Study on Human Appropriation of Net Primary Productivity in Tibet grassland
Human appropriation of net primary productivity(HANPP)is an important indicator for assessing ecological sustainability.However,we have no clear understanding of the HANPP in Tibet grassland to date.Based on the Biome-BGCMuSo model,this study simulated and analyzed the spatiotemporal dynamics of grassland HANPP in Tibet from 1979 to 2018.From 1979 to 2018,the annual average HANPP in Tibet grassland was 13.72 gC/m2,and showed a fluctuating increasing trend.Most grassland areas in Tibet had a HANPP of 0-20 gC/m2,and high values were mainly distributed in parts of southern Tibet.From 1979 to 2018,the annual average value of human occupied net primary productivity efficiency(HANPP efficiency)in Tibet grassland was 90.55%,and it showed a fluctuating downward trend after 2000.From 1979 to 2018,the annual average HANPP efficiency of most grassland areas in Tibet was between 80%and 100%.This study deepened the understanding of the grassland HANPP in Tibet,and provided theoretical guidance and data support for the sustainable use of the local grassland.