Saving the American Chestnut
On Saturday, May 6, Headwaters Master Naturalists were treated to a tour of Lesesne State Forest in Nelson County by forester John Scrivani. Thanks to Malcolm Cameron and Elaine Smith for organizing and hosting the trip and to Malcolm for this report!
John Scrivani retired from the Virginia Department of Forestry to work for the American Chestnut Foundation (ACF). He is the president of the Virginia Chapter of the American Chestnut Foundation and is involved with ACF at Lesesne State Forest.
Lesesne State Forest was established in 1968 when it was gifted to VDOF by Mrs. Anne DuPont Vaulk for the purpose of research to save the American chestnut. It is adjacent to the George Washington & Jefferson National Forest in Nelson County and has several chestnut orchards and open fields within a total of 422 acres. ACF plants and crossbreeds American chestnuts there with Chinese and Japanese chestnut trees.
The chestnut blight infected chestnut trees across its range in the Eastern U.S. in the early 1900s and by the 1940s they were mostly wiped out except for smaller shoots sprouting from the stumps. They were a foundation species before the blight and once comprised about 25% of Appalachian forests, serving as a key economic resource in many local economies. American chestnut trees were favored by fire which was more frequent in past decades.
ACF employs various methods to crossbreed the chestnut species, primarily by covering the female flowers on American Chestnut trees with paper bags once they bloom in June and hand application of pollen from the Chinese or Japanese species. Less than 10% of the catkins have female flowers. These methods have resulted in hybrid species that are 15/16 or more of the American genotype. The chestnut trees start producing nuts at age 7 years.
The ACF works with the State University of New York in aiding SUNY’s transgenic research in developing stronger chestnut tree hybrids. SUNY inserts genes from wheat into the American chestnuts and ACF of Virginia has planted some of those hybrids at Lesesne Forest. ACF at Lesesne strives for trees that are at least 80-90% American genotype and that have a blight resistance score of 60+. The score is largely determined by how well the trees are able to wall off the cankers in their bark and limit the impact to the tree health.
The Japanese-American chestnut hybrids are more blight resistant than the Chinese hybrids. John’s tour took us through several orchards in the lower field with various back-cross hybrids and at the end of day he showed us the upper orchard where several trees that were irradiated for the blight had been planted. Most of those trees died and other trees were grafted onto the stumps in the early 80’s with mixed results. Some trees in the upper orchard were backcrossed with transgenic chestnut trees.
ACF plans to begin doing more plantings of hybrid American chestnut trees at various locations in the next few years. ACF Virginia has already planted hybrids in a few locations in the GWJNF.
ACF Virginia welcomes volunteers to assist with their activities at Lesesne State Forest and elsewhere including at the VDOF nursery in Crimora.
Malcolm Cameron, Cohort II
Find more photos of the tour from Scott Jost HERE and from Elaine Smith HERE.