【摘要】 以福建武夷山典型常绿阔叶林1.44 hm2固定样地调查数据为基础,从群落物种组成、区系特征、径级结构和空间分布格局等4个方面分析该地区常绿阔叶林物种组成和群落结构,结果表明:样地内共有胸径≥1 cm的木本植物139种9,116株,隶属于34科65属;样地内有稀有种23种,偶见种46种,优势树种不明显。区系特征明显,科级与属级地理成分以温带性质较强。群落及重要值>3的12个植物种群径级结构呈倒"J"字型。从物种的空间分布格局来看,这12个植物种群和4个主要种群的大、中、小径木都表现出明显的集聚分布,但集聚度有所差异。大部分物种随着径级的增加集聚度变小。更多还原

【Abstract】 Subtropical evergreen broad-leaved forest typically forms in subtropical areas of the eastern coasts of continents which usually experience moist and monsoon climate conditions. This kind of forest is one of several representative vegetation types in China,which has the largest area covered by this kind of vegetation in the world. Even though subtropical evergreen broad-leaved forest is one of the key areas of biodiversity in China and is characteristic of much of the Wuyi Mountains,few studies have reported the species composition and community structure of this mountain range.Recently,dynamic monitoring of forest biodiversity has attracted increased attention of scientists and is known to provide detailed data for understanding the species composition and the community structure of these forests. In July,2011,a 1. 44hm2( 120 m × 120 m) permanent forest plot( 27°35’37″N,117°45’54″E,alt. 470—520 m) was established in the WuyiMountains for long-term monitoring of plant diversity. Parameters for each individual woody plant with DBH ≥ 1 cm was recorded,including the number of individuals in the plot,position,diameter at breast height( DBH),plant height,height under living branch,forest health condition and so on. Using our field data,the species composition and community structure of this plot were analyzed based on the species composition,floristic characteristics,size class structure and spatial patterns of the area. A total of 9,116 individuals( 1896 branches of trees with trunks in the plots were also included) were found,belonging to 139 species,65 genera and 34 families. Of the 139 species found,only one was a gymnosperm( Cunninghamia lanceolata( Lamb.) Hook.) and only one was a monocot( Phyllostachys edulis( Carrière) J.Houzeau); the rest were dicots. Twenty-three rare species( ≤ 1 individual / hm2) and 46 accidental species( 1—10individuals / hm2) were found in the plot,individuals of which together accounted for 2. 8% of the total individuals in the plot. For common species( > 100 individuals / hm2),Syzygium buxifolium Hook. & Arn. was most common with 601 individuals or 6. 6% of the individuals in the plot,while Altingia gracilipes Hemsl. had the fewest individuals( 156,1.7%) for a common species. No species appeared to be dominant in the plant community,as suggested by the abundance,basal area,the average DBH and importance values of the 139 species. However,the floristic characteristics of the plant community were very important; strong temperate aerial-type species were found at both the family- and genus-level,and a few tropical aerial-type species were intermixed. The size distribution of 12 species with importance value that higher than 3followed a reverse "J "shape. An evident difference was observed between the number of individuals and species that present with different size classes. For the entire plot,only 3. 89% of all individuals had a large DBH( > 20 cm),while73. 89% of all individuals had a small DBH( 1 cm ≤ DBH < 6cm). In addition,spatial pattern analysis showed the 12 tree species with high importance values and the large-diameter,mid-diameter and small-diameter trees of the four main species( Engelhardia fenzelii Merr.,Castanopsis carlesii( Hemsl.) Hayata,Castanopsis fordii Hance,S. buxifolium) were aggregated,and aggregation intensity decreased as DBH increased.更多还原