Edwards looked at core samples from white spruce trees living in the wilds of Mancha Creek, which flows into the Firth River near the Alaska-Yukon border, and growing on the flanks of Sukakpak Mountain, near Coldfoot.
She examined rings from trees that were alive in 1783 and are still alive, as well as buried wood from trees that are no longer alive.
“1783 looks weird,” she said in San Francisco. The early-season growth of the trees seemed normal, but Edwards noticed the trees did not produce a thick cell wall at the end of the growing season, as they did in every other year.
“That might be because of a temperature decrease and a dimming of the light,” she said of the late summer of 1783. “The trees might have thought the growing season was over.”
The birds are all right: Bird biologist Susan Sharbaugh contacted me about the physics of 40 below column that ran a couple weeks ago. She said not to worry, when you stop feeding birds even in the extreme cold, they will be OK:
“The chickadees have been caching since August,” she said. “They have lots of stored food to get them by. The redpolls are living in a birch-seed pantry. Lots of food available. And they have wings. They will go to where there is food, either your neighbor’s feeder or where the conditions are better.”
Since the late 1970s, the University of Alaska Fairbanks’ Geophysical Institute has provided this column free in cooperation with the UAF research community. Ned Rozell is a science writer for the Geophysical Institute.