摘要
在流域划分的基础上 ,以Ⅱ级流域为单元 ,根据流域内森林、草地、农田、湿地、水源等地类和自然环境异质程度的动态变化特点 ,确定了东北天然次生林区 4种经营类型 ,即封育型、培育型、利用型和改造型。通过采取人工造林、人工与天然多层混交、梯度采伐分层抚育等系统经营措施 ,使其各地类均处于优化配置状态 ,达到提高植被数量和质量、增强流域整体生态功能的目的。研究结果表明 ,林业用地面积 1997年与 195 8年相比增加了4 0 .2 % ,有林地增加了 14 1.7% ,无林地减少了 81.7% ,非林业用地减少了 16 .4 2 % ,森林覆被率相对增加了 131.9%。林业用地稳定 ,有林地增加 ,非林地和无林地减少 ,改变了不合理地类结构 ,从而提高了土地利用率。森林资源的数量和林分的质量得到了提高 ,总蓄积增加了 5 70 .5 % ,单位面积蓄积量提高了 189.5 % ,年公顷蓄积生长量增加了 95 .6 %。此外 ,1997年流域贮水量比 195 8年增加而流出量减少 。
On the basis of the watershed classification and according to the land types such as the forest, grassland, farm land, wetland, and the characteristics of the heterogeneous tendency of natural environment, the authors determined four types of the natural secondary forest in the Northeastern China as cultivated, reformed, set apart and cultivated, and utilized types with taking the second-class watershed as unit. Through the systematic management strategy such as planting, cultivation of man-made and natural mixed stand, terraced felling and different-layer tending treatments, the authors made every land type in optimal arrangement state, so as to achieve the aim of increasing the quantity and quality of the vegetation and then improving the complex ecological function. Results show that the area of the forestry land in 1997 was 40.2% more than that in 1958; forest areas get increased 141.7%; non-forest land has reduced 81.7%; non-forestry land has decreased 16.42%; the forest coverage has increased 131.9% relatively. As well as the quantity of forest resource gets increased, the quality of the stand has been improved. The total volume has increased 570.5%; the volume on unit area has been raised 189.5%. Besides, the water storage of the watershed in 1997 has increased 688.9% more than that in 1958, but the runoff has decreased significantly, which are the signs that the ecological environment of the watershed has been improved.
出处
《东北林业大学学报》
CAS
CSCD
北大核心
2002年第4期118-121,共4页
Journal of Northeast Forestry University
