喀纳斯泰加林火成演替草本层与林冠层关系研究

Taiga forests in Kanas are the typical representative of boreal dark-coniferous forests in China and have obvious value of nature conservation and scientific research. Pyrogenic succession, acting as the main succession form in taiga forests, plays an indispensable significant role in maintaining forest ecological integrity on the essence of biodiversity. However, how the dynamic linkage of interaction between the herbaceous layer species diversity and overstory species diversity of forest community in the process of pyrogenic succession is not clear. This project thus to virgin taiga forest ecosystems in Kanas as the research object, taking forest fire disturbance, species diversity of the herbaceous layer and tree species diversity of overstory as an integral component, uniting composition and structure of overstory tree species and composition and structure of the herbaceous layer species in the process of pyrogenic succession, studies the linkage between species diversity of the herbaceous layer and tree species diversity of overstory among pyrogenic succession on the basis of time of historical fire disturbance and fire disturbance severity in dark-coniferous forest. The project aims at revealing the time response after the fire of taiga forest ecosystem to different fire disturbance severity, testing hypothesis of the dynamic linkage of interaction between the herbaceous layer species diversity and overstory species diversity of forest community in the process of pyrogenic succession, and clarifying the dynamic mechanism for the linkage between species diversity of the herbaceous layer and tree species diversity of overstory in different stages of pyrogenic succession. Through the above research, with a view to providing reliable theoretic basis and feasible scientific approaches as for the biodiversity conservation of taiga forests which has the unity of species diversity of forest vegetation strata. Further, this project has important scientific value and widening applicable future to the ecological sustainable management in taiga forests and the forest sustainable development in Kanas.

火成演替作为泰加林演替的主要形式,对以生物多样性为本质的森林生态完整性维持具有不可或缺的重要作用。但是，在泰加林火成演替过程中，森林群落草本层与林冠层物种多样性相互作用的动态关联性如何尚不清楚。为此本项目以喀纳斯泰加林生态系统为研究对象，将森林火干扰、草本层物种多样性和林冠层树种多样性作为统一体，并把火成演替过程中草本层物种组成及结构与林冠层树种组成及结构作为不可分割的整体，从森林历史火干扰发生的时间与火干扰烈度、生态系统对火干扰烈度的火后时间响应和群落演替过程中草本层与林冠层物种多样性的关系等方面进行研究，从而揭示泰加林生态系统对自然火干扰烈度的火后时间响应规律，检验火成演替草本层与林冠层物种多样性相互作用的动态关联性假设，阐明泰加林火成演替不同阶段森林群落草本层与林冠层物种多样性的动态关联性形成机制，以期为同泰加林植被层物种多样性相统一的森林可持续经营提供理论依据和切实可行的科学途径。

喀纳斯泰加林作为我国唯有的西西伯利亚山地南泰加林的代表，同分布于世界上寒温带地区的其它山地森林一样，火成演替作为森林演替的主要形式，对以生物多样性为本质体现的生态完整性维持具有不可或缺的重要作用。但是，在泰加林火成演替过程中，森林群落草本层物种与林冠层物种之间的连锁关系如何尚不清楚。鉴于此，本项目以喀纳斯泰加林火成演替群落为研究对象，基于火成演替群落典型样地调查，采用数量生态学方法，分析了影响喀纳斯泰加林火成演替群落物种分布格局的主要环境因子和火干扰因子，分类得到了泰加林火成演替群落的主要类型，构建了泰加林群落火成演替序列，解析了泰加林群落火成演替物种多样性特征，检验了“泰加林火成演替草本层与林冠层物种连锁关系”假设，并阐释了其物种连锁关系的成因。研究结果表明：（1）影响喀纳斯泰加林火成演替群落物种分布格局的主要因子是地形因子的海拔、土壤因子的全钾含量和体积含水量、火干扰因子的火烈度和火后时间；（2）可辨识的喀纳斯泰加林火成演替群落主要有6种类型，分属三个演替阶段，即：演替前期的阔叶针叶混交林阶段、演替中期的针叶阔叶混交林阶段和演替后期的针叶混交林阶段；（3）不同烈度火干扰后，泰加林火成演替群落草本层的物种丰富度均在演替前期最高，呈先减少后增加的趋势，林冠层的物种丰富度指数均在演替中期最高，呈先增加后降低的趋势；草本层的物种优势度指数均在演替前期最高，林冠层的物种优势度指数均在演替后期最高；林冠层的物种多样性指数均呈先增加后减小的趋势，且在演替后期达到最低；（4）火干扰后，泰加林群落演替过程中草本层与林冠层物种之间存在连锁关系，且连锁关系是由草本层和林冠层物种多样性格局对相同环境梯度响应的一致性而产生的。火烈度从强到弱，森林群落演替过程中草本层与林冠层物种连锁关系由弱变强，且随着演替的向前发展，连锁关系的紧密程度在增加。在国内外学术刊物上发表学术论文10篇，培养毕业研究生8名（其中博士研究生1名）。