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Eric L. Margenau

Publications and source records attributed to Eric L. Margenau.

3 recordsLinked to original sources

Habitat management for stopover and breeding songbird communities along rights-of-way in forest-dominated landscapes

The proliferation of energy rights-of-way (pipelines and powerlines; ROWs) in the central Appalachian region has prompted wildlife management agencies to consider ways to use these features to manage and conserve at-risk songbird species. However, little empirical evidence exists regarding best management strategies to enhance habitat surrounding ROWs for the songbird community during stopover or breeding periods. We used a before-after-control-impact design to study cut-back border (linear tree cuttings along abrupt forest edges) harvest width (15 m, 30 m, and 45 m wide into the forest) and harvest intensity (14 m 2 /ha and 4.5 m 2 /ha basal area retention) prescriptions along ROWs and assessed their effects on mature forest and young forest songbird species and avian guilds (forest gap habitat, forest interior habitat, young forest habitat, and species of regional conservation priority) up to two years after treatment throughout West Virginia. Species richness during the spring stopover period initially decreased at one-year post-treatment but returned to pre-treatment levels by two-year post-treatment. Breeding season responses to cut-back border treatments varied across harvest width, harvest intensity, and time, but all responses of focal species abundance and guild richness were neutral or positive. Cut-back border harvest intensity had a stronger influence (i.e., more positive responses) than harvest width on breeding focal species abundances and guild richness. For harvest intensity, the more intense, 4.5 m 2 /ha retention treatment had a stronger influence (i.e., more positive responses) than the less intense, 14 m 2 /ha retention treatment. For harvest width, the narrowest treatment (15-m wide) had the strongest influence (i.e., more positive responses) of all width treatments, followed by the widest (45-m wide treatment) with the least influence from the 30-m wide treatment. Abundances and richness increased from pre-treatment to two-year post-treatment across all species and guilds that exhibited a response. These results suggest that cut-back borders increase breeding season habitat suitability along ROWs for the mature forest and young forest songbird community as well as for species of regional conservation priority in the short-term. These findings can aid development of management guidelines for the forest songbird community along abrupt forest edges of man-made habitat features in forest-dominated landscapes.

West Virginia

Efficacy and biases of cover object survey design for sampling eastern red-backed salamanders (Plethodon cinereus) at forest edge and interior locations

Terrestrial salamanders are adapted to moist, cool microenvironments that facilitate cutaneous respiration and decrease risk of desiccation. Warmer, drier microenvironments may induce habitat use changes by salamanders to alleviate stressful microenvironmental conditions. Changes in salamander habitat use may bias population metrics when sampling occurs in areas with different microenvironmental conditions. The objective of this study was to determine whether Plethodon cinereus (Eastern Red-backed Salamander) exhibit surface cover object refugia preferences or occupancy rate differences at sampling locations with different microenvironmental conditions and with respect to sampling day of year. We assessed P. cinereus occupancy rates and preference of surface cover refugia using artificial and natural cover objects in two sampling locations: forests along rights-of-way (EDGEFOR) and interior forests (INTFOR). Plethodon cinereus showed no preference for cover object type (coverboards, logs, and rocks) in either EDGEFOR or INTFOR sampling plots. Occupancy rates were greater under cover objects in INTFOR plots than EDGEFOR plots. Occupancy rates increased with increasing cover object width and decreased with day of year (spring-late summer) irrespective of cover object type or sampling location. Our study suggests that incorporating multiple cover object types into study designs will not incur bias resulting from preference of P. cinereus for cover objects.

West Virginia

Trade-offs relating to grassland and forest mine reclamation approaches in the central Appalachian region and its implications for the songbird community

Surface mining in the Appalachian region, USA, converts large areas of mature forest to early-successional habitat. This shift in landscape structure has the potential to reduce habitat availability and suitability for forest-dwelling songbirds by reducing and fragmenting mature forest, but also to increase habitat availability for grassland and shrubland-associated songbirds. We examined the influence of mountaintop mining/valley fill (MTMVF) reclamation habitats (grassland, shrubland, and remnant forest) on songbird community composition and abundance at three former MTMVF mines in southwestern West Virginia, relative to intact forest. We quantified the songbird community in 1999 and 2000 using point counts arranged throughout the mine complexes to assess landscape composition of the songbird community. Community analysis showed songbirds had strong associations with their respective guild based on species’ habitat preferences. Although remnant and intact forest treatments had similar species compositions, the forest interior guild had greater richness in intact than remnant forest. Total species richness was greatest in the reclaimed shrubland treatment. Focal species analysis followed similar trends as community assessments, as species’ abundances within treatment types were strongly associated with species’ habitat preferences. Our study indicates reclamation habitat decisions (i.e. grasslands versus forests) can have large effects on avian community composition. Determining appropriate mine restoration actions depends on the suite of species desired for long-term occupancy and their conservation priority.

Appalachian Basin