公益林可通过改善林下植被及土壤状况而发挥显著的生态效益,目前,滇中公益林林下植物组成及土壤特征尚不明确,对滇中4种典型公益林(旱冬瓜林、云南松林、元江栲林、华山松林)林下物种组成和土壤理化性质进行调查和测定,分析其林下灌木、草本物种多样性和土壤性质的差异性,揭示其物种多样性与土壤性质的关系。结果表明:1)云南松林下物种组成最为丰富(灌木和草本种类均最高,多样性指数和丰富度指数均最大),灌木层和草本层物种多样性最低的分别为华山松林和元江栲林;2)4种公益林土壤有机质较为丰富,旱冬瓜林的土壤全量养分(TN,TP,TK)和AP含量显著高于其它林分,元江栲林的土壤容重及TN,TK,AK的含量均最低;3)影响公益林林下灌木物种多样性的关键土壤因子是土壤AP,TP,TK和容重,而影响草本物种多样性的关键土壤因子是土壤TP和pH值。滇中公益林林下物种多样性与土壤性质密切相关,应注重土壤酸碱性、紧实性及N,P,K的选择性调控,改善林下灌木和草本结构,实现最佳效益。

Public welfare forest can play a significant ecological benefit by improving the understory vegetation and soil conditions.However,the composition of understory plants and soil characteristics of the public welfare forests in central Yunnan are not clear.In this study,the species composition and soil physicochemical properties of four typical public welfare forests (Alnus Nepalensi,Pinus Yunnanensis,Castanopsis Orthacantha and Pinus Armandii)in Yuxi were investigated.The species diversity and soil properties of understory shrubs and herbaceous plants were analyzed,and the relationship between species diversity and soil properties was revealed.The results showed that:1)The species composition under Pinus yunnanensis forest was the most abundant (both shrubs and herbs had the highest number of species,both diversity index and richness index were the highest).The lowest species diversity in shrub layer and herb layer were Pinus armandii and Castanopsis orthacantha;2) the soil organic matter of four kinds of public welfare forest were rich,the contents of soil total nutrients (total nitrogen,total phosphorus,total potassium)and available phosphorus in Alnus nepalensis were significantly higher than those in other forests,the soil bulk density,total nitrogen,total potassium and available potassium contents of Castanopsis orthacantha were the lowest;3)Soil available phosphorus,total phosphorus,total potassium and bulk density were the key factors affecting shrub species diversity under public welfare forests,the key factors affecting herbaceous species diversity were soil total phosphorus and pH.Species diversity under public welfare forests in central Yunnan was closely related to soil properties.Attention should be paid to soil acidity-alkalinity,compactness and selective regulation of nitrogen,phosphorus and potassium,so as to improve the structure of understory shrubs and herbaceous plants to achieve the best benefits.