关键词: 常绿阔叶林, 群落类型, 物种多样性, 土壤理化性质

Abstract: To better understand species diversity and soil physicochemical properties of evergreen broad-leaved forests in Bifengxia scenic spot, Sichuan Province, and thus put forward a reliable method for forest management and biodiversity protection, we used typical sampling method to investigate 27 plots. Through clustering and sorting, the plots were classified objectively. On this basis, we explored species diversity and soil physicochemical properties of different community types. Six types were classified when Bray-Curtis distance was 0.53, i.e., Symplocos sumuntia-Castanopsis fargesii community (Ⅰ), Symplocos sumuntia-Cyclobalanopsis glauca community (Ⅱ), Schima superba-Symplocos sumuntiacommunity (Ⅲ), Schima superba-Elaeocarpus japonicus community (Ⅳ), Castanopsis fargesii-Cunninghamia lanceolatacommunity (Ⅴ), and Castanopsis fargesii-Quercus serrata community (Ⅵ). The dominant species of each community was significantly different. Type Ⅲ had the highest diversity level; Types Ⅱ, Ⅵ and Ⅴ were in the middle; Types Ⅰ and Ⅳ had low diversity level. The soil in this area was relatively acidic and had ample water content. Soil total nitrogen, total phosphorus, total potassium and organic matter contents were the lowest in type Ⅲ. The nutrient contents of types Ⅰ and Ⅳ were in the middle, and type Ⅰ had the highest total phosphorus content. Types II and V had the highest total nitrogen, available phosphorus, total potassium, and available potassium contents. The results of redundancy analysis showed that organic matter, total nitrogen and soil water content were the main factors affecting species diversity of the community, which were significantly (P<0.05) or extremely significant (P<0.01) negatively correlated with each diversity index. In conclusion, species diversity of Types Ⅲ and Ⅵ were ranked first and second, respectively, but these diversity-rich vegetation consumed a lot of nutrients, which made the soil nutrient-deficient. The diversity level of Types Ⅰ and Ⅳ were low, and the community development trend was not good. Types Ⅱ and Ⅴhad a moderate level of diversity, and their soil fertility conservation were the best, indicating that they had the potential for the succession to climax community. We suggested that appropriate artificial measures should be taken to improve the ecological function and disturbance-resisting ability of stands.

Key words: evergreen broad-leaved forest, community type, species diversity, soil physicochemical property.