不同林龄杉木人工林林下灌木和草本物种组成及多样性分析

Species Composition and Diversity Analysis of Undergrowth Shrubs and Herbs in Cunninghamia lanceolata Plantations of Different Ages

选取广西壮族自治区融水县不同林龄的杉木Cunninghamia lanceolata人工林为研究对象,为深入了解不同林龄杉木林下群落多样性、群落演替以及对其生态效益提供理论技术支撑,采用典型抽样法,对林下植物物种组成和植物多样性进行调查研究。结果表明:4种不同林龄(3、7、13、17 a)杉木人工林林下物种共40科53属60种,3 a林物种总数最多,17 a林最少,两种多样性指数与均匀度指数均随林龄增加产生明显波动。杉木人工林下灌木层中粗叶榕Ficus hirta、大青Clerodendrum cyrtophyllum在各林龄中均有分布且占较大优势,鸭脚木Schefflera heptaphylla在17 a林下占绝对优势;林下草本层中狗脊Woodwardia japonica和乌毛蕨Blechnum orientale在各林龄均有分布,3 a林以五节芒Miscanthus floridulus为主,17 a林以金毛狗Cibotium barometz占绝对优势。灌木Shannon-Wiener指数和Simpson指数在3 a和7 a林均大于草本。灌木与草本的Piolou指数和Alatalo指数存在一定的差异。随着杉木林林龄增加,林下物种群落的共同物种和群落相似系数逐渐下降,17 a林下群落与其他林龄群落相似度低已趋于稳定。

Cunninghamia lanceolata plantations of different ages in Rongshui,Guangxi were selected as the research objects.In order to understand the community diversity,community succession of C.lanceolata plantations of different ages and provide theoretical and technical support for their ecological benefits,the species composition and plant diversity of undergrowth plants were investigated by using typical sampling method.The results showed that there were 60 species in 53 genera of 40 families in 4 different ages(3,7,13,17 a)of Chinese fir plantations.The total number of species in 3 a forest was the most,while that in 17 a forest was the least.The two kinds of diversity index and evenness index fluctuated significantly with the increase of age.Ficus hirta and Clerodendrum cyrtophyllum in the shrub layer under the C.lanceolata plantation are distributed and dominant in all ages,and Schefflera heptaphylla has an absolute advantage under the 17 a forest;Woodwardia japonica and Blechnum orientale in the understory herbaceous layer are distributed in all forest ages.The 3 a forest is dominated by Miscanthus floridulus,and the 17 a forest is dominated by Cibotium barometz.The Shannon-Wiener index and Simpson index of shrubs were higher than those of grasses in 3 a and 7 a forests.There is a certain difference between the Piolou index and the Alatalo index of shrubs and herbs.With the increase of the age of C.lanceolata plantations,the common species and community similarity coefficients of the understory communities gradually decreased,and the low similarity between the understory communities and other forest age communities in 17 a has stabilized.