THORNDIKE — More than 50 Unity College students got dirty Tuesday inside the McKay Farm and Research Station as they filled pods with soil as part of a project to prepare 1,000 American chestnut tree seedlings.

The multi-year replanting and study effort aims to restore the American chestnut tree around central Maine by growing seeds that are disease-resistant.

The American chestnut is classified as a tree of special concern in Maine because of the devastating effects of a blight accidentally imported to the East Coast more than 100 years ago, according to a college news release. Unity College is partnering with The American Chestnut Foundation and the New England Forestry Foundation on the project.

At the college’s Thorndike-based McKay Farm on Tuesday, professor Matthew Chatfield said the restoration project is necessary for the endangered tree, which has value as both a wildlife food and for wood products. Unity College students studying conservation biology and McKay Farm staff sowed and grew the American chestnut tree seedlings in the greenhouses at the research station.

Last year, the New England Forestry Foundation provided a planting location at its Thurston Memorial Forest in Knox and Montville. Volunteers on June 16 replanted trees in those areas.

Chatfield said the project’s study will reveal information about cold hardiness and disease resistance of American chestnuts as they are replanted in their native range.