探究贵州省黎平县典型马尾松混交林的林分空间结构特征,为该地区混交林经营及改造提供理论依据。以黎平县马尾松混交林中的马尾松为研究对象,根据混交树种及混交比例将研究区典型马尾松混交林划分为7种林分类型,分别是马尾松占40%(类型A)、50%(类型B)、70%(类型C)的与多种阔叶混交的针阔混交林,马尾松占30%(类型D)、50%(类型E)、70%(类型F)的与杉木混交的针叶混交林以及马尾松纯林(类型G),采用角尺度、胸径大小比数、树高大小比数、混交度和空间结构综合评价指标,对其空间结构进行分析。结果表明,在研究区中:1)7种林分类型中,马尾松均为轻度聚集分布状态,趋向于随机分布格局;2)类型F中,马尾松的树高、胸径处于中庸状态,其余类型中,马尾松的树高、胸径均处于亚优势状态;3)马尾松混交林的树种混交程度较高,通常在中度混交强度以上,而马尾松纯林处于弱度混交,接近于零度混交;4)林分综合评价排序为类型A>类型D>类型E>类型B>类型F>类型C>类型G;5)典型马尾松混交林中,马尾松的角尺度、胸径大小比数、树高大小比数之间无明显差异性,其空间结构的差异主要受混交度影响,混交林整体向随机分布、林木呈中庸竞争、混交度更高的顶级群落发展,但目前尚未达到自然顶级群落水平。

This paper explored the spatial structure characteristics of typical mixed forests of Pinus massoniana in Liping County,Guizhou,and provided theoretical basis for the management and transformation of mixed forests in this area.Taking Pinus massoniana in the mixed forest in Liping County as the research object,the typical Pinus massoniana mixed forest in the study area was divided into 7 forest types based on the mixed tree species and proportion.The types were broad-leaved mixed forest with Pinus massoniana propotion of 40%(type A),50%(type B),70%(type C) and coniferous mixed forests mixed with Chinese fir with Pinus massoniana propotion of 30%(type D),50%(type E),70%(type F) and pure forests of Pinus massoniana(type G).The spatial structure of all types were analyzed using comprehensive evaluation indicators such as angular scale,diameter at breast height ratio,tree height ratio,mingling degree and spatial structure.The results showed that:1) The seven types of Pinus massoniana stands in the study area were all in a light aggregation distribution state,tending to a random distribution pattern;2) The Pinus massoniana in type F of the study area had a moderate height and diameter at breast height,while the Pinus massoniana in other types were subdominant in height and diameter at breast height;3) The mingling degree in the Pinus massoniana mixed forest in the study area was relatively high,usually above moderate mingling degree,while the pure forest of Pinus massoniana was in weak mingling degree and nearly zero mingling degree.4) The ranking of forest stand comprehensive evaluation was:Type A>Type D>Type E>Type B>Type F>Type C>Type G;5) There was no significant difference in the spatial structure of typical Pinus massoniana in the study area in terms of angular scale,ratio of diameter at breast height to size,and ratio of tree height to size.The differences in spatial structure were mainly influenced by the mingling degree.The mixed forest as a whole qas developing towards a top level community with random distribution,moderate competition among trees,and higher mingling degree,but it had not yet reached the level of natural top level community.