西藏生态足迹与承载力动态分析

利用生态足迹模型,对2005—2010年西藏的生态足迹和生态承载力以及生态盈余进行了测算。研究发现,西藏2005—2010年人均生态足迹呈现出振荡式上升趋势,从2005年的0.34 hm2/人波动上升到2010年的0.83 hm2/人,其中人均林地消费所占比重最大,多年平均值占总消费的39.8%;人均耕地消费基本稳定在0.18—0.2 hm2/人之间,其他类型土地消费所占比重相对较少;人均生态承载力呈现平滑下降趋势,从2005年的14.78 hm2/人下降到了2010年的13.77 hm2/人,其中林地和牧草地及其转换的化石能源地人均生态承载力所占比重达到了95%,可耕地、牧草地、林地的人均生态承载力在2005—2010年之间呈现缓慢下降趋势,水域人均生态承载力变化不大;人均生态盈余较大,但呈现出递减趋势,2005年为14.44 hm2/人,而2010年下降到12.94 hm2/人;生态盈余中比重最大的是林地,但其足迹波动较大,介于1%—30%之间;草地人均生态足迹仅占生态承载力的5%左右,水域人均生态足迹占生态承载力的比例可忽略不计。

Dynamic analysis of the ecological footprint and carrying capacity of tibet

The study of ecological footprint and carrying capacity is a crucial basis for the settlement of environment deterioration and the realization of regional sustainable development. Based on ecological footprint models, this paper estimated the ecological footprint and carrying capacity of Tibet during 2005-2010. According to the land use properties in Tibet, the following six types were categorized: fossil fuel land, arable land, grassland, woodland, waters, and construction area. We found that the average ecological footprint per capita of Tibet increased from 0.34 hm² per capita in 2005 to 0.83 hm² per capita in 2010. Among the above 6 land use types, woodland consumption was the most important part, accounting for 39.8% of the total consumption. The average arable land consumption per capita stayed relatively stable, from 0.18 to 0.2 hm² per capita. Other types of land consumption constituted only a very small amount of the overall consumption. The average ecological caring capacity per capital showed a marginally decreasing trend, from 14.78 hm² per capita in 2005 to 13.77 hm² per capita in 2010. The ecological caring capacity per capita of woodland, grassland and fossil fuel lands accounted for 95% of the total capacity, and those of the former two and the arable land tended to decrease slowly during the study period. The average ecological caring capacity per capita of waterlands did not vary much. The average ecological surplus per capita is relatively large, though it decreased from 14.44 hm² per capita in 2005 to 12.94 in 2010. The largest part of Tibet's ecological surplus was observed in woodland in which drastic fluctuations in ecological footprint were found. The ecological footprint of woodland and grassland accounts for 1%-30% and 5% of the overall carrying capacity, respectively. The ecological footprint of waterland can be negligible due to its small amount. In all, the ecological footprint is much lower while the carrying capacity is much higher than the average values of China or the whole world, indicating that the economic development level of Tibet is still in a primary stage and there still exist great development potential. However, the ecological surplus tended to decrease during the last 6 years, suggesting that the environment deterioration does occur in some regions where the ecosystem maybe vulnerable. Therefore, when we are concentrating on the economic development of Tibet, we should pay close attention to the dangers brought by environment deterioration, which will ensure the sustainable development of resources and environment.