By Anupum Pant
Presence, or introduction of wolf population in an ecosystem can actually affect how the rivers flow and the other physical geography of the place. This is probably the most interesting thing I found in recent times. If not more, it is as interesting as the affect wind has on a tree’s life.
The most convincing example of the impact of wolves on the physical geography of an ecosystem is probably what was seen fairly recently in the Yellowstone National Park. It has to be listed among one of the most exciting scientific understandings in the last century. It’s called the Trophic cascade – An ecological process that starts at the top of a food chain and its affect is seen at the bottom of the food chain.
The last wolves of Yellowstone National Park were killed around the 1920s and since then the population of deer had been causing a severe vegetation scarcity in the ecology of the park. A solution was suggested by biologists that wolves be brought back to bring the balance back. Wolves are seen as killers. It isn’t very easy to superficially investigate their role in how deeply they can affect the ecology, even the physical geography of a place.
So, in the year 1995 wolves were brought back to the national park. Like they would in the wild, they started with killing deer for food. Of course it controlled the population of deer, which humans had not been able to do in spite of many efforts, but the cascading affect this introduction had was even more dramatic. They changed how deer population behaved.
Now, to avoid confrontation with the wolves, deer population started avoiding certain areas in the park. The places being avoided now started regenerating. On an average, trees started growing taller. Barren lands in the park started growing into thick forests within a few years. This attracted the birds. And then the beavers came in. And we already have seen in the past how beavers can affect the flow of rivers…
As a result, all kinds of animals bears, mice, eagles etc. started appearing. Ultimately, the introduction of wolves actually changed how rivers flowed there. From more vegetation, erosion became less, rivers started flowing in more fixed straight narrow channels and more pools – perfect for the wildlife.