Community And Phylogenetic Structure And Its Environmental Interpretation Of Evergreen Secondary Forest In The Liankang Mountains Natural Reserve

The study of the mechanism of species coexisting and community assembly is one of the major tasks in ecology,the niche characteristics and interspecific association can better explain the competition and utilization of resources in the community.Meanwhile,the study of community phylogenetic structure can reveal the relationship between species in the community.The evergreen broad-leaved forest of this study distributes in the Huaihe River Basin in the north-south transition zone of China and is also located at the northern edge of the northern subtropical.Therefore,the area has rich plant resources and complex forest ecology.The study of community numerical ecology characteristics and phylogenetic structure,which can contribute to the understanding of resource allocation and interspecific relationships,as well as understanding the structure,function and stability of communities,and provides important theoretical guidance for the restoration and protection of forest ecosystems and biodiversity conservation in the north-south transition zone of China.In this study,the evergreen broad-leaved forest at the northern edge of northern subtropical,China,were used as the research object.Fifty 20 × 20 m plots were established continuously.Based on a community survey,plant function traits and environmental factors,we conducted the study of community structure and phylogenetic community structure,respectively.The results show that:1.There are 56 species were recorded,belonging to 33 families and 47 genera,including 15 evergreens,45 deciduous plants,of which,Cyclobalanopsis glauca has the greatest important value and is the main constructive species of this community.The overall diameter class distribution of the community was inverted ‘J’ type.2.The variance ratio of community was above 1,which indicated a significant positive correlation among the community,and the chi-square test showed that the logarithm of positively linked species was more than the logarithm of negatively associated species,which was consistent with the results of Pearson correlation analysis and Spearman rank correlation analysis.There was a significant positive linear relationship between the Pearson correlation coefficient and the Spearman rank correlation coefficient between dominant species and their corresponding niche similarity and niche overlap values(P < 0.05).3.The niche characteristics of dominant species in the community were studied,and it was found that the Shannon niche breadth of Symplocos sumuntia was the largest with the Levins niche width,the Levins niche width of Liquidambar formosana Hance was the smallest,and the Shannon niche width of Alangium kurzii was the smallest.The species niche width ranking results were not consistent with the important value ranking results.The similarity value of species to niche in the community was less than 0.5,accounting for 88.39% of the total,and the overlap value of niche was less than 0.5,accounting for 80.21% of the total.The results showed that the overlap and similarity of niches between dominant species in the community were generally not large.4.The analysis of community phylogenetic structure showed that the NRI and NTI were significantly greater than 0(P < 0.01),showing a state of lineage aggregation,indicating that the deterministic process played a certain role in the community construction process,and the results of plant functional trait test showed that most traits had significant phylogenetic signals,indicating that the formation of traits was affected by evolution.5.The principal coordinates of phylogenetic structure and permutation test showed that superasterids and superrosids clades were the dominant in this community and soil p H、soil available nitrogen、soil total phosphorus and soil organic matter had significant effects on the community phylogenetic structure.6.The results of redundancy analysis displayed that the community of dominant species was significantly affected by soil organic matter、soil available nitrogen、soil total phosphorus、soil available potassium、soil available phosphorus and Aspect.The variance partitioning showed that soil total phosphorus was the largest factor affecting the distribution in this community.7.The mantel correlation analysis shows that the community phylogenetic β diversity distribution of evergreen broad-leaved secondary forest is significantly affected by the environment.Permutation multivariate analysis of variance shows soil p H、soil available nitrogen、soil total phosphorus、soil available potassium and soil available phosphorus are main environmental factors driving the distribution of community phylogenetic β diversity.