Land snails of the Big Thicket National Preserve

Coles, Brian

Representative sites within the Big Thicket National Preserve were searched for land snails, particularly for the presence of calcifuge species of Vertigo that have been associated with pocosins and pine flatwoods of the Atlantic coastal plain. 12 Sites were examined in December 2003 and March 2004, representing mature beech/magnolia forest (Beech Creek Unit); mixed-bottomland woodland (Turkey Creek Unit), pine woodland (Turkey Creek Unit, Hickory Creek Unit, Lance Rosier Unit) and baygalls (Turkey Creek Unit, Hickory Creek Unit, Lance Rosier Unit). The 31 species found consist of forms widely distributed in eastern/southeastern USA plus the more localized (SE TX, SW LA) Triodopsis vultuosa, and two species new to Texas: Paravitrea significans and Dryachloa dauca. The unusual Vertigo species that were the main target of the work were not found and this calcifuge assemblage probably does not extend into this region. Although these results should not be regarded as a definitive study of land snails of the BTNP, they indicate that land snails are not a prominent, nor exceptional, feature of the habitats examined. That is, diversity is consistent with that of other base-poor woodland sites in the Gulf Coastal Plain. Thus, based on these results, land snails do not need to be considered as high priority targets for conservation measures of the Big Thicket National Preserve. All specimens have been deposited in the Florida Museum of Natural History.