帽儿山红松人工林鞘翅目成虫群落小尺度空间异质性变化特征

空间异质性是群落空间格局形成的基础,也是物种共存的重要前提。基于地统计空间分析方法,研究20 m×20 m空间尺度上帽儿山红松人工林鞘翅目成虫群落及物种的空间自相关性及异质性分布格局。结果显示:5次调查共捕获鞘翅目成虫10科、42种、2721只个体,群落组成具有中等或较强的空间变异性和明显的时间变异性;Moran's I系数表明群落及部分物种具有显著的空间自相关性,各调查月份接近甚至超过一半的物种不存在空间自相关性;群落及部分物种表现为异质性特征并在特定空间尺度内形成集群,且这种空间分异多由结构性因素或结构性因素和随机性因素共同调控;物种之间表现为具有复杂正的或负的空间作用关系,这种空间关联性的形成主要是结构性因素或随机性因素单一调控的结果,但简单Mantel检验并未发现物种之间存在显著的空间关联性;群落的空间格局梯度分布特征较明显,随着季节的变化(夏天到秋天)聚集物种数量的斑块复杂程度降低。本文旨在揭示鞘翅目成虫空间异质性的变化特征,为鞘翅目成虫群落物种构建机制研究奠定基础。

Spatially heterogeneous dynamics of adult Coleoptera communities at a small scale in a Pinus koraiensis plantation on Maoer Mountain

Spatial heterogeneity is the basis of spatial pattern for a community, as well as the coexistence of a community. Many studies have uncovered the spatial heterogeneities of communities at relatively large scales, but it remains unclear at small scales, especially for artificial ecosystems. To determine the spatial heterogeneity dynamics of a community at a small scale, a study was conducted to investigate adult Coleoptera community in a Pinus koraiensis plantation at the Maoershan Ecosystem Research Station. The study site comprised a permanent plot was of 20 m × 20 m and was divided equally into 100 squares. Pitfall traps were used to collect the adult Coleoptera. In 2013 and 2014, 100 traps were set at the bottom-right corner of the 100 squares, with traps in 2013 containing 4% formalin solution, and traps in 2014 containing saturated salt solution. This study was conducted in June, July and September in 2013 and in August and October in 2014. Global Moran''s I index was used to explain the spatial autocorrelation of the abundance of Coleoptera community and species. Spatial semi-variogram was selected to reveal the spatial heterogeneity of the abundance of Coleoptera community and species. A combination of a cross-variogram and a simple Mantel test was performed to identify the spatial relationships between different species. Ordinary kriging method was used to map the spatial heterogeneity of the abundances of Coleoptera community and species. In total, 2721 individuals belonging to 10 families and 42 species were collected. Community composition showed significant spatial and temporal variability at different times. In 2013, significant differences (P < 0.01) in abundances among June, July, and September were observed. And significant differences (p < 0.01) in abundances between August and October were detected in 2014. The results of Moran''s I coefficient showed that abundances of adult Coleoptera communities, and a relatively small part of Coleoptera species in each season, had significantly spatial autocorrelations. The abundance of adult Coleoptera communities and some of the Coleoptera species in each season, showed spatial heterogeneous patterns, and those communities and species formed spatial aggregations at certain spatial scales. According to the values of (C₀/(C₀+C)), those spatial heterogeneities mainly were controlled by structured factors or combination of structured and random factors. The structure proportions of some species showed pure nugget effect resulting from sampling errors or spatial variability occurring within the minimum distance interval (2 m). For each community, the results of cross-variograme showed that the complex spatial relationships among different adult Coleoptera species existed at different spatio-temporal scales and were positive, negative or random spatial relationships. The values of (C₀/(C₀+C)) demonstrated that the spatial differentiations of adult Coleoptera species were mainly controlled by structured factors or random factors. However, significant spatial relationships between Coleoptera species were observed through the results of a simple Mantel test. The maps of ordinary kriging interpolation showed that the spatial patterns of communities with gradient distribution were obviously different in different seasons, and the strength of gradient distribution weakened from summer to autumn for each community. This study indicated that adult Coleoptera communities were obviously aggregated spatial distribution at a small scale (20 m). Spatial relationships between different species were complex, and the spatial relationships were seasonally variation. The results of this study will help us to understand the temporal and spatial variation mechanism of adult Coleoptera communities.