乐昌含笑人工林林分结构特征分析  

Analysis on the Stand Structure Characteristics of Michelia chapensis Plantation

作　　者：孟诗原 罗树凯 梁俊毅 陈婉颖 郑丹菁 熊咏梅 陈勇 赵志刚 MENG Shiyuan;LUO Shukai;LIANG Junyi;CHEN Wanying;ZHENG Danjing;XIONG Yongmei;CHEN Yong;ZHAO Zhigang(Guangzhou Institute of Forestry and Landscape Architecture/Guangzhou collaborative innovation center on science-tech of ecology and landscape,Guangzhou,Guangdong 510405,China;Guangzhou College of Applied Science and Technology,Guangzhou,Guangdong 511370,China)

机构地区：[1]广州市林业和园林科学研究院/广州市生态园林科技协同创新中心,广东广州510405 [2]广州应用科技学院,广东广州511370

出　　处：《林业与环境科学》2023年第2期67-75,共9页Forestry and Environmental Science

基　　金：广州市科技局社会发展项目(广州市生态园林科技协同创新中心资助,项目编号为202206010058)。

摘　　要：以广东省中部10 a生乐昌含笑Michelia chapensis郁闭林分为研究对象,分上、下两个坡位设置典型样地,分析各样地的胸径结构、树高结构等林分非空间结构特征以及角尺度(Wi)、大小比数(U_(i))等空间结构特征。结果表明:(1)各样地非空间结构特征近似,胸径结构和树高结构总体均呈正态分布,中小径级林木比例偏高;(2)各样地角尺度差异不明显,随机分布单木(W_(i)=0.5)比例均超过55%,林木整体分布格局属于随机分布。大小比数特征差异明显,上坡样地中优势木(U_(i)=0)与亚优势木(U_(i)=0.25)多于下坡样地,下坡样地内被压木(U_(i)=0.75或U_(i)=1.00)较多,下坡林木竞争压力相对较高;(3)随着树木的生长,林木的胸径结构和树高结构与正态分布的拟合性变差,树高和胸径分化明显。研究区内乐昌含笑人工林在造林8年后即已经出现较强的邻体竞争,并且随着林木生长而增强,导致树木生长减缓,并出现林木自然淘汰等问题,亟需进行合理的林分结构调整与优化,以提高乐昌含笑人工林林分质量。10 years old Michelia chapensis closed plantations were used as the research object,and four sample plots were set on the upper and lower slope positions respectively.The characteristics of the non-spatial structure and spatial structure of various places were analyzed.Non-spatial structure characteristics include DBH structure and height structure.Spatial structure characteristics include uniform angle index(W_(i))and dominance(U_(i)).The results showed that:(1)The non-spatial structure characteristics were similar in all plots.The DBH structure and height structure both were normally distributed,but there were more middle and small path trees in this plantation.(2)The uniform angle characteristics were similar in each plot,more than 55%of single trees was randomly distributed(W_(i)=0.5),and the overall distribution pattern of trees were random.The dominance characteristics were differences in plots.Dominant trees(U_(i)=0)and sub-dominant trees(U_(i)=0.25)were large portions in the upper slope plots,and suppressed trees(U_(i)=0.75 or U_(i)=1.00)were overmuch on the lower slope plots.Therefore,the competition pressure among trees were higher on the lower slope.(3)DBH and height were differentiated significantly with trees growing,and then the fitting of normal distribution of DBH and height structure to the normal distribution were further weaking.The neighbor competition was appeared strongly in M.chapensis plantation at 8 years old,and increased with the growth of trees at 10 years old.The excessive competition had led to tree growth reducing,natural elimination,and the stand quality decline noticeably.Based on the analysis,which was urgent to adjust and optimize the stand structure reasonably to improve the stand quality of M.chapensis plantation.

关 键 词：乐昌含笑 人工林 林分结构 森林经营 

分 类 号：S718.551.2[农业科学—林学]