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在干旱半干旱地区,造林通常被作为荒漠化防治最为有效的措施之一,然而这一区域人工林退化也是不可回避的事实。本文以半干旱农牧交错区的内蒙古伊金霍洛旗为例,对其林地退化状况进行评价。根据野外调查结果我们建立了一个林地退化概化模型,据此筛选出湿润指数、植被指数、土壤类型和土壤侵蚀模数4个评价指标,并采用GIS对该区人工林退化状况进行评价。结果表明,在336.09km2人工林中,退化面积达311.35km2,其中轻度、中度和重度退化面积分别为78.97,119.73和112.65km2。退化人工林的防治重点应放在现有林的改良和造林植物种特别是灌木种的选择上。图4参15。
In arid and semi-arid areas, afforestation is usually regarded as one of the most effective measures to combat desertification. However, the degradation of planted forests in this region is also an unavoidable fact. In this paper, we take the Ejinhuoluo Banner in the semi-arid farming-pastoral area as an example to evaluate its degradation. Based on the field survey results, we established a generalized model of forestland degradation. Based on the results, four evaluation indexes of wetting index, vegetation index, soil type and soil erosion modulus were selected, and the degradation status of artificial forest in this area was evaluated by GIS. The results showed that in the 336.09km2 plantation, the degenerated area reached 311.35km2, with mild, moderate and severe degeneration areas of 78.97, 119.73 and 112.65km2, respectively. The prevention and control of degraded plantations should focus on the improvement of existing forests and the selection of afforestation plant species, especially shrub species. Figure 4 Reference 15.