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从山体下部到上部调查了北京东灵山辽东栎林一个长 3 6 4m的样带 ,对优势林木种群的直径结构 ,按山体的上部、中部、下部三个不同部位进行统计。选定乔木层优势种群辽东栎、大叶白蜡、五角枫、棘皮桦和灌木层优势种群二色胡枝子、六道木、照山白、柔毛绣线菊为研究对象 ,结合生物学特性分析了 8种乔灌木种群的直径结构 ,及其沿环境梯度的动态趋势。在乔木层 ,棘皮桦在山体中部和下部的亚种群幼苗幼树株数少 ,个体生长不良 ,密度极低种群呈衰退趋势。其余3个物种种群的幼苗幼树数量多 ,种群密度较高。辽东栎种群从山体下部到上部的直径结构合理呈稳定状态。大叶白蜡和五角枫种群随海拔升高在数量、密度等方面呈现相互替代的现象。在灌木层 ,除过照山白种群 ,二色胡枝子、六道木和柔毛绣线菊 3个种群的幼苗株数丰富 ,直径结构合理。从整体上看 ,如果对辽东栎林群落不加人为的干扰和破坏 ,辽东栎林群落将进一步向成熟林方向发展。
From the lower part to the upper part of the mountain, a sample belt of 3 64 m in Quercus liaotungensis forest in Dongling Mountain of Beijing was surveyed. The diameter structure of the dominant tree species was counted according to the three parts of the upper, middle and lower parts of the mountain. The dominant species of Lespedeza oblata, Larix gmelinii, Larix gossypii, Maple, Betula platyphylla and shrub layer were selected as the research object, and the biological characteristics of 8 selected Lespedeza, Rhus chinensis, Diameter structure of species of shrub and shrub and their dynamic trend along the environmental gradient. In the arbor layer, P. echinophylla subspecies seedlings had fewer saplings in the middle and lower parts of the mountain, with poor growth and extremely low density populations. The remaining three species populations of seedlings sapling number, population density higher. The diameter structure of Quercus liaotungensis from the lower part to the upper part of the mountain was reasonably stable. Large white wax and maple five-pointed maple population with the elevation of the number, density and other aspects of the phenomenon of substitution. In the shrub layer, the seedlings of three populations except Zhezhao white population, Lespedeza bicolor, Rhus chinensis and Prunella breviflora were abundant, and their diameter structure was reasonable. On the whole, if the Quercus liaotungensis forest community without human interference and destruction, Quercus liaotungensis community will further develop toward mature forest.