Providing open forest structural characteristics for high conservation priority wildlife species in southeastern U.S. pine plantations

Abstract

The decline of early successional and open forests and their wildlife inhabitants has resulted in increased efforts to understand and conserve these communities. Natural and anthropogenic disturbances that historically created and maintained open forest conditions have been disrupted, necessitating wildlife use of alternative habitat sources (e.g., pine plantations, utility rights-of way, abandoned agricultural fields) to carry out their life history. We reviewed available literature to estimate the range of structural conditions suitable for four open forest species in regional decline and compared these ranges to available structure in loblolly pine (Pinus taeda) forests managed for economic return. Species included Bachman’s sparrow (Aimophila aestivalis), northern bobwhite (Colinus virginianus), prairie warbler (Dendroica discolor), and eastern diamondback rattlesnake (Crotalus adamanteus). We estimated habitat availability and connectivity for each of these four species during a 60-year simulation on an economically- and operationally-feasible pine landscape (>22,000 ha) managed for sawtimber production in the West Gulf Coastal Plain. Habitat requirements, including minimum patch size and dispersal constraints, of Bachman’s sparrow, northern bobwhite, prairie warbler, and eastern diamondback rattlesnake are generally met by pine stands in stand establishment and thinned, mid-rotation stages. However, habitat availability in pine plantations may be highly ephemeral, tends to occupy the upper end of basal area and canopy closure tolerance, and may be more suitable for open woodland species (e.g., Bachman’s sparrow) than grassland species (e.g., northern bobwhite). The range of habitat associations in this literature review highlights the need to refine targets of structural metrics identified by open pine restoration initiatives to encompass the full range of conditions occupied by open forest species. Current literature is strongly biased to avian habitat associations. Few papers explore habitat associations of herpetofauna of conservation concern in the southeastern U.S., and these species tend to be less mobile and therefore, more vulnerable to landscape changes and the ephemeral nature of open vegetative structure in pine plantations.