摘要
本研究在神农架南坡建立1hm2的常绿阔叶林动态监测固定样地,分析了该群落的物种组成、区系特征、垂直结构、径级结构和空间分布格局.结果显示,群落物种丰富,共调查到维管植物216种,隶属78科154属,其中胸径≥1 cm的木本植物38科69属107种.区系成分中,热带分布的科、属分别占总科、属数的50.00％和40.58％;温带分布的科、属分别占总科、属数的34.21％和53.63％.常绿树种占比55.14％(59种),落叶树种占比44.86％(48种),其中常绿树种的多度、胸高断面积和重要值占比分别为82.23％、64.79％和73.03％.偶见种占比33.64％(36种),稀有种占比8.41％(9种).群落垂直结构明显,可分为乔木层、灌木层和草本层,各个层次物种丰富.径级结构呈倒"J"型,属于增长型群落.优势种的空间分布呈现出不同程度的聚集分布.研究表明,该群落的常绿树种重要值明显高于落叶树种,属于小叶青冈(Cy-clobalanopsis myrsinifolia Blume)+曼青冈(Cyclobalanopsis oxyodon Miq.)群系,是该区域代表性的常绿阔叶林.区系成分体现出神农架作为中亚热带和北亚热带分界线的特征.群落有着较好的更新能力,呈现向常绿阔叶林顶极群落演替的趋势.
Abstract
This study established a 1-hm2 fixed plot for dynamic monitoring of broad-leaved evergreen forest on the southern slopes of Shennongjia to examine the species composition,floristic characteristics,vertical structure,diameter class structure,and spatial distribution pattern of this community.Results revealed high species richness,with a total of 216 vascular plant species identified,belonging to 78 families and 154 genera.Of these,107 species were woody plants with a diameter at breast height(DBH)≥1 cm,distributed across 38 families and 69 genera.In terms of floristic composition,families and genera with tropical distribution accoun-ted for 50.00％and 40.58％of the total,respectively,while those with temperate distribution accounted for 34.21％and 53.63％,respectively.Evergreen tree species accounted for 55.14％(59 species),while deci-duous tree species accounted for 44.86％(48 species),with the dominance,basal area,and importance values of evergreen tree species being 82.23％,64.79％,and 73.03％,respectively.Occasional species ac-counted for 33.64％(36 species)and rare species accounted for 8.41％(nine species).The vertical structure of the community was well-defined,with distinct tree,shrub,and herb layers,each exhibiting high species rich-ness.The diameter class structure exhibited a reverse"J"shape,indicative of a growth-type community.Spa-tially,dominant species showed varying degrees of clustered distribution.This study indicated that the impor-tance value of evergreen tree species in the community was significantly higher than that of deciduous tree species,belonging to the Cyclobalanopsis myrsinifolia Blume+Cyclobalanopsis oxyodon Miq.community,rep-resenting a typical evergreen broad-leaved forest in the region.The floristic composition reflects the cha-racteristics of Shennongjia as the boundary between the subtropical and north subtropical zones.The commu-nity demonstrates robust regenerative capability,indicating a successional trajectory toward climax evergreen broad-leaved forests.
维普
万方数据