTmax. Finally, monthly counts of frequency of extremes for each variable were derived for each time period.
Collapse
Affiliation(s)
- Emily Williams
- Climate Hazards Center, University of California, Santa Barbara, CA, 93106, USA.
- Sierra Nevada Research Institute, University of California, Merced, CA, 95343, USA.
| | - Chris Funk
- Climate Hazards Center, University of California, Santa Barbara, CA, 93106, USA.
| | - Pete Peterson
- Climate Hazards Center, University of California, Santa Barbara, CA, 93106, USA
| | - Cascade Tuholske
- Department of Earth Sciences, Montana State University, Bozeman, MT, 59717, USA
- Geospatial Core Facility, Montana State University, Bozeman, MT, 59717, USA
| |
Collapse
|
10
|
He Y, Zhang R, Li P, Men L, Xu M, Wang J, Niu S, Tian D. Nitrogen enrichment delays the drought threshold responses of leaf photosynthesis in alpine grassland plants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 913:169560. [PMID: 38154633 DOI: 10.1016/j.scitotenv.2023.169560] [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: 10/20/2023] [Revised: 12/05/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023]
Abstract
Extreme drought is found to cause a threshold response in photosynthesis in ecosystem level. However, the mechanisms behind this phenomenon are not well understood, highlighting the importance of revealing the drought thresholds for multiple leaf-level photosynthetic processes. Thus, we conducted a long-term experiment involving precipitation reduction and nitrogen (N) addition. Moreover, an extreme drought event occurred within the experimental period. We found the presence of drought thresholds for multiple leaf-level photosynthetic processes, with the leaf light-saturated carbon assimilation rate (Asat) displaying the highest threshold (10.76 v/v%) and the maximum rate of carboxylation by Rubisco (Vcmax) showing the lowest threshold (5.38 v/v%). Beyond the drought thresholds, the sensitivities of leaf-level photosynthetic processes to soil water content could be greater. Moreover, N addition lowered the drought thresholds of Asat and stomatal conductance (gs), but had no effect on that of Vcmax. Among species, plants with higher leaf K concentration traits had a lower drought threshold of Asat. Overall, this study highlights that leaf photosynthesis may be suppressed abruptly as soil water content surpasses the drought threshold. However, N enrichment helps to improve the resistance via delaying drought threshold response. These new findings have important implications for understanding the nonlinearity of ecosystem productivity response and early warning management in the scenario of combined extreme drought events and continuous N deposition.
Collapse
Affiliation(s)
- Yicheng He
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China; College of Grassland Science and Technology, China Agricultural University, Beijing 100193, China
| | - Ruiyang Zhang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
| | - Pengyu Li
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China; School of Grassland Science, Beijing Forestry University, Beijing 100083, China
| | - Lu Men
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China; Institute of Qinghai-Tibetan Plateau, Southwest Minzu University, Chengdu 610041, China
| | - Meng Xu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
| | - Jinsong Wang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
| | - Shuli Niu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dashuan Tian
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
11
|
Chen Z, Wang W, Forzieri G, Cescatti A. Transition from positive to negative indirect CO 2 effects on the vegetation carbon uptake. Nat Commun 2024; 15:1500. [PMID: 38374331 PMCID: PMC10876672 DOI: 10.1038/s41467-024-45957-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 02/08/2024] [Indexed: 02/21/2024] Open
Abstract
Although elevated atmospheric CO2 concentration (eCO2) has substantial indirect effects on vegetation carbon uptake via associated climate change, their dynamics remain unclear. Here we investigate how the impacts of eCO2-driven climate change on growing-season gross primary production have changed globally during 1982-2014, using satellite observations and Earth system models, and evaluate their evolution until the year 2100. We show that the initial positive effect of eCO2-induced climate change on vegetation carbon uptake has declined recently, shifting to negative in the early 21st century. Such emerging pattern appears prominent in high latitudes and occurs in combination with a decrease of direct CO2 physiological effect, ultimately resulting in a sharp reduction of the current growth benefits induced by climate warming and CO2 fertilization. Such weakening of the indirect CO2 effect can be partially attributed to the widespread land drying, and it is expected to be further exacerbated under global warming.
Collapse
Affiliation(s)
- Zefeng Chen
- National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, China
- Yangtze Institute for Conservation and Development, Hohai University, Nanjing, China
- College of Hydrology and Water Resources, Hohai University, Nanjing, China
| | - Weiguang Wang
- National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, China.
- Yangtze Institute for Conservation and Development, Hohai University, Nanjing, China.
- College of Hydrology and Water Resources, Hohai University, Nanjing, China.
| | - Giovanni Forzieri
- Department of Civil and Environmental Engineering, University of Florence, Florence, Italy
| | | |
Collapse
|
12
|
Tian F, Zhu Z, Cao S, Zhao W, Li M, Wu J. Satellite-observed increasing coupling between vegetation productivity and greenness in the semiarid Loess Plateau of China is not captured by process-based models. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167664. [PMID: 37832667 DOI: 10.1016/j.scitotenv.2023.167664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 10/15/2023]
Abstract
Global vegetation has experienced notable changes in greenness and productivity since the early 1980s. However, the changes in the relationship between productivity and greenness, i.e., the coupling, and its underlying mechanisms, are poorly understood. The Loess Plateau (LP) is one of China's most significant areas for vegetation greening. Yet, it remains poorly documented what changes in the coupling between productivity and greenness are and how environmental and anthropogenic factors affect this coupling in the LP over the past four decades. We investigated the interannual trend of coupling between Gross Primary Productivity (GPP) and Leaf Area Index (LAI), i.e., the GPP-LAI coupling, and its response to climate factors and afforestation in the LP using long-term remote-sensed LAI, GPP and Solar-induced Chlorophyll Fluorescence (SIF). We found a monotonically increasing trend in the GPP-LAI coupling in the LP from 1982 to 2018 (0.0043 yr-1, p < 0.05), in which the significant trend in the northwest LP was driven by increasing soil water and landcover change, e.g., increased grassland and afforestation. An ensemble of 11 state-of-the-art ecosystem models from the TRENDY project failed to capture the observed monotonically increasing trend of the GPP-LAI coupling in the LP. The consistent projection of a decreasing GPP-LAI coupling in LP during 2019-2100 by 22 Earth System Models (ESMs) under various future scenarios should be treated with caution due to the identified inherent uncertainties in the ecosystem component in ESMs and the notable biases in the simulation of future climate conditions. Our study highlights the need to enhance the key mechanisms that regulate the coupling relationships between photosynthesis and canopy structure in indigenized ecosystem models to accurately estimate the ecosystem change in drylands under global climate change.
Collapse
Affiliation(s)
- Feng Tian
- School of Urban Planning and Design, 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.
| | - Sen Cao
- 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
| | - Muyi Li
- School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Jianjun Wu
- Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Remote Sensing Science, Beijing Normal University, Beijing 100875, China
| |
Collapse
|
13
|
Dong G, Chen S, Liu K, Wang W, Hou H, Gao L, Zhang F, Su H. Spatiotemporal variation in sensitivity of urban vegetation growth and greenness to vegetation water content: Evidence from Chinese megacities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167090. [PMID: 37716675 DOI: 10.1016/j.scitotenv.2023.167090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 08/28/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023]
Abstract
Understanding the sensitivity of vegetation growth and greenness to vegetation water content change is crucial for elucidating the mechanism of terrestrial ecosystems response to water availability change caused by climate change. Nevertheless, we still have limited knowledge of such aspects in urban in different climatic contexts under the influence of human activities. In this study, we employed Google Earth Engine (GEE), remote sensing satellite imagery, meteorological data, and Vegetation Photosynthesis Model (VPM) to explore the spatiotemporal pattern of vegetation growth and greenness sensitivity to vegetation water content in three megacities (Beijing, Shanghai, and Guangzhou) located in eastern China from 2001 to 2020. We found a significant increase (slope > 0, p < 0.05) in the sensitivity of urban vegetation growth and greenness to vegetation water content (SLSWI). This indicates the increasing dependence of urban vegetation ecosystems on vegetation water resources. Moreover, evident spatial heterogeneity was observed in both SLSWI and the trends of SLSWI, and spatial heterogeneity in SLSWI and the trends of SLSWI was also present among identical vegetation types within the same city. Additionally, both SLSWI of vegetation growth and greenness and the trend of SLSWI showed obvious spatial distribution differences (e.g., standard deviations of trends in SLSWI of open evergreen needle-leaved forest of GPP is 14.36 × 10-2 and standard deviations of trends in SLSWI of open evergreen needle-leaved forest of EVI is 10.16 × 10-2), closely associated with factors such as vegetation type, climatic conditions, and anthropogenic influences.
Collapse
Affiliation(s)
- Guannan Dong
- Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shaohui Chen
- Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Kai Liu
- Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Weimin Wang
- Shenzhen Ecological and Environmental Monitoring Center of Guangdong Province, Shenzhen 518049, China; Guangdong Greater Bay Area, Change and Comprehensive Treatment of Regional Ecology and Environment, National Observation and Research Station, Shenzhen 518049, China; State Environmental Protection Scientific Observation and Research Station for Ecology and Environment of Rapid Urbanization Region, Shenzhen 518049, China
| | - Haoran Hou
- Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Long Gao
- Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Furong Zhang
- Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongbo Su
- Department of Civil, Environmental & Geomatics Engineering, College of Engineering & Computer Science, Florida Atlantic University, Boca Raton, FL 33431, USA.
| |
Collapse
|
14
|
Zheng C, Wang S, Chen J, Xiang N, Sun L, Chen B, Fu Z, Zhu K, He X. Divergent impacts of VPD and SWC on ecosystem carbon-water coupling under different dryness conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167007. [PMID: 37739082 DOI: 10.1016/j.scitotenv.2023.167007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 09/08/2023] [Accepted: 09/09/2023] [Indexed: 09/24/2023]
Abstract
Ecosystem water use efficiency (WUE) is an indicator of carbon-water interactions and is defined as the ratio of gross primary productivity (GPP) to evapotranspiration (ET). However, it is currently unclear how WUE responds to atmospheric and soil drought events in terrestrial ecosystems with different dryness conditions. Additionally, the contributions of GPP and ET to the WUE response remain poorly understood. Based on measurements from 26 flux tower sites distributed worldwide, the binning method and random forest model were employed to separate the sensitivities of daily ecosystem WUE, GPP, and ET to vapor pressure deficit (VPD) and soil water content (SWC) under different dryness conditions (dryness index = potential evapotranspiration/precipitation, DI). Results showed that the sensitivity of WUE to VPD was negative at humid sites (DI < 1), while the sensitivity of WUE to SWC was positive at arid sites (DI > 2). Furthermore, the contribution of GPP to VPD-induced WUE variability was 63 % at humid sites, and the contribution of ET to SWC-induced WUE variability was 68 % when SWC was less than the 60th percentile at arid sites. Consequently, one increasing VPD-induced decrease in GPP was generally linked to a decrease in WUE at humid sites, and one drying soil moisture-caused decrease in ET was linked to a WUE increase under low SWC conditions at arid sites. Finally, VPD had a stronger effect on WUE than SWC when VPD was less than the 90th percentile or SWC was greater than the 50th percentile. Our findings underscore the importance of considering ecosystem dryness when investigating the impacts of VPD and SWC on ecosystem carbon-water coupling.
Collapse
Affiliation(s)
- Chen Zheng
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shaoqiang Wang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; Key Laboratory of Regional Ecological Process and Environment Evolution, School of Geography and Information Engineering, Chinese University of Geosciences, Wuhan 430074, China.
| | - Jinghua Chen
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ning Xiang
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Leigang Sun
- Institute of Geographical Sciences, Hebei Academy of Sciences, Shijiazhuang 050011, China; Hebei Technology Innovation Center for Geographic Information Application, Shijiazhuang 050011, China.
| | - Bin Chen
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zheng Fu
- Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
| | - Kai Zhu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinlei He
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| |
Collapse
|
15
|
Tang ACI, Flechard CR, Arriga N, Papale D, Stoy PC, Buchmann N, Cuntz M, Douros J, Fares S, Knohl A, Šigut L, Simioni G, Timmermans R, Grünwald T, Ibrom A, Loubet B, Mammarella I, Belelli Marchesini L, Nilsson M, Peichl M, Rebmann C, Schmidt M, Bernhofer C, Berveiller D, Cremonese E, El-Madany TS, Gharun M, Gianelle D, Hörtnagl L, Roland M, Varlagin A, Fu Z, Heinesch B, Janssens I, Kowalska N, Dušek J, Gerosa G, Mölder M, Tuittila ES, Loustau D. Detection and attribution of an anomaly in terrestrial photosynthesis in Europe during the COVID-19 lockdown. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166149. [PMID: 37567315 DOI: 10.1016/j.scitotenv.2023.166149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 08/04/2023] [Accepted: 08/06/2023] [Indexed: 08/13/2023]
Abstract
Carbon dioxide (CO2) uptake by plant photosynthesis, referred to as gross primary production (GPP) at the ecosystem level, is sensitive to environmental factors, including pollutant exposure, pollutant uptake, and changes in the scattering of solar shortwave irradiance (SWin) - the energy source for photosynthesis. The 2020 spring lockdown due to COVID-19 resulted in improved air quality and atmospheric transparency, providing a unique opportunity to assess the impact of air pollutants on terrestrial ecosystem functioning. However, detecting these effects can be challenging as GPP is influenced by other meteorological drivers and management practices. Based on data collected from 44 European ecosystem-scale CO2 flux monitoring stations, we observed significant changes in spring GPP at 34 sites during 2020 compared to 2015-2019. Among these, 14 sites showed an increase in GPP associated with higher SWin, 10 sites had lower GPP linked to atmospheric and soil dryness, and seven sites were subjected to management practices. The remaining three sites exhibited varying dynamics, with one experiencing colder and rainier weather resulting in lower GPP, and two showing higher GPP associated with earlier spring melts. Analysis using the regional atmospheric chemical transport model (LOTOS-EUROS) indicated that the ozone (O3) concentration remained relatively unchanged at the research sites, making it unlikely that O3 exposure was the dominant factor driving the primary production anomaly. In contrast, SWin increased by 9.4 % at 36 sites, suggesting enhanced GPP possibly due to reduced aerosol optical depth and cloudiness. Our findings indicate that air pollution and cloudiness may weaken the terrestrial carbon sink by up to 16 %. Accurate and continuous ground-based observations are crucial for detecting and attributing subtle changes in terrestrial ecosystem functioning in response to environmental and anthropogenic drivers.
Collapse
Affiliation(s)
- Angela Che Ing Tang
- ISPA, Bordeaux Sciences Agro, INRAE, Villenave d'Ornon, France; Department of Environmental Sciences, University of Toledo, Toledo, OH, USA.
| | | | - Nicola Arriga
- Joint Research Centre, European Commission, Ispra, Italy
| | - Dario Papale
- University of Tuscia DIBAF, Viterbo, Italy; EuroMediterranean Center on Climate Change, CMCC IAFES, Viterbo, Italy
| | - Paul C Stoy
- Department of Biological Systems Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Nina Buchmann
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Matthias Cuntz
- Université de Lorraine, AgroParisTech, INRAE, UMR Silva, Nancy, France
| | - John Douros
- Royal Netherlands Meteorological Institute (KNMI), De Bilt, The Netherlands
| | - Silvano Fares
- National Research Council of Italy, Institute for Agriculture and Forestry Systems in the Mediterranean, Naples, Italy
| | | | - Ladislav Šigut
- Department of Matter and Energy Fluxes, Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
| | | | - Renske Timmermans
- Climate Air and Sustainability Unit, Netherlands Organisation for Applied Scientific Research (TNO), Utrecht, The Netherlands
| | - Thomas Grünwald
- Faculty of Environmental Sciences, Institute of Hydrology and Meteorology, Technische Universität Dresden, Tharandt, Germany
| | - Andreas Ibrom
- Technical University of Denmark (DTU), DTU-Sustain, Kgs. Lyngby, Denmark
| | - Benjamin Loubet
- UMR ECOSYS, AgroParisTech, INRAE, Université Paris-Saclay, Thiverval-Grignon, France
| | - Ivan Mammarella
- Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, Helsinki, Finland
| | | | - Mats Nilsson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Matthias Peichl
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Corinna Rebmann
- Department of Computational Hydrosystems, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Marius Schmidt
- Institute of Bio- and Geosciences: Agrosphere (IBG-3), Jülich Research Centre, Jülich, Germany
| | - Christian Bernhofer
- Faculty of Environmental Sciences, Institute of Hydrology and Meteorology, Technische Universität Dresden, Tharandt, Germany
| | - Daniel Berveiller
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique et Evolution, Orsay, France
| | - Edoardo Cremonese
- Environmental Protection Agency of Aosta Valley - Climate Change Unit, Saint-Christophe, Italy
| | - Tarek S El-Madany
- Max Planck Institute for Biogeochemistry, Department of Biogeochemical Integration, Jena, Germany
| | - Mana Gharun
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland; Faculty of Geosciences, University of Münster, Münster, Germany
| | - Damiano Gianelle
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Lukas Hörtnagl
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Marilyn Roland
- Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Andrej Varlagin
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
| | - Zheng Fu
- Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Bernard Heinesch
- TERRA Teaching and Research Centre, University of Liege, Gembloux, Belgium
| | - Ivan Janssens
- Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Natalia Kowalska
- Department of Matter and Energy Fluxes, Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
| | - Jiří Dušek
- Department of Matter and Energy Fluxes, Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
| | | | - Meelis Mölder
- Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden
| | | | - Denis Loustau
- ISPA, Bordeaux Sciences Agro, INRAE, Villenave d'Ornon, France
| |
Collapse
|
16
|
Chen N, Zhang Y, Yuan F, Song C, Xu M, Wang Q, Hao G, Bao T, Zuo Y, Liu J, Zhang T, Song Y, Sun L, Guo Y, Zhang H, Ma G, Du Y, Xu X, Wang X. Warming-induced vapor pressure deficit suppression of vegetation growth diminished in northern peatlands. Nat Commun 2023; 14:7885. [PMID: 38036495 PMCID: PMC10689446 DOI: 10.1038/s41467-023-42932-w] [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: 02/02/2023] [Accepted: 10/26/2023] [Indexed: 12/02/2023] Open
Abstract
Recent studies have reported worldwide vegetation suppression in response to increasing atmospheric vapor pressure deficit (VPD). Here, we integrate multisource datasets to show that increasing VPD caused by warming alone does not suppress vegetation growth in northern peatlands. A site-level manipulation experiment and a multiple-site synthesis find a neutral impact of rising VPD on vegetation growth; regional analysis manifests a strong declining gradient of VPD suppression impacts from sparsely distributed peatland to densely distributed peatland. The major mechanism adopted by plants in response to rising VPD is the "open" water-use strategy, where stomatal regulation is relaxed to maximize carbon uptake. These unique surface characteristics evolve in the wet soil‒air environment in the northern peatlands. The neutral VPD impacts observed in northern peatlands contrast with the vegetation suppression reported in global nonpeatland areas under rising VPD caused by concurrent warming and decreasing relative humidity, suggesting model improvement for representing VPD impacts in northern peatlands remains necessary.
Collapse
Affiliation(s)
- Ning Chen
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, 110016, Shenyang, China
| | - Yifei Zhang
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China
| | - Fenghui Yuan
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China
- Department of Soil, Water, and Climate, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Changchun Song
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China.
- School of Hydraulic Engineering, Dalian University of Technology, 116024, Dalian, China.
| | - Mingjie Xu
- College of Agronomy, Shenyang Agricultural University, 110866, Shenyang, China
| | - Qingwei Wang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, 110016, Shenyang, China
| | - Guangyou Hao
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, 110016, Shenyang, China
| | - Tao Bao
- Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
| | - Yunjiang Zuo
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China
| | - Jianzhao Liu
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China
- College of Surveying and Exploration Engineering, Jilin Jianzhu University, 130018, Changchun, China
| | - Tao Zhang
- College of Agronomy, Shenyang Agricultural University, 110866, Shenyang, China
| | - Yanyu Song
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China
| | - Li Sun
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China
| | - Yuedong Guo
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China
| | - Hao Zhang
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China
| | - Guobao Ma
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China
| | - Yu Du
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China
| | - Xiaofeng Xu
- Biology Department, San Diego State University, San Diego, 92182, USA.
| | - Xianwei Wang
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China.
| |
Collapse
|
17
|
Qiu R, Han G, Li S, Tian F, Ma X, Gong W. Soil moisture dominates the variation of gross primary productivity during hot drought in drylands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 899:165686. [PMID: 37482354 DOI: 10.1016/j.scitotenv.2023.165686] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 07/25/2023]
Abstract
The frequency and severity of hot drought will increase in the future due to impact of climate change and human activities, threatening the sustainability of terrestrial ecosystems and human societies. Hot drought is a typical type of drought event, high vapor pressure deficit (VPD) and low soil moisture (SM) are its main characteristics of hot drought, with increasing water stress on vegetation and exacerbating hydrological drought and ecosystem risks. However, our understanding of the effects of high VPD and low SM on vegetation productivity is limited, because these two variables are strongly coupled and influenced by other climatic drivers. The southwestern United States experienced one of the most severe hot drought events on record in 2020. In this study, we used SM and gross primary productivity (GPP) datasets from Soil Moisture Active and Passive (SMAP), as well as VPD and other meteorological datasets from gridMET. We decoupled the effects of different meteorological factors on GPP at monthly and daily scales using partial correlation analysis, partial least squares regression, and binning methods. We found that SM anomalies contribute more to GPP anomalies than VPD anomalies at monthly and daily scales. Especially at the daily scale, as the decoupled SM anomalies increased, the GPP anomalies increased. However, there is no significant change in GPP anomalies as VPD increases. For all the vegetation types and arid zones, SM dominated the variation in GPP, followed by VPD or maximum temperature. At the flux tower scale, decoupled soil water content (SWC) also dominated changes in GPP, compared to VPD. In the next century, hot drought will occur frequently in dryland regions, where GPP is one of the highest uncertainties in terrestrial ecosystems. Our study has important implications for identifying the strong coupling of meteorological factors and their impact on vegetation under climate change.
Collapse
Affiliation(s)
- Ruonan Qiu
- School of Remote Sensing and Information Engineering, Wuhan University, Wuhan 430079, China
| | - Ge Han
- School of Remote Sensing and Information Engineering, Wuhan University, Wuhan 430079, China; Perception and Effectiveness Assessment for Carbon-neutral Efforts, Engineering Research Center of Ministry of Education, Wuhan, China.
| | - Siwei Li
- School of Remote Sensing and Information Engineering, Wuhan University, Wuhan 430079, China.
| | - Feng Tian
- School of Remote Sensing and Information Engineering, Wuhan University, Wuhan 430079, China
| | - Xin Ma
- State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, China
| | - Wei Gong
- Electronic Information School, Wuhan University, Wuhan 430079, China; Hubei Luojia Laboratory, Wuhan, China
| |
Collapse
|
18
|
Gupta S, Deb Burman PK, Tiwari YK, Dumka UC, Kumari N, Srivastava A, Raghubanshi AS. Understanding carbon sequestration trends using model and satellite data under different ecosystems in India. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 897:166381. [PMID: 37595902 DOI: 10.1016/j.scitotenv.2023.166381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/13/2023] [Accepted: 08/15/2023] [Indexed: 08/20/2023]
Abstract
This study discusses carbon sequestration variability in different ecosystems of India. Four different biosphere regions, each over 0.5° × 0.5° area, have been selected considering the geospatial and climatic variability of these regions expanding from Central India (CI), the Northeast region (NER), the Western Ghats (WG), and the Western Himalayan region (WHNI). The climatic conditions of these four regions are different so are the biosphere constituents of these regions. We expect the Gross Primary Productivity (GPP) to enhance during the all India summer monsoon rainfall season but in varied magnitudes suggesting a role of climatic parameters and flora in these regions. The GPP from FLUXCOM for the duration of 2001 to 2019 (19 years) and satellite-derived vegetation indices like the Normalized Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Leaf Area Index (LAI) are used in this study to understand the response of regional vegetation to this variability. EVI seems to be better related to GPP in comparison to NDVI in the preliminary analysis. Further analysis suggests LAI correlates better to GPP than EVI and NDVI in different seasons in these four regions. Also, meteorological parameters like surface temperature, rainfall, soil water, and other derived parameters like Vapor Pressure Deficit (VPD) are studied. It is also observed that the year-to-year variability in the climatic conditions could also have a role to play in the observed features. It is proven that the climate around the world is experiencing changes. Vegetation is one of the potent markers to monitor the impact of climate change. These long-term data and trends were studied to understand if there is any significant impact of the changing climatic conditions on the vegetation in these regions. Our study shows that there is an increasing (positive) trend in GPP at these locations though at different rates. WG and WHNI have shown a significant high rate of increase (6.44 and 5.36 gCm-2 y-1, respectively) in GPP over the last two decades.
Collapse
Affiliation(s)
- Smrati Gupta
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India; Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, India
| | - Pramit Kumar Deb Burman
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India; Department of Atmospheric and Space Sciences, Savitribai Phule Pune University, Pune, India
| | - Yogesh K Tiwari
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India; Department of Atmospheric and Space Sciences, Savitribai Phule Pune University, Pune, India.
| | | | - Nikul Kumari
- Faculty of Science, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Ankur Srivastava
- Faculty of Science, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Akhilesh S Raghubanshi
- Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, India
| |
Collapse
|
19
|
Varghese S, Aguirre B, Isbell F, Wright A. Simulating atmospheric drought: Silica gel packets dehumidify mesocosm microclimates. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.06.561294. [PMID: 37873293 PMCID: PMC10592642 DOI: 10.1101/2023.10.06.561294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
1. As global temperatures rise, droughts are becoming more frequent and severe. To predict how drought might affect plant communities, ecologists have traditionally designed experiments with controlled watering regimes and rainout shelters. Both treatments have proven effective for simulating soil drought. However, neither are designed to directly modify atmospheric drought. 2. Here, we detail the efficacy of a silica gel atmospheric drought treatment in outdoor mesocosms with and without a cooccurring soil drought treatment. At California State University, Los Angeles, we monitored relative humidity (RH), temperature, and vapor pressure deficit (VPD) every 10 minutes for five months in a bare-ground experiment featuring mesocosms treated with soil drought (reduced watering) and/or atmospheric drought (silica packets suspended 12 cm above soil). 3. We found that silica packets dehumidified these microclimates most effectively (-5% RH) when combined with reduced soil water, regardless of the ambient humidity levels of the surrounding air. Further, packets increased microclimate VPD most effectively (+0.4 kPa) when combined with reduced soil water and ambient air temperatures above 20°C. Finally, packets simulated atmospheric drought most consistently when replaced within three days of deployment. 4. Our results demonstrate the use of silica packets as effective dehumidification agents in outdoor drought experiments. We emphasize that incorporating atmospheric drought in existing soil drought experiments can improve our understandings of the ecological impacts of drought.
Collapse
Affiliation(s)
- S. Varghese
- California State University Los Angeles, Department of Biological Sciences, Los Angeles, CA
- University of Minnesota, Department of Ecology, Evolution, and Behavior, Minneapolis, MN
| | - B.A. Aguirre
- Cornell University, Department of Ecology and Evolutionary Biology, Ithaca, NY
| | - F. Isbell
- University of Minnesota, Department of Ecology, Evolution, and Behavior, Minneapolis, MN
| | - A.J. Wright
- California State University Los Angeles, Department of Biological Sciences, Los Angeles, CA
| |
Collapse
|
20
|
Chen H, Chen P, Wang R, Qiu L, Tang F, Xiong M. Multi-Source Soil Moisture Data Fusion Based on Spherical Cap Harmonic Analysis and Helmert Variance Component Estimation in the Western U.S. SENSORS (BASEL, SWITZERLAND) 2023; 23:8019. [PMID: 37836849 PMCID: PMC10575404 DOI: 10.3390/s23198019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 09/16/2023] [Accepted: 09/18/2023] [Indexed: 10/15/2023]
Abstract
Soil moisture (SM) is a vital climate variable in the interaction process between the Earth's atmosphere and land. However, global soil moisture products from various satellite missions and land surface models are affected by inherently discontinuous observations and coarse spatial resolution, which limits their application at fine spatial scales. To address this problem, this paper integrates three diverse types of datasets from in situ, satellites, and models through Spherical cap harmonic analysis (SCHA) and Helmert variance component estimation (HVCE) to produce 1 km of spatio-temporally continuous SM products with high accuracy. First, this paper eliminates the bias between different datasets and in situ sites and resamples the datasets before data fusion. Then, multi-source SM data fusion is performed based on the SCHA and HVCE methods. Finally, this paper evaluates the fused products from three aspects, including the performance of representative sites under different climate types, the overall performance of validation sites, and the comparison with other products. The results show that the fused products have better performance than other SM products. In the representative sites, the minimal correlation coefficient (R) of the fused products is above 0.85, and the largest root mean square error (RMSE) is below 0.040 m3 m-3. For all validation sites, the R and RMSE of the fused products are 0.889 and 0.036 m3 m-3, respectively, while the R for other products is below 0.75 and the RMSE is above 0.06 m3 m-3. In comparison to other SM products, the fused products exhibit superior performance, generally align more closely with in situ measurements, and possess the ability to accurately and finely capture the spatial and temporal variability of surface SM.
Collapse
Affiliation(s)
- Hao Chen
- College of Geomatics, Xi’an University of Science and Technology, Xi’an 710054, China; (H.C.); (R.W.); (L.Q.); (F.T.); (M.X.)
| | - Peng Chen
- College of Geomatics, Xi’an University of Science and Technology, Xi’an 710054, China; (H.C.); (R.W.); (L.Q.); (F.T.); (M.X.)
- State Key Laboratory of Geodesy and Earth’s Dynamics, Innovation Academy for Precision Measurement Science and Technology, CAS, Wuhan 430077, China
- Beijing Key Laboratory of Urban Spatial Information Engineering, Beijing 100045, China
| | - Rong Wang
- College of Geomatics, Xi’an University of Science and Technology, Xi’an 710054, China; (H.C.); (R.W.); (L.Q.); (F.T.); (M.X.)
| | - Liangcai Qiu
- College of Geomatics, Xi’an University of Science and Technology, Xi’an 710054, China; (H.C.); (R.W.); (L.Q.); (F.T.); (M.X.)
| | - Fucai Tang
- College of Geomatics, Xi’an University of Science and Technology, Xi’an 710054, China; (H.C.); (R.W.); (L.Q.); (F.T.); (M.X.)
| | - Mingzhu Xiong
- College of Geomatics, Xi’an University of Science and Technology, Xi’an 710054, China; (H.C.); (R.W.); (L.Q.); (F.T.); (M.X.)
| |
Collapse
|
21
|
Li W, Pacheco-Labrador J, Migliavacca M, Miralles D, Hoek van Dijke A, Reichstein M, Forkel M, Zhang W, Frankenberg C, Panwar A, Zhang Q, Weber U, Gentine P, Orth R. Widespread and complex drought effects on vegetation physiology inferred from space. Nat Commun 2023; 14:4640. [PMID: 37582763 PMCID: PMC10427636 DOI: 10.1038/s41467-023-40226-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 07/12/2023] [Indexed: 08/17/2023] Open
Abstract
The response of vegetation physiology to drought at large spatial scales is poorly understood due to a lack of direct observations. Here, we study vegetation drought responses related to photosynthesis, evaporation, and vegetation water content using remotely sensed data, and we isolate physiological responses using a machine learning technique. We find that vegetation functional decreases are largely driven by the downregulation of vegetation physiology such as stomatal conductance and light use efficiency, with the strongest downregulation in water-limited regions. Vegetation physiological decreases in wet regions also result in a discrepancy between functional and structural changes under severe drought. We find similar patterns of physiological drought response using simulations from a soil-plant-atmosphere continuum model coupled with a radiative transfer model. Observation-derived vegetation physiological responses to drought across space are mainly controlled by aridity and additionally modulated by abnormal hydro-meteorological conditions and vegetation types. Hence, isolating and quantifying vegetation physiological responses to drought enables a better understanding of ecosystem biogeochemical and biophysical feedback in modulating climate change.
Collapse
Affiliation(s)
- Wantong Li
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany.
| | - Javier Pacheco-Labrador
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | | | - Diego Miralles
- Hydro-Climate Extremes Lab (H-CEL), Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Anne Hoek van Dijke
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Markus Reichstein
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
- Integrative Center for Biodiversity Research (iDIV), Leipzig, Germany
| | - Matthias Forkel
- Institute of Photogrammetry and Remote Sensing, Technische Universität Dresden, Dresden, Germany
| | - Weijie Zhang
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Christian Frankenberg
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
| | - Annu Panwar
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Qian Zhang
- School of Geomatics Science and Technology, Nanjing Tech University, Nanjing, China
| | - Ulrich Weber
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Pierre Gentine
- Department of Earth and Environmental Engineering, Columbia University, New York, NY, 10027, USA
| | - Rene Orth
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| |
Collapse
|
22
|
He P, Han Z, He M, Meng X, Ma X, Liu H, Dong T, Shi M, Sun Z. Atmospheric dryness thresholds of grassland productivity decline in China. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 338:117780. [PMID: 36965424 DOI: 10.1016/j.jenvman.2023.117780] [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: 10/06/2022] [Revised: 03/13/2023] [Accepted: 03/19/2023] [Indexed: 06/18/2023]
Abstract
Atmospheric dryness events are bound to have a broad and profound impact on the functions and structures of grassland ecosystems. Current research has confirmed that atmospheric dryness is a key moisture constraint that inhibits grassland productivity, yet the risk threshold for atmospheric dryness to initiate ecosystem productivity loss has not been explored. Based on this, we used four terrestrial ecosystem models to simulate gross primary productivity (GPP) data, analyzed the role of vapor pressure deficit (VPD) in regulating interannual variability in Chinese grasslands by focusing on the dependence structure of VPD and GPP, and then constructed a bivariate linkage function to calculate the conditional probability of ecosystem GPP loss under atmospheric dryness, and further analyzed the risk threshold of ecosystem GPP loss triggered by atmospheric dryness. The main results are as follows: we found that (1) the observed and modeled VPD of Chinese grasslands increases rapidly in both historical and future periods. VPD has a strongly negative regulation on ecosystem GPP, and atmospheric dryness is an important moisture constraint that causes deficit and even death to ecosystem GPP. (2) The probability of the enhanced atmospheric dryness that induced GPP decline in Chinese grasslands in the future period increases significantly. (3) When the VPD is higher than 40.07 and 27.65 percentile of the past and future time series, respectively, the risk threshold of slight ecosystem GPP loss can be easily initiated by atmospheric dryness. (4) When the VPD is higher than 82.57 and 65.09 percentile, respectively, the threshold of moderate ecosystem GPP loss can be exceeded by the benchmark probability. (5) The risk threshold of severe ecosystem GPP loss is not initiated by atmospheric dryness in the historical period, and the threshold of severe ecosystem GPP loss can be initiated when the future VPD is higher than 91.92 percentile. In total, a slight atmospheric dryness event is required to initiate a slight ecosystem GPP loss threshold, and a stronger atmospheric dryness event is required to initiate a severe ecosystem GPP loss. Our study enhances the understandings of past and future atmospheric dryness on grassland ecosystems, and strongly suggests that more attention be invested in improving next-generation models of vegetation dynamics processes with respect to the response of mechanisms of ecosystem to atmospheric dryness.
Collapse
Affiliation(s)
- Panxing He
- Henan Normal University, Xinxiang, 453007, China; Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, Xinjiang Agricultural University, Urumqi, 830000, China.
| | - Zhiming Han
- College of Resources and Environment, Northwest A&F University, Yangling, 712100, China
| | - Mingzhu He
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730020, China
| | - Xiaoyu Meng
- Key Research Institute of Yellow River Civilization and Sustainable, Development Collaborative Innovation Center on Yellow River Civilization, Henan University, Kaifeng, 475000, China.
| | - Xiaoliang Ma
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
| | - Huixia Liu
- Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, Xinjiang Agricultural University, Urumqi, 830000, China
| | - Tong Dong
- Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, Xinjiang Agricultural University, Urumqi, 830000, China
| | - Mingjie Shi
- Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, Xinjiang Agricultural University, Urumqi, 830000, China
| | - Zongjiu Sun
- Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, Xinjiang Agricultural University, Urumqi, 830000, China.
| |
Collapse
|
23
|
Xi X, Yuan X. Remote sensing of atmospheric and soil water stress on ecosystem carbon and water use during flash droughts over eastern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 868:161715. [PMID: 36682554 DOI: 10.1016/j.scitotenv.2023.161715] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/29/2022] [Accepted: 01/15/2023] [Indexed: 06/17/2023]
Abstract
Flash droughts are often accompanied by large soil and atmospheric moisture deficits, and the concurrence of flash droughts and high temperature may have a great impact on the ecosystem. However, the stress of soil and atmospheric moisture deficits on carbon and water use of the ecosystem during flash droughts, especially during the drought periods with hot conditions, are unclear over a large region. In this study, we decoupled the atmospheric and soil water stress over eastern China by using vegetation productivity data and photosynthetically active radiation data retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS). The analysis is conducted during flash droughts and their sub-periods that are accompanied by high temperature and intense radiation from 2003 to 2018. The results showed that soil moisture (SM) stress was significantly greater than the vapor pressure deficit (VPD) stress on vegetation productivity in the humid regions of eastern China during flash droughts. However, high VPD controlled the water stress on light use efficiency (LUE) of vegetation over 55 % of the regions. For the hot periods of flash droughts, the area subjected to VPD stress on vegetation productivity significantly increased in semi-arid and semi-humid regions. The concurrent hot and drought conditions also increased water use efficiency (WUE) for most areas, which suggests that the reduction percentage of vegetation productivity is larger than that of evapotranspiration. Our research emphasized the severe impact of compound hot and flash drought conditions on vegetation carbon and water use from a remote sensing perspective.
Collapse
Affiliation(s)
- Xiazhen Xi
- Key Laboratory of Hydrometeorological Disaster Mechanism and Warning of Ministry of Water Resources/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China; School of Hydrology and Water Resources, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China
| | - Xing Yuan
- Key Laboratory of Hydrometeorological Disaster Mechanism and Warning of Ministry of Water Resources/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China; School of Hydrology and Water Resources, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China.
| |
Collapse
|
24
|
Bloomfield KJ, Stocker BD, Keenan TF, Prentice IC. Environmental controls on the light use efficiency of terrestrial gross primary production. GLOBAL CHANGE BIOLOGY 2023; 29:1037-1053. [PMID: 36334075 PMCID: PMC10099475 DOI: 10.1111/gcb.16511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 10/12/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
Gross primary production (GPP) by terrestrial ecosystems is a key quantity in the global carbon cycle. The instantaneous controls of leaf-level photosynthesis are well established, but there is still no consensus on the mechanisms by which canopy-level GPP depends on spatial and temporal variation in the environment. The standard model of photosynthesis provides a robust mechanistic representation for C3 species; however, additional assumptions are required to "scale up" from leaf to canopy. As a consequence, competing models make inconsistent predictions about how GPP will respond to continuing environmental change. This problem is addressed here by means of an empirical analysis of the light use efficiency (LUE) of GPP inferred from eddy covariance carbon dioxide flux measurements, in situ measurements of photosynthetically active radiation (PAR), and remotely sensed estimates of the fraction of PAR (fAPAR) absorbed by the vegetation canopy. Focusing on LUE allows potential drivers of GPP to be separated from its overriding dependence on light. GPP data from over 100 sites, collated over 20 years and located in a range of biomes and climate zones, were extracted from the FLUXNET2015 database and combined with remotely sensed fAPAR data to estimate daily LUE. Daytime air temperature, vapor pressure deficit, diffuse fraction of solar radiation, and soil moisture were shown to be salient predictors of LUE in a generalized linear mixed-effects model. The same model design was fitted to site-based LUE estimates generated by 16 terrestrial ecosystem models. The published models showed wide variation in the shape, the strength, and even the sign of the environmental effects on modeled LUE. These findings highlight important model deficiencies and suggest a need to progress beyond simple "goodness of fit" comparisons of inferred and predicted carbon fluxes toward an approach focused on the functional responses of the underlying dependencies.
Collapse
Affiliation(s)
- Keith J. Bloomfield
- Georgina Mace Centre for the Living Planet, Department of Life Sciences, Imperial College LondonAscotUK
| | - Benjamin D. Stocker
- Department of Environmental Systems Science, ETHZurichSwitzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorfSwitzerland
- Institute of GeographyUniversity of BernBernSwitzerland
- Oeschger Centre for Climate Change ResearchUniversity of BernBernSwitzerland
| | - Trevor F. Keenan
- Department of Environmental Science, Policy and Management, UC BerkeleyBerkeleyCaliforniaUSA
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National LaboratoryBerkeleyCaliforniaUSA
| | - I. Colin Prentice
- Georgina Mace Centre for the Living Planet, Department of Life Sciences, Imperial College LondonAscotUK
- Department of Biological SciencesMacquarie UniversityNorth RydeNew South WalesAustralia
- Ministry of Education Key Laboratory for Earth System Modelling, Department of Earth System ScienceTsinghua UniversityBeijingChina
| |
Collapse
|
25
|
Niu X, Chen Z, Pang Y, Liu X, Liu S. Soil moisture shapes the environmental control mechanism on canopy conductance in a natural oak forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 857:159363. [PMID: 36240914 DOI: 10.1016/j.scitotenv.2022.159363] [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: 08/17/2022] [Revised: 10/04/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Canopy conductance (gc) is an important biophysical parameter closely related to ecosystem energy partitioning and carbon sequestration, which can be used to judge drought effect on forest ecosystems. It is very important to explore how soil moisture change affects the environmental control mechanism of gc, especially in natural oak forests in Central China where frequent extreme precipitation (P) and drought will occur in a context of climate change. In this study, variations of gc and its environmental control mechanisms in a warm-temperate forest over three consecutive years under different hydroclimatic conditions were examined by using eddy-covariance technique. Results showed that the averaged gc in the three growing seasons were 11.2, 11.3 and 7.8 mms-1, respectively, with a CV of 19.7 %. The lowest gc occurred in the year with the lowest P. Using three years of data, we found that vapor pressure deficit (VPD) exhibited the dominate effect on gc, both diffuse photosynthetically active radiation (PARdif) and air temperature (Ta) were positively correlated with gc. When relative extractable water content (REW) was larger than 0.4, however, inhibiting effect of high VPD on gc disappeared and the effect of direct photosynthetically active radiation (PARdir) on gc was larger compared to PARdif. When REW was <0.1, the positive relationship between Ta and gc became negative. Our results indicated that soil moisture ultimately shapes the environmental control mechanism of gc in a natural oak forest.
Collapse
Affiliation(s)
- Xiaodong Niu
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China; Institute of Forest Resource Information Techniques, Chinese Academy of Forestry, Beijing 100091, China
| | - Zhicheng Chen
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
| | - Yong Pang
- Institute of Forest Resource Information Techniques, Chinese Academy of Forestry, Beijing 100091, China
| | - Xiaojing Liu
- Baotianman National Nature Reserve Administrative Bureau, Nanyang 474350, Henan, China
| | - Shirong Liu
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China.
| |
Collapse
|
26
|
Desai AR, Murphy BA, Wiesner S, Thom J, Butterworth BJ, Koupaei‐Abyazani N, Muttaqin A, Paleri S, Talib A, Turner J, Mineau J, Merrelli A, Stoy P, Davis K. Drivers of Decadal Carbon Fluxes Across Temperate Ecosystems. JOURNAL OF GEOPHYSICAL RESEARCH. BIOGEOSCIENCES 2022; 127:e2022JG007014. [PMID: 37502709 PMCID: PMC10369927 DOI: 10.1029/2022jg007014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 07/29/2023]
Abstract
Long-running eddy covariance flux towers provide insights into how the terrestrial carbon cycle operates over multiple timescales. Here, we evaluated variation in net ecosystem exchange (NEE) of carbon dioxide (CO2) across the Chequamegon Ecosystem-Atmosphere Study AmeriFlux core site cluster in the upper Great Lakes region of the USA from 1997 to 2020. The tower network included two mature hardwood forests with differing management regimes (US-WCr and US-Syv), two fen wetlands with varying levels of canopy sheltering and vegetation (US-Los and US-ALQ), and a very tall (400 m) landscape-level tower (US-PFa). Together, they provided over 70 site-years of observations. The 19-tower Chequamegon Heterogenous Ecosystem Energy-balance Study Enabled by a High-density Extensive Array of Detectors 2019 campaign centered around US-PFa provided additional information on the spatial variation of NEE. Decadal variability was present in all long-term sites, but cross-site coherence in interannual NEE in the earlier part of the record became weaker with time as non-climatic factors such as local disturbances likely dominated flux time series. Average decadal NEE at the tall tower transitioned from carbon source to sink to near neutral over 24 years. Respiration had a greater effect than photosynthesis on driving variations in NEE at all sites. Declining snowfall offset potential increases in assimilation from warmer springs, as less-insulated soils delayed start of spring green-up. Higher CO2 increased maximum net assimilation parameters but not total gross primary productivity. Stand-scale sites were larger net sinks than the landscape tower. Clustered, long-term carbon flux observations provide value for understanding the diverse links between carbon and climate and the challenges of upscaling these responses across space.
Collapse
Affiliation(s)
- Ankur R. Desai
- Department of Atmospheric and Oceanic SciencesUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Bailey A. Murphy
- Department of Atmospheric and Oceanic SciencesUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Susanne Wiesner
- Department of Plant and Earth ScienceUniversity of Wisconsin–River FallsRiver FallsWIUSA
| | - Jonathan Thom
- Space Science and Engineering CenterUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Brian J. Butterworth
- Cooperative Institute for Research in Environmental SciencesCU BoulderBoulderCOUSA
- NOAA Physical Sciences LaboratoryBoulderCOUSA
| | | | - Andi Muttaqin
- Department of Atmospheric and Oceanic SciencesUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Sreenath Paleri
- Department of Atmospheric and Oceanic SciencesUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Ammara Talib
- Department of Civil and Environmental EngineeringUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Jess Turner
- Freshwater & Marine SciencesUniversity of Wisconsin–MadisonMadisonWIUSA
| | - James Mineau
- Department of Atmospheric and Oceanic SciencesUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Aronne Merrelli
- Department of Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | - Paul Stoy
- Department of Plant and Earth ScienceUniversity of Wisconsin–River FallsRiver FallsWIUSA
| | - Ken Davis
- Department of MeteorologyPennsylvania State UniversityUniversity ParkPAUSA
| |
Collapse
|
27
|
Tong B, Guo J, Xu H, Wang Y, Li H, Bian L, Zhang J, Zhou S. Effects of soil moisture, net radiation, and atmospheric vapor pressure deficit on surface evaporation fraction at a semi-arid grass site. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 849:157890. [PMID: 35944641 DOI: 10.1016/j.scitotenv.2022.157890] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 07/31/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
Surface energy partitioning is one of the most important aspects of the land-atmosphere coupling. The objective of this study is to examine how soil moisture (SM) and atmospheric conditions (net radiation, Rn and vapor pressure deficit, VPD) affect surface evaporation fraction (EF, determined by LE/(LE + H), where LE and H are latent and sensible heat flux, respectively) with measurements at a semi-arid grass site in China during the mid-growing season, 2020. The three factors (SM, Rn, and VPD) were divided into different levels, and then their effects on EF were investigated qualitatively using a combinatorial stratification method and quantificationally using a path analysis. Generally, the results indicated that the effect of one factor of SM, Rn and VPD on EF was influenced by the other two factors. EF tended to increase with increasing SM. Increased VPD (Rn) enhanced (weakened) the SM-EF relationship. When soil was dry, EF tended to decrease with increasing VPD; when soil was wet, EF initially levelled off and then decreased with increasing VPD. Increased Rn enhanced (weakened) the positive (negative) effect of VPD on EF when soil was wet (dry). In terms of Rn effect, EF tended to decrease as Rn increases. Further, path analysis suggested that SM, Rn, and VPD not only directly affected EF, but also indirectly affected EF, mainly through canopy conductance (Gs) and temperature difference between land surface and air (∆T). The direct effect of SM accounted for >50 % of its total effect on EF, while the total effects of Rn and VPD on EF were dominated by their indirect effects. These observational evidences may have implications for improving representation of land-atmosphere coupling in atmospheric general circulation models over the semi-arid regions covered by grass.
Collapse
Affiliation(s)
- Bing Tong
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, China
| | - Jianping Guo
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, China.
| | - Hui Xu
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, China
| | - Yinjun Wang
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, China
| | - Huirong Li
- Xilinhot National Climatic Observatory, Xilinhot, China
| | - Lingen Bian
- Chinese Academy of Meteorological Sciences, Beijing, China
| | - Jian Zhang
- Hubei Subsurface Multi-scale Imaging Key Laboratory, Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, China
| | - Shenghui Zhou
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions (Henan University), Ministry of Education, Kaifeng, China
| |
Collapse
|
28
|
Zheng Z. Climate Controls on the Spatial Variability of Vegetation Greenup Rate across Ecosystems in Northern Hemisphere. PLANTS (BASEL, SWITZERLAND) 2022; 11:2971. [PMID: 36365427 PMCID: PMC9653628 DOI: 10.3390/plants11212971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/29/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
Variations in individual phenological events in response to global change have received considerable attentions. However, the development of phenological stages is relatively neglected, especially based on in situ observation data. In this study, the rate of vegetation greenup (Vgreenup) across the Northern Hemisphere was examined for different plant functional types (PFTs) by using eddy covariance flux data from 40 sites (417 site-years). Then, the controls of climatic variables on the spatial distribution of Vgreenup across PFTs were further investigated. The mean Vgreenup was 0.22 ± 0.11 g C m-2 day-2 across all sites, with the largest and lowest values observed in cropland and evergreen needle-leaf forest, respectively. A strong latitude dependence by Vgreenup was observed in both Europe and North America. The spatial variations of Vgreenup were jointly regulated by the duration of greenup (Dgreenup) and the amplitude of greenup (Agreenup). However, the predominant factor was Dgreenup in Europe, which changed to Agreenup in North America. Spring climatic factors exerted significant influences on the spatial distribution of Vgreenup across PFTs. Specifically, increasing temperature tended to shorten Dgreenup and promote Agreenup simultaneously, resulting in an acceleration of Vgreenup. Dryness had a depression effect on Vgreenup for the whole study area, as exhibited by a lower Vgreenup with increasing vapor pressure deficit or decreasing soil moisture. However, Vgreenup in North America was only significantly and positively correlated with temperature. Without the limitation of other climatic factors, the temperature sensitivity of Vgreenup was higher in North America (0.021 g C m-2 day-2 °C-1) than in Europe (0.015 g C m-2 day-2 °C-1). This study provides new cognitions for Vgreenup dynamics from in situ observations in complement to satellite observations, which can improve our understanding of terrestrial carbon cycles.
Collapse
Affiliation(s)
- Zhoutao Zheng
- Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| |
Collapse
|
29
|
Devi MJ, Reddy VR, Timlin D. Drought-Induced Responses in Maize under Different Vapor Pressure Deficit Conditions. PLANTS (BASEL, SWITZERLAND) 2022; 11:2771. [PMID: 36297794 PMCID: PMC9611867 DOI: 10.3390/plants11202771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 10/12/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
Water stress in plants depends on the soil water level and the evaporative demand. In this study, the physiological, biochemical, and molecular response of maize were examined under three evaporative demand conditions (low—1.00 kPa, medium—2.2 kPa, and high—4.00 kPa Vapor pressure deficit (VPD)) at three different soil water content (SWC); well-watered, 45%, and 35% SWC. Plants grown at 35% SWC under high VPD had significant (p < 0.01) lower leaf weight, leaf area, and leaf number than low VPD. Plants under low, medium, and high VPD with drought stress (45% and 35% SWC) showed a 30 to 60% reduction in their leaf area compared to well-watered plants. Gas exchange parameters including photosynthesis, stomatal conductance, and water use efficiency exhibited significant differences (p < 0.01) between treatments, with the highest reduction occuring at 35% SWC and high VPD. Both drought and VPD significantly (p < 0.01) increased C4 enzyme levels and some transcription factors with increased stress levels. Transcription factors primarily related to Abssisic Acid (ABA) synthesis were upregulated under drought, which might be related to high ABA levels. In summary, severe drought levels coupled with high VPD had shown a significant decrease in plant development by modifying enzymes, ABA, and transcription factors.
Collapse
Affiliation(s)
- Mura Jyostna Devi
- USDA-ARS, Adaptive Cropping Systems Laboratory, Beltsville, MD 20705, USA
- USDA-ARS, Vegetable Crops Research Unit, Madison, WI 53706, USA
- Department of Horticulture, University of Wisconsin-Madison, Madison, WI 53706, USA
| | | | - Dennis Timlin
- USDA-ARS, Adaptive Cropping Systems Laboratory, Beltsville, MD 20705, USA
| |
Collapse
|
30
|
Wood DJA, Stoy PC, Powell SL, Beever EA. Antecedent climatic conditions spanning several years influence multiple land-surface phenology events in semi-arid environments. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1007010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Ecological processes are complex, often exhibiting non-linear, interactive, or hierarchical relationships. Furthermore, models identifying drivers of phenology are constrained by uncertainty regarding predictors, interactions across scales, and legacy impacts of prior climate conditions. Nonetheless, measuring and modeling ecosystem processes such as phenology remains critical for management of ecological systems and the social systems they support. We used random forest models to assess which combination of climate, location, edaphic, vegetation composition, and disturbance variables best predict several phenological responses in three dominant land cover types in the U.S. Northwestern Great Plains (NWP). We derived phenological measures from the 25-year series of AVHRR satellite data and characterized climatic predictors (i.e., multiple moisture and/or temperature based variables) over seasonal and annual timeframes within the current year and up to 4 years prior. We found that antecedent conditions, from seasons to years before the current, were strongly associated with phenological measures, apparently mediating the responses of communities to current-year conditions. For example, at least one measure of antecedent-moisture availability [precipitation or vapor pressure deficit (VPD)] over multiple years was a key predictor of all productivity measures. Variables including longer-term lags or prior year sums, such as multi-year-cumulative moisture conditions of maximum VPD, were top predictors for start of season. Productivity measures were also associated with contextual variables such as soil characteristics and vegetation composition. Phenology is a key process that profoundly affects organism-environment relationships, spatio-temporal patterns in ecosystem structure and function, and other ecosystem dynamics. Phenology, however, is complex, and is mediated by lagged effects, interactions, and a diversity of potential drivers; nonetheless, the incorporation of antecedent conditions and contextual variables can improve models of phenology.
Collapse
|
31
|
Ecological Engineering Projects Shifted the Dominance of Human Activity and Climate Variability on Vegetation Dynamics. REMOTE SENSING 2022. [DOI: 10.3390/rs14102386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Global greening and its eco-environmental outcomes are getting mounting international focus. The important contribution of China to the global greening is highly appreciated. However, the basic driving forces are still elusive. The Loess Plateau (LP) and Three-River Source Region (TRSR) were chased as study areas in Northern China. The prior one represents the region experiencing intensive human interventions from ecological engineering projects, while the latter is a typical region that is experiencing faster climate change. Hypothesized to be driven by a disproportionate rate of human activities and climates, also being regions of typical large-scale ecological engineering projects, the study goal is to identify the actual driving forces on vegetation dynamics in these two regions. Trend analysis, correlation analysis, and residual trend-based method (RESTREND) were utilized to understand the relationships between climate variability, human activities, and vegetation dynamics. The spatiotemporal variations of vegetation from 1982 to 2019 were evaluated and the respective impacts of climatic and anthropogenic factors on vegetation dynamics were disentangled. Indicating apparent vegetation restoration in LP and TRSR, the results depict that annual LAI has remarkably increased during the 38 years. Temperature and precipitation promoted vegetation growth, whereas the solar radiation and vapor pressure deficit hampered it. After implementing the ecological engineering projects, the primary climatic factor changed from temperature to precipitation. Meanwhile, human activities act as the major driving factor in vegetation greening in the entire study area, with a contribution rate exceeding 70%. This information highlights that ecological engineering can significantly reduce the risks of ecosystem degradation and effectively restore vegetation, especially in ecologically sensitive and vulnerable areas.
Collapse
|