Preliminary Research to Assess Deer Exclusion Influence on Survival and Growth of American Chestnut Planted in George Washington National Forest

Published March 17, 2017

We all know the story by now: a little more than 100 years ago, American chestnut (Castanea dentata) was rapidly removed as an overstory tree throughout the eastern United Sates by the fungal pathogen Cryphonectria parasitica, which causes chestnut blight. Now, The American Chestnut Foundation (TACF) is committed to restoring American chestnut through the hybridization of American chestnut with the highly blight resistant Chinese chestnut (Castanea mollissima), successively backcrossing the progeny with pure American chestnuts, and then intercrossing to fix resistance in our potentially blight-resistant (PBR) American chestnut.

Prior to planting, TACF volunteers help map and flag the site.

Prior to planting, TACF volunteers help map and flag the site.

However, our breeding work has not gone without setbacks and/or questions regarding future restoration plans. Deer browse is a perennial problem with chestnut growers, and this problem is significant in forest settings, where deer browse is greater and deer exclusion can be limited by topographical constraints. Some deer exclusion strategies in forest sites include deer cages and tall tree tubes. We decided to test both methods against no protection (as a control) in a replicated study in a recent cutover in the George Washington National Forest.

December, 2016, approximately twenty TACF volunteers and US Forest Service crewmembers met to put 600 PBR chestnuts to the test.  We established a completely randomized planting involving 200 seedlings protected with deer cages, 200 protected with tall tree tubes, and 200 unprotected.  This study will provide an initial set of data regarding the survival, growth and deer browse of American chestnut within a recently harvested site. We will also observe long-term blight resistance and American-type competitiveness.  This was all made possible by a generous grant from the National Forest Foundation’s Matching Awards Program.

Expected Results:

As progress continues through the TACF breeding program, American chestnut is poised for future reintroduction throughout its former range. We will expedite the restoration of this species by examining silviculture strategies that lead to successful establishment and long-term survival and growth rates. The expected results of this research will be to identify deer exclusion strategies that limit deer browse and lead to successful establishment of self-sustaining chestnut populations. With the ultimate goal being the development of American chestnut trees that are blight resistant, root rot resistant and American chestnuts that can grow and reproduce naturally thereby setting the stage for true species restoration throughout the eastern United States.

Volunteers take a break for some hot catered lunch!

Volunteers take a break for some hot catered lunch!

Some seedlings get deer cages, some get tall tree tubes, and some are left unprotected.

Some seedlings get deer cages, some get tall tree tubes, and some are left unprotected.

Some volunteers collect data, while others plant trees and install deer exclusion.

Some volunteers collect data, while others plant trees and install deer exclusion.

Sara Fitzsimmons in 2005 with Jim Gage, Dr Phil Arnold, Dr Robert Gregg

2005
Sara Fern Fitzsimmons with Jim Gage, Dr Phil Arnold, & Dr Robert Gregg

2006, Sara Fitzsimmons pollinates at Stockers

2006
Sara pollinating at Stockers, PA

Sara rating cankers at Thorpewood

Sara rating cankers at Thorpewood, MD

Sara at the 25th Annual TACF meeting

2008
Sara at the 25th Annual TACF Meeting

Sara and the Graves tree

2009
Sara in the PSU Graves Orchard

Sara Fern Fitzsimmons in the Glenn Swank stump, 2009

2009
Sara in the Glenn Swank stump, PA

Sara at the International Chestnut Symposium, 2012

2012
Sara at the International Chestnut Symposium

Sara in Vermont

2014
Sara with Harmony Dalgleish and the Berlin American chestnut in Vermont

Kendra and Sara in the field

Sara and Kendra Collins working in the field

Sara presenting at the 2022 TACF Spring Meeting

2022
Sara presenting at TACF’s Spring Meeting

Sara (in the rocker) with TACF staff at the Fall Meeting

2023
Sara (in the rocker) with TACF staff at the Fall Meeting

Sara Fern Fitzsimmons

2024
Sara in the Penn State greenhouses