中文摘要：

利用250m的MODIS—NDVI月值数据，通过适当改进CASA模型和野外生物量采样调整最大光能利用率参数，结合1980S、2000年、2005年和2007年四期土地利用数据，模拟太湖流域2000年-2007年净初级生产力（NPP）时空变化。研究表明：太湖流域NPP从2000年的16．4TgC减少到2007年的14．2TgC，减少2．2TgC，相当于燃烧140×10^4t标准煤释放的CO2；空间分布上，流域内除长兴和德清NPP呈增长趋势外，其他县市NPP都呈减少趋势，主要集中在太湖流域北部与东部快速城市化扩展区域；城市化快速扩展是影响太湖流域NPP减少的主导因素．土地整理和油菜／小麦种植比例下降有助于增加流域NPP；退耕还林短期内降低了相应区域的NPP，但长期趋势有助于增加流域NPP，而渔业养殖发展和耕地复种指数下降减少流域NPP。

英文摘要：

Net primary productivity （NPP） is a key component of the terrestrial carbon cycle, which reflects not only the productivity of a community of vegetation in its natural environment but also its carbon sequestration ability. This study examined spatial and temporal changes in NPP during the period 2000-2007 in the Tanhu basin, China＇s vital economic core area, which is helpful for formulating sustainable development policy and low-carbon economy development in the Taihu basin. NPP was estimated with the Carnegie Ames Stanford Approach （CASA） terrestrial carbon model combined with a major modification. The relationships between Fractional Photosynthetically Active Radiation （FPAR） and Normalized Difference Vegetation Index （NDVI） values for different vegetation types from the lookup table of NDVI-FPAR in the Moderate-resolution Imaging Spectroradiometer product （MOD15） were utilized to replace the original algorithm of FPAR in the CASA model. The regional moisture stress coefficient was estimated by monthly meteorological data and a regional evapotranspiration model. Due to small areas for forest and grassland in the Taihu basin, the maximal light use efficiency values for different forest types and grassland were specified as the average values of typical vegetation types in China, whilst the value for cropland was derived with field samples and least square functions. Historic datasets included 250 m 16-day MODIS-NDVI （MOD13） data of Feb 2000-Jan 2001, 2007, and Jun 2010-Oct 2010, land use in 2000 and 2007, land cover in the 1980s and 2005, and monthly meteorological data （including precipitation, mean temperature, and total solar radiation） from 2000 to 2010 obtained from the National Meteorological Center （NMC） of China. Results show that total NPP in the Taihu basin decreased by 2.2 TgC from 16.4 TgC in 2000 to 14.2TgC in 2007. The reduction in NPP was equivalent to the amount of CO2 emissions from 1.4＇06 tons of standard coal burning, accounting for 11.2% of the total CO2 em