干旱区绿洲荒漠交错带土地退化及生态重建

Land Degradation and Ecological Regeneration in the Ecotones between the Oases and Deserts in the Arid Areas

由于经济的发展 ,土地资源受到越来越大的压力。当这种压力超过了土地资源的承载能力 ,就导致了土地退化的发生。作为陆地生态系统的基础 ,土地资源的退化表现为 :土壤肥力降低 ,生物多样性降低 ,以及伴随的经济发展的落后。当前世界范围内对土地退化的治理 ,基本方法仍是基于生态学理论的生物方法。但对土地退化的恢复与生态系统的重建的研究 ,需要经过谨慎设计的长期实验。绿洲荒漠交错带的重要性 ,不仅表现为是绿洲的保护屏障 ,而且在绿洲经济的发展中也起到巨大的作用。通过对国内外大量研究的回顾 ,讨论了在不同地区进行的长期实验所采用的方法。有人为因素参与的退化土地恢复与生态重建 ,可以在短期内取得明显效果。产生土地退化的原因 ,不仅仅是土地资源特点与自然环境这样一些自然因素 ,还包括一些社会与经济因素。因此退化土地的恢复与生态重建的成功 ,需要一种考虑自然。

Land is the valuable natural resources and is difficult to be restored when degraded. A sustainable use of land resources can be achieved only the land bearing capacity is not exceeded. Land resources suffer more and more serious pressure with the economic development. Land degradation will occur when this pressure is higher than the land bearing capacity. As the basis of the land ecosystems, land degradation includes the reduction of soil fertility and of biodiversity as well as the corresponding backward economic development. Currently, the basic control ways of land degradation in the world are still based on the ecological theory and the biological ways. However, the restoration of the degraded land and the regeneration of the ecosystems need a long-term practice, which is cautiously designed. The ecotones between the oases and deserts are not only the protective barriers of the oases, but also play a great role in the oasis economic development. Reviewing a lot of domestic and foreign references, this paper discusses the ways taken in the long-term experiments of the control of land degradation in the different regions. An obvious effect can be achieved during a short period in restoring the degraded land and in regenerating the ecology affected by artificial factors. The causes of land degradation not only include the natural factors, such as the characteristics of land resources and the natural environment, but also the social and economic factors. Therefore, the success of restoration of the degraded land and of regeneration of the ecosystems need some synthetic ways, in which all the natural, social and economic factors are considered.