April 12, 2017

What is Your Home... River?

What is home?  Many an ecologist would argue that what really counts is your watershed - your "home river". It's a logical boundary to use for land management, and the water in your watershed is crucial to life and livelihoods.

Our home river is the Bow, and we live a mere 30 minutes from its headwaters. Last fall we had the opportunity to learn about its deepest nature.

We attended a talk by Dr. Richard Hauer on gravel-bed rivers in the mountain west. In a recently published paper, he and colleagues have documented and explained how important these kinds of rivers are to wildlife and ecosystems here.

We've been using this story on our snowshoe trips, as we travel beside and on the Bow River.
Nadine & Jun along the beautiful Bow River
It's the first time scientists have put this big picture story together, and it really is big news, big enough to have been covered by the New York Times.  The article summarizes nicely:

"Melting snow and groundwater flow down the channel; this is what we think of as a “river.” But underground, far more water is moving slowly through a labyrinthine network of cobbles, gravel and sand that make up the entire valley bottom. [our emphasis]

This deeply buried habitat is far more important and far more productive than thought. The matrix of gravel and sand cleans the water, filtering organic material and freeing up nitrogen and phosphorous embedded in the gravel.

These natural fertilizers spread across the valley bottom, a shot of adrenaline that nourishes plants in the flood plain such as willows and aspen, which in turn draw birds and beavers, elk and caribou. The plant-eaters attract predators like wolves and grizzly bears."

We've always known that rivers were movement corridors and hotbeds of biodiversity, but now we can see the bigger picture: the smallest sediments and the largest carnivores are tightly connected.

These days, we look at our "home river" with different eyes.