Objective Forest is a region with the richest biodiversity. Researches on plant diversity of different forest types are of great importance to study vegetation characteristics and its conservation. Xinfengjiang Reservoir is an important water source in South China, and forest in the reservoir area has an important role in biodiversity conservation and water purification. The analysis on species diversity of different forest types in the Xinfengjiang reservoir area can provide a scientific basis for the conservation and tending management of forests in the reservoir area.

Method Three types of typical forests, i.e., evergreen broad-leaved forest, coniferous and broad-leaved mixed forest and coniferous forest were selected as study areas. The tree, shrub and grass in the plots were recorded and species composition and diversity index were analyzed.

Result The species composition of forest vegetation in the Xinfengjiang reservoir area was relatively rich, with 47 families, 66 genera and 165 species recorded in the sample sites, among them, the numbers of species and individuals of Lauraceae, Fagaceae, Cupressaceae and Rubiaceae were higher. In general, species diversity showed a trend of evergreen broad-leaved forest > coniferous and broad-leaved mixed forest > coniferous forest. The species richness indexes of different forest types ranged from 19 to 32, the Shannon-Wiener indexes from 2.02 to 2.92, the Simpson dominance indexed from 0.77 to 0.92, and the Pielou evenness index from 0.69 to 0.85.

Conclusion The species diversity of evergreen broad-leaved forests in the reservoir area is high. Scientific and effective tending measures should be taken to promote coniferous forest succession reasonably. Long-term locational monitoring is also necessary to understand the relationship between forest and environmental factors. The study results can provide a scientific basis for conservation and utilization of biodiversity in the Xinfengjiang reservoir area.