EVALUATION OF MINE SPOIL SUITABILITY FOR THE INTRODUCTION OF AMERICAN CHESTNUT HYBRIDS IN THE CUMBERLAND PLATEAU

摘要

American chestnut (Castanea dentata (Marsh.) Borkh.) was formerly the most important hardwood species throughout the forests of eastern North America. The introduction of an exotic fungal blight (Cryphonectria parasitica (Murr.) Barr) in the early 20~(th) century decimated C. dentata populations. Blight-resistant chestnut hybrids may soon be available for widespread distribution through The American Chestnut Foundation's breeding program, although the development of blight-resistant hybrids is only the first step of the restoration process. For successful introduction, more information must be attained about site requirements necessary for successful establishment and growth of American chestnut. Surface mine spoils in the Appalachian coal region and elsewhere may prove suitable for the establishment of founder populations of blight-resistant chestnut hybrids which may then act as reservoirs for chestnut dispersal into surrounding forests. Six research plots composed of three different loose-graded spoil types have been constructed in the Cumberland Plateau of eastern Kentucky to evaluate their effects on tree performance. The three spoil types are: (1) predominately brown weathered sandstone; (2) predominately gray un-weathered sandstone; and (3) equally mixed brown and gray sandstones and shale. C. dentata sub-plots were planted within each of the six plots to serve as proxies for the blight-resistant chestnut hybrids. Preliminary data suggest that initial survival rates are significantly higher (100 percent) on the mixed spoil material over that of the weathered brown sandstone (79.5 percent). Survival on the un-weathered grey sandstone (93.2 percent) was not significantly different than that observed on the other two spoil types.