Spatiotemporal Association and Attribution Analysis of Vegetation and Drought in the Yangtze River Basin
Global climate change and human activities have led to continued increases in the frequency and inten-sity of droughts.Recently,drought has become a key factor that affects vegetation growth and diversity,which further impacts agricultural production,ecosystem stability,and socioeconomic development.Therefore,mas-tering the relationship between vegetation dynamics and drought will help to reveal the physiological mechanism of terrestrial ecosystems and formulate effective management strategies.Here,we used long-term datasets of(2001～2020)Solar-Induced chlorophyll Fluorescence(SIF)and Normalized Difference Vegetation Index(NDVI)to explore vegetation changes and their linkage to meteorological drought(SPEI index)across differ-ent vegetation types in the Yangtze River Basin(YRB).Firstly,the correlation analysis method was applied to obtain the maximum correlation coefficient between SPEI and SIF(NDVI),and the differences of SIF and NDVI responses to meteorological drought of different vegetation types were compared and analyzed.Then we employed an improved partial wavelet coherence method to quantitatively analyze the influence of large-scale cli-mate models and solar activity on the interaction between vegetation response to meteorological drought.The re-sults show that:(1)from 2001 to 2020,the YRB experienced frequent droughts,with summer dryness and wetness exerting the significant impact on its annual climate;(2)SPEI exhibits a greater association with SIF than NDVI does.(3)NDVI has a longer response time(3～6 months)to drought than SIF(1～4 months),with cropland and grassland displaying shorter response times and evergreen broadleaf and mixed forests show-ing longer response times.(4)There is a significant positive correlation between drought and vegetation,with a period of 4～16 months.The teleconnection factors of Pacific Decadal Oscillation(PDO),El Niño Southern Oscillation(ENSO),and sunspots are crucial drivers in establishing the interaction between drought and vege-tation,with sunspots having the most significant impact.Overall,this study indicates that drought is an essen-tial environmental stressor in disturbing vegetation growth over the YRB.Additionally,SIF has great potential and advantages in monitoring drought and vegetation responses.These findings have reference significance for drought prediction,early warning,and ecosystem protection planning in the YRB.
Climate changeMeteorological droughtVegetation dynamicsSIFNDVIYangtze River Basin
万方数据
维普
