Estimation and analysis of net primary productivity by integrating MODIS remote sensing data with a light use efficiency model

Estimates of regional net primary productivity (NPP) are very useful in modeling regional and global carbon cycles. This work proposed a new method to study NPP characteristics and changes in the Inner Mongolia Autonomous Region, China. To estimate NPP accurately, we integrated photosynthetically active radiation (PAR) with a light use efficiency model, derived from Moderate Resolution Imaging Spectroradiometer atmospheric and land products. Validation analyses showed that the PAR and NPP values simulated by the model matched observed data well. Annual NPP in the study area was about 0.25 PgC a−1 from 2003 to 2008. In spatial distribution, NPP decreased from northeast to southwest in the Inner Mongolia Autonomous Region. NPP from May to September accounted for 84.2% of annual NPP, while that from July to August accounted for 44.3%. NPP was significantly correlated to both precipitation and temperature at monthly temporal scales. NPP also changed with the fraction of absorbed PAR.