Abstract
Anthropogenic activities and climate change affect the type, structure and function of ecosystems, resulting in important changes in vegetation net primary productivity (NPP). Therefore, in this study we used the vegetation photosynthesis model (VPM) to reveal the spatiotemporal variations in NPP in Xinjiang from 2000 to 2019. The impacts of climate change and anthropogenic activities on NPP changes were quantified and separated by the residual analysis-control variables (RES-CON) method. The results showed that the average NPP in Xinjiang increased by 17.77% from 2000 to 2019. Anthropogenic activities and climate change generally had a positive impact on NPP from 2000 to 2019. The most important anthropogenic activity was land use and land cover (LULC) transformation from grass to arable land, which significantly increased vegetation productivity. Regarding climate change, precipitation has played a significant role in promoting the productivity of vegetation. Overall, the average contribution of climate change (temperature and precipitation) to NPP variation (21.44%) is much greater than the contribution of anthropogenic activities (3.46%), but in areas where anthropogenic activities occur, the average contribution of anthropogenic activities to NPP variation (75.01%) is much greater than the average contribution of climate change (15.53%). Where there are no anthropogenic activities, the average contribution of climate change to NPP variation is 21.72%. In summary, anthropogenic activities are the main driver of NPP variation in areas where anthropogenic activities occur, while the total area in Xinjiang where climate change is the most important driver is larger than the total area where anthropogenic activities are the dominant driver.
Highlights
Xinjiang has a typical temperate continental arid climate, and the ecological environment is fragile
In estimating the Net primary productivity (NPP) of terrestrial ecosystems, the vegetation photosynthesis model (VPM) considers dividing vegetation leaves and crowns based on the concepts of nonchlorophyll and chlorophyll parts, and the effective radiation ratio of vegetation absorption photosynthesis is divided into nonphotosynthetic vegetation absorption (FPARnpv ) and chlorophyll absorption (FPARchl ); only the photosynthetically active radiation (PAR) absorbed by FPARCchl is used for photosynthesis [35,36]
Our research showed that the quantitative representation of the effects of climate change and anthropogenic activities on the NPP variation based on the residual analysis-control variables (RES-CON) method was reasonable
Summary
Xinjiang has a typical temperate continental arid climate, and the ecological environment is fragile. With natural environmental change and anthropogenic activities (e.g., ecological engineering and construction, urban expansion and other influential processes), vegetation dynamics have become increasingly complex [1]. Net primary productivity (NPP) refers to the total amount of organic dry matter accumulated by vegetation per unit time and area, including the production of plant branches, leaves and roots and dead plant matter [2]. NPP can reflect ecosystem productivity on a uniform scale [1] and is a good indicator of the productivity of vegetation. NPP is a critical component of the global carbon cycle, with significant implications for the global carbon balance [3,4]. Temporal changes in NPP are affected by the complex interactions among temperature, precipitation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
