Below you will find links to three videos on the American chestnut. The videos provide valuable updates about the restoration of the species following it’s demise from the blight.
These first two videos, from
the USDA Forest Service’s Southern Research Station, are on restoration of the
American chestnut in the southern Appalachians. The videos feature information
on the Southern Research Station’s chestnut research, the National Forest
System’s silvicultural program, The University of Tennessee’s Tree Improvement
Program, and The American Chestnut Foundation’s backcross breeding
program.
Video: Restoration Research ofthe American Chestnut (Part 1 Intro)
The American chestnut was once a
common and abundant tree species that occupied 200 million acres in the eastern
hardwood forests of North America. The species had a cultural significance and
was a keystone species, providing wildlife with food and habitat sources. Two
non-native pathogens led to the chestnut’s extirpation in the 20th century, but
efforts are underway to conserve and restore this iconic tree.
Video: Restoration Research ofthe American Chestnut (Part 2: Science in Action)
The USDA Forest Service, The
University of Tennessee, and other partners showcase their research on the
American chestnut (Castanea dentata), a species that was extirpated by a
non-native pathogen (Cryphonectria parasitica) that causes chestnut blight
disease. Over 4,000 hybrid chestnuts that were bred for blight-resistance were
planted on three national forests since 2009, and research is still ongoing.
This next video is by Dr. William
A. Powell. Dr. Powell is the Director of
the American Chestnut Research & Restoration Project at the SUNY College of
Environmental Science and Forestry. His team has focused on enhancing blight
tolerance by adding only a couple genes to the approximately 38,000 gene pairs
in the chestnut genome using the tools of genetic engineering (GE). This is
important because these GE tools retain all of the American chestnut genes
required for its adaptation to its forest ecosystem.
The most promising gene tested to
date comes from bread wheat (Triticum aestivum) and encodes an oxalate
detoxifying enzyme, called oxalate oxidase (OxO). This gene is a common defense
gene found in many plants and it can confer enhanced blight tolerance in
American chestnut. The original blight tolerant trees have been outcrossed to
susceptible American chestnut trees through three generations to date,
increasing genetic diversity and local adaptation. Environmental impact
experiments have been completed and these trees are currently under federal
review before being released to the public and to restoration programs. This video
describes the program and its current progress toward restoring this keystone
species.
Video: The Chestnut Tree: Bringing Back an American Icon
Billions of American Chestnut
trees used to grow in America—and then a fungal blight spread throughout its
native range. By the 21st century, this population had all but disappeared. Using
revolutionary technology, the American Chestnut Research & Restoration
Project aims to resuscitate the Castanea dentata. In this Stories of Impact
video, William A. Powell (SUNY ESF) and Rex Mann (The American Chestnut
Foundation) discuss the American chestnut and their goal of restoring the
iconic tree to its former glory. Supported by the Templeton World Charity
Foundation, this first-of-its-kind project is engineering a blight-resistant
chestnut and reintroducing it to its native habitat.