Cai Yunlong, Meng Jijun
Land degradation is a major representation of global environmental change. In degraded land, people get into the trouble of PPE (poverty-population-environment) spiral. Land degradation takes various forms in China, such as land desertification, soil erosion, farmland pollution, surface mining, farmland salinization and soil fertility deterioration. Among these the former two are the most distributing and the most influencing. A great amount of poor population assembles in these lands, for example, in the karst areas of southwest China and in the Loess Plateau of northwest China. This paper especially pays more attention to the reversal of impoverishment-degradation spiral in the karst areas of southwest China. Since the PPE spiral is caused by ecological and, in particular, social factors, the solution must be in a social approach. Poverty alleviation is a systematic project with great complexities. Any single approach can not success and integrated measures should be taken. Obviously, the key to escape the vicious spiral is the reconstruction of the local ecosystem, economy and society so that the self development capacity of the local people may be enhanced. Thus the poverty can be essentially eliminated. On the other hand, it is unrealistic to let the degraded land naturally recover under the pressure of population growth and economic development. The degraded land needs ecological reconstruction through social investment, while the local economy and society should be restructured. Ecological reconstruction of the degraded land involves not only the degraded and underdeveloped localities but also developed regions. The guidelines of degraded land reconstruction should be the concepts of sustainability and economic viability, and the theory of landscape ecology. Sustainability includes the idea of a type of development that does not compromise, and even promote, the future use of land. Economic viability is profitability of the reconstructed land, although in a long term consideration. In other words, the reconstructed land and its use should obtain productivity, stability, sustainability, equability and autonomy. According to landscape ecology, reasonable land use and landscape patterns should be allocated at a macro scale, and an appropriate productivity and ecological conditions should be created at a micro scale. It is necessary, in the degraded land reconstruction, to identify different issues at different spatial scales, for example, land productivity at site, land use pattern at local, urban rural relation at a region, and economic cooperation at inter region. In temporal scale, it is necessary to establish realistic targets of short term (to emphasize viability), middle term (to get into benign spiral) and long term (to realize sustainability) respectively. As a social approach, the reconstruction of degraded land includes ideology innovation, institute transformation, and science and technology popularization.
