土地利用与覆盖变化对中小城市净初级生产力的影响

为了探索研究当前城市化进程中，土地利用与覆盖变化对中小城市净初级生产力的影响，以张家港为研究区域，利用MODIS遥感影像数据和NPP相关模型，分别估算2008年的实际和潜在的净初级生产力（NPPact和NPPo），研究土地利用覆盖变化造成NPP损失(NPPlucc)的空间分布。结果表明，在张家港的城市化进程中，由于土地利用和覆盖方式的改变损失了大量的NPP，城市区域年净初级生产量以较大幅度减少；林草生态系统的NPPlucc较低，农业用地由于灌溉、施肥、田间管理等，导致其具有比潜在NPP更高的生产力，在所有用地类型中NPPlucc最低。张家港市的NPPlucc在城乡梯度上的变化呈现出从城市中心到农村纵深地区逐渐下降的趋势，其中在城乡结合部位、在农村工业区有2个上升的峰状突起。研究认为，可通过政策管理措施和工程技术手段，改善对自然生态系统的干扰，进而减少由于土地利用/覆盖变化和人类活动对周边植被干扰造成的NPP损失，是降低人类社会对净初级生产力的占用(HANPP)的可行途径，也是解决人们广泛关注的生物资源耗竭性问题与可持续发展问题的有效手段。

The Influence of Land Use and Cover Change on Net Primary Productivity of Middle-sized and Small Cities

In order to explore and research the influence of land use and cover change(LUCC) on net primary productivity of middle-sized and small cities during urbanization process,taking Zhangjiagang City as the study area,the author applied the MODIS image data and models related to net primary productivity(NPP) to estimate the act and potential NPP in 2008 and studied the characteristics of spatial distribution of the losing NPP caused by LUCC.The results showed that,in urbanization,because of the LUCC of Zhangjiagang City,it lost a lot of NPP,the NPP in city area decreased sharply,the value of NPPluccin forest and grassland relatively low,and which of agro-ecosystems was minimum for irrigation and fertilization,so had a higher production than potential NPP.The NPPlucc in Zhangjiagang appeared to have a decline trend from city to rural areas,there had two protuberance peaks on the urban and rural connecting areas and industrial regions in countryside.The results also showed that,the disturbance to natural ecosystem was decreased by applying management measures and technology ways,then the loss of NPP caused by LUCC and human activities was minimized.It took a feasible way to decrease human appropriation of net primary production(HANPP) and resolve existing problems in related to natural resource exhausted and sustainable development.