Abstract Detail

Ecology

Medeiros, Ian [1], Rajakaruna, Nishanata [1].

Serpentinite Outcrops Do Not Support a (Particularly) Distinctive Biota in Western Massachusetts.

Although serpentinite ("serpentine") outcrops are frequently thought of as edaphically stressful sites supporting a biota distinct from neighboring lithologies in both diversity and physiognomy, outcrops of serpentinite in western Massachusetts do not follow this pattern. We surveyed serpentinite and adjacent schist and amphibolite outcrops in Hampden and Berkshire Counties to assess soil chemistry and the diversity of vascular plants, bryophytes, and lichens. Despite soils which have the typical first-order characteristics of serpentinite-derived soils (Ca:Mg ration less than one, elevated Ni, and elevated pH), and despite foliar chemistry which indicates that plants growing on serpentinite outcrops take up higher levels of Ni and have a lower tissue Ca:Mg ratio than their non-serpentine counterparts, western Massachusetts serpentine sites support closed-canopy forest with few obvious vegetation differences relative to adjacent, non-serpentine areas. The reasons for this are not clear, but possible explanations will be discussed in our presentation. Both the serpentine and non-serpentine sites studied were dominated by an overstory of Fagus grandifolia and Tsuga canadensis, with a sparse understory consisting mainly of Maianthemum canadense, Aralia nudicaulis, and Eurybia divaricata. Although there is one serpentine-endemic vascular plant species in western Massachusetts (Moehringia macrophylla), it is an exception rather than the rule. Interestingly, bryophytes characterized substrate more effectively than vascular plants, with the bryoflora of distant serpentine sites more similar than the bryoflora of adjacent rock types. Within serpentinite sites, cliff faces do seem to represent a distinctive habitat, hosting certain species (e.g., Asplenium trichomanes) lacking on cliff faces of other nearby lithologies, and lacking other species (e.g., Umbilicariaceae lichens) that are abundant on cliffs of other rocks. From a conservation perspective, serpentinite outcrops in Western Massachusetts represent a rare habitat (within the state) that is likely to experience significant change in the near future as insect and fungal pests alter the composition of the overstory.

1 - College Of The Atlantic, 105 Eden Street, Bar Harbor, ME, 04609, USA

Keywords:
geoecology
Serpentine
Massachusetts
bryophyte ecology
edaphic factor
Lichen ecology
hemlock wooly adelgid.

Presentation Type: Oral Paper
Session: 6, Ecology Section: Population Biology
Location: 201/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 9:15 AM
Number: 6004
Abstract ID:603
Candidate for Awards:Ecological Section Best Undergraduate Presentation Award