Study on the β Diversity of Secondary Natural Forest Communities in an Earthy-rocky Mountainous Region in West Shanxi Province

In this paper,the species richness and β diversity of arbor communities at different altitudinal gradients in an earth-rocky mountainous region in west Shanxi Province are analyzed.The results reveal that the species richness of all the ligneous plants decreases with the increase of altitude.The richness of tree species in the communities in the regions with high altitude is high,but the richness of shrub species in the communities in the regions with low altitude is high.The research results reveal that the Cody indexes and Whittaker indexes of β diversity of the neighboring plant communities are the lowest in the study area,but the higher the altitude difference between the plant communities are,the higher the index values will be.Contrarily,the similarity indexes including the Jaccard and Sorenson indexes are increased with the increase of altitude difference between the plant communities.The study results of the β diversity of plant community can provide a theoretical basis for vegetation regeneration in the Loess Plateau.