GROWTH OF THREE APPALACHIAN HARDWOOD SPECIES IN DIFFERENT MINE SPOIL TYPES WITH AND WITHOUT TOPSOIL INOCULATION 1

The goal of many landowners who own reclaimed mined land is to restore the diverse mixed mesophytic forest for environmental, economic, and cultural reasons. However, native hardwoods tend to grow poorly on mined sites due to their physical, chemical and biological mine spoil properties. A 4 x 2 x 3 factorial greenhouse experiment was conducted with one-year-old seedlings. We examined the suitability of four growth media: forest topsoil (FT), weathered sandstone (WS), unweathered sandstone (US), and unweathered shale (UH), as well as the effects of inoculation with topsoil (none verses inoculated), on the growth of three native hardwood species: Fraxinus americana, Q. rubra, and L. tulipifera. Tree growth, foliar nutrients, and soil properties were measured and characterized. The WS was the mine spoil material most conducive to growth for F. americana and Q. rubra. L. tulipifera did not respond to any treatments. Foliar nutrient analysis indicated that adequate nutrition of Q. rubra was independent of spoil type (p = 0.49), F. americana was somewhat dependent on spoil type for nutrient uptake (p =<0.0001), and L. tulipifera was highly dependent, (p < 0.0001). Topsoil inoculation significantly increased growth on the UH spoil type, but not the US or WS spoil types. Topsoil inoculation significantly increased the number of herbaceous plants growing in the pots and improved foliar nutrient indices in 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 sandstone or shale. The results of this study show that trees are sensitive to spoil type and that certain spoil types should be selected during the reclamation process. Topsoil inoculation should also be considered as it may increase tree growth on some spoil materials, improve tree nutrition and help return the diverse native plant population that was present prior to mining.