Divergent impacts of droughts on vegetation phenology and productivity in the Yungui Plateau, southwest China

Wenyan Ge; Jianqiao Han; Daojun Zhang; Fei Wang

Ecological Indicators (Aug 2021)

Divergent impacts of droughts on vegetation phenology and productivity in the Yungui Plateau, southwest China

Wenyan Ge,
Jianqiao Han,
Daojun Zhang,
Fei Wang

Affiliations

Wenyan Ge: Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, Shaanxi Province, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources, Yangling 712100, Shaanxi Province, China
Jianqiao Han: Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, Shaanxi Province, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources, Yangling 712100, Shaanxi Province, China
Daojun Zhang: College of Economics and Management, Northwest A&F University, Yangling 712100, Shaanxi Province, China
Fei Wang: Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, Shaanxi Province, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources, Yangling 712100, Shaanxi Province, China; Corresponding author.

Journal volume & issue: Vol. 127
p. 107743

Abstract

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Climate change has led to an increase in the severity and frequency of extreme weather events, especially droughts. Quantifying the impacts of droughts on vegetation activities is essential to study the effects of climate change on the ecosystem. Using Gross Primary Productivity (GPP), phenological metrics, and Standardized precipitation evaporation index (SPEI) with multi-timescales, we evaluated the divergent responses of vegetation activities to droughts in the Yungui Plateau from 2001 to 2017. Besides, the sensitivity of vegetation to drought was analyzed by the maximum correlation coefficients between vegetation activities and SPEI over the plateau. Results revealed that the overall changes of the start (SOS) and end (EOS) of growing season in the plateau exhibited nonsignificant changes during the study period. Meanwhile, two extreme droughts of the study period caused a tremendous decrease in GPP and severe delays in SOS and EOS. Vegetation activities increased significantly in the eastern plateau because of the strong drought resistance of vegetation. Conversely, the dynamics of vegetation activities, especially phenological metrics, were nonsignificant in the west due to the weak drought resistance of vegetation. Preseason droughts of spring phenology played a key role in determining SOS dynamics. Besides, drought before summer contributed to the delay of EOS, while summer drought leads to early EOS. Hence, preseason droughts of autumn phenology nonlinearly impacted EOS due to strong interaction between SOS and EOS. More importantly, the stronger influences of SOS on annual GPP compared to EOS suggest that preseason droughts of SOS are essential to the vegetation productivity in the plateau. Given that the continuous warming of the climate will lead to more frequent droughts, it is essential to investigate the resilience of vegetation growth to drought in future work.

Published in Ecological Indicators

ISSN: 1470-160X (Print); 1872-7034 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Science: Biology (General): Ecology
Website: https://www.sciencedirect.com/journal/ecological-indicators

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