Date of Graduation
Davis College of Agriculture, Natural Resources and Design
Wildlife and Fisheries Resources
This dissertation focuses on the effects of various young forest habitat management techniques on the avian and salamander community in West Virginia. Wildlife species associated with the nascent stage of forest succession are experiencing precipitous population declines throughout much of the eastern United States due to decreases in the amount of young forest area which have been brought on by changes in disturbance regimes over the past century. As a result, the need to find novel approaches for creating young forest habitats to sustain young forest wildlife populations is necessary. However, young forest habitat creation often negatively affects species that are considered disturbance-avoidant. As a result, I assessed the tradeoffs between creating young forest habitat for disturbance-associated species with the potential negative effects of reducing habitat suitability for disturbance-avoidant species throughout this dissertation. In Chapter 1, I summarize how historical land use practices in West Virginia have created current young forest conditions and the effects that these conditions have had on wildlife species that are specialized in exploiting young forest areas. I also introduce the study sites where this research was conducted and provide chapter objectives and topics of this dissertation.
The recent proliferation of linear energy infrastructure throughout the central Appalachian region has prompted managers to explore ways of managing the young forest bird community in association with these long, linear openings but little empirical data exist. At the same time, forest interior songbirds and woodland salamanders are often negatively affected by energy infrastructure within forest dominated landscapes and any young forest management in these landscapes may further degrade habitats for forest interior species. In chapter 2 we studied how harvest size (15 m, 30 m, and 45 m wide) and intensity (14 m2/ha and 4.5 m2/ha residual basal area) of cut-back borders, which are linear tree cuttings adjacent to gas/oil pipeline and utility powerline rights-of-way (ROWs) or wildlife openings, influenced habitat suitability along ROWs and wildlife openings for the young forest and forest interior communities. The objectives of this chapter were to examine whether the implementation of cut-back borders increased habitat suitability for wildlife species and which cut-back border treatments optimized the tradeoff between maximizing positive responses of disturbance-dependent species (i.e., young forest species) while minimizing negative responses of disturbance-avoidant species (i.e., forest interior species). We found that young forest species’ abundances and species richness increased one-year and two-years after treatment, particularly in the 15-m wide borders, likely due to the increase of young forest habitat in conjunction with existing habitat in ROW corridors or wildlife openings. Additionally, we found that forest interior songbirds and woodland salamander, groups that are often negatively affected by ROWs in forested landscapes, did not decrease in cut-back borders following treatment likely because the retention of canopy trees in combination with adjacent mature forests retained suitable habitat conditions. These results suggest that cut-back borders along abrupt forest edges of ROWs and wildlife openings create suitable habitat conditions for young forest avifauna without negatively affecting forest interior avifauna. Cut-back borders, particularly those 15-m in width, appear to be a viable management option for managing forest bird communities in ROW and wildlife opening landscapes.
Due to the prominence of commercial logging as a means to create young forest habitat, forests of low- or poor-quality stocking are often overlooked and thus limit options for management and conservation of young forest wildlife species. In order to promote habitat for young forest wildlife species, more opportunities for creating young forest habitat via forest management are greatly needed. In chapter 3 we assessed three non-commercial young forest management treatments (clearcut-and-leave [CL], clearcut-and-windrow [CW], and hack-and-spray [HS]) for promoting young forest habitat. Similar to Chapter 2, the objectives of this chapter were to examine whether the non-commercial young forest management treatments increased habitat suitability for young forest wildlife species and to determine which treatments optimized the tradeoff between maximizing positive responses of disturbance-dependent species and minimizing negative responses of disturbance-avoidant species. Additionally, we included a cost-benefit analysis to quantify the tradeoffs between maximizing songbird richness (cavity nesting guild, forest gap habitat guild, forest interior habitat guild, and young forest habitat guild) and minimizing cost of forest management. Implementation of regeneration treatments induced a dichotomous response from the avian community. Young forest songbird species responded positively to the CL treatment and negatively to the HS treatment, while forest interior songbirds responded positively to the HS treatment and negatively to the CL treatment. Eastern red-backed salamander (Plethodon cinereus), a terrestrial salamander most suited to forest interiors, responded positively to the HS treatment immediately following treatment. Based on our cost-benefit analysis, the CL treatment was the optimum treatment for maximizing songbird species richness and minimizing cost of habitat management followed by the control, the HS treatment, and the CW treatment. These results suggest that non-commercial forest management can provide suitable habitat conditions for young forest songbirds but can negatively affect forest interior songbirds, while other treatments retain suitable habitat conditions for forest interior species but do not provide immediate suitable habitat for young forest species.
Land managers must be able to assess the influence of habitat features across multiple spatial scales when developing management plans. Stand-level habitat management measures are often thought to have the most profound effect on species presence, but broader spatial habitat features may limit the effectiveness of local-level management if not fully considered. In chapter 4, we assessed the influence of local- (100-m radius surrounding point counts) and landscape-level (500-m radius) habitat features on the forest songbird community in cut-back borders along rights-of-way (ROWs) and wildlife openings. We examined four local-level variables (stand-level canopy cover, proportion of maintained early-successional habitat, proportion of young forest/shrubland habitat, and ROW/wildlife opening width) and five landscape-level variables (proportion of young forest/shrubland, core forest, and mature forest and distance to and size of nearest young forest/shrubland patch) to determine which variables had the strongest influence on species abundances and guild richness in cut-back borders. Landscape-level variables had the strongest influence on abundances and richness of young forest, forest gap, forest interior, and conservation priority species. Distance to nearest young forest/shrubland patch negatively influenced abundances of Carolina wren, eastern towhee, and hooded warbler (i.e., abundance increased with decreasing distance to nearest young forest/shrubland patch), and positively influenced abundance of ovenbird. Size of nearest young forest/shrubland patch positively influenced common yellowthroat abundance, and negatively influenced black-and-white warbler and indigo bunting abundances. Proportion of young forest/shrubland habitat at the landscape-level positively influenced mature forest-associated species black-and-white warbler, cerulean warbler, and hooded warbler as well as the species of conservation priority guild. No local-level variables strongly influenced abundance or richness in cut-back borders. These results indicate that within forest dominated landscapes, cut-back borders located closer to pre-existing young forest/shrubland patches benefit young forest species while size of nearest young forest/shrubland patch is likely species-specific. For mature forest species, presence of young forest/shrubland area at the landscape level appears to increase abundances in cut-back borders.
The focus of this dissertation has been on implementing novel young forest management techniques and evaluating their effects on the forest fauna. Our results indicate that young forest management techniques generally benefitted young forest birds but their effects on forest interior songbirds and woodland salamanders varied. Future implementation of young forest management should consider the tradeoffs between maximizing positive responses of the young forest community while minimizing negative responses of the forest interior community in order to develop broad ecosystem-based management strategies for wildlife communities.
Margenau, Eric L., "Avian and salamander response to young forest management in West Virginia" (2020). Graduate Theses, Dissertations, and Problem Reports. 7945.