Net Primary Productivity Distribution in China from a Process Model Driven by Remote Sensing

This paper aims to simulate China's terrestrial NPP using a carbon-water coupled process model based on remote sensing, and explore tempo-spatial patterns of China's terrestrial NPP and the mechanisms of its responses to various environmental factors. For these purposes, a national wide input database and a validation database have been set up on a 1 day-1 km tempo-spatial resolution, and the BEPS model has been improved and applied. Using these databases and BEPS model, Maps of NPP for the entire China's landmass in 2001 have been produced: China's terrestrial total NPP and mean NPP were 2.235GtC and ${\bf 235.2 gC\bullet m^{2}\bullet yr}$; and gross primary productivity (GPP), total GPP and mean GPP were 4.418GtC and ${\bf 465 gC\bullet m^{2}\bullet yr}$; autotrophic respiration (RA) have been estimated; total RA and mean RA were 2.227GtC and ${\bf 234 gC\bullet m^{2}\bullet yr}$; On average, NPP was 50.6% of GPP. In addition, the responses of NPP to changes in some key factors in 2001 have been analyzed.