四川盆周山地5种典型林分的植物多样性分析

Analysis of plant diversity of five typical forests in mountain areas around Sichuan basin

【目的】了解四川盆周山地西缘5种典型林分(杉木Cunninghamia lanceolata林、柳杉Cryptomeria fortunei林、杉木-柳杉混交林、人工-天然混交林、天然次生林)林下植物多样性的现状和差异。【方法】选择立地条件和林龄相近的5种典型林分,进行灌木和草本物种多样性调查,计算其物种丰富度、Shannon-Wiener、Simpson和Pielou指数,采用单因素方差分析和多重比较分析林分之间的物种多样性差异,用Jaccard相似性指数来衡量林分之间的物种相似性。【结果】1、人工林(杉木林、柳杉林、杉木-柳杉混交林)的草本优势种均为蕨类,如红盖鳞毛蕨Dryopteris erythrosora、尖头蹄盖蕨Athyrium vidalii;人工林的优势灌木主要为耐荫的常绿种类,如西南红山茶Camellia pitardii、川黔尖叶柃Eurya acuminoides;天然次生林优势灌木为喜阳的先锋种类,如高粱泡Rubus lambertianus、川莓R.setchuenensis。2、天然次生林的林下灌木层和草本层物种多样性高于其余4种林分,其灌木层和草本层的物种丰富度指数分别为4.37、4.63,Shannon-Wiener指数分别为1.20、1.29,Simpson指数分别为0.63、0.67。3、杉木林、柳杉林、杉木-柳杉混交林、人工-天然混交林4种林分之间灌木层的Shannon-Wiener指数和Simpson指数均无显著差异(P>0.05),4种林分的草本层Shannon-Wiener指数和Simpson指数亦无显著差异。4、3种人工林之间(杉木林和柳杉林、杉木林和杉木-柳杉混交林、柳杉林和杉木柳杉混交林)的相似系数分别为19.35%、23.60%和21.95%,大于其他林分之间的群落物种相似系数。【结论】1、在四川盆周山地西缘5种典型林分中,天然次生林林下的物种多样性水平最高。2、杉木林、柳杉林、杉木-柳杉混交林、人工-天然混交林的林下物种多样性水平相当。

【Objective】To understand the current status and differences of understory plant diversity of five typical forests(Cunninghamia lanceolata plantation,Cryptomeria fortunei plantation,Cunninghamia lanceolata-Cryptomeria fortunei mixed plantation,artificialnatural mixed forest,and natural secondary forest)in the western hill area around the Sichuan basin.【Method】An investigation was conducted into five typical forest plots with similar site conditions and ages to explore the shrub and herb diversity.The species richness index,Shannon-Wiener index,Simpson index,and Pielou index of five forest plots were calculated.We compared the species diversity in those five forest plots by ANOVA and multiple comparison,and used the Jaccard coefficient to infer the similarity of species in those forest plots.【Result】1、The most dominant herb species under C.lanceolata plantation,C.fortunei plantation,and C.lanceolata-C.fortunei mixed plantation were fern species,such as Dryopteris erythrosora and Athyrium vidalii;The dominant shrub species under C.lanceolata plantation,C.fortunei plantation and C.lanceolata-C.fortunei mixed plantation were mainly shade-tolerant and ever green species,such as Camellia pitardii and Eurya acuminoides;The dominant shrub species under natural secondary forest were shade-intolerant and pioneer species,i.e.,Rubus ambertianus and R.sutchuenensis.2、The understory species diversity in the natural secondary forest showed the highest level in those five forest types.Besides,the species richness index of shrub and herb layers in the natural secondary forest were 4.37 and 4.63,the Shannon-Wiener index were 1.20 and 1.29,and the Simpson index were 0.63 and 0.67,respectively.3、There were no significant differences(P>0.05)of shrub and herb layers in Shannon-Wiener index and Simpson index among C.lanceolata plantation,C.fortunei plantation,artificial-natural mixed forest,and C.lanceolata-C.fortunei mixed plantation.4、The Jaccard coefficient between C.lanceolata plantation and C.fortunei plantation,C.lanceolate plantation and C.lanceolata-C.fortunei mixed plantation,C.fortunei plantation and C.lanceolata-C.fortunei mixed plantation were 19.35%,23.60%,and 21.95%,respectively,which had higher Jaccard coefficient than other forest plots.【Conclusion】1、Of the five typical forests in the western hill area around the Sichuan basin,natural secondary forest exhibited the highest species diversity.2、C.lanceolata plantation,C.fortunei plantation,C.lanceolata-C.fortunei mixed plantation,and artificialnatural mixed forest showed the close species diversity levels.