How Wolves Change Rivers

Wolves, it seems, can shape the land around them, even determining the course of rivers in their territory. If you are curious about the details you can find a National Geographic video that outlines everything, but essentially it all comes down to the interaction of the wolves with deer. Wolves died out of Yellowstone National Park in the 1930s due to over-hunting, but a small number of them were reintroduced in 1995. In the intervening years, the deer and elk populations had exploded. The deer have had nothing to do but stand around and eat, just like they do to the poor fig tree in my yard and every azalea bush at the church. The wolves, once reintroduced, immediately killed some of the deer—the old and the sick. Their presence caused a dramatic shift in the activity of the deer. No longer did they mill about in open spaces in the valleys and river banks. Without the gluttonous deer, Birch and Aspen trees exploded in growth. Song bird and eagle populations rose. Beavers moved back into the area, creating new river ecosystems. The river itself narrowed. The extra vegetation that grew when the deer left held the banks firm. The river stopped shifting and winding through the park, no longer eating up more and more land, but staying true to its course.

Scientists have a name for this top down ecological effect—trophic cascade. Small changes can create system-wide differences and growth. I wonder what that might mean for the church. Perhaps we have grown too comfortable and too safe, like the deer. Perhaps we need to add a little risk into our system in order to see real change. Risk can be scary because it often means that something has to die, but the story of our faith is that resurrection only happens where there are graves. Perhaps by trusting God in the midst of death we might find new life blooming around us.