【作者】 刘凤芹；

【导师】 王百田；

【作者基本信息】 北京林业大学 ， 生态环境工程， 2011， 博士

【摘要】 结构决定功能,结构是构成森林生态系统组成要素的一种重要组织形式。本研究针对冀北山区防护林结构不合理、生态退化等关键区域问题,以结构决定功能的原理,研究了冀北山区三种典型林分(落叶松桦木混交林、山杨桦木混交林和油松蒙古栎混交林)优势树种群落的内部结构特征,为解决冀北生态林建设和林场林木生产经营的可持续发展提供参考。其主要研究结果如下：(1)采用公顷级大样地调查法,调查分析了三种典型林分类型的物种组成及多样性、直径结构、树高结构等数量化特征。采用Weibull分布函数对胸径和树高的分布进行预测和拟合：直径分布为近似的反“J”形分布、正态分布和双峰或单峰山状分布,树高分布为正态分布、近似的正态分布、单峰或双峰曲线分布。(2)典型林分林木分形特征研究表明,三种林分中不同树种的冠形存在差异,且相同树种不同年龄个体间存在差异,针叶树冠幅分形维数均大于阔叶树的分维数,落叶松的分形维数(1.690)>黑桦(1.257)>白桦(0.997),不同树种的侧枝数量和侧枝倾角在各方向上分布规律不同,不同树种分枝格局的分维数不同,且同一树种在不同样地的分维数也有所差异,这是树种本身的遗传性质及外界环境共同作用的结果。(3)利用林分空间结构参数混交度、大小比数和角尺度以及点格局分析方法对典型林分类型群落空间结构进行研究,其结果表现为优势树种的混交度、大小比和角尺度在各等级均有分布；伴生树种的混交度较高但优势度不高,但对于维持群落多样性有重要意义。(4)植物群落物种多样性与生长型的关系密切,物种多样性指数草本层>灌木层>乔木层；物种丰富度指数在海拔梯度上变化规律不明显；通过典范对应分析得出选取的地形因子对样点草本的影响程度大小依次为,坡向>海拔>坡度>坡位>坡形。(5)通过种群数量径阶频谱法对三种林分演替规律分析,结果表明,落叶松桦木混交林中,落叶松、白桦和黑桦为优势树种,演替受人为干扰影响较大；山杨桦木混交林中,白桦和黑桦的生长趋势良好,山杨数量最大,呈增长态势,是优势种,将向针阔混交林演替；油松蒙古栎混交林中,油松为优势树种,幼苗更新良好,是典型的进展种,蒙古栎属于巩固种,该群落近似为顶级群落。(6)结构的研究是为森林的健康可持续经营提供理论基础,本文将点格局理论和林木空间结构理论结合起来,以健康稳定的森林结构特征为约束,通过对健康森林生态系统和顶级群落结构特征的分析和模拟,得出森林生态系统的结构最优化模式；对林木水平分布格局、树种组成和竞争关系的调整使得森林生态系统达到结构化最优。更多还原

【Abstract】 Structure decides a function, the structure is composed of forest ecosystem elements of an important organizational form. This study In allusion to the Shelter forest structure unreasonable, Ecological degradation problems. function, Studied internal structure features of three typical Superiority species trees (pinus mongolian oak mixed forest, L.gmellini and Betula mixed forest, Pobulus davidiana and Betula platyphylla Suk mixed forest) with the principle of structure decides function.provide the reference for solving the forest ecology construction and forest production. Its main research results are as follows:(1) Using One hectare sample surveys, Investigated and analyzed the characteristics of species composition and diversity, diameter structure, the the height structure. Prediction and fitting height and diameter distributions Using Weibull distribution function. Diameter distribution for approximate reverse "J" form distribution, normal distribution and petronas or the single-peak mountain shape distribution, tree height distribution for normal distribution, approximate normal distribution, the single-peak or diauxie curve distribution.(2) Typical forest trees fractal characteristics research shows that:there are differences in the shape of the crown in three species of forest, the same species differences between individuals of different ages. Acerola crown picture of fractal dimension is greater than the fractal dimension of broadleaf. dahurian larch (1.690)>black birch (1.257)> White Birch (0.997) distribution regularity of the Quantity and Angle are different in different species. Different species of fractal dimension branching pattern is different,the same tree species have different fractal dimension in the same sample plot. This is the result of genetic nature and external environment.(3) Using Mingling index, Uniform Angle Index, Neighborhood Compariso and point pattern analysis method to study the typical forest types community space structure. The results show the Superiority species distribution in various ranks in Mingling, Uniform Angle Index, Neighborhood Compariso. Associated tree had low degree in Mingling index, but have the important meaning to maintain community diversity.(4) The type of plant species diversity is closely related to growth. Species diversity index of herb layer> shrub layer> tree layer; species richness index in variation of the altitudinal gradient is not obvious; Canonical correspondence analysis obtained by the selected sample herbal topography on the order of the degree of influence:aspect> elevation> slope> slope> slope shape.(5) Throughing of spectrum analysis population diameter class analyzes the three stand-order of succession regular:showing that the mixed forest of larch birch, larch, white birch and black birch were the dominant tree species, succession influenced by human disturbance is serious, in aspen birch mixed forest, birch and black birch has a good growth trend.,aspen has the largest number, showing a rising trend,,is the dominant species, it will Success to conifer; in the mixed forest of Quercus mongolica and Pinus, pine is the dominant tree species, seedlings appears a good update, is a typical species of progress,Mongolian oak species belonging to consolidate, the community is approximately the top community.(6) The research of structure provides the basis of theory for sustainable management of forest health,this article combines the research of point pattern theory and the theory of forest spatial structure, the healthy and stable forest structure as constraint, viaing analyze and simulate the forest ecosystem health and Top-level community structure,reach the conclusion that structural optimization model of forest ecosystem;The adjustment of horizontal distribution pattern of trees and species composition and relationship of competition makes the structure of forest ecosystems to achieve optimal.更多还原