Factors Affecting Performance of Artificially Regenerated American Chestnut on Reclaimed Mine Sites

Abstract

The use of SMCRA approved practices for mined land reclamation has resulted in arrested succession throughout many areas of central Appalachia. The combination of heavily compacted soils and the addition of aggressive, often nonnative, grasses and forbs creates an environment characterized by high soil bulk density and aggressive ground-layer competition. This results in a situation where trees are unable to recruit and thus many lands are unable to return to original forest cover through natural processes of succession. Using the basic principles of the Forestry Reclamation Approach (FRA), we report on two experiments conducted in Ohio: one designed to remediate a 30-yr arrested succession and the other designed to encourage immediate reforestation at the time of reclamation. We conducted these experiments using American chestnut (Castanea dentata) to explore the potential for using these sites as part of the national restoration plan under development by the American Chestnut Foundation (ACF). The first experiment utilized deep soil ripping and a combination of plowing and disking treatments. After three years, the results are clear. Simply planting chestnut into untreated existing habitat is ineffective. Some type of surface treatment to reduce soil bulk density and competition is necessary for seedling establishment. The more significant the disturbance, the better the survival and growth of chestnut. The second experiment utilized loose end-dumping at the time of reclamation. Various methods of chestnut deployment and planting were evaluated including direct seeding and bare-root seedlings. Plantings were done with and without protection from predators in different microsites. While survival of seedlings was greater than seeds, the most noticeable enhancement to survival was the addition of a tree shelter, which nearly doubled the survival rate. In summary, American chestnut appears to thrive on mine land reclamation sites-this may prove to be a useful focal point for restoration of the species while aiding in the reforestation of old and new reclamation sites.

Evaluating the Use of Tree Shelters for Direct Seeding of Castanea on a Surface Mine in Appalachia

“…Two of these studies also assessed survival of trees planted as unsheltered seeds. In Ohio, McCarthy et al [12] found a significant sheltering effect; however, survival of unsheltered trees was around 55% in their study, which was much greater than survival of unsheltered trees found in our study. Similarly, unsheltered chestnuts in West Virginia survived well through four growing seasons (57%).…”

“…Other studies report first year survival of sheltered trees planted as seeds: 76% in Virginia [15] and >80% in Ohio [12]. These values are higher than first-year survival in our study (65%).…”

“…We found that trees protected by the 60 cm shelters were significantly higher than unsheltered trees after five growing seasons. Similarly, McCarthy et al [12] found that unprotected trees were characterized by lower growth rates than trees sheltered with 120 cm tubes, a relationship they attributed to heavy herbivory on unprotected trees. In contrast, Skousen et al [14] reported similar average heights of trees between sheltering treatments.…”

“…In Ohio, McCarthy et al [12] found that first-year survival of bareroot seedlings planted into mined land was heavily influenced by soil physical characteristics, particularly bulk density. Seedlings planted into compaction-mitigated treatments survived well (90%-95%).…”

“…One study found that tree shelters did not significantly influence growth or survival of chestnuts planted into reclaimed mine land after the first growing season [14]. In contrast, some research suggests that sheltering improves survival of direct-seeded chestnuts into reclaimed mine land both by reducing predation of seeds and reducing herbivory of seedlings [12]. Thus, strategies for using tree shelters to improve establishment and growth of American chestnut in restoration projects remain unclear.…”