长白山森林景观破碎的遥感探测(英文)

Remote sensing of forest landscape fragmentation on Changbai Mountain

天然林数量的减少以及质量的降低对中国的生态环境和经济发展产生不利影响。虽然林地的破碎对各种自然灾害起到关键性作用 ,林地是如何被破碎的尚不十分清楚。应用卫星遥感技术 ,以及地理信息系统和空间分析手段研究中国东北一原始的针阔混交林的破碎过程。结果表明 ,本来完整的原始森林 ,已经被一种“复叶”状小面积皆伐作业分割为零碎的斑块。采伐地的面积平均为 1 5 hm2 ,但随着采伐的继续 ,采伐地段连为一体 ,增大了采伐迹地的面积 ,从而保留的林地面积越来越小。采伐地点的选择没有考虑物种和环境的保护。林地破碎的特征是保留林地面积的缩小 ,中、小林地数量的增加 ,林地斑块形状的改变 ,以及林缘长度的增加。

The degradation of natural forests and environments has led to ecological and economic difficulties in China. Forest fragmentation plays an important role in natural disasters but how forests are fragmented is poorly understood. This study utilized satellite Thematic Mapper (TM) data, a geographic information system (GIS), and spatial analysis tools (Fragstats) to examine the fragmentation of an old growth mixed forest in Northeastern China, one of the most important timber bases in China. The study showed that the old growth forest has been fragmented into small patches by leaflet like “small area clearcutting”. The size of clearcutting was around 15 hm 2 on average at the beginning stage of forest harvesting but was expanded rapidly as clearcutting continued. No specific cutting preferences or restrictions have been given to certain aspects or slopes where important winter or lowland habitats may be located. Fragmentation conditions were characterized by the reduced forest patch sizes, the increased frequency of small or medium sized forest patches, changes in patch shape, and the increase in forest edges. Several recommendations have been proposed to improve forest policy and management planning in order to protect the integrity of native forests in the region.