Spatiotemporal Variation of Vegetation Carbon Fixation Capabilities in Micangshang National Nature Reserve

Net primary productivity (NPP) is an important component of carbon cycle and regulating ecological processes in terrestrial ecosystems, which can directly reflect the vegetation carbon fixation capabilities. In order to discover the changes in the vegetation carbon fixation capabilities in Micangshan National Nature Reserve, the method of spatio-temporal fusion STARFM were selected to improve the spatial resolution of the data in the study area to 10 meters. Then, the improved CASA model was used to estimate the NPP in 2018, 2020 and 2021, and its spatial distribution, its time-varying characteristics were analyzed and compared with the variation of major climate factors. According to the results, the overall pattern of NPP in different years was relatively stable with little variation. The annual variability is significant, and the annual total amount of NPP is the highest in 2020, followed by 2021, and the lowest in 2018. The monthly variation was mainly controlled by temperature and radiation, and vegetation showed obvious physiological response to these two factors.