基于生态服务价值评价的局地土地利用格局厘定

量化土地利用生态效益有利于土地利用效益间的直接比较，更重要的是基于此厘定土地利用格局为局地土地可持续利用创造了条件。该研究以重庆市沙坪坝区为研究区，采用土地利用现状数据库，运用生态服务价值系数，分析其生态服务价值的时空变化及其分布，厘定土地利用格局。结果表明，在1996～2006年间生态服务价值从＄1.50×107降 低到＄1.40×107，净损失＄1.00×106，平均每公顷土地净损失生态服务价值＄25.54；采用Costanza等人赋予耕地、林地和园地的生物量生态服务价值系数总和接近于区域真实值，但水域相差甚远，调整30%达5667＄/hm2·a更接近于真实值；研究区基于生态效益变化的土地利用表现为4种类型：稳定区，主要集中于井口镇与回龙坝镇两镇；先降后升区，主要集中于覃家岗镇和虎溪镇；敏感区，主要集中于陈家桥镇、曾家镇和土主镇；持续增长区，主要集中于歌乐山镇和中梁镇。

Redefinition of land-use patterns at local level based on evaluation of ecological service value

Quantizing ecological benefits of land use is favorable for comparing directly with the land use benefits. Based on the quantitative ecological benefits, redefinition of land-use patterns at local level can provide a good condition for land sustainable utilization. Therefore, taking Shapingba district in Chongqing as an example, adopting land-use situation database, using coefficients of ecological service value, the temporal-spatial changes of ecological service value were analyzed, and the spatial distribution of ecological service value was analyzed, the future patterns of land use were redefined. The results indicated that the ecological service value reduced from $1.50 million to $1.40 million, the net loss reached $ 0.10 million in the study region from 1996 to 2006. Accordingly, each hectare land suffered an average loss of $25.54 in the Shapingba district, Chongqing. The coefficient values for cultivated land, garden land, woodland raised by Costanza et al. were close to regional actual values. However, the coefficient values for water land were far away from the coefficient values of the lake/river (8498$/hm2·a). By rectifying 30 percent of the previous coefficient by 5667$/hm2·a, it was very close to the actual one. According to the spatial distribution of ecological service value and its changes, the future pattern of land use had four trends as follows: the stable zone, mainly in Jingkou town and Huilongba town; the descend-to-rise zone, mainly in Qinjiagang town and Huxi town; the sensitive zone, mainly in Chenjiaqiao town, Zengjia town and Tuzhu town; the sustainably-increased zone, mainly in Geleshan town and Zhongliang town.