基于退耕还林还草的科尔沁沙地景观结构变化——以通辽市奈曼旗为例

Changes of Landscape Structure in Horqin Sandy Land Based on Conversion of Cropland to Forest or Grassland——Taking an Example of Naiman Banner in Tongliao City

在遥感和GIS技术支持下,对TM、ETM遥感影像进行目视解译,获得内蒙古通辽市奈曼旗各类景观的基础数据,并运用景观生态学的基本理论和方法,对奈曼旗实施退耕还林还草工程后的景观格局及其景观动态变化进行分析研究.结果表明,奈曼旗实施退耕还林还草工程以后,其景观结构得到了明显改善,耕地景观和沙地景观面积明显减少,林地景观和草地景观面积明显增加;景观多样性降低,优势度提高,破碎度下降;景观结构逐渐向均质、稳定的方向发展,而且其破碎度降低,使得一些景观类型得以连通,物种生境逐渐好转,退耕还林还草生态效应显著.

With support of RS and GIS,TM and ETM images were visually interpreted and basic data of Naiman Banner landscape gotten. Using landscape ecology theology and methods, changes of landscape patterns after conversion of cropland to forest or grassland were studied. The results showed that after the conversion,landscape structure there is better than before, cropland and sandyland reduces, forest land and grassland increases obviously,and landscape diversity decreases,landscape dominance increases,fragmentation degree declines,landscape structure tend to be homogeneous and stable. Because of the fragmentation degree declining,some landscape types can connected with each other, the environment of species become better gradually,so the ecological effects of conversion of cropland to forest or grassland is obvious.