The new study, published in the journal Science last week, showed that forests in far northern latitudes could one day act as a climate refuge for the all-important black spruce, the foundation tree for the Northwoods ecosystem.
The Northwoods region is a major source of the world’s pulpwood for paper, home to the snowshoe hare, caribou, lynx, and sable, as well as the ideal nesting site for dozens of migratory bird species, reports Science News Line.
Loïc D’Orangeville, a postdoctoral researcher at Université du Québec à Montréal and Indiana University, who led the collaboration of scientists from six institutions in the U.S. and Canada says, “During this century, the Northwoods will experience some of the Earth’s largest increases in temperature.”
“A warming climate increases the amount of water boreal forests need to survive,” explains D’Orangeville. “It’s possible that only a relatively small part of North America’s boreal forest will have enough water to compensate for the increased demand.”
While warmer temperatures actually stimulate tree growth, it only works if there is enough precipitation. Otherwise, warmer temperatures dry out the forest. North of latitude 49 degrees North, according to the study, snow has been melting earlier, increasing the growing season. And this may be good news for tree growth. According to the research team, by 2070, fully two-thirds of the forests above the 49th parallel should still be doing well, and this suggests that Quebec could be a refuge for the boreal forest.
But below the 49th parallel, things will certainly be different. Warming and a lengthened growing season will create drought stress, something that could overwhelm the black spruce. This is already happening in the region. This part of the forest could adapt to climate change in our lifetime if future warming stays below the temperature threshold,” says Neil Pederson, co-author of the study and a senior ecologist at Harvard Forest.
But Pederson admits that the future is unpredictable. He cites the recent mega-fires in boreal forests in western Canada and Alaska. But he still offers us some hope. “In a world where many ecological forecasts appear dire for plants, animals, and people,” says Pederson, “Identifying areas that could serve as potential havens for biodiversity during potentially tumultuous times is good news.”
The world’s boreal forests
The taiga or boreal forest consists of coniferous trees, mostly pines, spruce, and larch trees. The boreal forest is the globe’s largest terrestrial biome, however, main tree species, the length of the growing season and temperatures may vary, depending where the boreal forests may be.
As we have noted, in North America, the black spruce is the predominant tree, while in Scandinavian and Finnish boreal forests, we find a mix of spruce, pines, and birch trees. Russia’s boreal forests have spruce, pines, and larches. In Eastern Siberia, the taiga is primarily a huge larch forest.
The taiga biome makes up 29 percent of the Earth’s forests, with the largest areas in Canada and Russia. But the taigas of Canada and Russia are starting to be impacted by global warming, especially in the southern portions as the warmer temperatures slowly inch their way northward.
