西藏色季拉山急尖长苞冷杉种群点格局分析  

Spatial point pattern analysis of Abies georgei var.smithii in forest of Sygera Mountains in southeast Tibet,China

作　　者：解传奇[1,2] 田民霞 赵忠瑞 郑维列[2] 王国严[2] 

机构地区：[1]西藏高原生态研究所,西藏林芝860000 [2]西藏大学农牧学院,西藏林芝860000

出　　处：《应用生态学报》2015年第6期1617-1624,共8页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(31260147);西藏林芝高山森林生态系统定位研究项目资助

摘　　要：基于4 hm2色季拉山长期监测样地调查资料,采用成对相关函数点格局方法,分析西藏色季拉山冷杉林群落优势种急尖长苞冷杉种群活立木不同生长阶段和不同大小死亡木的空间格局及它们之间的空间关联性.结果表明：急尖长苞冷杉种群活立木径级分布连续,呈倒＂J＂型,为增长型种群.小树在小尺度（0~7 m）上呈显著聚集分布,随着龄级和研究尺度的增加,冷杉种群聚集强度逐渐减弱,最终趋向于均匀或随机分布格局.小树与大树、中树与大树在小尺度（0~35和0~30 m）上呈负关联,在大尺度（45~100和80~100 m）上呈正关联,且个体间龄级相差越大,其关联性越强.冷杉死亡所释放的空间不足以影响大树对小树的距离制约,大径级死亡木与小树在小尺度（0~34和5~27 m）上具有负关联性,在大尺度（49~100和73~100 m）上具有正关联性.自疏作用和Janzen-Connell假说中的距离制约效应可能是色季拉山急尖长苞冷杉种群空间格局形成的重要原因.In this study, based on a 4 hm2 stem-mapping plot, we analyzed spatial distributions of Abies georgei var. smithii, the dominant species in forest of Sygera Mountains in southeast Tibet, China. Pair-correlation function was used to characterize univariate spatial point patterns of three size classes of the population and bivariate spatial patterns between those and different sizes of dead wood. A. georgei var. smithii population was characterized by reverse J-shaped DBH distribution, in- dicating an increasing population Saplings of the population were spatially obviously aggregated at the small scales （0-7 m）, and mid-sized trees and large-sized trees of the population were random- ly or uniformly distributed. The aggregation intensities of A. georgei var. smithii decreased with the increasing diameter classes and spatial scales. Saplings and mid-sized trees were significantly and negatively associated with large-sized trees at the small scales （0-35 and 0-30 m）, but the associ- ations reversed at the large scales （45-100 and 80-100 m）. In addition, with the increasing age difference between diameter classes of the population, the intensities of positive or negative correla- tions increased. Spatial associations between saplings and dead large-sized trees, and between mid- sized trees and dead large-sized trees were negative at positive at the large scales （49-100 and 73-100 m）. to dead large-sized trees is not enough to weaken their that self-thinning effect and Janzen-Connell hypothesis pattern formation of A. georgei var. smithii population. the small scales （0-34 and 5-27 m）, but This suggested that released niche space due negative impacts on saplings. We concluded may be the main mechanisms for the spatial

关 键 词：急尖长苞冷杉 活立木 死亡木 点格局分析 

分 类 号：S718.54[农业科学—林学]