【摘要】 【目的】通过分析大兴安岭兴安落叶松天然林结构参数,了解兴安落叶松天然林的结构特征,为兴安落叶松林的经营和保护提供科学依据。【方法】以大兴安岭兴安落叶松天然林为研究对象,设置50m×50m固定样地,利用固定样地内每木定位调查数据和分析统计软件,对兴安落叶松林的结构参数角尺度、混交度、大小比数进行一元分布特征分析,同时将3个参数进行两两组合,进行二元分布特征分析,了解兴安落叶松林林木的微环境特征。【结果】兴安落叶松林直径分布为多峰山状分布且呈左偏,树高分布为多峰山状分布且呈右边;兴安落叶松林分布格局为随机分布,接近均匀分布;树种隔离程度低,属于弱度混交;林分中落叶松胸径大小分布差异明显,整体表现为中庸状态。不同分布状态的林木优劣性差异较小;随机分布时混交度为零度混交和弱度混交的林木比例最大;当混交度为零度混交(M=0)时,大小比数分布频度在劣态状态下达最大值;当混交度为极强度混交(M=1)时,大小比数分布频度在中庸状态下达最小值。【结论】大兴安岭兴安落叶松天然林结构不合理,需要进行密度调整和结构优化从而提高其林分质量。更多还原

【Abstract】 【Objective】By analyzing the structural parameters of L. gmelinii natural forest in Daxing’an Mountains,to understand the structure characters of L. gmelinii natural forest and provide the basis for protection and management.【Method】Fixed a sample plot of L. gmelinii forest with 50 m×50 m was set up. and the structural parameters of L. gmelinii forest were analyzed by fixed sample survey of each tree positioning data with statistical software,and the three spatial structural parameters of uniform angle index,mingling degree and competition index were analyzed.At the same time,the three parameters were combined into two groups to analyze the bivariate distribution characteristics and understand the microenvironment characteristics of L. gmelinii forest.【Result】The DBH distribution and tree height distribution of L. gmelinii followed a multi-shaped peak curve,the DBH distribution was left and the tree height distribution was right;the spatial distribution pattern is random distribution,close to uniform distribution;the degree of tree species segregation was lower and the average value of mingling was weak;The DBH of L. gmelinii was significantly differentiated,the average state belonged to medium.There were little difference in dominance under different distribution patterns;In random distribution,the proportion of trees with zero degree of mingling and weak degree of mingling is the largest;when the degree of mingling is zero degree of mingling(M=0),the frequency of size ratio distribution reaches the maximum in bad state;when the degree of mingling is extreme intensity mingling(M=1),the frequency of size ratio distribution reaches the minimum in the middle state.【Conclusion】The structure of L. gmelinii natural forest on Daxing’an Mountains is unreasonable;some measures of density adjustment and structure optimization should be taken to improve the forest health.更多还原