滨海湿地植物种群Allee效应驱动机制研究进展

Abstract

Allee效应是指生物个体适应度与种群规模或密度之间呈正向关联的现象, 因与植物种群动态和种群灭绝密切相关而受到生态学家的普遍重视。阐释多重胁迫下滨海湿地植物种群响应机制, 从保护生物多样性和维持生态系统稳定性层面发展系统性生态修复措施成为相关研究关注的重点。本研究分别从遗传过程、花粉扩散过程和生物互作关系不同层面, 总结分析了植物种群Allee效应驱动机制的研究进展。一方面, 植物因遗传过程中近交衰退、遗传变异丧失、有害突变累积等遗传结构改变造成繁殖失败而引发Allee效应；另一方面, 植物花粉扩散过程和动植物互作关系影响下的花粉限制也通过影响植物种群繁殖力成为驱动Allee效应的关键因素。滨海湿地水盐梯度变异及格局破碎化影响下, 植物种群遭受Allee效应的风险需引起关注, 维持滨海湿地植物种群适宜分布格局和生物连通过程成为缓解Allee效应的重要手段。结合生理学与化学生态学研究手段和长时间尺度动态监测技术, 有助于进一步阐释环境及生物等多重胁迫下Allee效应的非线性驱动机制。;Allee effect, the positive association between individual fitness and population size or density, has attracted more attentions from ecologists because of its closely relationship with plant population dynamics and population extinction. By explaining Allee effect of plant population under multiple stresses, developing systematic ecological restoration measures based on the biodiversity protection and ecosystem stability has become the focus of relevant research. This study systematically summarized the research results of different driving mechanisms of Allee effect in plant population in coastal wetlands based on genetic process, pollen dispersal process and plant-pollinator interaction. On the one hand, Allee effect was driven by reproductive failure due to genetic structure changes, such as inbreeding depression, genetic variation loss, and harmful mutations accumulation in the genetic process. On the other hand, Allee effect was caused by changes in plant population fecundity due to pollen limitation, which was affected by pollen dispersal process and plant-pollinator interaction. In the context of water and salt gradient variation and pattern fragmentation in coastal wetlands, it is conspicuous for the risk of Allee effect on plant population. It is important for alleviating Allee effect of plant population in coastal wetlands through providing suitable habitat, ensuring biological connectivity, and constructing population patches. Combination of physiological and chemical ecological research methods as well as long-term dynamic monitoring will help to further explain the nonlinear driving mechanism of Allee effect under multiple environmental and biological stresses.