白龙江林区2种次生林群落组成与结构特征

分析白龙江林区2种次生林群落与结构组成,丰富该地区森林动态资料,为该地区生物多样性保护和生态恢复提供一定的科学依据。采用群落生态学研究方法,于自然恢复林中选取次生林栎林（LL）和桦木林（HM）2种林分,分别设置8块20 m×20 m固定样地,对胸径≥3 cm的林木进行每木检尺,计算群落多样性指数、特征值和相似性系数等指标。结果表明,HM和LL中树种丰富且在群落内空间分布比较均匀。LL中共有植物70种,属于46个属、26个科,以壳斗科、蔷薇科、松科、忍冬科为主;HM中共有植物63种,属于35个属、22个科,以桦木科、蔷薇科、松科、杨柳科为主。LL和HM径级结构均呈倒“J”型,群落个体主要集中在Ⅰ～Ⅲ级,Ⅴ龄级以后个体较少,表明2种群落均为增长型。2种次生林群落树种组成、空间结构存在异同,HM和LL群落均表现出多数种集中在少数科。说明试验林分植被恢复遵循群落演替动态规律,选择起源和演化具有相似性的树种作为建群种。建议在该地区搭配合理的其他树种,提高林分质量,加强次生林优势植物的利用。

Community Composition and Structural Characteristics of Two Secondary Forests in Bailongjiang Forest Area

To analyze the community composition and structure of two secondary forests occurring in Bailongjiang forest area,to enrich the dynamic data of the forest and to provide a scientific basis for the protection of biodiversity and ecological restoration.Based on the theory of community ecology,firstly,secondary oak forests (LL) and birch forests (HM) were selected from the naturally restoring forests,in which sample 8 plots with the size of 20 m×20 m were set up.Secondly,all the tally trees with the breast diameter greater than 3 cm were measured.Finally,diversity index,characteristic value and similarity coefficient of the trees were calculated.There were abundant tree species in HM and LL groups and their spatial distributions in the community were relatively uniform.Seventy plant species,belong to 26 families and 46 genera were observed in LL group,with the dominant family Fagaceae,Rosaceae,Pinaceae and Caprifoliaceae; 63 plant species were found in HM group,belonging to 22 families and 35 genera,with the dominant family Betulaceae,Rosaceae,Pinaceae and Salicaceae.The diameter class structures of LL and HM groups presented a “J” pattern.The community individuals were mainly concentrated in gradesⅠto Ⅲ,and there were fewer individuals large thanⅤgrade,indicating that the two groups were the growing type.Differences and similarities in tree species of composition and spatial structure existed between the two groups,in which most species were concentrated in a minority group of the family level.The vegetation restoration in the experimental forests followed the dynamic law of community succession,and tree species with similar origins and evolution should be selected as constructive species.Therefore,it was recommended to mix reasonable tree species in the secondary forests to improve the quality of the stands in Bailongjiang forest area to strengthen the use of dominant plants.