Effects of Sandplain Grassland Management on Spider Richness and Abundance on Nantucket Island

These data were collected for a 2009 Master's Thesis.

Sandplain grassland is a globally rare habitat that is found abundantly on Nantucket Island, Massachusetts. It is disturbance dependent and prescribed burning and mowing are management techniques used to impede shrub encroachment and maintain grassland. We used pitfall traps to investigate the effects of one time burning and mowing, annual mowing, and no management on spider richness and abundance in sandplain grasslands located in the Smooth Hummocks Coastal Preserve on Nantucket Island. In 2352 trap nights, we captured 1663 spiders representing 67 species. Burned treatments had significantly higher abundance because the most abundant species, Pardosa saxatilis (Lycosidae) was almost exclusively captured in burned areas. Accounting for P. saxatilis, abundance and richness were similar across all treatments. Guild structure was also very similar. In a correspondence analysis, we identified species that prefer recently managed grassland and those that prefer less recently managed grassland and conclude that maintaining several treatments in the area increases overall spider diversity. Euryopis gertschi (Theridiidae) was the third most abundant species and is an unusual component to the sandplain grassland species composition.

File descriptions:

allSpiderData.csv - spider counts by species and trap
dataDictionary.csv - Description of variable for all data
grassHeight.csv - grass height for transects
litterMass.csv - Litter mass from each transect
plotData.csv - location information for each plot
vegetationData.csv - percent cover for each transect