黄土高原森林次生演替过程中基于功能性状的群落构建机制的演变

群落构建机制是群落生态学研究的中心论题，而群落演替则是正在进行中的动态群落构建过程。对次生演替过程中的群落构建机制及其变化的探索，不仅具有重要的理论意义，对退化生态系统的恢复与重建也有重要的实践意义。本研究针对黄土高原森林区的完整演替系列群落（从一年生草本群落到顶极群落6个演替阶段），基于多个维度的功能性状和环境因子，通过构建零模型、群落性状梯度分析、性状峭度比率以及核密度分布估计等方法，来检验确定性过程和随机过程、以及环境过滤和相似性限制在各个演替阶段群落构建中的相对贡献，并探讨在群落水平上功能性状对环境的响应，阐明环境因子对不同演替阶段群落构建过程的作用，同时验证我们提出的灌丛阶段是群落构建由随机过程向确定性过程转变的关键阶段的假说。本研究有望提供暖温带森林演替过程中群落构建机制变化的新证据，对丰富群落构建理论有重要的理论意义，同时也可为该区植被的恢复重建提供重要的理论依据。

Community assembly has long been a central issue in community ecology，and succession is community assembly in action. Exploring the mechanism of plant community assembly across secondary succession seres and the effect of environment factors on the change of community assembly are important in ecological theory and restoration and reconstruction of degraded ecosystem. Based on the multi-dimensionality of plant fuctional traits and soil and topoghrphy characteristics, the project will test the relative importance of deterministic and stochastic process, as well as environmental filtering and similarity constraint, across whole 6 successional stages from abandoned field to climax forest on the Loess Plateau of northern Shaanxi. By means of null model, community trait gradient analysis, traits Kurtosis-ratio and kernel density estimate, we attempt to inquire into the response of traits to environment at community level, to elucidate the effect of environment on community assembly of different successional stages, and to test the hypothesis that shrub is the key stage in which the deterministic and stochastic process of community assembly change over. The fulfillment of this study may provide new evidence of transitional assembly process in warm temperate forest zone and has a bearing on community assembly theory, and will simultaneously provide application basis to guide vegetation restoration and reconstruction in region of the Loess Plateau.