DOCUMENTING THE ROCKS, SOILS, AND BIOTA OF SERPENTINITE OUTCROPS IN WESTERN MASSACHUSETTS

The serpentinite outcrops in western Massachussetts have previously recieved some geological study, but there have been few comparative assessments of their soil chemistry and biology relative to neighboring lithologies, and no biological assessments which took a comprehensive look at bedrock geology, soils, vascular plants, bryophytes, and lichens. Due to a low Ca:Mg ratio, high Ni, and other edaphic qualities, serpentinite-derived soils are often a stressful habitat for plants and other organisms. Although the serpeninite outcrops of western Massachusetts are not "typical" in that they have a closed canopy and well-developed forest soils, they do have some biological distinctions, and their deviation from the commonly understood serpentine syndrome is in itself interesting. In an interdisciplinary geoecological project, we systematically documented several of these outcrops by (1) producing new, fine-scale bedrock geologic maps for the serpentinite lenses and their immediate surroundings, (2) conducting soil sampling guided by those maps, (3) collecting and identifying the vascular plant, bryophyte, and lichen sepecies occurring on serpentinite and neighboring schist and amphibolite, and (4) collecting vascular plant tissue samples for foliar chemistry analysis. In this poster, we present preliminary results from these lines of inquiry, including: geologic maps, graphs of soil chemistry and physical characteristics along lithologic contacts, data on the foliar chemistry of Tsuga canadensis, Fagus grandifolia, and Eurybia divaricata on and off serpentinite, and comparisions of the biodiversity of the serpentinite, schist, and amphibolite series at geographically distant outcrops. The data from the last of these will be used to test the primary hypothesis of this study, that geographically distant serpentinite outcrops in western Massachusetts are more similar, in terms of biodiversity, than adjacent serpentinite and schist or serpentinite and amphibolite outcrops.