宝天曼自然保护区树附生苔藓空间格局分析

采用单变量g(r)函数,选用同质性泊松、异质性泊松、同质性托马斯和异质性托马斯4个零模型,分析了宝天曼自然保护区内1 hm2样地中11种树附生苔藓物种的空间分布格局.结果显示,11个物种中,有6个物种在同质性泊松模型下表现出聚集分布,在同质性托马斯模型下的聚集程度有所减弱,但在异质性泊松模型下完全变为随机分布.与同质性泊松模型下的分布相比,在异质性泊松模型下,有4个物种在较大尺度上的聚集分布变为随机分布;而在同质性托马斯模型下,有2个物种在较小尺度上的聚集分布变为随机分布.研究表明:1)生境异质性和扩散限制均对树附生苔藓空间分布格局的形成有影响,且生境异质性起主要作用;2)生境异质性可在小尺度上影响树附生苔藓的空间分布,扩散限制也能在大尺度上发挥作用.

Spatial pattern analysis for epiphytic bryophytes in Baotianman Nature Reserve

In this study,we analysed the spatial pattern of 11 epiphytic bryophytes species by using univariate of g (r) function,along with homogeneous Poisson model,heterogeneous Poisson model,homogeneous Thomas model and heterogeneous Thomas model,in the 100 m × 100 m plot area of Baotianman Nature Reserve.The results showed that:1) 6 out of 11 species showed aggregation distribution in the homogeneous Poisson model,and the aggregation decreased under the homogeneous Thomas model.But all of them were randomly distributed in the heterogeneous Poisson model;2) Compared with the distribution under the homogeneous Poisson model,4 species' aggregation distribution turned into random distribution on the large scale of the heterogeneous Poisson model;And 2 species' aggregation distribution developed into random distribution on a small scale of homogeneous Thomas model.The research suggests that:1) Both habitat heterogeneity and dispersal limitation have effects on the spatial distribution pattern of epiphytic bryophytes,and the habitat heterogeneity plays a major role;2) Habitat heterogeneity can affect the spatial distribution of epiphytic bryophytes on a small scale,and dispersal limitation can also work on a large scale.