Restoration of the American chestnut will require more than a blight-resistant tree.

Abstract

The American chestnut (Castanea dentata) was a keystone species that was decimated by nonnative diseases, most notably a fungus (Cryphonectria parasitica) that causes chestnut blight disease, during the early 20th century in eastern North America. Breeding for a blight-resistant tree began over 100 years ago, and a backcross breeding approach that incorporated blight-resistant genes from Chinese chestnut (C. mollissima) was initiated in the 1980s. Field trials to test pure American chestnuts and hybrid trees from different breeding generations were established from 2009 to 2017. These research plantings were established as a collaborative effort among the USDA Forest Service’s National Forest System (Eastern and Southern Regions) and Research and Development (Southern Research Station, Northern Research Station) branches, a state agency (Connecticut Agricultural Experiment Station), state universities (The University of Tennessee, The University of Vermont), and a nonprofit organization (The American Chestnut Foundation). The goals of this paper were to: (1) summarize the present status of chestnut restoration research plantings established on the NFS using the most advanced breeding material currently available, and (2) summarize NFS field managers' insights on potential obstacles and contributions affecting future restoration efforts.