基于功能性状和系统发育的防城季节性雨林群落构建机制研究

Study on Community Assembly Mechanism of Seasonal Rainforest in Fangcheng Based on Functional Traits and Phylogeny

关键词:  植物功能性状  系统发育  群落构建  季节性雨林  零模型

Key words:  plant functional traits  phylogeny  community assembly  seasonal rainforest community  null model

摘要:

本研究以防城大石坪、妹仔田和那山子的季节性雨林群落为研究对象，对其组成种类及株高、胸径等功能性状进行测定。通过分析样地内的详细植物调查和系统发育分析，探讨了季节性雨林群落的构建机制和演化动态。研究表明，大石坪和那山子季节性雨林群落的净亲缘关系指数（NRI）和最近亲缘关系指数（NTI）均小于0，表明这两个群落的发育结构呈发散格局；而妹仔田季节性雨林群落的NRI指数和NTI指数大于0，表明群落的发育结构呈聚集格局。三个季节性雨林群落物种的株高（H）和胸径（DBH）功能性状指标的系统发育信号K值均小于1，说明物种功能性状受系统进化影响较小，物种功能性状未表现出较强的系统发育保守性。通过应用零模型分析，尽管不同群落类型的物种在DBH上差异不显著，但在H上部分群落间存在显著差异，暗示了不同环境和演化压力的作用。功能性状分析表明胸径和树高呈现趋同进化，而群落系统发育结构分析揭示了群落内物种的亲缘关系和演化历程，表明生境过滤和种间竞争对群落构建具有显著影响。通过系统发育多样性、功能性状和系统发育信号等分析，可为揭示季节性雨林群落构建的生态过程和演化机制提供重要依据。

Abstract:

This study investigated the seasonal rainforest communities in Dashiping，Meizaitian and Nashanzi of Fangcheng，focusing on their species composition and functional traits such as tree height (H) and breast height diameter (DBH). By conducting detailed vegetation surveys and phylogenetic analyses within plots, we explored the mechanisms of community assembly and evolutionary dynamics in seasonal rainforests. The results showed that the net?relatedness?index (NRI) and nearest taxon index?(NTI) of Dashiping and Nashansi seasonal rainforest communities are both less than 0，indicating that the phylogenetic structure of these two communities is divergent； while the NRI and NTI indexes of Meizitian seasonal rainforest community are greater than 0，indicating that the phylogenetic structure of the community is aggregated.The phylogenetic signal K values of two plant functional traits，H and DBH，of the three seasonal rainforest communities are all less than 1，indicating that species functional traits are less affected by phylogenetic evolution and do not show strong phylogenetic conservation. Through the application of null model analysis, although there were no significant differences in species DBH among different community types, significant differences in H were observed among some communities, suggesting the influence of different environments and evolutionary pressures. Functional trait analysis revealed convergent evolution of DBH and H, while community phylogenetic structure analysis revealed the phylogenetic relationships and evolutionary processes of species within the communities, indicating significant effects of habitat filtering and interspecific competition on community assembly. Habitat filtration and interspecific competitive exclusion jointly affect the community assembly processes of seasonal rainforest.The analysis of phylogenetic diversity，functional traits and phylogenetic signals can provide an important basis for revealing the ecological process and evolutionary mechanism of seasonal rainforest community.