The days are getting shorter - it's dark in the morning now - and the first acorns have begun to fall. Intimations of mortality and decline creep around the periphery of thought. It's time to start preparing: winter is coming. I've already started cutting fire wood, though it's still so hot that the labor is killing and seems inappropriate.

Last year I did some investigation of the oak Mast Cycle in an attempt to resolve some folk myths about the prescience of trees. For much of American history the mast cycle was less important than now because of that marvelous species the American Chestnut.

Ecologists have long bemoaned the destruction of the American chestnut, but the general public has been far less aware of the magnitude of the blight's effects. As Freinkel appropriately points out, nearly everyone noticed the downfall of the American elm, because it was an urban shade tree, whereas the loss of the chestnut was most acutely felt by rural Americans whose histories were oral rather than written. The nuts were an important cash crop for them, and they found many uses for its timber and bark. . .

The American chestnut had valuable traits that made it superior in a number of ways both to the closely related Chinese chestnut species and to some Eastern forest species. For one thing, it was aggressive and could compete more effectively with other types of trees. Also, by most accounts American chestnuts were more flavorful than their Chinese cousins. And unlike many other large-seeded species—hickory and oak, for example—which have good production of mast (the nuts that accumulate on the forest floor) one year and poor production the next, the American chestnut produced a great deal of mast fairly consistently, making it a reliable source of food for wildlife.

In addition, wood from the tree was easy to work and resistant to rot—in the southern Appalachians it is still possible to find cabins and barns made of chestnut wood. The American chestnut could also regenerate rapidly from cut stumps and grow high-quality wood in the process. At one point the trees provided about two thirds of the tannic acid (used in the leather-tanning industry) produced in the United States.

Most of them were dead before I was born. I only know them from stories, songs, poems, books about woodworking and an occasional rustic piece of antique furniture. But they aren't extinct.

One approach to restoration has been to introduce genes for resistance to the fungus by crossbreeding American chestnuts with the resistant Chinese species. The first step is to backcross resistant hybrids and genetically pure American chestnuts for three generations (a process that takes decades), producing a tree that is fifteen-­sixteenths American. Ideally, that tree will have the rapid growth in height and straight trunk of the American chestnut and will take from the Chinese species only the two or three genes known to confer resistance. However, meiotic recombinations make targeting specific genes an arduous business. Chestnuts have thousands of genes, and even the one-­sixteenth of these that would have come from the Chinese species could confer numerous undesirable traits. The likely result will be the creation of trees that are lacking some of the genes required to restore the American chestnut to its former sylvan dominance.

Another restoration strategy involves inoculating trees with a weakened form of the blighting fungus. This idea arose after chestnut populations in several places were discovered to be recovering from blight; investigation revealed that the fungus on those trees had been infected with a hypovirus. The idea of using the hypovirulent fungus to inoculate trees seemed promising, but it hasn't worked very well in practice. Complicating matters are the genetic differences between individual trees and the fact that there are hundreds of strains of the blight fungus and four variants of the hypovirus.

Yet another approach, one that has encountered opposition, has been to use transgene technology to place genes from plants such as wheat into American chestnuts to enhance resistance to the fungus. Blight-resistant transgenic chestnut trees may someday shade our descendants, but at this point only a few transgenic chestnut treelets exist, and no one knows yet whether their ability to resist blight will be adequate.

Finally, there is always the possibility that somewhere in the American chestnut tree's native range, there are trees capable of resisting the blight just long enough to reproduce; I have twice seen in the wild American chestnuts with burs containing seeds, indicating that reproduction had occurred. Perhaps mutation and natural selection can yet produce a truly blight-resistant American chestnut.

I'd welcome transgenic American Chestnut trees that were as much like those of yore as possible, except for being able to survive chestnut blight. I'm always amazed to hear that some wanker opposes such things due to some sort of thoughtless transgenic taboo. Why do we listen to these people? Why do their silly ideas garner support from anyone? In this, as in so many things, environmentalists are a threat to the environment.