Spatial Analysis on the Fluctuation of Regional NPP in the Typical Steppe, in China

Assessing the inter-annual variation of regional grassland productivity is imperative to meet the local requirements of grassland adaptive management at regional- or landscape- scale. For the semiarid grassland of Inner Mongolia, the improved CASA model, a kind of light-energy-efficiency model, was used to simulate the Net Primary Productivity (NPP) of the regional grassland. And this study further calculated the Standard Deviation (SD) and Coefficient of Variation (CV) of the regional NPP. Both of SD and CV were used to reflect the fluctuations of regional NPP in the study area among years. Approximately 1/3 of the regional NPP over the years were dramatically changed, frequently up to large amplitude by an average rate of 1 times or more.