Spatial and Temporal Variation Pattern of Vegetation NPP in Guangxi Based on GIS

NPP is an extremely important ecological vegetation index and an indicator for evaluating the healthy development and sustainable use of vegetation ecosystems. [...]the spatial and temporal variation pattern of vegetation NPP is a hot spot in the present ecology studies. [...]in ArcGISlO. 2 software, using the vector files of Guangxi Zhuang Autonomous Region, we cut the NPP data of the study area. 2.2 Unary linear regression method Through studying the variations of vegetation NPP in Guangxi, we can know which regions have NPP increase, which regions have NPP decline, so as to find out the variation trend of ecosystems in the study area. According to the study of Tian Yichao et al. 1101 , in the ArcGIS10.2, we used natural breakpoint method to divide NPP fluctuations into five grades, namely, large fluctuation, larger fluctuation, small fluctuation, smaller fluctuation, and general fluctuation. 77 - 803.97 gC/m2 a, with Beihai being the lowest (498.77 gC/m2 a) and Wuzhou being the highest (803.97 gC/m2 - a). Besides , the fluctuations of vegetable NPP are mainly small fluctuations and the area of grades of NPP fluctuation is different from each other; the vegetation NPP fluctuations of Guangxi are mainly distributed in Wuzhou, Fangchenggang, and Hezhou; regions with larger NPP fluctuations are mainly distributed in Baise and Chongzuo; regions with general NPP fluctuations are mainly distributed in Hechi and Guilin; regions with small NPP fluctuations are mainly distributed in Guigang, Beihai, and Yulin, showing significant spatial distribution differences of NPP fluctuations.