水保所知识产出(1956---)知识库

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 dy-
namics 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 be-
tween 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.