Abstract:

The calculated area for cropland by Wackernagel's method does not consider the influence of cropping index. For this reason, the production in certain country or region is achieved by annual multiple cropping, and in some areas there is an abandon of cropland. The result of calculated land by this method in ecological footprint is the area of planting of crop but not of the cropland. From this view, Wackernagel's method enlarges or dwindles the ecological footprint what human need in fact. So, footprint of cropland is not in accordance with biocapacity of cropland, for the area of cropland in biocapacity is not planting. There is a logic error of ecological remainder / deficit for the identical problem of footprint and biocapacity. The paper improved the method of ecological footprint by regulated cropland area with cropping index. The result is the area of cropland that human needed, but not of cropping. Ecological supply/demand and development ability in Funing County of Jiangsu Province from 1995 to 2003 were analyzed with the improved method of ecological footprint. It is suggested that ecological remainder/ 10 000 yuan GDP as the indicator of regional sustainable development ability. From 1995 to 2003, ecological footprint in Funing County decreased from 1.1207 hm2 per capita to 2.434 0 hm2 per capita, ecological capacity per capita changed very little, ecological deficit increased from 0.8153 hm2 per capita to 2.017 2 hm2 per capita, development ability increased from 1.330 6 to 3.140 7, ecological deficit per 10 000 yuan GDP decreased from 1.226 5 hm2 to 0.495 7 hm2. The correlation index calculated by the improved ecological footprint method between development ability and GDP per capita is larger than that by the Wackernagel's method, indicating that the development ability based on the improved ecological footprint method may represent the social economic situation better than that based on Wackernagel's method.

Key words: ecological footprint, cropping index, ecological capacity, ecological remainder, ability of development