THE ECOLOGICAL BOUNDARIES OF SIX CAROLINA BAYS: COMMUNITY COMPOSITION AND ECOTONE DISTRIBUTION

• Published in: Wetlands (Wilmington, N.C.) N.C.), 2007-12, Vol.27 (4), p.873-883
• Main Authors: Laliberte, Lorrie, Luken, James O., Hutchens, John J., Godwin, Kevin S.
• Format: Article
• Language: English
• Subjects: altitude; Bays; botanical composition; Boundaries; buffer; cluster analysis; Community composition; Composition; ecological boundaries; Ecological effects; Ecotones; elevation; Endemic plants; Endemic species; Environmental factors; Environmental gradient; fire; Flowers & plants; Hydrology; indicator species; indigenous species; jurisdictional wetland boundary; landscape ecology; Nutrients; ordination, pocosin; plant communities; Plant species; Plants (botany); REGULAR SUBMISSIONS; soil chemical properties; Soil moisture; Soil nutrients; Soil properties; Soil surfaces; Species composition; statistical analysis; topography; transect; transects; water quality; wetland boundary; Wetlands
• ISSN: 0277-5212; 1943-6246
• DOI: 10.1672/0277-5212(2007)27[873:TEBOSC]2.0.CO;2

Community and environmental gradients within the ecological boundaries of Carolina bay wetlands may provide important information on the interaction between Carolina bays and associated uplands, and may also provide guidance for improved management. We established twelve 30-m transects on the sloping rims of each of six Carolina bays in northeastern South Carolina to characterize the community gradient, as well as important environmental factors producing this gradient. Mid-points of the transects were placed on jurisdictional wetland boundaries. Hydrology, soil properties, and plant species composition were measured within these transects. On average, transects included an elevation change of 0.6 m that corresponded with gradients of hydrology, soil properties, and community characteristics. Decreasing surface soil moisture (i.e., fewer flood events) and decreasing soil nutrients were associated with a shift from shrub-bog vegetation with relatively low alpha diversity and prominence of evergreens to a relatively diverse and heterogeneous community characterized by grasses, herbs, low shrubs, and vines. Ecotones, identified by abrupt changes in community composition, were more frequently found outside jurisdictional wetland boundaries. Likewise, five near-endemic and endemic plant species were found outside the wetland boundaries. Our data reinforce the need for better understanding of how Carolina bays interact with adjacent landscape elements, and specifically how ecological boundaries are influenced by this interaction.