Temporal And Spatial Dynamics Of Grassland Climatic Productivity In Xilinguole From 2000 To 2014

The climate change has exerted a far-reaching influence on the global ecosystem including the grassland ecosystem which is a significant terrestrial ecosystem. For the sake of exploring the specific affect from climate change to grassland ecosystem, here, we introduce a relevant concept:grassland climatic productivity which represents the most productivity determined by the climatic conditions. As the important indicator for judging the grassland ecosystem’s sustainable development, grassland productivity is compared with the climatic productivity in order to find out the influence on grassland ecosystem from climate change and to provide the scientific guidance for managing and utilizing the grass resources.Based on the remote sensing data:MOD17A3 and meteorological grid date, we achieved the annual NPP from MOD 17A3, the annual temperature and precipitation from meteorological grid date in ENVI software. Grassland climatic productivities of various grasslands have been calculated by the Thornthwaite Memorial model. Analyses of the temporal-spatial dynamic characteristics of climatic factor, NPP and grassland climatic potential productivity have been studied by the trend analysis method and anomaly analysis method while correlation analysis between the climatic factors and the climatic potential productivity has also been carried out. The final conclusions are given:(1) The rising trend of temperature in Xinlinguole grassland is demonstrated including all grasslands, in 2000-2014;(2) The downward trend of precipitation in Xinlinguole grassland is demonstrated including all cover types, in 2000-2014, while a significantly positive correlation between the precipitation and grassland climatic potential productivity is showed;(3) The downward trend of grassland climatic potential productivity in Xinlinguole grassland is demonstrated in 2000-2014, and the similar undulation pattern between the precipitation and grassland climatic potential productivity is showed;(4) The downward trend of NPP in Xinlinguole grassland is demonstrated including all cover types, in 2000-2014. The positive correlation is performed between grassland climatic potential productivity and NPP in most regions and the negative correlation exists in a few regions where the greater interference of human beings to ecosystem instead of the climate change is exerted;The change of precipitation is on intimate with grassland climatic potential productivity variation so the more attentions to precipitation variation need to be paid in order to study the trend of grassland productivity in Xinlinguole.In the paper, we studied the climatic potential productivity and net primary productivity based on the different grassland and combines the two productivities which are different from the previous.