Strong positive direct impact of soil moisture on the growth of central asian grasslands

• Published in: The Science of the total environment Vol. 954; p. 176663
• Main Authors: Liu, Liang, Zheng, Jianghua, Guan, Jingyun, Li, Congren, Ma, Lisha, Liu, Yujia, Han, Wanqiang
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2024
• Subjects: biomass production; Central Asia; climate change; Climate factors; climatic zones; Cumulative and time-lagged effects; Dominant factors; environment; fractional vegetation cover; Grassland indices; grasslands; Impact pathways; leaf area index; net primary productivity; path analysis; regression analysis; soil water; vapor pressure deficit; water content; Central Asia; Cumulative and time-lagged effects; Grassland indices; Dominant factors; Climate factors; Impact pathways
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.176663

As the issue of global climate change becomes increasingly prominent, the grassland ecosystems in Central Asia are facing severe challenges posed by the impacts of climate change. However, the dominant factors, impact pathways, and cumulative and time-lagged effects of climate factors on various grassland indices remain to be explored. This study selected data from 1988 to 2019, including Fractional Vegetation Cover (FVC), Leaf Area Index (LAI), Net Primary Productivity (NPP), and Vegetation Optical Depth (VOD), to characterize grassland coverage, greenness, biomass accumulation, and water content features. Utilizing multiple linear regression, path analysis, and correlation analysis, this study investigated the dominant effects, direct impacts, indirect influences, and cumulative and time-lagged effects of climate factors on various grassland indices from spatial and climatic zone perspectives. The research findings indicate that over time, the grassland FVC and NPP exhibited increasing trends, while the LAI and VOD showed decreasing trends. Grassland indices are primarily influenced by precipitation and soil moisture (SM). The direct impact of SM on grassland indices was higher than precipitation. Vapour pressure deficit (VPD) has a direct negative impact on grassland indices. Grassland indices are subject to positive indirect effects from precipitation via SM and negative indirect effects from VPD via SM. Precipitation and SM mainly exhibited no cumulative and time-lagged effects on the impact of grassland VOD. VPD primarily demonstrated cumulative and time-lagged effects on grassland indices. The research findings offer valuable insights for conserving grassland ecosystems in Central Asia, as well as for shaping socioeconomic strategies and formulating climate policies. [Display omitted] •Responses of multiple grassland indices to climate factors were studied.•Path analysis explored the mechanisms of climate factors' impact on grassland.•Strong positive direct impact of soil moisture on grassland indices.•Direct impact of soil moisture on grassland indices was higher than precipitation.•Negative direct impact of VPD (Vapour pressure deficit) on grassland indices.