黄土高原退耕还林条件下的土壤干化问题

Soil Desiccation under the Returning Farms to Forests on the Loess Plateau

介绍了土壤干化的概念及其对黄土高原生态环境的严重危害和对退耕还林还草工程的不利影响 ,说明了黄土高原地区土壤干化现象的出现是树 (草 )种选择不当和过分追求经济效益的结果 ,论述了黄土高原的植被建设几十年来没有取得成效的原因在于人类活动的逆向作用 ,包括植被类型选择失当 ,群落生产力过高 ,忽视了生物多样性在植被恢复演替中的重要作用等。这些不合理的措施一方面导致了大面积低效低产林的形成 ,另一方面又恶化了植被赖以生存的水分生态条件 ,加速了土壤干化现象的出现。由于其对植被建设的严重不良影响 ,必然影响到黄土高原生态环境的重建 ,在此意义上 ,解决土壤干化问题是目前退耕还林 (草 )工程面临的最为关键的课题之一。

The definition of soil desiccation was explained,and its harms to environment and project for returning farms to forests were discussed.The paper thought that soil desiccation is the result of unsuitable species use and over emphasis on economic benifit.In addition,the reasons for failure of vegetation construction in Loess Plateau were studied,that is the negative function of human activities such as unsuitable vegetation type,over high community production,and overlooking the bio diversity,etc.Those measurements caused the formation of large areas of low efficient and productive plantation,deteriorated the eco conditions of soil water,and accelerated the soil desiccation.Therefore,we should pay more attentions to soil desiccation that has very bad effect on vegetation restoration and environment reconstruction,and to solve it is one of the key issues for returning farms to forests.