Assembly Mechanism Of Forest Community Based On Phylogeny And Functional Traits

Community assembly has been the core topic of ecological research in the past 100 years what includes the ecological process of the formation of the interaction between all organisms and the environment in the forest.The Forest community assembly mainly includes stabilizing mechanisms and equalizing mechanisms,which represent two opposite processes of promoting species coexistence and drive competitive exclusion,and are two driving forces in the process of community assembly.At present,the research methods of community assembly mainly focus on phylogenetic development and functional traits.Based on the relationship between phylogeny and functional traits of plants in the community,and compared with the random zero model,the distribution pattern of phylogeny and traits can be judged,and the main ecological processes affecting the community assembly can be inferred.In addition,based on phylogenetic and trait methods,the level of community biodiversity and phylogenetic signal patterns can be understood to verify the process of community assembly from different aspects.Based on the 6 hm2 large sample plot of Jinzi mountain of Hubei Enshi national positioning observation and research station,this study combined the phylogenetic and functional traits to analyze the scale effect of community phylogenetic and functional traits on different sampling scales and diameter scales.At the same time,the diversity and distribution pattern of phylogenetic and functional traits were discussed at different spatial scales.In addition,the variation rules of functional traits were also studied at the level of family,genus,species,individual and leaf to comprehensively detect the driving forces in the community assembly process and reveal the internal community assembly mechanism.Results show:(1)The variation of interspecific leaf area and specific leaf area can reflect the spatial niche differentiation,which is conducive to the diversity maintenance of evergreen deciduous broad-leaved mixed forest.(2)Most of the variation of functional traits comes from interspecific variation,and species of the same family and genus generally have similar functional trait values.(3)Except SLA and LDMC,most functional traits show significant phylogenetic signals,indicating the significant influence of phylogenetic history.(4)The functional structure index of the seven traits increased with the increase of the sampling scale,showing a transition from mild aggregation to significant aggregation,and the phylogenetic structure of the community as a whole and at different diameters was mostly insignificant and mild aggregation.(5)Phylogenetic and functional traits diversity have obvious distance attenuation effect,diffusion restriction effect is not obvious,and habitat filtration plays a leading role on a large scale.(6)The diversity pattern of phylogeny showed a slight aggregation trend,while the diversity pattern of functional traits showed a significant divergence,and the structural differences of functional traits were obvious between communities.In conclusion,the stabilization mechanism in the Jinzi mountain sample community promoted the coexistence of multiple species,which was also beneficial to the coexistence of related species on a small scale,and resulted in the differentiation of community functional character structure on a large scale.The equalization mechanism leads to competitive exclusion at small scales and among individuals of the same size.