January 15, 2008
Boreal forest researchers refer to both roads and hydro transmission lines as “linear features” but to some forest-dwellers they might simply be called bad news.
“The more of these you build, the more negative effects you’ll get in the system,” said Stan Boutin, a professor of biological sciences at the University of Alberta.
Boutin said in Alberta, whitetail deer and coyotes are using linear features to expand north into the boreal forest, where they never lived before.
The deer, especially, have a negative effect on moose and woodland caribou, because wolves are attracted to the high number of deer.
GETS HARDER
One of the caribou’s survival strategies, Boutin said, is to avoid other ungulates, such as moose and deer, to also avoid their predators, but that becomes harder when deer come around, attracted by shoots growing along trimmed cutlines.
“Any time we enhance the system to favour other ungulates, it has a negative effect on caribou,” he said.
Erin Bayne, an assistant professor of biological sciences at the U of A, noted gravel roads leave "dust plumes" that kill the most sensitive vegetation close to roads. Lichens, a favoured food of caribou, are among the species vulnerable to dust.
Linear features also introduce earthworms, which aren’t native to the boreal forest, but which are introduced through dirt on vehicles or in construction materials, said Bayne.
In Minnesota, the worms have completely eaten away underlayer vegetation and leaf litter in some places, affecting songbirds, small mammals and vegetation such as ferns that rely on such layers.
“What’s good for the garden isn’t necessarily good for the forest,” said Boutin.