Analysis On Potential Change And Impact Of Human Activities In Vegetation NPP In Ili River Basin From 2000 To 2017

The dynamic change of terrestrial ecosystem is not only an important content of scientific research,but also the scholars of different fields pay close attention to it.The carbon cycle runs through the whole process of material cycle and energy flow in terrestrial ecosystems,which determines the importance and complexity of carbon cycle simulation in ecosystems.The integrated biosphere model(IBIS),as a process model of highly complex,includes land surface process,vegetation phenology,vegetation canopy physiological process,carbon balance and vegetation dynamic process and terrestrial biochemical cycle process.Which is able to simulate the dynamic changes of terrestrial ecosystems in an all-round way.Based on the IBIS model,this paper completed the regionalization for vegetation type,vegetation function type and vegetation physiological parameters.The improved IBIS model was used to simulate the potential change of vegetation NPP in the Ili River Basin,and the differences between potential NPP and the monitoring NPP ware analyzed.The results show that:(1)Through regionalization of the vegetation type,the vegetation function type and the verification of GLO-PEM NPP data for simulation results,the results of IBIS simulation can meet the accuracy requirements of regional vegetation NPP potential change analysis(R~2=0.73,P<0.01),and can reflect the potential change trend of vegetation NPP in the Ili River Basin.(2)The change trend of potential NPP in the Ili River Basin from2000 to 2017 was consistent with the monitored NPP.However,due to the influence of human activities,the vegetation NPP was better than the natural state in the basin area,the vegetation NPP was worse than the natural state in the mountainous region.(3)cultivated land and construction land directly impact the surface shape of land,where vegetation is better than natural state.And the trend of vegetation improvement continues to increased in cultivated land,but the trend of vegetation improvement decreased in construction land.Grazing activities had a negative impact on the regional vegetation status,and with the continuous increase of the regional livestock load,the local vegetation status continued to deteriorate.The construction of protected areas and the implementation of forest closure measures can greatly improve the environment and have a positive impact on the regional vegetation NPP.