Determining the dominant factors determining the variability of terrestrial ecosystem productivity in China during the last two decades

摘要

Terrestrial ecosystem productivity (TEP) is an important component of ecological services. The variability of the TEP is driven by multiple factors, both natural and anthropogenic. However, little is known about the dominant factor driving the TEP change at the pixel level, which may hinder ecosystem management particularly in face of global climate changes. In this study, a 22-year-long dataset including climate, net primary production (NPP), and human activity was obtained to identify, at a pixel level, the dominant factors of NPP variation in China from 1992 to 2013. The results showed that: (a) the total NPP of China varied from 3.37 to 4.55 PgC/yr and continued to increase with a larger proportion being contributed from eastern China, (b) radiation is the greatest contributor to the NPP variation in China, followed by temperature and precipitation, (c) human activity-driven pixels are relatively dispersed, and are mainly located in the rural-urban fringe zones, and (d) a total of five subregions are identified, of which Regions I and II require more attention with regard to future NPP evolution. The results of this study are important at the policy level for future management of China's ecosystems.