## 5 Conclusions  
We studied changes in ecosystem WUE caused by drought to improve our understanding of ecosystem resistance under drought conditions. This study suggests that remote sensing data products and open-source data can be used to monitor the resistance and resilience of ecosystems in response to drought. Our analysis establishes a framework to use these sources of information to understand differences in ecosystem responses to drought at large spatial scales. The difference between an extreme weather event WUE and a normal year WUE can indicate the expected resistance of an ecosystem in response to climate. \(\Delta\)WUE is an important indicator of the fragility of an ecosystem. The availability of resources leads to changes in the structure and functional landscape of the entire ecosystem. Over the period of 113 years, the average SPEI was 0.073, the extremely wet threshold was 0.91, and the extreme drought threshold was \(-\)0.67. Central Asia experienced extremely wet events in 2002 and 2003 and a drought in 2008. Sufficient wetness can increase ecosystem resistance, whereas continuous wetness reduces ecosystem resistance; drought also reduces ecosystem resistance. After a wet event, the wet area had stronger resilience than the arid area, whereas, after a drought event, the arid area had stronger resilience than the wet area. In the wet and dry years, conversion between shrubland grassland was the main reason for the changes in ecosystem resistance and resilience. Previous literature concerning ecosystem responses to climate change has mostly been conducted over a one-year period, we analyzed the change process of ecosystems during climate events for two consecutive years, and we comprehensively analyzed the changes in the structural and functional stability of ecosystems. These findings are important for understanding the impacts of climate change on ecosystem stability. In future studies, we will focus on the time lag/cumulative effects of climate events to determine precisely the time at which an ecosystem begins to experience drought or wetness.  
[PERSON] and [PERSON] conceived and designed this study, [PERSON] carried out the analyses and wrote the paper; [PERSON] contributed to the discussion and manuscript refinement. [PERSON] made important contributions to the figures. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the National Natural Science Foundation of China (Nos. 32260287 and 41961059), the Doctoral Research Start-up Fund Project of Xinjiang University (No. 620320025), and the Sino-German interdisciplinary joint program for innovative talent training funded by the China Scholarship Council (CSC, No. 201807015008).  
Data Availability Statement: The gross primary productivity (GPP) and evapotranspiration (ET) and land cover type climate modeling grid (CMG) product (MCD12C1) data were downloaded from [[http://www.ntsg.umt.edu](http://www.ntsg.umt.edu)]([http://www.ntsg.umt.edu](http://www.ntsg.umt.edu)) (accessed on 30 May 2018); the Global SPEI database were downloaded from [[https://spei.csic.es/](https://spei.csic.es/)]([https://spei.csic.es/](https://spei.csic.es/)) (accessed on 15 June 2019).