塞罕坝机械林场自然保护区森林生态功能评价

Evaluation of forest ecological function in Nature Reserve Saihanba Mechanized Forestry Farm

以塞罕坝机械林场2019年更新的二类调查数据库为依据,参考《森林资源规划设计调查技术规程》对主要森林类型的生态功能等级进行评价。结果表明,自然保护区森林生态功能等级整体处于中等及以下水平,其中较差林分占38.3%,天然林生态功能较人工林并无优势;华北落叶松人工林和白桦天然次生林生态功能等级为中级的森林面积占比分别达到各自林分的79.5%和93.3%,而樟子松人工林生态功能等级为中级的森林面积占比不足35%;8种不同森林类型中,针阔混交林生态功能指数最高(0.57),油松人工林生态功能指数最低(0.35);幼龄林生态功能等级为中级的森林面积不足30%,近熟林和成熟林中生态功能等级为中级的森林面积达到80%以上,然而,过熟林生态功能明显退化。本研究表明,塞罕坝自然保护区森林生态功能等级整体偏低,在对自然保护区内的森林进行严格管护的基础上,亟需进行适当的经营。

The evaluation of the ecological function of main forest types in Saihanba Mechanized Forestry Farm was conducted with reference to the technical regulations for forest resources planning,design and investigation,which was based on the updated investigation database in 2019.The results showed that the forest ecological function grades in the nature reserve was integrally below the medium level,in which the poor stand accounted for 38.3%.The ecological function of natural forest had no advantage over artificial forest.The proportion of forest area with intermediate ecological function grade in Larix principis-rupprechtii plantation and Betula platyphylla natural secondary forest reached 79.5%and 93.3%respectively,while the proportion of forest area with intermediate ecological function grade in Pinus sylvestris var.mongolica plantation was less than 35%.The ecological function index of coniferous and broad-leaved mixed forest was the highest(0.57)among the 8 different forest types,but that of Pinus tabuliformis plantation was the lowest(0.35).The forest area with intermediate ecological function grade in young forest was less than 30%,and the forest area with intermediate ecological function grade in near mature forest and mature forest was more than 80%.However,the ecological function of over mature forest was obviously degraded.The study showed that the forest ecological function grade of nature reserve was poor,thus it was urgent to carry out appropriate management on the basis of strict management and protection of the forest in the nature reserve.