Widespread Increasing Ecosystem Water Limitation During the Past Three Decades in the Yellow River Basin, China. Issue 2 (30th January 2023)

• Record Type: Journal Article
• Authors: Zhao, Fubo; Wang, Xi; Ma, Shuai; Wu, Yiping; Qiu, Linjing; Sun, Pengcheng; Li, Qiang
• Is Part Of: Journal of geophysical research. Volume 128:Issue 2(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-30
• Subjects: atmospheric CO2 -- climate change -- vegetation -- water limitation -- Yellow River Basin; Geobiology -- Periodicals; Biogeochemistry -- Periodicals; Biotic communities -- Periodicals; Geophysics -- Periodicals; 577.14
• DOI: 10.1029/2022JG007140
• Languages: English
• ISSNs: 2169-8953

Abstract

Abstract: Terrestrial ecosystems provide crucial ecosystem services to human beings, and their functions are largely dependent on soil moisture availability. Although many studies have evaluated the effects of vegetation and climate changes on soil moisture at the ecosystem scale, changes in ecosystem water limitation remain poorly understood. This study evaluated the spatiotemporal changes of ecosystem water limitation in the Yellow River Basin (YRB)—the second largest river basin of China—during 1982–2016 and identified the major drivers by establishing ecosystem limitation index (ELI) using soil moisture, transpiration, net radiation, and air temperature. The results show a significant and widespread spatiotemporal increase in the water limitation of ecosystems in YRB during the 35‐year study period. Temporally, areas with positive ELI (water‐limited regime) exhibited a significant upward trend ( p < 0.01). Spatially, above 75.0% of the total areas showed an upward trend in ELI. Almost all ecosystems showed significant upward trends in water limitation over this period. Further analysis using two different but comparable methods, partial correlation and Lindeman‐Merenda‐Gold, show that vegetation change was the major driver of changes in water limitation, with contributions of more than 35.0%. Air temperature and atmospheric CO2 changes contributed comparably to changes in positive ELI, followed by precipitation changes. These findings improve the understanding of the spatiotemporal pattern and underlying mechanisms of ecosystem water limitation in the greening and warming YRB. Plain Language Summary: Functions of terrestrial ecosystems are largely dependent on soil moisture availability. Plenty of past studies have been conducted to investigate the vegetation and climate effects on soil moisture. However, the ecosystem water limitation and its spatiotemporal changes are rarely explored. We used a correlation difference as the ecosystem limitation index (ELI) to investigate the ecosystem water limitation over the Yellow River Basin (YRB)—the second largest river basin of China during 1982–2016. We found a significant and widespread increase in the water limitation of all ecosystems in YRB during the 35‐year study period. In total, above 75.0% of the total areas showed an upward trend in ELI (increasing water limitation). We used two different methods to attribute ELI and found that vegetation change was the major driver of changes in water limitation, with contributions of above 35.0%. Air temperature and atmospheric CO2 changes contributed comparably to ELI, followed by precipitation changes. The findings highlight the key role of vegetation in ecosystem water limitations in the greening and warming YRB. Key Points: Widespread increasing ecosystem water limitation was found in Yellow River Basin during 1982–2016 All ecosystem types showed significant increasing water limitation regimes Vegetation was found to be the major driver of the increased ecosystem water limitation