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(Ui
)
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(Wi
=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(Ui
=0)与亚优势木(Ui
=0.25)
多于下坡样地,下坡样地内被压木(Ui
=0.75 或 Ui
=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。 |
关键词: 乐昌含笑 人工林 林分结构 森林经营 |
DOI: |
分类号: |
基金项目: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“乐昌含笑中幼龄林竞争调控研究”,202206010058)第一作者:孟诗原(1197904981@qq.com),硕士。通讯作者:赵志刚(zhaozhigang1979@126.com),副研究员,博士。引文格式: |
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Analysis on the Stand Structure Characteristics of Michelia chapensis Plantation |
MENG Shiyuian1, LUO Shukai1, LIANG Junyi1,2, CHEN Wanying1, ZHENG Danjing1, XIONG Yongmei1, CHEN Yong1, ZHAO Zhigang1
|
1.Guangzhou Institute of Forestry and Landscape Architecture;2.Guangzhou College of Applied Science and Technology
|
Abstract: |
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 (Wi
) and dominance
(Ui). 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 (Wi=0.5), and the overall distribution pattern of trees were random. The dominance characteristics were differences in plots. Dominant trees (Ui=0) and sub-dominant trees (Ui=0.25) were large
portions in the upper slope plots, and suppressed trees (Ui
=0.75 or Ui
=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. |
Key words: Michelia chapensis plantation stand structure forest management |