A team led by Kevin Anchukaitis of the Lamont-Doherty Earth Observatory Tree Ring Lab is currently in Alaska’s Arctic National Wildlife Refuge, studying the effects of changing climate on trees. Ferried in by a bush pilot who landed on the tundra to drop them off, they are practically at treeline–the place where it is too far north for trees to grow. But there are still some spindly white spruces here, and they are taking cores from these, which can be used to measure weather of the past. One member of the team is Colorado schoolteacher Susy Ellison, who is keeping a blog of the expedition. She reports some concerns about grizzly bears, mosquito hordes and other workaday matters of the far northern summer; but so far, so good.
Even though these trees are small, the rings of some might be hundreds of years old. Combined with weather data, satellite observations and rings collected by others, the samples should allow Anchukaitis and others to assess how trees are responding to recent warming-induced season changes; distinguish between manmade warming and natural warm events of the past; and see how changes in tree growth might influence the arctic and global environments in the future. Among other things, there is already evidence that interior boreal forests are suffering outbreaks of disease and insects due to higher temperatures; on the other other hand, the treeline may be advancing, as conditions in marginal places like this maybe get better for trees. Keep tuned; Ellison files a report every few days; the latest post contains revelations on backcountry communications technology and cookery.