Fig. 1. Basic information for the study area. Panel (a) shows the grassland types on the NTP and sampling sites used in this study. Panel (b) shows the spatial distribution of precipitation amounts and Panel (c) shows the change trend of total precipitation during the growing season (GSP). Panel (d) shows the spatial distribution of average temperatures and Panel (e) shows the change trend of the average temperature during the growing season (GSMT).

Fig. 2. The correlations between the model simulation and field observations of aboveground biomass (AGB). (a) is for aboveground biomass of fenced grasslands (AGB_F) and (b) is for aboveground biomass of open grasslands under grazing (AGB_G)

Fig. 3. Inter-annual variations of aboveground biomass (AGB) in alpine grassland on the northern Tibetan Plateau. (a) is for aboveground biomass of fenced grasslands (AGB_F), (b) is for aboveground biomass at open grasslands under grazing (AGB_G), and (c) is for human-induced aboveground biomass (AGB_H).

Fig. 4. Spatial distribution and change trends for aboveground biomass from 2000 and 2016 on the northern Tibetan Plateau. (a), (c) and (e) show the spatial distribution of aboveground biomass for fenced grasslands (AGB_F), for open grasslands under grazing (AGB_G) and for human-induced aboveground biomass (AGB_H), respectively. (b), (d) and (f) show the change trends for aboveground biomass for fenced grasslands (AGB_F), for open grasslands under grazing (AGB_G) and for human-induced aboveground biomass (AGB_H), respectively.

Fig. 5. Inter-annual variations of carrying capacity of alpine grasslands on the northern Tibetan Plateau.

Fig. 6. The carrying capacity of alpine grasslands from 2000 and 2016 for each county of the northern Tibetan Plateau

Fig. 7. Inter-annual variations of the grazing pressure index on the northern Tibetan Plateau. (a) shows the grazing pressure index obtained by the statical method and (b) shows the grazing pressure index obtained by the dynamic method.

Fig. 8. The grazing pressure index in each county of the northern Tibetan Plateau between 2000 and 2016. (a) shows the grazing pressure index obtained by the statical method and (b) shows the grazing pressure index obtained by the dynamic method.