Improving forest health through tree improvement

Forests are under increasing stress from invasive pests and pathogens and climate change. Forest resilience mainly depends on the health of foundational tree species. Improving the genetics of foundational species is more important now than ever and will be dependent on innovative applications of new technologies to increase the efficiency and effectiveness of tree improvement.

Rows of chestnut seedlings in small containers. — Mississippi-origin American chestnut genotypes being propagated for genetic conservation and restoration breeding. The work is being done by SRS-4160 at the Southern Institute of Forest Genetics on the Harrison Experimental Forest near Saucier, MS. About 25 rare genotypes have been identified throughout the species native range in Mississippi. These are valuable genotypes for the region-wide breeding and genetic engineering program being conducted by partners, including The American Chestnut Foundation (TACF) and the School of Environmental Sciences and Forestry at the State University of New York (SUNY-ESF). USDA Forest Service photo by Chance K. Parker.

Invasive pests, pathogens, and plants harm forests across the country and internationally. In addition, climate change exacerbates this harm while also changing patterns of rainfall, other precipitation, and temperature. Improving and managing the genetics of impacted tree species in these forest systems is a promising mitigation and adaption approach.

Traditional genetic engineering has yielded a genotype of American chestnut with promising resistance to chestnut blight. At the same time, traditional breeding approaches show promise for developing ash populations with enhanced emerald ash borer tolerance. Researchers are also developing new genetic engineering approaches for silencing emerald ash borer genes.

Traditional tree breeding and genetic engineering are both promising tools for addressing long-standing and emerging invasive pest problems in foundational forest trees, as this research shows. Furthermore, viewing the technologies as complementary and integrating them early in the tree improvement process is critical for success in research and development as well as applications to reforestation and restoration.

Principal Investigator: C. Dana Nelson, Project Leader
RWU: 4160 - Forest Genetics and Ecosystems Biology
Publication: Breeding for resistance to tree pests: Successes, challenges, and a guide to the future
Research Partners: Richard Sniezko, Pacific Northwest Region; Carolyn Pike, Eastern Region State and Private Forestry; Jennifer Koch, Northern Research Station