阿拉善高原生态环境退化研究进展

区域生态环境退化问题是当前研究的热点内容,分析其研究现状及存在问题能更好地把握其核心领域并开展更进一步的研究。本文以典型生态环境脆弱区——阿拉善高原为研究对象,系统梳理了该区域土地沙漠化、沙尘暴演化、土地利用/覆被变化、绿洲退化、水量减少与水质恶化等与生态环境退化相关领域的研究进展。在分析已有研究成果的基础之上,就不同生态环境退化问题研究存在的不足进行了归纳总结,并提出了今后需要重点开展的研究内容,以期为阿拉善高原乃至其他生态环境脆弱区生态系统的研究提供参考。

Research progress of eco-environmental degradation in Alxa Plateau

Background, aim, and scope The issue of regional eco-environmental degradation is one of the hot topics of current researches. We can better grasp the core field concerning the eco-environmental degradation and carry out further studies through analyzing its research status and existing problems. Materials and methods Wechose the Alxa Plateau, a typical ecological fragile area, as the research case and systematically reviewed the land desertification, evolution of sandstorms, land use/cover change, oasis degradation, the decrease of water flow, deterioration of water quality and other related research filed progress in terms of eco-environmental degradation in Alxa Plateau. Results (1) In the aspect of land desertification issue, how to distinguish between the contribution of natural and humanistic driving factors to the desertification, and quantitatively analyze the driving mechanisms of humanistic factors (e.g. the development of farming and grazing, ecological immigration, regulations and policies) in desertification still remains unclear. (2) With respect to the sandstorms, only limited studies investigated the coupling relationship between sandstorms and the degradation of ecological environment, the trend and forecast of sandstorms development under the background of global warming and the engineering measures for preventing the sandstorms. (3) It is urgently needed to enhance the research about the microcosmic mechanism of ecological environment degeneration induce by the unreasonable land use types and the interaction between land cover change and the effect of ecological environment. (4) The primary cause of the degradation of the oasis in Alxa Plateau is that the soil and water resources have not been well developed. Therefore, we should make the limited water and soil resources distributed and utilized rationally and minimize ineffective dissipation and losses in oasis through quantitatively analyzing the ecological water demand in oasis, optimizing the cultivation patterns and providing the relative engineering and management measurements. (5) The water resources endowment in Alxa Plateau is limited by its natural environment. The institution of water allocation in Heihe River basin is the principal approaches to guarantee the water flow of Ejina River basin. And there are not appropriate approaches to solve the key ecological environmental degradation problems that excessive exploitation and the destruction of groundwater resources, which could lead to the decrease of the underground water level and continuous deterioration of water quality. Thus, it is urgently necessary to deal with these problems in terms of water resources. Discussion In order to fundamentally mitigate the increasingly tense man-land relationship and to restrain the degradation of ecological environment, related engineering and policy should be carried out, which can strengthen the protection of ecological system and the natural environment. Consequently, the restoration and rebuild can be acquired in ecological system of fragile zone. Conclusions The major eco-environmental degradation problems present in the Alxa Plateau are interacted and coupled. In addition, the background factor of ecological environment degradation is the fragile natural environment (climate change, limited water resources), but the main driving factor of that is the inconsistency of man-land relationship due to the irrational human activities have effects on the fragile ecological system. Recommendations and perspectives The studies about the ecological environment degradation in Alxa Plateau, including land desertification, sandstorms, land use/cover change, oasis degradation, reduction of water flow and deterioration of water quality, have acquired remarkable progress and achievements. However, there are still some scientific problems to be solved or further investigated. We summarized the shortages of studies regarding the eco-environmental degradation and suggested the research contents that need special focus on in the future, on the basis of analysis related to existing research results. Additionally, we hope the results of this study may provide the references for the study of ecosystems in Alxa Plateau and even other weak ecological environment areas.