Ectomycorrhizal Fungi and Chestnut Restoration in Reclaimed Coalmine Areas

This research is no longer active. 
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Research Issue

The American chestnut, once the third most dominant tree in eastern United States forests, has been almost eliminated by an invasive fungus, Cryphonectria parasitica Murrill. First introduced to North America in 1904, the fungus quickly spread among defenseless chestnut trees.
Extensive research during the last two decades has provided hope for restoring this beloved tree to its natural range. A tree breeding program initiated by The American Chestnut Foundation appears very close to establishing a blight-resistant American chestnut. Another research effort, focused on reducing the strength and disease-causing properties of the fungus through genetic engineering, has also shown great potential.
Besides studying the trees themselves and the fungus that attacks them, researchers also need to understand environmental growing conditions as we try to restore American chestnuts in our forests. This includes understanding soil and light conditions where trees are planted as well as the role of mycorrhizal fungi in helping trees survive and grow.

Our Research

[photo] Mycorrhizal chestnut  roots as seen under a dissecting microscope.We have worked on restoring American chestnuts on former mine lands where the tree was once common. Some of these lands have been severely scarred and degraded by coal mining operations. Hostile growing conditions include little topsoil, high soil temperatures, low soil pH, and high concentrations of metals.
Our research uses ectomycorrhizal fungi to improve the trees’ chances of getting established and growing successfully in difficult conditions. Ectomycorrhizal fungi grow along tree roots, helping them take up water and nutrients from the soil. This is especially important in places where growing conditions for trees are less than ideal.
Before we undertook this research, there had been no systematic studies to identify and analyze the fungi that are found along chestnut tree roots. In our laboratory, we tested several species of ectomycorrhizal fungi for their ability to form beneficial relationships with American chestnut roots. We identified five known and two new strains of ectomycorrhizal fungi that can fill this role.

[photo] Mycorrhizal chestnut seedlings.We grew chestnut seedlings, introduced mycorrhizal fungi to the chestnut roots in the laboratory, and planted them on reclaimed mined lands in southeast Ohio. We monitored them over a number of years for growth and survival and we also evaluated the terrains, soils, and presence/absence of other vegetation at the planting sites.

Expected Outcomes

Our research has successfully identified mycorrhizal fungi that help American chestnut trees grow on disturbed lands such as abandoned coal mines. We have also discovered that once our trees become established, native mycorrhizal fungi already found in the soil or associated with other trees eventually replace the fungi we added to the tree roots in the lab before planting.

Research Results

Hiremath, Shivanand; Lehtoma, Kirsten; Bauman, Jenise M. 2014. Native mycorrhizal fungi replace introduced fungal species on Virginia pine and American chestnut planted on reclaimed mine sites of Ohio. Journal of American Society of Mining and Reclamation. 3(1). 1-15.

Bauman, Jenise M.; Keiffer, Carolyn H.; Hiremath, Shiv; McCarthy, Brian C. 2013. Soil preparation methods promoting ectomycorrhizal colonization and American chestnut Castanea dentata establishment in coal mine restoration. Journal of Applied Ecology. 50: 721-729.

Bauman, Jenise M.; Keiffer, Carolyn H.; Hiremath, Shiv. 2012. The efficiency of introduced pisolithus tinctorius inoculum on backcrossed chestnut germination and survival. In: Barnhisel, R.I., ed. Proceedings of the 2012 National meeting of the American Society of Mining and Reclamation; 2012 June 8-15; Tupelo, MS. ASMR, Lexington, KY: 6-23.

Bauman, Jenise M.; Keiffer, Carolyn H.; Hiremath, Shiv. 2012. Facilitation of American chestnut (Castanea dentata) seedling establishment by Pinus virginiana in mine restoration. International Journal of Ecology. 2012: Article ID 257326. 12 p. doi:10.1155/2012/2573

Bauman, Jenise M.; Keiffer, Carolyn H.; Hiremath, Shiv. 2011. The influence of inoculated and native ectomycorrhizal fungi on morphology, physiology and survival of American chestnut. In: Barnhisel, R.I., ed. Proceedings of the 2011 National meeting of the American Society of Mining and Reclamation; 2011 June 11-16; Bismarck, ND. ASMR, Lexington, KY: 16-37.

Hiremath, Shiv; Lehtoma, Kirsten; Bauman, Jenise M. 2013. Survey for the presence of Phytophthora cinnamomi on reclaimed mined lands in Ohio chosen for restoration of the American chestnut. Journal American Society of Mining and Reclamation. 2(1): 68-79.

Hiremath, Shiv; Lehtoma, Kirsten; Nagle, Annemarie; Bonello, Pierluigi. 2011. Screening for Phytophthora cinnamomi in reclaimed mined lands targeted for American chestnut restoration projects. In: McManus, Katherine A; Gottschalk, Kurt W., eds. 2010. Proceedings. 21st U.S. Department of Agriculture interagency research forum on invasive species 2010; 2010 January 12-15; Annapolis, MD. Gen. Tech. Rep. NRS-P-75. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station: 92.

Bauman, Jenise; Keiffer, Carolyn; Hiremath, Shiv. 2009. Environmental variables as predictors for ectomycorrhizal species in American chestnut (Castanea dentata) mine reclamation. Proceedings, Annual Ecological Society Meeting, 2009. No. 20119, p 58.

Research Participants

Principal Investigator

  • Shiv Hiremath, US Forest Service, Northern Research Station, Research Biologist (retired)

Research Partners

  • Last modified: May 6, 2019