Background/Question/Methods
Coal mining is an important industry in the state of Ohio and in 2008 approximately one-third of this mining was associated with surface mines. It is estimated that Ohio has 11.5 billion tons of economically recoverable coal reserves, and over 26 million tons of coal was produced from 11 underground mines and 86 surface mines in 2008 (a 56.5% increase from 2007). Many of these recent surface mines, as well as abandoned mined-lands, have been reclaimed as grasslands following the implementation of the 1972 Ohio and 1977 federal regulations. However, recent efforts, including the Appalachian Regional Reforestation Initiative (ARRI) co-sponsored by the Office of Surface Mining and regional state government agencies (e.g., Ohio Department of Natural Resources), are working to increase the planting of high-value hardwoods on reclaimed coal mined-lands. As part of this initiative, we have been reviewing the half-century of research and practices on reforestation of mined-lands conducted by at the Ohio Agricultural Research and Development Center (OARDC). Specifically, we are examining how the results of these studies can be utilized to develop specific guidelines for reclaiming mined-lands of Ohio within the context of ARRI’s Forestry Reclamation Approach (FRA).
Results/Conclusions
The FRA focuses on several principles, including: 1) creating suitable rooting media for good tree growth; 2) ensuring loosely graded topsoil or topsoil substitutes to create a non-compacted growth medium; 3) using native and non-competitive ground covers compatible with growing trees; and 4) planting both early successional species and commercially valuable crop trees. In terms of creating suitable and non-compacted rooting media, researchers from OARDC have found that grading and fertilizing mined sites has mixed effects on planted tree survival and growth, with Liriodendron tulipifera L. exhibiting the greatest decline in survival and growth of the species considered. Furthermore, researchers using both greenhouse and field experiments have compared the competitive influences of common ground covers, different grading and fertilization treatments, and seedling origin (e.g., planted or volunteer) on the growth and survival of different species, including important early successional species such as nitrogen-fixing Robinia pseudoacacia L. and key commercial species including Quercus rubra L. and Prunus serotina Ehrh. Through these efforts, we are identifying gaps in our understanding of how these reclamation practices affect important ecosystem processes, which is providing us with a basis to design retrospective studies to understand how reclaimed sites develop over time.