暖温带-北亚热带生态过渡区物种生境相关性分析

Species habitat correlation analysis in temperate-subtropical ecological transition zone

物种生境相关性分析有利于更好的理解群落构建机制。以暖温带-北亚热带过渡区的宝天曼自然保护区1 ha固定监测样地调查数据为依托,选择胸径(DBH)≥1 cm、个体数≥5的43种木本植物作为分析对象,选择4个地形因子和15个土壤因子作为两类环境因子,用典范对应分析(CCA)研究了地形因子和土壤因子对物种分布的影响,用Torus-translation检验来分析物种与不同生境的关联。结果如下:(1)CCA分析表明地形因子对物种分布的解释量为7.3%,土壤因子对物种分布的解释量为16.2%。(2)Torus-translation检验结果表明,被检验的43个物种中,23.3%的物种与地形4个生境关联,其中正相关物种数最多的是山脊,占正相关数的57%;46.5%的物种与土壤6个生境关联,正相关物种数最多的是两个主分量中的高浓度区,占正相关数的52.6%,明显高于中浓度区和低浓度区正相关的物种数,负相关物种数最多的仍是高浓度区,占负相关数的42.8%,其次为低浓度区,占26.3%。结果表明,土壤生境分化对暖温带-北亚热带过渡区物种的空间分布有着重要作用;样地内大部分物种存在生境分化,这不仅是对地形生境分化的利用,而且更多的是对土壤生境分化的利用;研究结果支持物种共存机制中的生态位理论,地形和土壤生境分化是宝天曼暖温带-北亚热带过渡区物种共存的重要机制之一,在一定程度上解释了该区物种多样性的维持机制。

Species habitat correlation analysis is important for understanding the mechanism behind community assemblages. The relationship between environmental factors and species distribution have important implications for developing optimal strategies for conservation of species diversity, sustainable management and utilizing plant resources. Baotianman Nature Reserve （BNR） is located in the warm temperate and subtropical transition zone. Due to the geographic location, there are complex communities and high species richness. BNR is the most well preserved natural broad-leaved forest areas in east China. However, studies on species and environmental correlation have not been reported in the warm temperate and subtropical transition zone. In the following study, 43 wood species with ≥5 individuals and diameter at breast height （DBH） ≥ 1.0 cm were selected in a 1-hm2 plot to study the correlation of species distribution and environmental factors including four topographic factors and 15 soil factors. Topographic factors included mean elevation, mean slope, mean aspect, mean convexity and soil factors included Al, Cu, Fe, Mg, Mn, S, Zn, Ca, pH, MO, C, TN, P, K, JN. Canonical Correspondence Analysis （CCA） was used to explore the influence of topographic and soil factors on species spatial distribution. Torus-translation test was employed to test the significance of the species-topography and species-soil association. CCA analysis showed that the topographic factors explained 7.3%, and soil factors explained 16.2% of the species distribution. Torus-translation test showed that 23.3% of species showed significant associations with the four habitats of topographical environment. Ridge habitat had the most positive species association, accounting for 57% of the positive association number. Forty seven percent of species showed significant associations with the six habitats of soil environment. High concentration habitat had the most positive species association accounting for 52.6% of the positive association number, and was significantly higher than the medium concentration and low concentration habitat. High concentration habitat also had the most negative association number accounting for 42.8% of the negative association number, followed by low concentration habitat, which accounted for 26.3%. The above results suggest that soil habitat has significant effects on the spatial distribution of species in the warm temperate and subtropical transition zone. Species-topographic associations also contribute to species distribution but to a lesser extent. The results support the ecological niche theory as an important mechanism of species coexistence in the warm temperate and subtropical transition zone.