鼎湖山南亚热带常绿阔叶林不同树种存活对邻体组成的响应差异 / Difference in survival response of tree species to neighborhood crowding in a lower subtropical evergreen broad-leaved forest of Dinghushan
理解群落结构和动态的主导机制是生态学研究的基本目标之一。群落内树种的存活受到其邻近树木的显著影响。为探究不同树种的存活对邻体组成的响应差异, 本研究基于鼎湖山南亚热带阔叶林20 ha森林动态监测样地中常见的90个树种的存活监测数据和功能性状数据, 建立了一系列关于邻体效应的树种存活模型。结果表明: 约58%的树种存活对邻体组成有敏感的响应, 共存树种间的功能性状差异影响着50%的树种存活动态。不同树种对邻体组成的响应差异与其耐阴性相关, 耐阴能力较弱的树种更倾向于表现出对邻体的敏感性。低比叶面积、高叶干物质含量、木材密度和最大胸径意味着较强的耐阴能力, 与光资源利用策略有关的生态位分化可能是邻域尺度上物种共存的原因。本研究为量化邻体间的相互作用和解释局域群落的物种共存提供了新的视角。
Identifying the mechanisms that drive community structure and dynamics is one of the most fundamental goals in ecology. The local neighborhood in which trees grow significantly influences species survival. In order to understand the mechanisms underlying the various survival responses to neighborhood crowding among species, we compared the survival responses of focal tree species through modeling tree survival in terms of neighborhood effects. These effects were quantified in different ways, based on the survival monitoring and functional trait data of 90 species commonly observed in a lower tropical evergreen broad-leaved forest 20-ha plot in the Dinghu Mountains. We found that among all species tested, 58% showed sensitivity to neighborhood effects and that the survival response of 50% were mediated by functional trait differences among co-occurring species. Shade tolerance of species is associated with species sensitivity to its neighborhood as species with lower shade tolerance are intended to be sensitive to their neighbors. Lower specific leaf area, higher leaf dry matter content, wood density and maximum diameter at breast height indicate higher shade tolerance. Niche difference associated with light acquisition strategies may underlie species coexistence at the neighborhood scale. Our study provides new insights into quantifying neighborhood interaction and species coexistence at the local neighborhood scale.