论文部分内容阅读
土左旗国营大青山林场白石头沟营林区,三十年来,在全面管护好现有林基础上,努力扩大森林资源,大搞封山育林,取得显著成绩。这个营林区,封育以前只有60由零星分布的白桦、山杨次生林。阴坡机被覆盖率仅20～30％;阳坡更少,整个沟内水土流失比较严重。封育后,植被覆盖率逐年增长。到目前为止,流域范围内以白桦、山杨为主的次生林和人工营造的油松林共有5.79万亩,活立木蓄积达到12万立方米,加上3.38万亩灌木林,森林覆盖率已达引37.6％,乔灌草植被
For the past 30 years, on the basis of overall management and protection of existing forests, Tuzuo Banner endeavored to expand its forest resources and vigorously engage in closing hillsides for afforestation and achieved remarkable success. This forest area, sealed only 60 from the sporadic distribution of white birch, mountain Yang secondary forest. Shade slope machine coverage rate of only 20 to 30%; sunny slope less erosion throughout the trench more serious soil erosion. After the enclosure, the vegetation coverage will increase year by year. So far, there are 57,900 mu of secondary forests mainly composed of white birch and poplar, and artificially-built oil pine forests. The living stock has reached 120,000 cubic meters, and with 3.38 mu of shrubs, the forest coverage rate has reached 37.6%, arborvitae vegetation