三峡库区马尾松次生林林分结构特征分析  

Structure characteristics of Pinus massoniana secondary forest in the Three Gorges Reservoir area

作　　者：胡文杰[1] 崔鸿侠[1] 王晓荣[1] 雷静品[2] 潘磊[1] 唐万鹏[1] 庞宏东[1] 袁秀锦 HU Wenjie;CUI Hongxia;WANG Xiaorong;LEI Jingpin;PAN Lei;TANG Wanpeng;PANG Hongdong;YUAN Xiujin(Hubei Academy of Forestry, Wuhan 430075, China;Research Institute of Forestry,Chinese Academy of Forestry, Beijing 100091,China)

机构地区：[1]湖北省林业科学研究院,湖北武汉430075 [2]中国林业科学研究院林业研究所,北京100091

出　　处：《南京林业大学学报（自然科学版）》2019年第3期67-76,共10页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金："十二五"农村领域国家科技支撑计划(2015BAD07B0403)

摘　　要：【目的】马尾松林是三峡库区重要的防护林类型之一,了解林分空间结构特征是实现森林可持续经营的重要途径。笔者从垂直结构上分析三峡库区马尾松林分结构特征,为进一步研究林分演替、制定合理的防护林经营措施提供依据。【方法】以湖北省秭归县九岭头林场马尾松林为研究对象,选取大小分别为50 m×60 m、50 m×60 m和50 m×50 m的3块样地,基于样地调查,考虑不同高度林木冠层光合作用的生态学特性,采用树冠光竞争高度法将林分划分为上林层、中林层和下林层,并在此基础上分析各林层径级分布、树种组成及空间结构等特征。【结果】①3样地平均胸径随着垂直层次的升高而增大,下林层、中林层、上林层的平均胸径变幅分别为7.34～8.95 cm、14.42～18.15 cm和24.48～26.06 cm。不同林层间蓄积量存在极显著差异,上林层占整个林分蓄积量的比例最高,为63.06%～76.78%,而下林层蓄积量占比仅为4.32%～7.10%。②随着垂直层次的上升,林木径级分布变广,林分密度变小,上林层径级主要分布在22和30 cm径级,呈不规则多峰曲线,中林层径级主要分布在10、18和22 cm径级,主要呈左偏峰分布,下林层径级呈倒"J"形分布,即随着径级的增大,林分密度急剧减小;③下林层的树种主要以本土阔叶树种为主,代表了整个林分的树种组成。随着林层的上升,树种数总体呈减小趋势。马尾松是上林层的优势树种,其数量占比为69.72%～94.62%,但随着垂直层次的下降,其比例大幅减少,表明在马尾松林演替进程中,林下更新环境较好,有利于本土阔叶树种的生长;④角尺度在不同林层间未表现出明显的变化规律,林分整体呈聚集分布或随机分布,而大小比数、混交度及林木竞争指数随着林层的降低而增大,表明随着林层的降低,林木大小分化程度越明显,树种隔离程度越高,同时林木个体间的竞争也越激烈;�【Objective】Understanding the spatial structure of forests is important for developing sustainable forest management practices. The Pinus massoniana forest is an important protected forest type in the Three Gorges Reservoir area. This study was conducted to provide a theoretical basis for further analyzing forest succession trends and taking reasonable management measures for forest protection by analyzing the vertical structure characteristics of the P. massoniana forest.【Method】 Using the P. massoniana forest in Jiulingtou Forest Farm, Zigui County, Hubei Province as the research object, sample plots with sizes of 50 m × 60 m, 50 m × 60 m and 50 m × 50 m were investigated, and the principle of the canopy competition(in height) for light was examined to divide the vertical structure into an upper layer, middle layer and lower layer while considering the ecological characteristics of the canopy photosynthesis at different heights. The diameter at breast height(DBH) distribution, tree species composition, and spatial structural characteristics were analyzed.【Result】①The average DBH increased with the vertical layer, and the average DBH values of the lower, middle to the upper forest layer were 7.34-8.95 cm, 14.42-18.15 and 24.48-26.06 cm, respectively. There was a significant difference in the volumes among the different layers. The upper layer showed the highest proportion of the total forest volume of 63.06%-76.78%, while the volume proportion of the lower layer only occupied 4.32%-7.10%.②The diameter class increased as the vertical layer increased, while stand density decreased. The upper layers were mainly distributed in classes 22 and 30 cm, showing an irregular multi-peak curve. The middle layers were mainly distributed in classes 10, 18 and 22 cm, showing a mainly left-skewed peak. The lower layer showed a typical inverted "J" distribution, indicating that stand density decreased sharply with increasing diameter grades.③ The main tree species in the lower layer were native hardwood speci

关 键 词：马尾松次生林 垂直结构 空间结构 演替趋势 

分 类 号：S718[农业科学—林学] S750