大兴安岭北部白桦次生林空间结构多元分析  

Multivariate Analysis of Spatial Structure of Betula platyphylla Secondary Forest in Northern Daxing’anling Area

作　　者：刘磊 萨如拉[1] 高明龙 王子瑞 铁牛[1,2] LIU lei;SA Ru-la;GAO Ming-long;WANG Zi-rui;TIE niu(Forestry College,Inner Mongolia Agricultural University,Hohhot Inner Mongolia 010000,P.R.China;Inner Mongolia Forestry Research Institute,Hohhot Inner Mongolia 010010,P.R.China)

机构地区：[1]内蒙古农业大学林学院,内蒙古呼和浩特010010 [2]内蒙古自治区林业科学研究院,内蒙古呼和浩特010010

出　　处：《西部林业科学》2022年第5期118-126,共9页Journal of West China Forestry Science

基　　金：内蒙古自治区科技计划项目“大兴安岭白桦次生林生态修复关键技术研究与示范(2020GG0067)”。

摘　　要：以大兴安岭北部白桦次生林2种林型为研究对象,采用密集度、混交度、大小比数和角尺度等4个参数的N元分布分别描绘白桦纯林和白桦-落叶松混交林空间结构特征。结果显示:(1)从零元分布来看,白桦纯林和白桦-落叶松混交林的角尺度分别为0.5220和0.5397呈轻微团状分布,白桦-落叶松混交林生长状态优于白桦纯林;从一元分布来看,2种林型中随机分布的林木均占林分总株数的一半以上,白桦纯林不同大小比数的林木比例相近;二元至四元分布看,不管结构参数如何组合,林木大多以随机分布为主。(2)白桦纯林中,占比最多的林木空间结构单元为随机分布下零度混交且与周围林木非常密集伴生的绝对优势木;白桦-落叶松混交林林分中,占比最多的林木空间结构单元为随机分布下弱度混交且与周围林木非常密集伴生的中庸木;白桦-落叶松混交林与白桦纯林相比在一定取值范围林分中优势木比例无明显增多,但劣势木占比较少,中庸木占比明显增多,进一步证明白桦-落叶松混交林生长状态优于白桦纯林。可得结论:大兴安岭白桦次生林存在着结构不合理的问题,2种林型林分混交度较低,树种结构单一,树冠重叠严重,种内竞争激烈,不利于群落正向演替。Two forest types of Betula platyphylla secondary forest in the northern Daxing’anling area were studied.The spatial structure characteristics of B.platyphylla forest and B.platyphylla-Larix gmelinii mixed forest were described using N element distribution of density,Uniform angle index,Neighborhood comparison,Mingling degree and Crowding degree.The results showed that the Angle scales of B.platyphylla forest and B.platyphylla-L.gmelinii mixed forest were 0.5220 and 0.5397,respectively.The growth state of birch-larch forest was better than pure birch forest.In terms of univariate distribution,trees randomly distributed in the two forest types accounted for more than half of the total number of stands,and the proportion of trees with different sizes in B.platyphylla was similar.From bivariate distribution to quaternion distribution,no matter how the structural parameters are combined,most trees are randomly distributed.In B.platyphylla forest,the spatial structure units of trees with the largest proportion are the absolute dominant trees which are randomly distributed at zero degree and closely associated with surrounding trees.In B.platyphylla-L.gmelinii mixed forest stand,the trees with the largest proportion of spatial structure units are the medium trees which are weakly mixed under random distribution and closely associated with the surrounding trees.In a certain range of values,the proportion of dominant trees in B.platyphylla-L.gmelinii mixed forest did not increase significantly compared with pure birch forest,but the proportion of inferior trees was less,and the proportion of neutral trees was significantly increased,which further proved that the growth status of mixed forest was better than pure forest.The structure of Betula platyphylla secondary forest in Daxing’anling is unreasonable.The Mingling degree of two forest types is low,the structure of tree species is single,the crown overlap is serious,and the intra-species competition is fierce,which is not conducive to the community’s positive succe

关 键 词：白桦次生林 林分空间结构 多元分布 大兴安岭北部 

分 类 号：S792.153[农业科学—林木遗传育种]