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Zhang T, Quan W, Tian J, Li J, Feng P. Spatial and temporal variations of ecosystem water use efficiency and its response to soil moisture drought in a water-limited watershed of northern China. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 355:120251. [PMID: 38422844 DOI: 10.1016/j.jenvman.2024.120251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/22/2024] [Accepted: 01/27/2024] [Indexed: 03/02/2024]
Abstract
Drought synchronously affects the water cycle and interferes with the carbon cycle in terrestrial ecosystems. Ecosystem water use efficiency (WUE), serving as a vital metric for assessing the interplay between water and carbon cycles, has found extensively use in exploring how ecosystems responses to drought. However, the effects of soil moisture drought on WUE are still poorly recognized. Taking Ziya River Basin as an example, the spatial-temporal variations of WUE from 2001 to 2020 were estimated by the Penman-Monteith-Leuning Version 2 (PML-V2) data. Based on the Standardized Soil Moisture Index (SSI) calculated from Soil Moisture of China by in situ data, version 1.0 (SMCI1.0) data, the sensitivity and thresholds of different vegetation WUE to drought magnitudes were investigated, and the influences of both lagged and cumulative effects of drought on WUE were further analyzed. Results showed that the annual mean WUE was 2.160 ± 0.975 g C kg-1 H2O-1 in the Ziya River Basin, with a significant increasing trend of 0.037 g C kg-1 H2O-1 yr-1 (p < 0.05). For all the vegetation types, the WUE reached the maximum value at a certain drought threshold (SSI = -1.5 ± 0.1). The dominant factor controlling WUE sensitivity to drought changed from evapotranspiration (ET) to gross primary production (GPP) when severe drought transformed into extreme drought. Significant lagged and cumulative effects were found in the response of WUE to drought in nearly 58.64 % (72.94 %) of the study area, with an average time scale of 6.65 and 2.11 months (p < 0.05) respectively. Drought resistance in descending order was: forest > shrub > grassland > cropland. Our findings enrich the understanding of the coupled carbon and water cycle processes in terrestrial ecosystems and their response to soil moisture drought in the context of global climate change.
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Affiliation(s)
- Ting Zhang
- State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, 300072, China
| | - Wenjie Quan
- State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, 300072, China
| | - Jiyang Tian
- China Institute of Water Resources and Hydropower Research, Beijing, 100038, China; Research Center on Flood & Drought Disaster Reduction, The Ministry of Water Resources of China, Beijing, 100038, China.
| | - Jianzhu Li
- State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, 300072, China
| | - Ping Feng
- State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, 300072, China
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Kong R, Zhang Z, Yu Z, Huang R, Zhang Y, Chen X, Xu CY. Increasing sensitivity of dryland water use efficiency to soil water content due to rising atmospheric CO 2. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167087. [PMID: 37716683 DOI: 10.1016/j.scitotenv.2023.167087] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 09/02/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023]
Abstract
Examining the intricate interplay between ecosystem carbon-water coupling and soil moisture sensitivity serves as a crucial approach to effectively assess the dilemma arising from escalating global carbon emissions and concomitant water scarcity. Using the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ), this study investigated the potential effects of climate change and soil water content (SWC) on terrestrial ecosystem water use efficiency (WUE) across China from 1982 to 2060. The results revealed that: (1) WUE was higher in South China and Northeast China, but lower in Northwest China and it had shown a significant upward trend in the past 40 years, especially in Northwest China where grasslands were widely distributed. The increase in WUE was mainly closely related to the greening of vegetation. In the past 40 years, the area of net primary productivity (NPP), evapotranspiration (ET), and WUE showing an upward trend accounted for 85.85 %, 63.66 %, and 83.88 % of the total area of the country, respectively. Although ET also showed an increasing trend nationwide, the increase of NPP was more obvious; (2) The control experiment showed that WUE showed a significant increase trend in arid and semi-arid areas of Northwest China with the increase of CO2 concentration, while SWC showed a significant drying trend, but both WUE and SWC showed an increasing trend in humid areas. The sensitivity of WUE to SWC was enhanced in arid and semi-arid areas, and the effect of soil drought was partially offset by the increase of WUE; (3) Future climate projections also indicated that the CO2 fertilization effect will contribute to an increase in WUE while causing drier soil moisture conditions in the arid and semi-arid regions. Especially under the SSP5-8.5 scenario, CO2 fertilization in Northwest China contributed more than 14 % to WUE from 2015 to 2060, while the impact on SWC depletion exceeded 3 %. This highlights the potential implications of rising atmospheric CO2 concentration, as it may promote a significant rise in WUE and exacerbate the drying of soil moisture in these areas. These findings emphasize the need for careful attention and consideration in managing water resources in arid and semi-arid regions in the face of future climate change.
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Affiliation(s)
- Rui Kong
- State Key Laboratory of Hydrology-Water Resources and Hydraulics Engineering, College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China.
| | - Zengxin Zhang
- State Key Laboratory of Hydrology-Water Resources and Hydraulics Engineering, College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China; Joint Innovation Center for Modern Forestry Studies, College of Forestry, Nanjing Forestry University, Nanjing 210037, China.
| | - Zejiang Yu
- State Key Laboratory of Hydrology-Water Resources and Hydraulics Engineering, College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China
| | - Richao Huang
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Ying Zhang
- State Key Laboratory of Hydrology-Water Resources and Hydraulics Engineering, College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China.
| | - Xi Chen
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China.
| | - Chong-Yu Xu
- Department of Geosciences, University of Oslo, 0316 Oslo, Norway.
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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.
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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
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Ma T, Wang T, Yang D, Yang S. Impacts of vegetation restoration on water resources and carbon sequestration in the mountainous area of Haihe River basin, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 869:161724. [PMID: 36708819 DOI: 10.1016/j.scitotenv.2023.161724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 01/05/2023] [Accepted: 01/16/2023] [Indexed: 06/18/2023]
Abstract
The mountainous region of the Haihe River basin (MHRB) plays an important role in the water resource supply of its nearby mega-cities, including Beijing and Tianjin, and large areas of cropland. With the implementation of afforestation projects in recent decades, vegetation and carbon (C) uptake have greatly increased in the MHRB. In addition, the annual runoff has significantly declined, threatening regional water security. The trade-off relationship between water yield and C uptake in the MHRB remains unknown. This study employed a biogeochemical model (Biome-BGC) to simulate the natural vegetation dynamics and gross primary productivity (GPP) during 1982-2019 driven by climate forcing. A distributed hydrological model (geomorphology-based hydrological model, GBHM) was adopted to assess the impact of vegetation restoration on the hydrological processes. The results indicated that the leaf area index in the MHRB increased significantly (P < 0.01) during 1982-2019, which led to evapotranspiration increase and runoff (R) reduction. Under the influence of vegetation restoration, both the GPP and the water use efficiency (WUE) increased significantly in the MHRB during 2000-2019, however, the improvement of WUE decreased with the aridity index increasing. Our results showed that vegetation restoration can improve C sequestration efficiency in the MHRB and that the trade-off between water yield and C sequestration should be considered in planning ecological projects to achieve C neutrality.
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Affiliation(s)
- Teng Ma
- State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China
| | - Taihua Wang
- State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China
| | - Dawen Yang
- State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China.
| | - Shuyu Yang
- State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China
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Wang C, Li S, Wu M, Zhang W, He H, Yang D, Huang S, Guo Z, Xing X. Water use efficiency control for a maize field under mulched drip irrigation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 857:159457. [PMID: 36252664 DOI: 10.1016/j.scitotenv.2022.159457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/26/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Agricultural ecosystem water use efficiency (WUE) is an important indicator reflecting carbon-water coupling, but its control mechanisms in managed fields remain unclear. In order to reveal the influencing factors of WUE in the agricultural field under mulched drip irrigation (DM), we carried out the 8-year continuous observations in a maize field from Northwestern China. The structural equation model, relative importance analysis and principal component analysis were used to quantify the regulation effects of environmental and biological factors on WUE at different time scales, in different growth stages and under different hydrothermal conditions. The results showed that annual WUE varied between 2.18 g C Kg-1 H2O and 3.60 g C Kg-1 H2O, with a multi-year mean of 2.91 g C Kg-1 H2O. The total effects of air temperature on the daily WUE in the whole growth period, the vegetative growth stage, the warm and dry years, the cold and wet years, and the warm and wet years were the largest, with values of 0.61, 0.80, 0.70, 0.70 and 0.91 respectively. However, vapor pressure deficit and net radiation had the largest total effect in the cold and dry years (-0.63) and the reproductive growth stage (-0.49), respectively. Leaf biomass played a leading role in regulating the daily and interannual WUE, and the relative importance of leaf biomass to WUE in the vegetative growth stage was up to 75 %. In the warm and wet years, the relative importance of root biomass to WUE was 33 %, slightly higher than that of leaf biomass (31 %). At the same time, we found that Ta has the potential to increase WUE under future climate warming. Our results improve the understanding of carbon-water coupling mechanisms and provide important enlightenment on how crop ecosystems should adapt to future climate change.
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Affiliation(s)
- Chunyu Wang
- Center for Agricultural Water Research in China, China Agricultural University, Beijing 100083, China; National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Sien Li
- Center for Agricultural Water Research in China, China Agricultural University, Beijing 100083, China; National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China.
| | - Mousong Wu
- International Institute for Earth System Science, Nanjing University, Nanjing 210023, China.
| | - Wenxin Zhang
- Department of Physical Geography and Ecosystem Science, Lund University, Lund SE-22362, Sweden
| | - Hongxing He
- Department of Geography, McGill University, Burnside Hall, 805 Sherbrooke Street West, Montreal, Quebec H3A OB9, Canada
| | - Danni Yang
- Center for Agricultural Water Research in China, China Agricultural University, Beijing 100083, China; National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Siyu Huang
- Center for Agricultural Water Research in China, China Agricultural University, Beijing 100083, China; National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Zhenyu Guo
- Center for Agricultural Water Research in China, China Agricultural University, Beijing 100083, China; National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Xiuli Xing
- International Institute for Earth System Science, Nanjing University, Nanjing 210023, China
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Afzal A, Rafique MS, Iqbal SS, Rafique M. Deportment of cobalt bismuth nanoferrites in Kevlar‐supported c
ellulose acetate
membranes for heavy metal‐salts rejection profile. J Appl Polym Sci 2022. [DOI: 10.1002/app.52962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Amina Afzal
- Physics Department University of Engineering and Technology (UET) Lahore Pakistan
| | | | - Sadia Sagar Iqbal
- Department of Physics The University of Lahore (UOL) Lahore Pakistan
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Spatiotemporal Variability in Water-Use Efficiency in Tianshan Mountains (Xinjiang, China) and the Influencing Factors. SUSTAINABILITY 2022. [DOI: 10.3390/su14138191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Water-use efficiency (WUE) is a crucial physiological index in carbon–water interactions and is defined as the ratio of vegetation productivity to water loss. The variation in climatic variables and drought have the most significant effects on WUE and evapotranspiration (ET). Nevertheless, how WUE varies with climate factors and drought processes in the Tianshan Mountains (TMS) is still poorly understood. In the present work, we analyzed the spatiotemporal variations in WUE, and investigated the correlations between WUE, climate factors, and drought, in the study area. The results showed that, in the TMS during 2000–2020, annual net primary productivity (NPP) ranged from 147.9 to 189.4 gC·m−2, annual ET was in the range of 212.5–285.8 mm, and annual WUE ranged from 0.66 to 0.78 gC·kg−1·H2O. Both NPP and ET exhibited an increasing trend with some fluctuation, whereas WUE showed the opposite tendency during the study period. The obtained results demonstrated that the decrease in WUE was primarily because of the increase in ET. There were obvious differences in WUE, under different land-use types, caused by NPP and ET. However, the interannual variation in WUE showed small fluctuations and the dynamic process of WUE in each land-use type showed good consistency. Temperature and wind speed had a positive influence on WUE in the middle and eastern regions of the TMS. Precipitation also played a mainly positive role in enhancing WUE, especially on the northern slope of the TMS. There was strong spatial heterogeneity of the correlation coefficient (0.68, p < 0.05) between WUE and the temperature vegetation drought index (TVDI). Moreover, the slopes of WUE and TVDI showed good consistency in terms of spatial distribution, suggesting that drought had a significant impact on ecosystem WUE. This work will enhance the understanding of WUE variation, and provide scientific evidence for water resource management and sustainable utilization in the study area.
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8
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Chemical Regulation Effect of Water Use Efficiency of Maize Intercropping. J CHEM-NY 2022. [DOI: 10.1155/2022/2914749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In order to solve the practical problems of large water demand and shortage of water resources in traditional wheat/maize intercropping, a planting method of changing stubble retention method is proposed in this paper. This method was used to study the effects of three stubble retention methods of traditional wheat straw incineration, straw return, and straw stubble on grain yield, water use efficiency (WUE), and economic benefits of wheat/maize intercropping. The results showed that, compared with the grain yield of burning and returning, the single cropping of wheat increased by 7.2% and 5.1%, the intercropping of wheat increased by 6.2% and 5.1%, the single cropping of corn increased by 4.7% and 2.5%, and the intercropping of corn increased by 7.2% and 3.3%, respectively; compared with the burned and returned WUE, wheat monoculture increased by 20.4% and 16.2%, respectively, wheat intercropping increased by 17.9% and 14.6%, respectively, corn monoculture increased by 16.7% and 10.9%, respectively, and corn intercropping increased by 11.8% and 17.0%, respectively. In terms of the average value of monoculture wheat, monoculture corn, and wheat/corn, the net benefits of incineration, turning, and stubble treatment are 10946, 11471, and 13454 yuan • hm−2, respectively. Considering the grain yield, water use efficiency, and net income, the standing stubble planting mode is the best planting mode of wheat/maize in this area.
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Inherent Water-Use Efficiency of Different Forest Ecosystems and Its Relations to Climatic Variables. FORESTS 2022. [DOI: 10.3390/f13050775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Inherent water-use efficiency (IWUE) is a vital parameter connecting the carbon and water cycles. However, the factors influencing the IWUE in different forest ecosystems are still a subject of debate. In this work, FLUXNET platform measurements of 67 forest sites were used to detect trends of the IWUE of four forest ecosystems, namely deciduous broadleaf forests (DBF), evergreen broadleaf forests (EBF), needle-leaf forests (ENF), and mixed forests (MF). The IWUE differed significantly among different forest ecosystems and positively correlated with temperature and solar radiation. The IWUE of EBF was the highest at 32.02 g·C·Kg·H2O−1. The values of DBF and MF were similar and higher than that of ENF. With increasing latitude, the IWUE increased first and then decreased, with a maximum of 35° N. The IWUE of EBF was negatively correlated with precipitation and leaf area index. Temperature and solar radiation were the main factors controlling the IWUE of forest ecosystems, whereas precipitation was the major factor controlling the inter-annual variation in the ΔIWUE of forest ecosystems. Our results provide a scientific basis for the study of forest carbon sinks, forest eco-hydrological processes, and forest ecosystem responses to global climatic changes.
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Spatial and Temporal Drought Characteristics in the Huanghuaihai Plain and Its Influence on Cropland Water Use Efficiency. REMOTE SENSING 2022. [DOI: 10.3390/rs14102381] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Understanding the relationship between drought and the water use efficiency (WUE) in terrestrial ecosystems can help reduce drought risk. It remains unclear what the correlation between the cropland water use efficiency (CWUE) and drought during drought events. We aim to identify the spatiotemporal relationship between drought and the CWUE and to ensure the service capacity of cultivated land ecosystems. In this study, the cubist algorithm was used to establish a monthly integrated surface drought index (mISDI) dataset for the Huang–Huai–Hai Plain (HHHP), and the run theory was used to identify drought events. We assessed the spatio-temporal variations of drought in the HHHP during 2000–2020 and its influence on the CWUE. The research results were as follows: from the overall perspective of the HHHP, the mISDI showed a downward trend. Drought had an enhanced effect on the CWUE of the HHHP, and the enhancement of the CWUE in the eastern hilly area was more significant. The CWUE response to drought had a three-month lag period and a significant positive correlation, and it was shown that the cultivated land ecosystems in this area had strong drought resistance ability. This study provides a new framework for understanding the response of the CWUE to drought and formulating reasonable vegetation management strategies for the HHHP.
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11
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Response of Ecohydrological Variables to Meteorological Drought under Climate Change. REMOTE SENSING 2022. [DOI: 10.3390/rs14081920] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Drought is the most widespread climatic extreme that has negative impacts on ecohydrology. Studies have shown that drought can cause certain degrees of disturbances to different ecohydrological variables, but the duration and severity thresholds of drought that are sufficient to cause changes in ecohydrological variables remain largely unknown. At the same time, we should not ignore the dynamic variation of drought’s effect on ecohydrological variables under the condition of climate change. Here, we derived the thresholds of several ecohydrological variables in response to drought in a historical period (1982–2015), including evapotranspiration (ET), soil moisture (SM), the vapor pressure deficit (VPD) and the normalized difference vegetation index (NDVI), and we projected the occurrence probability’s change trend of drought events that cause changes in ecohydrological variables under future climate change. The results show that the impact of drought on ecohydrological variables is not dependent on drought indicators. ET and NDVI were expected to decrease in most parts of the world due to increases in radiation (RAD) and temperature (TEMP) and decreases in precipitation (PRE) during drought periods. SM decreased in most regions of the world (93.47%) during the drought period, while VPD increased in 85.41% of the globe. The response thresholds for different ecohydrological variables to drought in the same area did not differ significantly (especially for ET, SM and VPD). When a drought lasted for 8 to 15 months and the corresponding drought severity reached 10 to 15 (the inverse of the cumulative values of the drought index when the drought occurs), the drought caused changes in the ecohydrological variables in most regions of the world. Compared with arid and semiarid regions, ecohydrological variables are more sensitive to drought in humid and semihumid regions (p < 0.05), and high-intensity human activities in different climatic conditions increased significantly the severity of drought processes. Between 2071 and 2100, more than half of the world’s ecohydrological variables are expected to be more susceptible to drought disturbances (regions with shorter return periods of drought events that cause significant changes in ET, SM, VPD and NDVI account for 60.1%, 64.4%, 59.6% and 54.5% of the global land area, respectively).
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Somorowska U. Amplified signals of soil moisture and evaporative stresses across Poland in the twenty-first century. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 812:151465. [PMID: 34742798 DOI: 10.1016/j.scitotenv.2021.151465] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 11/01/2021] [Accepted: 11/01/2021] [Indexed: 06/13/2023]
Abstract
In Poland, recent summer droughts have had devastating environmental, social, and economic consequences, but the trend of growing season dryness remains unclear. This study focuses on the soil moisture and evaporative stress conditions, analyzed in a multiyear period between 1981 and 2019. Country scale trends in growing season drought severities are assessed using indices derived from the model-based estimates of soil moisture and evapotranspiration. These are compared with indices derived from meteorological variables. Soil droughts are assessed by the Standardized Soil Index (SSI), while the ecological droughts are related to evapotranspiration by the Standardized Evaporative Stress Ratio (SESR). Moreover, the Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), and self-calibrating Palmer Drought Severity Index (sc-PDSI) are used for comparison. A Drought-Prone Area (DPA) is delineated based on a criterion defined as simultaneous occurrence of statistically significant drying trends in surface and root zone soil moisture and evaporative stress. It was found that soil and ecological drought severities have remarkably increased in the growing season. This confirms the hypothesis that intensified soil drying is accompanied by intensified water stress imprinted in evapotranspiration. The most severe drought sequence has occurred in recent years, amplified by exceptionally high air temperature, low precipitation, and high deficit in the climatic water balance. The highest correlation is observed between annual growing season drought severities derived from the SSI and SESR; only SPEI approximates an increasing trend, while the SPI and sc-PDSI do not follow such a trajectory. The study shows an almost contiguous spatial pattern of DPA, which takes 42% of the country. One important implication of this study is that soil moisture and evapotranspiration should be considered in assessing drought severity in addition to traditionally used meteorological variables.
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Affiliation(s)
- Urszula Somorowska
- Department of Hydrology, Faculty of Geography and Regional Studies, University of Warsaw, Krakowskie Przedmieście 30, 00-927 Warsaw, Poland.
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13
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Liu Y, Jiang Q, Wang Q, Jin Y, Yue Q, Yu J, Zheng Y, Jiang W, Yao X. The divergence between potential and actual evapotranspiration: An insight from climate, water, and vegetation change. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:150648. [PMID: 34619219 DOI: 10.1016/j.scitotenv.2021.150648] [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: 06/17/2021] [Revised: 09/14/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
Recently, unprecedented extreme drought has appeared around the world. As the most direct signal of drought, evapotranspiration deserves a more systematic and comprehensive study. Further depicting their divergence of potential (ETp) and actual evapotranspiration (ETa) will help to explore the limitation of evapotranspiration. In this paper, the multi-source remote sensing datasets from the Climate Research Unit (CRU), Gravity Recovery and Climate Experiment (GRACE) and its follow-on experiment (GRACE-FO), the Global Land Data Assimilation System (GLDAS), and the Moderate Resolution Imaging Spectroradiometer (MODIS) during 2002 to 2020 were employed to explore the influence of meteorological, hydrological and botanical factors on ETp, ETa and their divergence - reduction of evapotranspiration (Er) which represents regional vegetation and water limitations. According to the Pearson correlation analysis and the Boruta Algorithm based on Random Forest, the temperature is the first decisive promoter of evapotranspiration in the most area while the sparse vegetation is the primary or second determinant limiting the evapotranspiration in 61.84% of the world. In addition, the Coupled Model Intercomparison Project (CMIP6) data from 2030 to 2090 and the support vector machine regression (SVMR) model were applied to predict the future global ETp, ETa and Er on the pixel scale. Predicted results of the model considering the water change not only can highly improve the model performance (with higher R2), but also can simulate the drought in Europe and the more intense ETa in Africa. Thus, Er proposed in this study provide a good reference for regional ETa except for ETp. The future evapotranspiration value derived by introducing the water storage changes into the machine learning model in this study is also valuable for climate change adaptation and drought warning.
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Affiliation(s)
- Yuan Liu
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Qi Jiang
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Qianyang Wang
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Yongliang Jin
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Qimeng Yue
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Jingshan Yu
- College of Water Sciences, Beijing Normal University, Beijing 100875, China.
| | - Yuexin Zheng
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Weiwei Jiang
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Xiaolei Yao
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
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Zhao F, Wu Y, Ma S, Lei X, Liao W. Increased Water Use Efficiency in China and Its Drivers During 2000–2016. Ecosystems 2022. [DOI: 10.1007/s10021-021-00727-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Comprehensive Assessment of Performances of Long Time-Series LAI, FVC and GPP Products over Mountainous Areas: A Case Study in the Three-River Source Region, China. REMOTE SENSING 2021. [DOI: 10.3390/rs14010061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Vegetation biophysical products offer unique opportunities to examine long-term vegetation dynamics and land surface phenology (LSP). It is important to understand the time-series performances of various global biophysical products for global change research. However, few endeavors have been dedicated to assessing the performances of long-term change characteristics or LSP extraction derived from different satellite products, especially in mountainous areas with highly fragmented and rugged surfaces. In this paper, we assessed the time-series characteristics and LSP detections of Global LAnd Surface Satellite (GLASS) leaf area index (LAI), fractional vegetation cover (FVC), and gross primary production (GPP) products across the Three-River Source Region (TRSR). The performances of products’ temporal agreements and their statistical relationship as a function of topographic indices and heterogeneous pixels, respectively, were investigated through intercomparison among three products during the period 2000 to 2018. The results show that the phenological differences between FVC and two other products are beyond 10 days over more than 35% of the pixels in TRSR. The long-term trend of FVC diverges significantly from GPP and LAI for 13.96% of the total pixels, and the percentages of mismatched pixels between FVC and two other products are 33.24% in the correlation comparison. Moreover, good agreements are observed between GPP and LAI, both in terms of LSP and interannual variations. Finally, the LSP and long-term dynamics of the three products exhibit poor performances on heterogeneous surfaces and complex topographic areas, which reflects the potential impacts of environmental factors and algorithmic imperfections on the quality and performances of different products. Our study highlights the spatiotemporal disparities in detections of surface vegetation activity in mountainous areas by using different biophysical products. Future global change studies may require multiple high-quality satellite products with long-term stability as data support.
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Ecosystem Productivity and Evapotranspiration Are Tightly Coupled in Loblolly Pine (Pinus taeda L.) Plantations along the Coastal Plain of the Southeastern U.S. FORESTS 2021. [DOI: 10.3390/f12081123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Forest water use efficiency (WUE), the ratio of gross primary productivity (GPP) to evapotranspiration (ET), is an important variable to understand the coupling between water and carbon cycles, and to assess resource use, ecosystem resilience, and commodity production. Here, we determined WUE for managed loblolly pine plantations over the course of a rotation on the coastal plain of North Carolina in the eastern U.S. We found that the forest annual GPP, ET, and WUE increased until age ten, which stabilized thereafter. WUE varied annually (2–44%), being higher at young plantation (YP, 3.12 ± 1.20 g C kg−1 H2O d−1) compared to a mature plantation (MP, 2.92 ± 0.45 g C kg−1 H2O d−1), with no distinct seasonal patterns. Stand age was strongly correlated with ET (R2 = 0.71) and GPP (R2 = 0.64). ET and GPP were tightly coupled (R2 = 0.86). Radiation and air temperature significantly affected GPP and ET (R2 = 0.71 − R2 = 0.82) at a monthly scale, but not WUE. Drought affected WUE (R2 = 0.35) more than ET (R2 = 0.25) or GPP (R2 = 0.07). A drought enhanced GPP in MP (19%) and YP (11%), but reduced ET 7% and 19% in MP and YP, respectively, resulting in a higher WUE (27–32%). Minor seasonal and interannual variation in forest WUE of MP (age > 10) suggested that forest functioning became stable as stands matured. We conclude that carbon and water cycles in loblolly pine plantations are tightly coupled, with different characteristics in different ages and hydrologic regimes. A stable WUE suggests that the pine ecosystem productivity can be readily predicted from ET and vice versa. The tradeoffs between water and carbon cycling should be recognized in forest management to achieve multiple ecosystem services (i.e., water supply and carbon sequestration).
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