by Phil Levin, Lead Scientist
A salmon swims after spawning at The Nature Conservancy's Ellsworth Creek Preserve in Southwest Washington. Photo by Bridget Besaw.
Many ecologists identify with a specific plant or animal. My father, like me, a biologist, will forever be associated with Phlox – a North American wild flower that has found its way into nurseries. I’m a fish guy. I’ve worked on lots of species in lots of places, but I’m a fish guy. So, when someone asks me to write something about trees, I really don’t have much to say. Trees don’t move me. Sorry.
But then, I remembered in some places trees ARE FISH.
Millions of salmon return each year to forests in the Pacific Northwest. This throng of salmon flesh coming into our forests results in a mass movement of nutrients from the salt waters of the ocean to the forest floor. After salmon spawn and die, their rotting carcasses on the sides of streams fertilize the soil beneath them. And as bears and other animals like gulls, ravens, crows, and eagles pull salmon into the forest, the decomposing fish, rich in nitrogen that help trees and shrubs grow, enhance the soil far from the water’s edge. In some areas, an average bear will drag up to 700 salmon into the forest each year.
Then, we can look at the trees and ask how much of the nitrogen in the trees come from salmon. The answer varies from place to place, but in the Pacific Northwest and SE Alaska values of 25% are not uncommon. So when you are in salmon country and come across a Sitka Spruce, its fair to say that ¼ of that tree is, on average, a fish. And I guess since I like fish, I like 25% of the forest.
