摘要
为揭示华北落叶松人工纯林林分密度对林分结构的影响,探讨其近成熟林分适宜生长的密度,为其林分结构优化和人工林健康可持续发展提供科学依据。以内蒙古阴山中部40 a生华北落叶松人工纯林为研究对象,设置10种林分密度(975、1050、1150、1225、1250、1325、1575、1600、1700和2050株/hm^(2))样地,对其进行径阶分布、树高结构、空间分布特征研究,以明晰各密度林分的生长发育规律。结果显示:(1)秩和检验显示参试各密度华北落叶松人工纯林生长存在显著差异。随着林分密度递增,平均胸径、平均冠幅呈现减小趋势,枝下高则呈增加趋势,树高没有表现出明显规律。(2)林分径阶分布基本呈现偏态分布规律,20 cm或22 cm径阶为主要峰值区,密度大于1575株/hm^(2)峰值发生左偏,中小径阶乔木优势增强。(3)林分树高主要集中分布在15.0~19.9 m,高度结构单一。(4)林分角尺度分布呈近似正态分布,随机木占比近半数,随密度增加林分角尺度减小,中密度林分1150、1225、1250、1325、1575株/hm^(2)为随机分布格局。研究结果表明:阴山中部华北落叶松近成熟人工林保持稳定发展的林分密度上限是1575株/hm^(2)。
The purpose of this study was to reveal the effect of stand density on stand structure of Larix principis-rupprechtii plantation,and to explore the suitable stand density for near-mature plantation,so as to provide scientific basis for stand structure optimization and sustainable development of plantation.The 40a L.principis-rupprechtii plantation in central Yinshan Mountain in Inner Mongolia was studied.A plot with 10 stand densities(975,1050,1150,1225,1250,1325,1575,1600,1700 and 2050 plants/hm^(2))was set up to study the characteristics of diameter class distribution,tree height structure and spatial distribution.Clarify the growth and development law of each density stand.The results showed that:(1)The rank sum test showed that there were significant differences in the growth of plantation with different densities.With the increase of stand density,the average diameter at breast height and average crown width decreased,the height under branch increased,and the tree height did not show obvious regularity.(2)The distribution of stand diameter class basically showed a skewed distribution.The diameter class of 20 cm or 22 cm was the main peak area.The peak value of density greater than 1575 plants/hm^(2) was left-skewed,and the dominance of small and medium-sized trees was enhanced.(3)The tree height of the stand was mainly concentrated in 15.0-19.9 m,and the height structure was single.(4)The distribution of uniform angle scale was approximately normal distribution,and the proportion of random trees was nearly half.With the increase of density,the uniform angle scale decreased.The middle density stands of 1150,1225,1250,1325 and 1575 trees/hm^(2) were random distribution patterns.The results showed that the upper limit of stand density was 1575 plants/hm^(2) for the steady development of near mature L.principis-rupprechtii plantation in the middle of Yinshan Mountains.
作者
莎仁图雅
刘坤
张翠霞
乌日恒
SHA Ren-tuya;LIU-kun;ZHANG Cui-xia;WU Ri-heng(Inner Mongolia Academy of Forestry Science,Hohhot Inner Mongolia 010010,P.R.China;Inner Mongolia Daqing Mountain Forest Ecosystem Research Station,Hohhot Inner Mongolia 010010,P.R.China;Ordos Forestry and Grassland Business Development Center,Ordos Inner Mongolia 017010,P.R.China;Inner Mongolia Daqingshan National Nature Reserve Administration,Hohhot Inner Mongolia 010010,P.R.China;Desert Biological Resources Conservation and Cultivation Key Laboratory of the State Forestry Administration,Hohhot Inner Mongolia 010010,P.R.China)
出处
《西部林业科学》
CAS
北大核心
2022年第6期17-23,共7页
Journal of West China Forestry Science
基金
内蒙古自然科学基金项目(2019MS03007)。
关键词
华北落叶松
人工林
林分密度
林分结构
角尺度
Larix principis-rupprechtii
plantation forest
stand density
stand structure
uniform angle index
