极小种群植物水松群落系统发育多样性分析

极小种群植物水松（Glyptostrobus pensilis（Staunton ex D.Don）K.Koch）是著名的孑遗植物,被列为我国Ⅰ级重点保护和极小种群野生植物,在IUCN红色名录中被评估为"极危"等级,且种群数量仍在继续减少。水松主要分布于我国华南和东南地区以及越南和老挝。本研究对我国42个水松种群周边植被、种群健康状况、群落干扰类型、外来植物入侵状况等进行了调查,采用系统发育多样性相关指数对该物种所在群落进行了研究。结果显示,系统发育多样性指数对水松种群状况具有一定的指示性,人为干扰对所在群落的影响越严重,种群的健康状况愈差;具有较高系统发育多样性水平（PD值）的群落内水松种群状况良好;入侵物种的存在会使群落系统发育结构聚集,系统发育多样性水平降低。因此,在对水松种群进行保护时,要尽量减少群落中人为恶性干扰因素和外来植物的入侵威胁,以增强水松种群和个体的健康水平,维持群落系统发育的多样性,从而提高水松种群抵抗力和恢复力的稳定性。

Phylogenetic diversity analysis of the community of extremely small populations of Glyptostrobus pensilis

Glyptostrobus pensilis (Staunton ex D. Don) K. Koch, also called the Chinese swamp cypress or water pine, is a well-known relict plant and "living fossil". It is listed as a "Grade Ⅰ" wild plant under the state key protected list, and is only known from extremely small populations in South and South-East China, as well as Vietnam and Laos. It is also categorized as "Critically Endangered" with a decreasing trend according to the IUCN evaluation criteria. We investigated the community vegetation, health status, disturbance factors, and alien invasive plants of 42 wild populations of G. pensilis in China in 2016. Community phylogenetic diversity analysis indicated that the health status of the G. pensilis populations was related to the degree of threat of anthropogenic disturbance. In addition, populations with high phylogenetic diversity values were always in good condition. The presence of alien invasive species in the community will make the phylogenetic structure clustered and result in the decrease of the phylogenetic diversity value. It should be noted, therefore, that the exclusion of anthropogenic activities and elimination of alien invasive plants will improve the health status of populations and individuals, increase the phylogenetic diversity of the community, and enhance the resistance and recoverability of G. pensilis populations.