灵空山油松-辽东栎林乔木树种群落学特征及空间分布格局

参照CTFS技术规范对灵空山自然保护区油松(Pinus tabuliformis)-辽东栎(Quercus wutaishanica)林的乔木进行每木调查的基础上分析了不同乔木树种的群落学特征及空间分布格局。结果表明,4hm2样地中共有乔木树种25种,总计8210株。隶属于12科18属,种的区系以东亚、温带亚洲及中国特有分布类型为主。油松、辽东栎是群落中的共优种,个体占总个体的86.81%,杜梨(Pyrus betulifolia)、白蜡树(Fraxinus chinensis)、漆树(Toxicodendron vernicifluum)为群落中主要的伴生种。优势种的径级结构与所有乔木个体的径级结构相似,近似于倒"J"形,以小径级个体居多,林下更新良好。主要树种的空间分布格局在小尺度上表现为聚集分布。油松小径级个体在20 m以内的尺度上呈聚集分布,当空间尺度超过60 m时表现为随机分布,大径级个体在所有尺度上均呈随机分布;辽东栎不同径级个体在小尺度范围内呈现聚集分布,随着尺度增大由随机分布趋于均匀分布。主要树种除漆树外在坡度较缓的生境下分布密度大。灵空山自然保护区油松-辽东栎林中油松种群优势地位更显著,各个乔木种群处于相对稳定状态。

Tree community characteristics and spatial patterns of the forms Pinus tabuliformis -Quercus wutaishanica in Lingkong Mountain

The community characteristics and spatial distribution were analyzed for the Forms Pinus tabuliformis-Quercus wutaishanica in the Nature Reserve of Lingkong Mountain by following the CTFS protocols, in which all free-standing trees were mapped and identified. The results showed that a total of 25 tree species in 18 genera and 12 families were recorded among the 8210 individuals. Most species are commonly found in the Temperate Asia and East Asia including the Endemic to China. The dominant species of P. tabuliformis and Q. wutaishanica accounted for 86.81% in abundance. The mian companion species were also observed as the Pyrus betulifolia, Fraxinus chinensis, Toxicodendron vernicifluum in the community. The diameter-class structure of dominant species was found similar to that of the whole community, roughly in inversed "J" shape, in which most individuals were in small diameter-class, suggesting sound community renewal under wood. Meanwhile, the main species demonstrated the bottleneck phenomena to various degrees, most like due to the self-thinning effects of P. tabuliformis and Q. wutaishanica, especially among the young trees of 4 cm and 15 cm in DBH respectively. In comparison, Pvrus betulifolia showed a faultage phenomena among the trees of 2-5cm in DBH, probably due to the thinning effect by other species. The age structure of Fraxinus chinensis suggested the transition from growth to stable phase. The diameter-class structure of Toxicodendron vernicifluum was approximately in inversed "J" shape, showing active natural renewal as being indicated by the seedlings in high abundance. In small scale the clustered distribution was observed among the dominant species. In P. tabuliformis the individuals of small diameter-class demonstrated clustered distribution in the scale of less than 20m, but random distribution in scale of 60-100m that is the same as that of the individuals of big diameter-class in all scales. In comparison, the Q. wutaishanica showed the trend from clustered to even and random distribution along the scale gradient from small to large. The trees of Pyrus betulifolia of small diameter-class showed clustered distribution in the scale of less than 10m but random distribution in scale of 10-100m; and the trees of big diameter-class demonstrated random distribution in all scales. The small diameter-class individuals of Fraxinus chinensis showed clustered distribution in scale of 0-25m and even distribution in scale of 25-70m, demonstrating trend to random distribution with the increase of spatial scale. Toxicodendron vernicifiuum showed clustered distribution in scale of 0-20m and even distribution over of 20m. The main species showed high density in relatively flat habitats except for Toxicodendron vernicifiuum. The data indicated P. tabuliformis being dominant over Q. wutaishanica in the community and all tree populations being in relatively steady state in the Nature Reserve of Lingkong Mountain.