Mine Soil Suitability for Native Appalachian Forest Trees.

One and half million acres have been disturbed by surface mining in the Appalachian region since federal law began regulating coal mining activity in 1978. Disturbed land must be restored to its original level of capability. Topsoil substitutes are commonly used for restoring the surfaces of reclaimed land, but their suitability for supporting native forest is largely unknown. Using a 4 x 2 x 3 factorial greenhouse experiment, we examined the suitability of four growth media available for use on many mined sites in the central Appalachians:  forest topsoil (FT), weathered sandstone (WS), unweathered sandstone (US), and unweathered shale (UH), as well as the effects of inoculation with topsoil (none vs. inoculated), on the growth of three native hardwood species:  Fraxinus americana, Quercus rubra, and Liriodendron tulipifera. The WS was the spoil most conducive to growth for F. americana and Q. rubra.  L. tulipifera did not respond to any treatments.  Tree growth was highly correlated with mineralizable soil nitrogen and extractable soil phosphorus. Topsoil inoculation significantly increased growth on the UH, but not on the US or WS.  Topsoil inoculation improved foliar nutrient content of F. americana and L. tulipifera.  Many properties, such as pH, microbial activity, and water availability of the WS more closely approximated the control soil than the US or UH.  This study showed that trees are sensitive to spoil type and that certain spoil types should be used during the reclamation process, particularly if native topsoil is not applied.  Native topsoil improved tree growth on some spoil materials, improved tree nutrition, and helped restore native soil organisms and plants that were present prior to mining.