Dynamic Monitoring of Vegetation NPP in Wuhan Based on MODIS

The net primary production (NPP) model was improved by developing and comparing different regional photosynthetically active radiation (PAR) models, studying the relationships between fraction of PAR and NDVI and EVI, and considering the difference in maximum light use efficiencies for different vegetation types. The seasonal and interannual variation patterns of vegetation NPP in Wuhan was studied with MODIS data and climatic materials. It is indicated that NPP changed greatly with seasons, high in summer, then the spring and autumn, low in winter, and the highest NPP value appeared in Mid July with about 85gCm 2month 1. There was an increasing trend in annual NPP from 2001 to 2011 for all kinds of vegetation, and the maximum value was observed in 2008 with 562gCm 2a 1. It was also found that NPP values of different vegetation types varied greatly at the same study period, evergreen broadleaf vegetation showed the highest annual NPP value, and the annual broadleaf vegetation displayed the smallest value due to the difference in light use efficiencies.