Topsoil and Mulch Effects on Plant Species and Community Responses of Revegetated Mined Land

Abstract

Replacement of topsoil and the use of mulches for soil stabilization have become important components of mined land reclamation plans in the western United States. Four topsoil depths (0, 20, 40, and 60 cm) and 2 mulch methods [crimped straw and standing barley (Hordeum vulgare L. Otis) stubble] were investigated on uranium mined land in Wyoming. Although 20 cm of topsoil provided initial benefits to stand establishment, after 4 growing seasons, 40 cm of topsoil was required to improve seeded grass growth over that found in non-topsoiled plots. Forty centimeters of topsoil was also found to result in the lowest biomass of invading annual and biennial forbs (nonseeded species). Barley stubble mulch resulted in significantly (P = 0.05) higher biomass of seeded grass species than did crimped straw mulch when at least 40 cm of topsoil was present.