内蒙古大兴安岭白桦次生林空间结构特征

Spatial Structure Characteristics of Betula platyphylla Secondary Forest in Daxing′anling of Inner Mongolia

分析内蒙古大兴安岭白桦次生中幼龄林的空间结构,为大兴安岭天然次生中幼龄林的科学经营和功能提升提供一定科学参考。以内蒙古大兴安岭白桦次生中幼龄林为研究对象,基于角尺度、大小比数、混交度的计算,采用空间结构参数一元和二元分布,分析白桦次生林的空间结构特征。结果表明:一元分布中,3块样地以随机分布为主,处于随机分布的林木约占51%~59%;3块样地主要树种白桦的大小比数均值分别为0.481,0.521,0.466,林分整体处于中庸状态;3块样地混交度分别为0.175,0.131,0.183,均为弱度混交,树种隔离程度低。二元分布中,团状分布的劣势木较多,随机分布中高度混交的林木极少,低度混交的劣势木较多。白桦次生中幼龄林存在部分林木团状分布、树种混交度低等问题,需采取措施调整空间结构,提高混交度,保持森林生态系统健康稳定发展。

The spatial structure of Betula platyphylla secondary young and middle aged forest in Daxing′anling,Inner Mongolia,was analyzed,which provided a scientific reference for the scientific management and function improvement of natural secondary young and middle aged forest in Daxing′anling.Taking the Betula platyphylla secondary young and middle aged forest as the research object,the spatial structure characteristics of Betula platyphylla secondary forest were analyzed by using single distribution and binary distribution based on the calculations of uniform angle index,dominance and mingling.The results showed that:In terms of single distribution,three plots were randomly distributed;the random distribution of trees accounted for 51%~59%.The mean dominance of Betula platyphylla in three plots were 0.481,0.521 and 0.466,respectively;and the growth of whole stand was in the moderate state.Three plots were weakly mixed with low stand heterogeneity,and the mingling degrees were 0.175,0.131 and 0.183,respectively.In terms of binary distribution,there were more inferior trees distributed in cluster state.While in random state,there were very few trees with high mingling,and more oppressed trees with low mingling distributed.There were some problems in Betula platyphylla secondary young and middle aged forest in Daxing′anling,Inner Mongolia,such as cluster distribution of some trees and low mingling degree of tree species.It was necessary to adjust the stand spatial structure through measures and to improve the mingling and maintain the healthy and stable development of forest ecosystem.