An experimental assessment of American chestnut growth and survival on reclaimed mine lands across central Appalachia

Background/Question/Methods

In the last century, coal surface mining and decimation of the American chestnut (Castanea dentata) by chestnut blight (Cryphonectria parasitica) have heavily impacted many forests in the Appalachian Region. Reforestation of former mined lands has become a new priority in this region. Concurrently, mined lands are under consideration as potential reintroduction sites for blight-resistant chestnut hybrids when they become available. The American Chestnut Foundation (TACF) and the Appalachian Regional Reforestation Initiative (ARRI) initiated a project in 2008 to field-test the growth and survival ability of hybrid chestnuts on reclaimed mine lands across a wide geographic range. Five chestnut taxa (C. dentata, C. mollissima (Chinese chestnut), and three intermediate backcrossed hybrids) were planted as seeds on reclaimed mine lands in six Appalachian states. Results from the first two years of growth indicated little to no difference among the five taxa, though we hypothesized that growth patterns would diverge over longer time periods. We revisited plantings in Pennsylvania, Ohio, Kentucky, and Tennessee in 2012, five years after planting, to assess chestnut growth and survival. Site characteristics (e.g., soil properties, vegetation cover) that may influence chestnut success were also assessed at each location. 

Results/Conclusions

Though Chinese chestnuts had significantly higher five-year survival than later backcrossed hybrids (P << 0.01) and American chestnuts (P << 0.01), total height did not differ among chestnut taxa (P = 0.376). However, site had a very strong influence on chestnut growth. Total height and root collar diameter differed significantly by site (P << 0.01) with the best mean growth occurring in Kentucky and Tennessee. Plantings in Ohio and Pennsylvania had the lowest mean growth, but also had the highest total vegetation cover (P << 0.01). Identification of additional site characteristics favorable to chestnut growth will facilitate reforestation and the successful reintroduction of this species.