Native Hardwood Tree Seedling Establishment Following Invasive Autumn-Olive (Elaeagnus umbellata) Removal on a Reclaimed Coal Mine

Abstract

AbstractThe Appalachian region of the United States is home to the largest temperate deciduous forest in the world, though surface mining has caused significant forest loss. Many former coal mines are now dominated by invasive plants, which often inhibit establishment of desirable species, especially slower-growing native trees. Autumn-olive (Elaeagnus umbellataThunb.) is a nonnative, nitrogen-fixing shrub that was historically planted on former coalfields, but now impedes reclamation. To better understand the influence ofE. umbellatamanagement practices on hardwood establishment, we evaluated two common management practices: cutting and cut stump herbicide treatment. Planted native tree species, including black cherry (Prunus serotinaEhrh.), pin oak (Quercus palustrisMünchh.), and red maple (Acer rubrumL.), were monitored for survival and performance over two growing seasons followingE. umbellataremoval. In each plot, we also measured plant-available nitrate (NO3−) and ammonium (NH4+) in soils using ionic exchange membranes. At the end of the first growing season, native tree survival was high, and the presence or absence ofE. umbellatahad little effect on tree survival or growth, despite the higher plant-available nitrate whereE. umbellatawas present. By the end of the second growing season, native tree survival dropped to 20% to 60% and varied amongE. umbellatatreatments. Survival was highest whenE. umbellatawas cut and treated with herbicide, though tree growth was similar across all treatments withoutE. umbellata. When establishing native trees to replaceE. umbellata, cutting and herbicide application treatment of the invader resulted in the highest overall efficacy (100% control), though the most cost-effective method may be to simply cut mature stands despite regrowth, as this resulted in equivalent native tree growth over 2 yr. While this allowedE. umbellataregeneration, it provided sufficient invader control to allow initial tree establishment. Cutting and herbicide application treatment resulted in lessE. umbellataregeneration and appears to provide greater assurance that established trees will persist over the long term.