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.

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
dataDictionary.csv - Data dictionary for all data files
mckenna-foster-report-2009.pdf - report describing project
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。

楠塔基特岛的冰水沉积平原上，砂原草原（sandplain grassland）与沿海石楠灌丛（coastal heathland）两类生境交错镶嵌，形成复杂的景观格局。黑果越橘（*Gaylussacia baccata*，俗称黑越橘，black huckleberry）是沿海石楠灌丛的优势物种，可形成大面积的克隆单优种群落。随着此类克隆群落的扩张，其会逐步取代草原生境，降低区域整体植物物种多样性。

本项先导性研究针对不同大小等级的黑果越橘克隆群落采集蜘蛛样本，旨在探究克隆群落规模是否会对蜘蛛物种多样性产生影响；同时记录了主要植物物种的组成差异。

研究结果显示，小型克隆群落中两种狼蛛物种——*Pardosa saxatilis*与*Schizocosa bilineata*的个体数量显著更高；小型克隆群落的蜘蛛物种丰富度整体高于大型克隆群落。此外，小型克隆群落的草本植被盖度占比更高，而黑果越橘的盖度更低。

本研究建议，未来应分别针对砂原草原与沿海石楠灌丛生境构建物种-面积曲线，以确定能够最大化蜘蛛物种丰富度的最优面积配比。

allSpiderData.csv
dataDictionary.csv - 所有数据文件的数据字典
mckenna-foster-report-2009.pdf - 项目研究报告
vegetationData.csv