千岛湖片段化景观中蜘蛛群落物种多样性和功能群结构及其影响因素

生境片段化对蜘蛛群落有着重要影响,目前这方面的研究较少,多集中于不同植被类型间蜘蛛群落的比较研究。在千岛湖片段化景观中选取16个陆桥岛屿,从2010年春季到2011年秋季,按季度(春、夏、秋季)6次采用Winkler法收集蜘蛛标本,分析其物种多度、多样性、季节动态和功能群差异,并对不同大小岛屿上蜘蛛的功能群的多度以及功能群比例差异进行单因素方差分析。结果表明:共收集到蜘蛛标本3503头,用于统计分析的成蛛1438头,归属于30科82种,其中幽灵蛛科(Spermophora)、管巢蛛科(Clubionidae)、螲蟷科(Ctenizidae)、蟹蛛科(Thomisidae)分别占总数的7.37%、6.61%、5.84%、5.29%,螲蟷科(Ctenizidae)在16个岛屿上均有分布。Shannon-Wiener指数在不同季节间差异显著(P0.05),物种丰富度在秋季最高。在功能群上,伏击型蜘蛛的多度最高,其次为游猎型蜘蛛,结圆网型蜘蛛多度最低,穴居型蜘蛛的多度与其他各功能群呈显著差异(P0.05);游猎型蜘蛛与伏击型蜘蛛的多度均显著高于结皿网型蜘蛛与结圆网型蜘蛛(P0.05);蜘蛛的各功能群数量在小岛与大岛这两种不同的岛屿类型上表现出显著差异,小岛上伏击型蜘蛛的物种数显著高于大岛上的物种数;比例上,结皿网型蜘蛛和伏击型蜘蛛在小岛上占功能群总体数目的比例显著低于大岛上的比例(P0.05),小岛上的游猎型蜘蛛占功能群总体数目的比例显著高于大岛上的比例(P0.05),结圆网型蜘蛛与穴居型蜘蛛在不同类型的岛屿间不存在显著差异。总体而言,秋季蜘蛛物种丰富度最高,蜘蛛的多样性与季节相关;生境片段化对蜘蛛功能群的分布产生了一定影响。

Species diversity, functional group structure, and influencing factors of spider community in fragmented landscape of Thousand Island Lake

Habitat fragmentation has important effects on the spider community; however, the few research studies in this area are mostly comparative studies between different forest types. In this study, we sampled spiders using Winkler traps six times from 2010 to 2011 (in three seasons, spring, summer, and autumn) on 16 land-bridge islands in the Thousand Island Lake, East China. We analyzed the species abundance, diversity, and seasonal dynamics and compared the differences between functional groups. Furthermore, one-way analysis of variance was used to analyze the effects of island area on different spider functional groups. The results showed that 3503 spider individuals were collected, including 1438, which were identifiable adults belonging to 30 families and 82 species. Among the identifiable individuals, Spermophora sp. 1, Clubionidae sp. 2, Ctenizidae sp. 2, and Thomisidae sp. 3 accounted for 7.37%, 6.61%, 5.84%, and 5.29%, and Ctenizidae sp. 2 were sampled on all 16 islands. The Shannon-Wiener index revealed that the difference in the spider diversity between the various seasons was significant (P < 0.05). Spiders showed the highest diversity in autumn compared with that in spring and summer. For the functional group structure, the abundance of Ambush predators was the highest, followed by that of Cursorial hunters was, and that of Orb weavers was the lowest. There was a significant difference in individuals between the Burrowing spiders and other functional groups (P < 0.05). The individual Cursorial hunters and Ambush predators were significantly higher than those of Sheet-line and Orb weavers were (P < 0.05). The individuals in the functional group showed significant differences between the small and large islands. The diversity of Ambush predators on small islands was significantly higher than that on the large islands was. The proportion of Sheet-line weavers and Ambush predators on the small islands was significantly lower than that on the large islands was; the proportion of Cursorial hunters on small islands was significantly higher than that on large islands; but for Orb weavers and Burrowing spiders, there was no significant difference between the small and large islands. In conclusion, spider diversity showed seasonal dynamics and, to a certain extent, the habitat fragmentation affected the distribution of different spider functional groups.