Evaluating the use of woody debris to enhance native plant establishment from seeds on legacy coal mines in West Virginia (USA)

Abstract

In biodiverse ecosystems of high conservation value, such as the high elevation red spruce (Picea rubens Sarg. [Pinaceae]) forests of Appalachia, disturbed landscapes are in need of damage repair and improved early successional habitat. Increasing plant diversity through direct seeding and repurposing downed woody debris from legacy mine plantations could add valuable habitat components for ecological restoration projects. We direct seeded native herbaceous and shrub species on a reclaimed surface mine in the Monongahela National Forest, West Virginia, to examine the influence of woody debris on native seed germination, seedling survival, and cover in the first growing season. We selected 9 native herbaceous and 1 shrub species based on importance in the red spruce ecosystem, their height to compete with tall aggressive grasses, value to pollinators, and commercial availability. The 10 species were individually sown in autumn 2018 after soil decompaction in 1 m² (10.76 ft²) plots and replicated 3 times with and without 2.27 kg (5 lb) of woody debris. Some seeds of all species germinated and produced cover. Germination ranged from 1.6±0.9% (Mean±SE; tall white beardtongue [Penstemon digitalis Nutt. ex Sims (Scrophulariaceae)], wood) to 66.7±7.9% (showy ticktrefoil [Desmodium canadense (L.) DC. (Fabaceae)], no wood); survival ranged 0% (purple node joe pye weed [Eupatorium purpureum (L.) E.E. Lamont (Asteraceae)], no wood) to 98.1±1.9% (staghorn sumac [Rhus typhina L. (Anacardiaceae)], wood); and final cover ranged 0.5±0.0% (butterfly milkweed [Asclepias tuberosa L. (Asclepiadaceae)], wood, and Eupatorium purpureum, no wood) to 14.4±9.0% (blackeyed Susan [Rudbeckia hirta L. (Asteraceae)], no wood). The odds of survival for all species with woody debris versus without was approximately 2:1 (P = 0.011). Future monitoring will provide long-term data on the survival and potential of these species for use in restoration projects.