August 2020 Edition | Volume 74, Issue 8
Published since 1946
Managing Young Forest Wildlife Habitats in Rights-of-Way Landscapes
The central Appalachian region is extensively forested, but the majority of stands are >60 years old and young forest age classes are generally lacking in the landscape. Although mature forests support a diverse bird community, populations of species that require habitats in the early stages of forest succession (young forest species) are experiencing precipitous declines in part due to changes to disturbance regimes. This has prompted the U.S. Geological Survey West Virginia Cooperative Fish and Wildlife Research Unit (West Virginia Unit) and partners to develop management strategies that increase young forest habitat availability and conserve priority young forest species in the region. At the same time, the central Appalachian region has experienced an increase in the amount of linear energy infrastructure (e.g., underground gas pipeline and overhead utility powerline rights-of-way, hereafter “ROW”) from natural resource extraction (e.g., hydraulic fracking) and urbanization into rural areas.
Young forest habitat two years after treatment in a 30 m wide, 4.5 m2/ha intensity cut-back border along an overhead utility powerline right-of-way in West Virginia.
West Virginia Coooperative Fish & Wildlife Research Unit
Considering the proliferation of ROWs within the central Appalachian region, researchers at West Virginia University, the West Virginia Unit, and West Virginia Division of Natural Resources (WVDNR) were interested in examining habitat management strategies that could be incorporated with ROWs to benefit the young forest bird community. They examined the effects of linear tree cuttings (hereafter “cut-back borders”) along forest edges of ROWs at WVDNR wildlife management areas throughout West Virginia. This technique creates young forest habitat for a suite of species that requires specific vegetation characteristics (e.g., high woody stem densities, vertical forest structure) that are often not met within the ROW corridor, where periodic mowing and herbicide spraying prevent development of young forest habitats. Researchers evaluated combinations of three harvest widths (15, 30, and 45 m into the forest, perpendicular to forest edge) and two harvest intensities (14 m2/ha and 4.5 m2/ha basal area tree retention). They monitored wildlife species responses over three years (pre-treatment through two-year post-treatment) to assess which cut-back border treatment combinations were most effective for providing habitat for young forest birds. Additionally, researchers were interested in the effects of cut-back border combinations on forest interior bird species and the woodland salamander species eastern red-backed salamander as these species are often negatively affected by ROWs fragmenting forested landscapes.
Researchers found that young forest bird species abundances and species richness generally increased one-year and two-years after treatment, particularly in the 15-m wide cut-back borders. The increase of young forest habitat created via cut-back borders in conjunction with ephemeral habitat within ROW corridors may effectively widen ROW corridors and help to alleviate pressures related to area-sensitivity that some young forest birds are known to exhibit. Additionally, no mature forest bird species decreased post-treatment in any cut-back border width or intensity treatment. Thus, increasing habitat quality for young forest species had no negative consequences on mature forest bird species abundances. Captures of eastern red-backed salamanders generally declined one-year post-treatment but returned to pre-treatment levels during two-year post-treatment.
Young forest bird populations throughout the central Appalachian region continue to experience declines in part due to habitat loss or conversion. The West Virginia Unit’s research suggests that cut-back borders along abrupt forest edges of ROWs create suitable habitat conditions for young forest birds without negatively affecting forest interior birds. Based on their results, cut-back borders appear to be a suitable management tool for conserving young forest avifauna within ROW landscapes in the central Appalachian region.
The ONB features articles from U.S. Geological Survey Cooperative Fish and Wildlife Research Units across the country. Working with key cooperators, including WMI, Units are leading exciting, new, fish and wildlife research projects that we believe our readers will appreciate reading about. Story by Eric Margenau, USGS West Virginia Cooperative Fish and Wildlife Research Unit, West Virginia University/Division of Forestry and Natural Resources and Petra Wood, Assistant Unit Leader, USGS West Virginia Cooperative Fish and Wildlife Research Unit, West Virginia University/Division of Forestry and Natural Resources