Spatiotemporal Characteristics and Influencing Factors of Vegetation NEP in Qinghai Province from 2000 to 2020

Abstract

In the context of global climate change and "carbon neutrality", it is important to study the detection of vegetation carbon sources/sinks and their influencing factors in Qinghai Province. Based on the improved CASA model and soil respiration model, the spatial and temporal distribution patterns and changes of NEP were analyzed using MODIS products from 2000 to 2020, combining topographic data, meteorological data and land use data, and exploring the contribution of each driver, in order to reveal the spatial and temporal characteristics of vegetation NEP in Qinghai. The results showed that: 1. The results show that: 1. from 2000 to 2020, the interannual fluctuation of vegetation NEP in Qinghai Province is obvious, showing an increasing trend, and its carbon sink capacity is increasing. 2. the spatial NEP of vegetation in Qinghai Province is high in the southeast and low in the northwest, gradually increasing from the northwest to the southeast. 3. the NEP of vegetation in Qinghai Province increases with slope and elevation, showing an increasing trend and then decreasing. The influence of slope direction on vegetation NEP was not significant. The correlation and partial correlation analyses between vegetation NEP and climatic factors showed that both temperature and precipitation mainly promoted vegetation NEP, and the coupling effect was more obvious.4. The influence of driving factors on vegetation NEP in Qinghai Province had the highest average annual precipitation, and the interaction effect was mainly enhanced by two factors.