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林业科学 ›› 2015, Vol. 51 ›› Issue (1): 132-139.doi: 10.11707/j.1001-7488.20150116

• 研究简报 • 上一篇    下一篇

中幼龄兴安落叶松过伐林垂直结构综合特征

玉宝1, 张秋良2, 王立明3   

  1. 1. 国家林业局管理干部学院 北京 102600;
    2. 内蒙古农业大学林学院 呼和浩特 010019;
    3. 中国人民武装警察部队警种指挥学院 北京 102202
  • 收稿日期:2014-03-10 修回日期:2014-06-19 出版日期:2015-01-25 发布日期:2015-01-23
  • 通讯作者: 张秋良
  • 基金资助:

    国家科技支撑计划(2012BAD22B0204).

Comprehensive Characteristics of the Vertical Structure of Middle Young Over Cutting Forest of Larix gmelinii

Yu Bao1, Zhang Qiuliang2, Wang Liming3   

  1. 1. State Academy of Forestry Administration Beijing 102600;
    2. College of Forestry, Inner Mongolia Agricultural University Huhhot 010019;
    3. Command College of Armed Police Forces Kinds of China Beijing 102202
  • Received:2014-03-10 Revised:2014-06-19 Online:2015-01-25 Published:2015-01-23

摘要:

[目的]分析中幼龄兴安落叶松过伐林的垂直结构特征,为进一步研究演替趋势和优化林分结构等提供参考依据.[方法]以内蒙古根河林业局潮查林场境内在20世纪80年代初主伐利用后形成的兴安落叶松过伐林为研究对象,利用10块标准地数据,采用树冠光竞争高度原理将兴安落叶松过伐林林分垂直层次划分为主林层、演替层和更新层,分析各层高度、径级分布、树种组成、蓄积量和水平格局特点[垂直结构各层次特点均基于a(截止系数)取值0.5,量化分析各林层的结果].[结果]1) 主林层、演替层和更新层平均高度分别为11.2,6.8和2.8 m,各层次高度间在0.01水平上差异极显著.2) 随着林分垂直层次增高,其径级分布由反J型向左偏单峰型转变,最终呈无规则单峰型形状.主林层径级分布呈无规则的单峰型,峰值在8~16径级处,以12和14径级为多数;演替层径级分布呈左偏单峰型,峰值主要在8径级处;更新层径级分布呈反J型,峰值在2径级处.3) 各层树种组成差异较大.主林层对整个林分树种组成起关键作用,二者组成成数非常接近,也直接影响更新层的树种组成; 演替层树种组成揭示,未来林分演替趋势将出现落叶松成数增多、白桦成数逐渐增多和树种组成相对稳定3种可能性.4) 随着林分层次增高,其蓄积量增大,主林层、演替层和更新层蓄积量占林分总蓄积量的平均比例分别达67.3%,28.6%和4.1%.5) 各层分布格局主要呈聚集分布,与林分整体分布格局并非完全一致.随着林层的下降,其聚集系数逐渐增大,聚集化程度明显增加.6) 各层次对林分结构与功能具有不同的作用.随林龄增长,更新层株数减少,向演替层转移,演替层分布径级变大,逐渐接近主林层径级分布.[结论]要通过优化结构、调控林分演替可持续地经营复层异龄林,须从林分各层入手控制各树种径级株数比例、合理高度,并持续地确保有更新层的存在.林分垂直结构是林分某个特定阶段的结构特征,随着林龄增长,在不同生长阶段垂直结构将会发生变化,如何动态表述林分垂直结构特征将是今后研究的重点;在林分中,不同树种达到不同林层高度以及形成现有垂直层次结构时所需要的时间等方面也需深入研究.

关键词: 兴安落叶松, 过伐林, 复层异龄林, 垂直结构, 演替趋势

Abstract:

[Objective]Larix gmelinii over cutting forest formed at the beginning of 1980s located at the chaocha forest farm, genhe forestry bureau, inner Mongolia, was selected as research object. The objective of this paper is to reveal the vertical structure characteristic of multi storied uneven-aged stand, and to provide some references for the further study on the succession trend and stand structure optimization.[Method]Based on the data of 10 sample plots in the larix gmelinii forest, the vertical stratification of stands of the over-cutting forest of Larix gmelinii was divided into main canopy layer, succession layer and regeneration layer, by using the principle of the canopies competition in height for light. The height, diameter distribution, species composition, forest stock volume and horizontal pattern of each layer were analyzed. [Result]1)The average height of the main canopy layer, succession layer and regeneration layer are 11.2 m, 6.8 m and 2.8 m, respectively. Through the variance analysis, the level was apparently difference at the level of 0.01. 2)With the increasing of vertical stratification of forest stands, the diameter distribution shifts from the reverse J-type distribution to the left-skewed unimodal-type distribution, and finally forms an irregular unimodal shape. The diameter distribution of main canopy layer was unimodal irregular, the peaks were found at 8~16 diameter. The highest peaks were found at 12 and 14 diameter. The succession layer level is left unimodal size distribution. The peak was mainly found at 8 diameter. The diameter class distribution of regeneration layer was reverse J type. The peak was found at 2 diameter. 3)The species composition in each layer varies apparently. The main canopy layer plays a vital role in the composition of the entire forest species, and the composition percentages of the two layers are closed to each other, which directly affects the composition of species in the regeneration layer. The species composition in the succession layer reveals three possibilities for the future forest stand succession trend: the Larix gmelinii percentage may increase; the white birch percentage may gradual increase; the species composition may be relatively stable. 4)With the increasing of forest layers, the forest stock volume increased. The average proportions of the main canopy layer, the succession layer and the regeneration layer in the total forest stock volume reached 67.3%, 28.6% and 4.1%, respectively. 5)The distribution pattern of each layer is of clustering type, which is not entirely consistent with the overall distribution pattern of stands. With the decline in the forest layer, the clustering coefficient increased gradually, and the degree of aggregation increased apparently. 6)Each layer has different effects on the forest structures and functions. With increasing the age of forest, trees in the regeneration layer will decrease. The regeneration layer will shift to the succession layer, and the diameter distribution in the succession layer will move to the right and gradually approach the diameter distribution in the main canopy layer. 7)The characteristics of different levels of the vertical structure of this study are based on the a (cut-off coefficient) value is 0.5. The results of each forest layer were quantitative analyzed. [Conclusion]We shall control the proportions and reasonable heights of trees for each diameter class of species and continuously ensure the existence of the regeneration layer, by starting with each layer of forest stand, optimizing the structure, regulating the succession of forest stand, and continuously managing the multiple-layer uneven-aged forest. Vertical structure is the characteristic of a particular stage of the forest. Along with the age growth, the vertical structure will be changed at different growth stages. How the expression of the vertical stand structure characteristics dynamically will be the focus of future research. In the stand, in-depth research is required for different species reach various forest layer heights and the time for the formation of the existing vertical hierarchy.

Key words: Larix gmelinii, over cutting forest, multi storied uneven-aged stand, vertical structure, succession trend

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