Response of climate and soil texture to net primary productivity and precipitation-use efficiency in the Tibetan Plateau

Precipitation-use efficiency (PUE) can be used as an indicator of ecosystem function. This study collected remote sensing data of net primary productivity and meteorological and soil texture data for the Tibetan Plateau for the period from 2000 to 2015. We used regression analysis, correlation analysis and structural equation modeling to characterize the relationships between productivity and precipitation across different soil texture types. NPP was positively correlated with precipitation, and precipitation (|r| = 0.71, P < 0.001) and temperature (|r| = 0.67, P < 0.001). PUE was positively correlated with precipitation (|r| = 0.4, P < 0.001) and temperature (|r| = 0.56, P < 0.001), but temperature had a larger effect on PUE than precipitation. Soil sand content and PUE were positively correlated (|r| = 0.41, P < 0.001), and soil clay content and PUE were negatively correlated (|r| = 0.35, P < 0.001). The results of the structural equation modelling showed that the influence of soil sand content on NPP and PUE was much greater than that of clay content. Therefore, precipitation is the main limiting factor affecting NPP, but the temperature is the main limiting factor affecting PUE. The soil clay content can inhibit the infiltration of precipitation, and improved the PUE of vegetation. We expect the findings of this study to draw attention to the influence of soil texture on PUE and provide scientific theoretical guidance for ecological restoration under different texture conditions.