Effects of the Dominate Plant Families on Elevation Gradient Pattern of Community Structure in a Subtropical Forest

Abstract

Dominant groups and rare groups often coexist in forests. Dominate plant families generally have more species diversity and occupy most of the biomass. However, their effects on community construction and species diversity maintenance remain to be studied. This study aims to investigate this question by using the two dominant plant families in a Chinese subtropical forest (Lauraceae and Fagaceae). In this study, 22 forest dynamic plots were established in the forest distribution area of Daming Mountain Nature Reserve at an elevation of 300–1400 m. We explored the elevational change in the community structure and its relationship with Lauraceae and Fagaceae using generalized additive models (GAM) and a regression analysis. Then we used a correlation analysis to describe the relationship between environmental factors and the community structure. Our results showed the species diversity index showed a hump-shape trend along the elevation, and the total basal area showed no significant change along the elevation. The richness of Lauraceae and Fagaceae showed a positive correlation with the species diversity, but only the richness of Fagaceae showed a positive correlated with the total basal area. Species diversity was positively correlated with soil total nitrogen and soil organic matter. Species diversity and the total basal area were negatively correlated with the soil pH. In summary, Lauraceae and Fagaceae are correlated for community structure, and this correlation is not affected by elevation. Fagaceae has played a more important role than Lauranceae. This study highlights the impact of dominant plant families on the forest community assembly along the elevational transect.