Artificial woodland degradation in semi-arid agro-pastoral transitional area： conceptual model and status assessment

Planting trees was used as one of cost-effective measures for desertification control in add and semi-add areas of China. Woodland degradation, however, is becoming an inevitable issue in these areas. In this paper, a typical county, Ejin Holo County, Inner Mongolia, China was selected for its assessment of artificial woodland degradation. A conceptual model for woodland degradation was delineated qualitatively based on field sampling survey, and four model-based indicators as humidity index （HI）, vegetation index （NDVI）, soil type （ST） and soil erosion modulus （EM） were screened out and used to a GIS-based method for artificial woodland degradation assessment in this semi-add agro-pastoral transitional area. All the indicator layers were overlaid and desertification assessed using simplified equation with equal weights for each indicators. The assessment results showed that in 336. 09 km^2 of total woodland area, 311.35 km^2 woodland were under degradation, and the area for slight, medium, severe degradation was 78.97, 119.73 and 112.65 km^2, respectively. It was suggested that much attention should be paid on woodland improvement and plant species selection, especially shrub species, before revegetation in similar areas.

种树在中国的干旱、半干旱的区域为 desertificationcontrol 被用作划算的措施之一。然而，树林降级在这些区域正在成为一个不可避免的问题。在这篇论文，一个典型的县， Ejin Holo 县，内部蒙古，中国为它对人工的树林的评价被选择降级。为树林降级的一个概念的模型作为湿度指数基于现场取样调查，和 基于fourmodel 的指示物是描出的品质上(嗨)，植被索引( NDVI )，土壤类形(圣)和土壤侵蚀模量(他们)外面被屏蔽并且在这半干旱的agro牧剧为人工的树林降级评价使用了到一个官方补给底的方法过渡区域。所有指示物层被覆盖，沙漠化评定了为每指示物与相等的重量使用简化方程。评价结果在 336 显示出那。全部的树林区域的 09 km^2， 311.35 km^2woodland 在降级，和区域下面因为细微、中等、严重降级分别地是 78.97,119.73 和 112.65 km^2。它那么被建议注意应该在树林改进和植物种类选择上被给予，特别灌木种类，在在类似的区域的植被前。