Calculations of the National Average Yield, Equivalence Factor and Yield Factor in Ten Years Based on National Hectares’ Ecological Footprint Model – A Case Study of Xiamen City

Abstract

The concept of "national hectare" is introduced into the calculation of ecological footprint model in this article. That is, the national average yield is used instead of the global average yield. Based on this concept, the national average yields of plantation products, forest products, aquatic products and livestock products, the equivalence factors and the yield factors of Xiamen City from 2000 to 2009 are calculated. The main conclusions can be summarized as the following:(1) In the calculation of national average yield of livestock products, the types of productive land for beef, mutton and milk should be expanded from grassland to grassland and farmland according to the actual situation in China. The proportion of the productive land for livestock products attributed to grassland is lower, which affects the calculation result of equivalence factor of grassland. (2) The equivalence factor in the ecological footprint model based on the concept of national hectare is calculated by calorific value method. The results indicate that the equivalence factor of farmland is the maximum, and the grassland is the minimum. (3) It can be seen from the result that the yield factor of grassland in Xiamen City decreases continuously with the years. The biological productivity of grassland in Xiamen City declines continuously compared with the average biological productivity of the national grassland. However, there are large fluctuations for the yield factors across the years, but no obvious rules are identified. This study is conducive to the further calculation of ecological footprint and the comparison of ecological footprint across the provinces and cities. Thus, the utilization and sustainable development trends of natural capitals in China can be reflected.