β-diversity of the herbaceous layer plant communities in natural forests and its influencing factors in Henan Province

Conducting research on β-diversity(beta diversity)and its components, which reflect spatial or temporal variations in species composition among communities, helps to improve the understanding and knowledge of community structure and its maintenance mechanisms. The herbaceous layer of forest is an important part of forest community and forest ecosystem. Although some studies have been conducted on β-diversity of the understory herbaceous plant communities, there is still a lack of consensus on the proportion of β-diversity components such as turnover and nestedness components, as well as the influencing factors and the extent of their impact on β-diversity. This study was based on the survey data of herbaceous layer plant communities from 168 natural forest plots in Henan Province. It analyzed the β-diversity patterns of herbaceous layer in natural forests in Henan Province using Jaccard dissimilarity index, variance partitioning and other methods, and quantified the relative contributions of influencing factors such as spatial distance, environmental factor, and species richness to its β-diversity. The results were as follows:(1)The total β-diversity(as measured by the Jaccard dissimilarity index)of the herbaceous layer plant communities in natural forests was 0.94, which was mainly derived from the species turnover component(accounting for 96.8% of the total β-diversity).(2)The total β-diversity and its species turnover component of plant communities in the herbaceous layer of natural forests showed a significant increasing trend with increasing spatial distance, while the nestedness component showed a significant decreasing trend with increasing spatial distance.(3)Mantel test showed that spatial distance, environmental factor, and species richness had significant effects on the total β-diversity of plant communities in the herbaceous layer of natural forests, with environmental factor, spatial distance, and species richness having the greatest, second, and least effect, respectively; variance partitioning results further showed that spatial distance, environmental factor, and species richness accounting for 27.14% and 20.35% of the variation in total β-diversity and its turnover component, respectively, with environmental factor alone accounting for the most variation(10.62% of total β-diversity and 9.35% of turnover component). This study helps to enhance the understanding of the variation rules of plant composition in the herbaceous layers of natural forests and its influencing factors, thereby providing a solid scientific basis for the protection and management of forest vegetation and ecological restoration.