Background on American chestnut and chestnut blight
The American Chestnut Research and Restoration Project
History of the American chestnut and the chestnut blight
Before the turn of the century, the eastern half of the United States was dominated by the American chestnut. Because it could grow rapidly and attain huge sizes, the tree was often the outstanding visual feature in both urban and rural landscapes. The wood was used wherever strength and rot-resistance was needed. In colonial America, chestnut was a preferred species for log cabins, especially the bottom rot-prone foundation logs. Later posts, poles, flooring, and railroad ties were all made from chestnut lumber. The edible nut was also a significant contributor to the rural economy. Hogs and cattle were often fattened for market by allowing them to forage in chestnut-dominated forests. Chestnut ripening coincided with the Thanksgiving-Christmas holiday season, and turn-of-the-century newspaper articles often showed train cars filled to overflowing with chestnuts rolling into major cities to be sold fresh or roasted. The American chestnut was truly a heritage tree.
All of this began to change at or slightly before the turn of the century with the introduction of Cryphonectria parasitica, the causal agent of chestnut blight. This disease reduced the American chestnut from its position as the dominant tree species in the eastern forest to little more than an early-succession-stage shrub. There has been essentially no chestnut lumber sold in the United States for several decades and the bulk of the annual 20-million-pound nut crop now comes from introduced chestnut species or imported nuts.
Despite its decimation as a lumber and nut-crop species, the American chestnut has not gone extinct. The species has survived by sending up stump sprouts that grow vigorously in logged or otherwise disturbed sites, but inevitably succumb to the blight and die back to the ground. The most recent USDA Forest Service survey for New York State indicates that there may be as many as 60 million of these sprout clumps in New York State, a rich gene pool for starting a restoration effort.
Utilization of Chestnut
Chestnut heartwood is legendary for its rot resistance. Logging of standing dead trees and then of the fallen logs took place for decades after the chestnut trees were killed. Like redwood, lumber made from chestnut heartwood needs no pressure treatment before being put into service, and leaches no toxic compounds upon weathering. In an increasingly environmentally conscious society, marketing a naturally rot resistant alternative to both pressure treated lumber and old-growth redwood lumber should be easy.
Despite its relatively rapid growth, it will be many decades before plantations or hedgerows of chestnut begin producing significant quantities of timber. However, unlike many other timber-tree species, American chestnut also produces edible nuts. Flowering begins in as little as five years, and as trees mature, crops become frequent and copious. These can serve as a cash crop while the trees mature. Marketing the nuts will be even easier than the lumber. Not every new crop has its own Christmas carol already ingrained into the culture!
Yet a third new use for the species is in producing biomass for an alternative energy source. Chestnut coppices vigorously, exhibits rapid juvenile growth, and has higher specific gravity than many of the other candidates for biomass production. It also performs well on dry upland ridges where other biomass tree species, such as poplar or willow, would fail.
Enhancement of biodiversity
Biodiversity in forested ecosystems is coming to be recognized as an important attribute. In addition to directly increasing biodiversity by reintroducing a species that was once an important component of many forest ecosystems, reintroduction of the American chestnut may have a positive effect on wildlife populations. In many forest ecosystems various oaks have replaced the American chestnut as the primary mast producers. However, the oaks are notorious for producing sporadic mast crops. Before the blight, the chestnut could be counted on to produce a large mast crop nearly every year. This large and predictable mast crop was stored away by squirrels and other rodents, and consumed in large quantities by deer, bears, turkeys, and many other wildlife species to fatten up for the winter. Reintroducing this primary producer into the forest ecosystem may very well make the job of managing for multiple non-timber values easier.
- Field Guide for locating, pollinating, and harvesting nuts from flowering American Chestnut Trees (Castanea dentata)
- Can Genetic Engineering Help Restore 'Heritage' Trees?
- THE NEW CHESTNUT BARK DISEASE, I. C. WILLIAMS, Science 29 September 1911 34: 397-400
- THE FUNGUS OF THE CHESTNUT-TREE BLIGHT, W. G. Farlow, Science 10 May 1912 35: 717-722
- Three American tragedies: chestnut blight, butternut canker, and Dutch elm disease
- Nutgrafting for American Chestnut Restoration