广西大明山刨花润楠种群结构及其分布格局研究

为了解刨花润楠在自然分布状态下的种群结构及其分布特性,为其野生资源保护和人工造林提供理论参考,在广西大明山自然保护区设置3.2 hm2固定大样地,通过野外监测调查,运用林木径级结构代表年龄结构法,对大明山山地常绿阔叶林中刨花润楠的种群结构、空间分布格局及其动态等进行分析.结果显示:大明山自然保护区刨花润楠种群的各级分布结构整体上呈“L”型,种群中Ⅰ级幼树和Ⅱ级小树的个体数分别占47.75％和39.45％,92.4％的个体高度在10m以下;种群的Deevey存活曲线接近于Ⅱ型,表明种群在不同生长阶段中表现出相近一致的死亡消失率;种群的总体空间分布格局为聚集分布型,并具有从早期生长阶段的聚集分布逐渐转变成后期生长阶段均匀分布的动态特征.大明山山地常绿阔叶林的刨花润楠种群结构相对完整,属于增长种群,在自然潜在干扰影响中目前仍处于稳定状态.

Structure characteristics and spatial distribution of Machilus pauhoi population in Damingshan National Nature Reserve, Guangxi

To reveal the population structure and distribution of natural Machilus pauhoi, and provide scientific basis for its conservation of wild resources and reforestation, population structure, spatial pattern and dynamics of M. pauhoi were investigated in a 3.2 hm2 forest dynamic plot of evergreen broadleaved forest in the Damingshan National Nature Reserve in south China, using the age structure and survivorship curve. The results indicated that the DBH size-class structure of M. pauhoi exhibited an L-shaped pattern. The individuals of seeding and sapling represented 47.75% and 39.45% of the total individuals. The tree heights of 92.4% of individuals were below 10 m. The survivorship curve of M. pauhoi population generally matched a Deevey Type , indicating the same mortality rate in different size classes. M. pauhoi population showed an aggregated spatial distribution and tended to uniform with age scale increasing. The results indicated that there was a good regeneration of M. pauhoi across the community. Intraspecific competition rather than interspecific competition was not severe in a wet and warm habitat in Damingshan National Nature Reserve, may affect the clustering intensity of different growth periods.