The study of tree rings and climate is called dendroclimatology.
Tree rings are analyzed world wide, and provide a useful record of climatic conditions. The width of annual growth rings can reveal information about the amount of water available, and other climatic information . Studying samples from different trees in an region allows scientists to gain an impression of which factors - such as temperature, rainfall, sunlight, wind - have been affecting growth.
By taking core samples, then sealing over the hole made to prevent disease, it is possible to extract this information without felling the tree.
Rings, bears & belugas by the banks of the Hudson Bay
After some incredibly complicated manoeuvres to get to Churchill, a remote town in northern Manitoba, I arrived at the station and was picked up by an old 13 seated mini-bus from the research centre. Churchill is a small town, built around the remains of a military base, but now uses its unique location on the arctic edge for tourism and scientific research.
My reason for being there was to work at the Northern Studies Centre to help with some Earthwatch research into climate change led by Professor Peter Kershaw from the University of Alberta. His research in Churchill involves taking core samples from trees, examining plant reclamation and “live-trapping” small mammals. All three techniques help scientist to follow changes in the delicate environment in this region.
It is an area of breathtaking natural beauty, but there are also significant natural hazards. These come in extreme sizes - at the tiny end, tireless swarms of voracious mosquitoes which make West Highland Midges look like cissies. They force you into protective clothing, seriously impact on your ability to get on with your work, and grind you down with relentless attacks. At the other end of the ecological scale bar, we were all thoroughly warned about the danger of marauding polar bears. They are a hazard that people who live in this area are well used to, but nobody can afford to take for granted, and Churchill's proud boast is that it is 'Polar Bear Capital of the World'.
As a visitor, of course, the thought of seeing one of these powerful animals - preferably from a safe but spectacular distance - is exciting as well as frightening. The field group working on identifying plants saw four polar bears, but all my time spent in tree coring activity seemed to mean that I wouldn't have much to do with them...
Tree coring: was fairly uneventful but hot, strenuous work. Buried in thick winter clothing in 30°C weather (someone told me it was cold in the arctic!!) and covered in DEET to ward off clouds of blood thirsty mosquitoes I heroically took samples from Black Spruce, White Spruce and Larch. Actually, there’s nothing to it really, just push and twist, like tapping a large wooden beer keg but with less of a payoff!
...I thought I wasn't even going to glimpse a polar bear, and I was starting to feel a little disappointed. When I finally did see one, however, it was a lot closer than I expected - when this one came right up to the centre door, and jumped up against the glass, just a foot away from me! Quite a sighting!
Live Trapping: Out of 6 traps checked at different times, 4 were always empty, and the other two were the same unfortunate vole. Turns out little PL2 (as he is affectionately known in the data log) is quite the peanut butter nibbler and had gone back for seconds. I can’t blame him. If someone set a trap in the refrigerator next to the leftover chocolate cake I would have been snared 3 or 4 times today before I figured it out.
With all our data successfully collected, the Earthwatch team members headed home to await any results of our investigations. Working with the Earthwatch team was a great experience. When we had a day off we we had time to visit the wreck of the Ithaca (a Russian cargo ship that had run aground years ago), looked at the unique local scenery of arctic tundra and we took out kayaks and watched some of the beluga whales which visit the Hudson Bay between June and August up close. It's not just the clear northern air that takes your breath away...