青藏高原高寒区草地生态环境系统退化研究

青藏高原高寒地区的草地生态环境是高原生态环境的重要组成部分.近几十年来,在人类活动的强烈干扰和自然环境变化的影响下,高寒草地生态环境严重退化.在退化草地选取典型样地,调查研究了草地退化后土壤水文过程、土壤结构、植被状况等的变化.结果表明:高原高寒地区草场退化以后,土壤水文过程都发生改变,植被退化越严重土壤含水量变化越强烈、土壤入渗过程越快.退化草地的植被群落演替变化明显,优势种群退化严重,植物个体出现了小型化现象.水土流失日趋严重,土壤贫瘠化、沙化、荒漠化增强,鼠虫害等自然灾害频繁.

Degradation of the Eco-Environmental System in Alpine Meadow on the Tibetan Plateau

The grassland environment in the cold regions of the Tibetan Plateau is an important parts of the tableland environment,because of the influence of the natural environment changes and the disturbances from the human activities;the meadow environment of the tableland is in great degradation now.In a representative area in the degraded meadow,the changes of the soil moisture in the grassland,the edaphic structures and the status of the vegetations are studied.It is revealed that after the grassland degradation,the courses of the soil moisture have changed a lot,and the more vegetation degenerates,the more soil moisture changes,and the process of the water entering into soil also becomes quick.Then, the succession of communities become more distinct,the preponderant plant degenerates greatly,and the plants become small.The soil erosion becomes heavy than ever and in the arid regions,desertification becomes more serious.The natural disasters,including the pests from rats and insects,will be frequent.