Soil seed banks as catalysts for succession on surface-mined lands in Central Appalachia

Typical reclamation practices in the central Appalachian coal region often utilize compacted spoils as a suitable topsoil replacement, and these soils are revegetated with mixtures of aggressive grasses and legumes. This reclamation approach results in an herbaceous-dominated landscape with limited natural succession by native flora. A potential alternative reclamation method is to save topsoil prior to mining, stockpile it during mining, and then replace it among uncompacted spoils to "inoculate" the site with native plant species. The practicality of this procedure, however, is unknown. In an effort to test this approach, vegetation assessments were performed at a site in Clay County, KY, prior to mining on eight 15x15m plots. Bulk soil samples were removed from the plots and subjected to cold stratification for 13 weeks, after which seeds were allowed to germinate under greenhouse conditions for 1 year. Topsoil (0-20cm) was removed from the plots and spread on fresh spoil in eight 2x5m plots. Controls consisted of uncompacted spoil material substrate only. Species richness was 96 in the forest surveys, 83 in the greenhouse, 57 in relocated topsoil plots, and only 3 in control spoil plots. A total of 150 species was recorded in the study. Of the species unique to only one of the four assessments (85 total), the forest surveys had 59%, the greenhouse 35%, and the relocated topsoil plots 6%. Our results indicate that application of topsoil could enhance plant diversity and native species reestablishment on surface-mined lands.