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以冀北山区杨桦次生林为研究对象,通过对3块公顷级大样地进行林木调查数据对比分析,研究了不同群落的近自然度和优势度。结果表明,不同天然次生群落的近自然度和优势度具有较明显的差异,次生杨桦混交群落在自然度和优势度两个方面均优于山杨和白桦纯林,更接近天然林的稳定结构,也是该地区次生杨桦林演替发展的方向。
Taking the secondary birch of Betula platyphylla in northern mountainous area of Hebei Province as the research object, comparative analysis of forest survey data of three hectares of large sample plots was conducted to study the closeness and dominance of different communities. The results showed that the near natural degree and the dominant degree of different natural secondary communities had obvious differences. The secondary mixed population of Betula platyphylla was superior to the natural forests and the pure Betula platyphylla in both natural and dominance degrees, much closer to the natural forest It is also the direction of the succession development of secondary poplar birch forest in this area.