Gardeners could be excused for thinking climate change may actually benefit plant life—what with milder winters and all that extra carbon dioxide floating about—but global warming is destined to profoundly change the way we garden.
Food crops affected by climate change tend to grab the headlines, but trees are similarly influenced by shifts in temperature, erratic rainfall patterns, elevated levels of ultraviolet rays and increasingly severe pest infestations.
While it’s hard to predict what Canada’s northern forests will look like 50 years hence, it seems clear they’ll extend farther north than at present, although the tree species the woodlands will be composed of may be altered as much as the weather.
The fragile balance of nature is being upset, as evidenced by the increase in insects such as the mountain pine beetle—thoroughly native to Canada but previously kept in check by cold winters (which killed off most of the overwintering larvae). According to Tree Canada, at the current rate of destruction, 80 per cent of mature pine trees in British Columbia will be dead by 2013.
And there are plenty of other insect pests for the rest of us to fret about: emerald ash borer in Quebec and Ontario—with the latter also having to contend with the Asian long-horned beetle—and the brown spruce longhorn beetle in Nova Scotia. What then, is a gardener to do?
The answer should be obvious: get outside and plant more trees. Often called “the lungs of the planet,” trees take in carbon dioxide and give off oxygen in greater quantities than any other flora. They store carbon in their wood, and their nitrogen-rich leaves are nature’s own mulch par excellence.
Trees will help to slow and combat climate change, provide habitat for wildlife and generally enhance the patch of earth you call home. Tall or short, wide or narrow, leafed or needled, there’s a tree out there that’s a perfect match for every garden, and for every gardener.
Since its launch in 1994, Green Streets Canada (a flagship program of Ottawa-based Tree Canada) has encouraged the adoption of innovative management practices and policies to help our urban forests deal with the harmful pressures of climate change, invasive pests, development and drought. To date, 355 municipalities countrywide are involved in the program (applications for the 2009-10 season are available online).
Winning municipalities from 2008-09 included Burns Lake, British Columbia, where trees lost to the mountain pine beetle were replanted; Kingston, Ontario, where a new urban forest is being created; and Gatineau, Quebec, where a tree inventory project is underway.
For more information, visit the Tree Canada Foundation website at treecanada.ca.