COS 22-3 - Pine clearcuts as potential avenues for American chestnut reintroduction and diversity restoration

Monday, August 7, 2017: 2:10 PM
B115, Oregon Convention Center
Keith E. Gilland, Biology, University of Wisconsin-Stout, Menomonie, WI and Carolyn H. Keiffer, Department of Botany, Miami University, Middletown, OH

Prior to its demise from an introduced fungal pathogen, American chestnut was an ecologically and economically important species in Eastern Deciduous Forest. Development of a putatively disease-resistant tree is near but identification of ideal site conditions for successful reintroduction of chestnut populations remains an area in need of research. Here, we sought to determine if clearcutting of aging Pinus strobus monoculture plantations, created on degraded Appalachian landscapes during the 1930s, can serve as both successful chestnut population introduction sites as well as an avenue to restore native biodiversity that has been suppressed due to biotic and abiotic factors related to these sites histories and management. To investigate, we planted 2,000 hybrid American chestnut seedlings across 5 sites in southeastern Ohio that had been recently clearcut of their dominant pine overstory. Seedlings were protected with 3 different styles of tree shelters and monitored for first year survival. Vegetation surveys were conducted at each site to determine the effect on individual woody species competition from seedlings and sapling layers as well to document successional changes post-clearing. Logistic regression was used to examine the influence of competing vegetation, site history, and tree shelter type on initial survival of the trees in our study.


Time since clearcutting (1, 2, or 3 years) did not significantly affect initial American chestnut survival (Wald Test: Χ2 = 0.36, df = 2, P = 0.45) nor did the dominant composition prior to clearcutting (Pinus strobus vs. Pinus virginiana; Wald Test: Χ2 = 0.23, df = 1, P = 0.38). Total woody seedling competition did not significantly affect survival, nor did total sapling cover. There were some woody species that were positively associated with chestnut survival, namely thorny cane-form shrubs in the genus Rubus (Wald Test: Χ2 = 14.1, df = 2, P < 0.001). Percent graminoid cover had a significant negative relationship on chestnut survival (Wald Test: Χ2 = 17.2, df = 3, P < 0.001). Further data collection in spring and summer 2017 will involve soil collection for fine root biomass comparisons, measurement of survival, and comparison of species composition across clearcut and adjacent intact pine-overstory stands. Thus far, though, these results suggest that management of herbaceous competition on former pine plantation sites targeted for chestnut restoration may be desirable but this must be balanced with the desire to restore understory diversity on these sites.