太白山巴山冷杉林主要树种与开花秦岭箭竹的空间点格局分析

采用单变量和双变量O-ring函数对太白山大熊猫栖息地巴山冷杉林主要树种的空间分布格局、种间关联性及其与林下开花箭竹的空间关联性进行了多尺度分析.结果表明: 巴山冷杉林中,巴山冷杉数量最多,但种群结构衰退,白桦种群相对年轻,种群结构稳定,红桦种群也呈衰退趋势;3个主要树种在小尺度上呈聚集分布,随尺度增加,逐渐表现为随机分布.3个树种的空间关联性主要表现在小尺度范围内,随尺度增加,空间分布格局逐渐表现为不关联;巴山冷杉和白桦与开花秦岭箭竹在大、中尺度内呈现正相关,而红桦与开花秦岭箭竹在大、中尺度上表现出负相关.大熊猫栖息地内乔木和林下秦岭箭竹共同推动森林的动态演替和发展,进而影响秦岭大熊猫栖息地的环境变化.

Spatial point pattern analysis of main trees and flowering Fargesia qinlingensis in Abies fargesii forests in Mt Taibai of the Qinling Mountains,China

In Abies fargesii forests of the giant panda’s habitats in Mt. Taibai, the spatial distribution patterns and interspecific associations of main tree species and their spatial associations with the understory flowering Fargesia qinlingensis were analyzed at multiple scales by univariate and bivaria-te O-ring function in point pattern analysis. The results showed that in the A. fargesii forest, the number of A. fargesii was largest but its population structure was in decline. The population of Betula platyphylla was relatively young, with a stable population structure, while the population of B. albo-sinensis declined. The three populations showed aggregated distributions at small scales and gradually showed random distributions with increasing spatial scales. Spatial associations among tree species were mainly showed at small scales and gradually became not spatially associated with increasing scale. A. fargesii and B. platyphylla were positively associated with flowering F. qinlingensis at large and medium scales, whereas B. albo-sinensis showed negatively associated with flowering F. qinlingensis at large and medium scales. The interaction between trees and F. qinlingensis in the habitats of giant panda promoted the dynamic succession and development of forests, which changed the environment of giant panda’s habitats in Qinling.