秦岭山地华山松林群落学特征研究

以秦岭南坡华山松群落为对象，分析了其群落特征，结果表明，华山松群落共容纳种子植物166种，分属51科111属，区系组成丰富；在植物区系地理成分上，属的分布类型以温带性质居多，共65个，占总属数的66．7％，表明了群落植物区系组成的温带亲缘；在群落外貌特征上，华山松群落高位芽植物最多，占75．9％，叶级以中型叶为主，共96种，占57．8％，叶型以单叶为主，共139种，占83．7％；群落可分为乔、灌、草3个层次，亦有层间植物伴生；随年龄增长，群落中华山松种群空间结构呈集群分布→随机分布→集群分布变化，聚块指标变化不大，其聚块面积在100m^2左右波动；种群格局强度随年龄阶段变化缓慢，处于较弱的生境异质性变化状态中；尽管缺失某些年龄阶段的幼数、幼苗现象存在，华山松林作为一个稳定群落在该区域仍占有优势地位。

Community characteristics of Pinus armandi forest on Qinling Mountains

The community characteristics of Pinus armandi forest distributed on the mid-west zone of Qinling Mountains' south slope were investigated.The results showed that there were 166 seed plants belonging to 51 families,111generas.Among them,65 genera,66.7% of the total,belonged to temperate biome.There was a closely relationship between Pinus armandi forest and the temperate biome.As regards to the physiognomy of the community,phanerophyte made up 75.9% of the total,dominating the community.In the community,96 species with middle-sized leaves made up 57.8%,and there were 139 single leaf species,accounted for 83.7% of the total.There was a complicated vertical structure in the community,which could be divided into three layers:arbor layer,shrub layer and herb layer.In addition,there were also a lot of inter-stratum plants in the community.It is also found that the lack of seedlings,saplings and small trees was due to both the self-thinning caused by intra-specific competition and the alien-thinning by inter-specific competition for the light resource in the stand.The population of P.armandi was characterized with the patch size about 100 m 2.The dynamics of the community showed that the community was stable and in a process of development.