植物群落构建机制研究进展

群落构建研究对于解释物种共存和物种多样性的维持是至关重要的,因此一直是生态学研究的中心论题。尽管近年来关于生态位和中性理论的验证研究已经取得了显著的成果,但对于局域群落构建机制的认识仍存在很大争议。随着统计和理论上的进步使得用功能性状和群落谱系结构解释群落构建机制变为可能,主要是通过验证共存物种的性状和谱系距离分布模式来实现。然而,谱系和功能性状不能相互替代,多种生物和非生物因子同时控制着群落构建,基于中性理论的扩散限制、基于生态位的环境过滤和竞争排斥等多个过程可能同时影响着群落的构建。所以,综合考虑多种方法和影响因素探讨植物群落的构建机制,对于预测和解释植被对干扰的响应,理解生物多样性维持机制有重要意义。试图在简要回顾群落构建理论及研究方法发展的基础上,梳理其最新研究进展,并探讨整合功能性状及群落谱系结构的研究方法,解释群落构建和物种多样性维持机制的可能途径。在结合功能性状和谱系结构研究群落构建时,除了考虑空间尺度、环境因子、植被类型外,还应该关注时间尺度、选择性状的种类和数量、性状的种内变异、以及人为干扰等因素对群落构建的影响。

Research advances in plant community assembly mechanisms

The study of plant community assembly is integral for understanding species coexistence and biodiversity maintenance, and it has long been a central issue in community ecology. The mechanistic theories of community assembly generally fall into two classes: niche theory and neutral theory. Although validation studies of niche theory and neutral theory have achieved great advances in recent years, some difficulty remains in understanding the mechanisms of local community assembly. Advances in statistics and theory make it possible to infer community assembly mechanisms based on functional traits and phylogenetic structures, by testing the dispersion patterns of trait and phylogenetic distance among co-occurring species. Both trait and phylogenetic community methods share the same conceptual approach. The observed distribution of either traits or phylogenetic distances within a local community is compared to a null expectation generated by drawing species at random from a regional pool of potential colonists. Deviations from the null expectation can be used as evidence for a number of ecological processes in the assembly of the local community. Both the approaches for measuring species differences can be aggregated at the community level to summarize the degree to which the constituent species differ in terms of their function, niche, or evolutionary history. However, traits and phylogenies provide different, and perhaps complementary, information in understanding patterns of community assembly. To adequately test assembly hypotheses, a framework integrating the information provided by functional traits and phylogenies is required. In addition, many biotic and abiotic factors (competition, facilitation) control community assembly. Different factors shape the distribution and abundance of species at different spatial and temporal scales. Multiple processes, including dispersal limitation based on neutral theory, and environmental filtering and limiting similarity based on niche theory, may simultaneously affect community assembly. The relative importance of these processes will differ among communities. The same process may cause opposing diversity patterns, and the same pattern may result from different processes. Therefore, it is important to simultaneously consider multiple methods and influence factors when exploring mechanisms of plant community assembly, predicting plant response to disturbance, and understanding biodiversity maintenance. In this paper, we provide a review of the histories, theories, methods, and new advances in community assembly explanations. We discuss ways to explain plant community assembly mechanisms by integrating functional trait and phylogenetic structure methods. We argue that time scale, number and type of traits, intraspecies trait variation, and interference should be considered in a study of community assembly, but spatial scale, environmental factors, and vegetation type need not be considered.