Journal of Plant Ecology ›› 2023, Vol. 16 ›› Issue (5): 0-.DOI: 10.1093/jpe/rtad008

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  • 收稿日期:2022-12-20 修回日期:2023-01-23 接受日期:2023-02-13 出版日期:2023-10-01 发布日期:2023-02-23

Seven-decade forest succession reveals how species colonization and extinction drive long-term community structure dynamics

Shan Rao1, Xin-Yu Miao2, Shu-Ya Fan1, Yu-Hao Zhao1, Chi Xu2,3,*, Shao-Peng Li1,*   

  1. 1Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China;
    2School of Life Sciences, Nanjing University, Nanjing 210023, China;
    3Breeding Base for State Key Lab. of Land Degradation and Ecological Restoration in northwestern China; Key Lab of Restoration and Reconstruction of Degraded Ecosystems in northwestern China of Ministry of Education, Ningxia University, Yinchuan 750021, China

摘要: 在过去的几十年中,揭示群落谱系和功能性状结构如何随着演替变化引起了广泛关注。但长期动态数据的缺乏限制了我们对于群落格局和构建机制的理解,这一问题在森林群落中尤为突出。本研究基于南京灵谷寺森林1951、1981、2002和2019年的定点样带调查数据,分析了这一中国东南部亚热带森林68年的次生演替动态。研究发现,随着演替的深入,群落谱系和性状结构呈现相反的变化趋势。尽管近缘物种间的谱系距离在下降,物种间的平均谱系距离却在增加,群落谱系结构整体上趋于发散。相反,无论用平均还是最近距离作为度量,物种间的性状距离均随着演替逐渐下降,群落功能性状结构趋于聚集。我们进一步拆分了物种定殖和丧失对群落谱系和性状结构动态的相对贡献。结果表明:谱系结构趋于发散主要是由于定殖的物种本身亲缘关系较远,也和群落中原有的物种有着较远的亲缘距离;性状结构趋于聚集主要是因为那些与群落中原有的物种性状相似的物种具有更高的定殖机会但从群落中丧失的概率却更低。这一研究结果表明,拆分物种定殖和丧失过程是解开长期演替进程中群落动态和构建机制的关键。

关键词: 群落构建, 竞争, 环境过滤, 森林演替, 谱系结构, 功能性状

Abstract: Understanding how community phylogenetic and functional structures change over succession has gained increasing attention during the last decades, but the lack of long-term time-series data has limited our understanding of the patterns and mechanisms of these changes. This is especially the case for forest communities. Here, we used an exceptionally long-term data over 68 years to analyze the secondary succession dynamics of a subtropical forest in Southeast China. We found that community phylogenetic and functional structures showed opposite temporal trends. The mean pairwise phylogenetic distance between species increased, but the mean nearest taxon distance decreased over succession, indicating both phylogenetically distantly related and sister species co-occurred in late-successional communities. In contrast, both the mean pairwise functional distance and mean nearest functional distance between species decreased over time, and community functional structure switched from overdispersion to clustering. We further distinguished the contributions of species colonization and extinction to community structural changes. We found that the new colonists were generally more distantly related to each other and to the residents than the local extinct species, resulting in increased phylogenetic overdispersion over succession. In contrast, from a functional perspective, we found that species with more similar traits to the resident species had a greater chance to colonize but a lower chance to go locally extinct, which shifted community functional structure toward clustering. Together, our study highlights the critical role of species colonization and extinction in disentangling assembly mechanisms underlying community phylogenetic and functional structures over long-term succession.

Key words: community assembly, competition, environmental filtering, forest succession, phylogenetic structure, functional traits