I had also been to the tropical forests of South America, where there is more of everything—more trees, more animals, more insects, more tumult. But I prefer the understated charms of the boreal, with its limitless expanse of lakes and ponds and its gentle gradations of green: the pale hues of the reindeer lichen, the black-green of the spruce, the lighter, almost chartreuse tints of aspen and birch. More than anything, perhaps, I am partial to the light of the north woods—slanting rays that in the warmer months cast long evening shadows and suffuse the landscape with a crystalline glow.

On just such an evening in early June I found myself in Alberta’s boreal forest with Richard Thomas, a bird expert and author of a government report on the fragmentation of the province’s north woods. We were in Sir Winston Churchill Provincial Park, easing our way down a path in a dusky grove of birch, balsam fir, and white spruce, several nearly three feet in diameter and towering 90 feet (30 meters) overhead. In places the forest floor was an orderly tableau of ferns, moss, and piles of shredded pinecones left by squirrels. In other places it was an impassable tangle of blown-down trees, their collapse clearing a hole in the canopy, allowing light to nourish new growth. On a rotting “nurse log,” saplings had begun to grow. The air was perfumed with the scent of balsam fir.

Get the whole story in the pages of National Geographic magazine.

—Elizabeth Connell and Lynne Warren