Spider species composition in Gaylussacia baccata clones of varying sizes on Nantucket Island, Massachusetts

This research was funded by grants from the Nantucket Land Bank and the Nantucket Land Council in 2008.<br> <br> Sandplain grassland and coastal heathland habitats intermingle to form a mosaic on Nantucket’s glacial outwash plain. Gaylussacia baccata (black huckleberry) is a dominant species in coastal heathland and forms large clonal monocultures. As these clones expand they replace grassland and reduce overall plant species diversity. In this pilot study I captured spiders in different size classes of G. baccata clones to determine if clone size affects spider species diversity. I also recorded differences in major plant species. Smaller clones had significantly higher numbers of two wolf spider species: Pardosa saxatilis and Schizocosa bilineata. Smaller clones tended to have a higher number of spider species than larger clones. Smaller clones had higher percentages of grass cover and less G. baccata coverage. I suggest that future work should produce separate species area curves for sandplain grassland and coastal heathland habitats to determine an optimum ratio of areas to maximize spider species richness. allSpiderData.csv<br> dataDictionary.csv - Data dictionary for all data files<br> mckenna-foster-report-2009.pdf - report describing project<br> vegetationData.csv本研究于2008年获得楠塔基特土地银行（Nantucket Land Bank）与楠塔基特土地委员会（Nantucket Land Council）的资助。 楠塔基特岛的冰川冰水冲积平原上，砂质草原生境与滨海石楠灌丛生境相互交织，形成镶嵌状景观。黑越橘（Gaylussacia baccata，black huckleberry）是滨海石楠灌丛的优势物种，可形成大面积的无性系单优群落。随着此类无性系群落扩张，它们会取代草原生境，降低整体植物物种多样性。 本先导研究中，研究者针对不同大小的G. baccata无性系群落采集蜘蛛样本，以探究群落规模是否会影响蜘蛛物种多样性；同时记录了主要植物物种的组成差异。结果显示，小型无性系群落中，两种狼蛛物种——Pardosa saxatilis与Schizocosa bilineata——的个体数量显著更多。相较大型群落，小型无性系群落的蜘蛛物种总数整体更高。此外，小型无性系群落的草本盖度占比更高，而G. baccata的盖度更低。 笔者建议，后续研究应分别针对砂质草原与滨海石楠灌丛生境构建物种-面积曲线，以确定可最大化蜘蛛物种丰富度的最优生境面积比例。 本研究附带数据集如下： - allSpiderData.csv - dataDictionary.csv：所有数据文件的数据字典 - mckenna-foster-report-2009.pdf：本项目研究报告 - vegetationData.csv