中亚热带天然阔叶林林层特征研究

The storey characteristics are the most important content of vertical forest structure. They play significant theoretical and practical roles in the research of inventory and community structure of multi-storied forests. Due to the difficulties of accurate measurement of tree height and crown in field, there were few researches in the quantitative techniques for the identification of canopy stratification and researches on storey characteristics were weakness. Based on the accurate measurement of tree height and crown of the demonstration stands, the different models and methods (such as TSTRAT model, Baker method and other clustering methods) and the three-dimension levels, quantitative techniques for the identification of canopy stratification in mid-subtropical natural broad-leaved forests will be studied. Based on quantitative techniques for the identification of canopy stratification, the storey characteristics (including mensuration and community characteristics) of each stratum in mid-subtropical natural broad-leaved forests and their effects to the storey characteristics of whole community will be studied, and correlation of the storey characteristics between each stratum in mid-subtropical natural broad-leaved forests will be analyzed. Based on the above research results, the techniques of inventory and analysis of storey characteristics in mid-subtropical natural broad-leaved forests will be discussed.

林层特征是森林垂直结构的最重要内容，在复层林调查和群落结构研究中都具有重要的理论和实践意义；由于野外准确树高和树冠测定的困难，林层定量划分技术方面的研究很少，国内外对林层特征的研究非常薄弱。本研究在对试验林分进行树高与树冠准确测定的基础上，采用不同的模型与方法（如TSTRAT模型、Baker方法和其他聚类方法等）不断尝试，从三维尺度上，研究中亚热带天然阔叶林林层定量划分技术；根据提出的林层定量划分技术，研究中亚热带典型天然阔叶林各林层特征（包括测树学与群落学特征）及其对全林的影响与贡献，并分析各林层特征之间的相关性；基于以上研究成果，探讨中亚热带天然阔叶林林层特征调查与分析技术。

林层特征是森林垂直结构的最重要内容，由于野外准确树高和树冠测定的困难，林层定量划分技术方面的研究很少，国内外对林层特征的研究非常薄弱。本项目主要研究内容：（1）现有林层划分方法对典型中亚热带天然阔叶林的适用性检验；（2）中亚热带天然阔叶林林层划分新方法——最大受光面法；（3）典型中亚热带天然阔叶林各林层直径分布；（4）典型中亚热带天然阔叶林各林层树高胸径关系；（5）典型中亚热带天然阔叶林各林层物种多样性与相似性；（6）典型中亚热带天然阔叶林各林层主要测树因子特征及蓄积量估测。本项目重要研究结果：（1）现有的林层划分方法（包括剖面图法，TSTRAT法，LMS法和各种聚类分析法等）对典型中亚热带天然阔叶林林层划分都不合适，难以反映其垂直结构的自然分异规律；（2）依据林木树冠是否接受到垂直光照和林木树冠接受到垂直光照的程度提出了林层划分新方法——最大受光面法，该方法揭示了典型中亚热带天然阔叶林垂直结构的自然分异规律，同时野外调查与确认简单易行，具有重要的理论与实践意义。（3）基于最大受光面法的林层划分结果，研究了典型中亚热带天然阔叶林各林层直径分布、各林层树高胸径关系、各林层物种多样性与相似性和各林层主要测树因子等主要林层特征。（4）基于最大受光面法的林层划分结果，还研究了典型中亚热带天然阔叶林分各亚层空间格局与关联性、基于分层的典型中亚热带天然阔叶林分局部生物多样性和种间关联性等林层特征。（5）基于最大受光面法，探讨了中亚热带天然阔叶林主要林层特征调查与蓄积量估测新技术。中亚热带天然阔叶林林层特征研究将为改进与完善中亚热带天然阔叶林调查、评价、监测和可持续经营技术提供重要基础依据。