Keystone Species in Action: The Beaver


In college I remember learning about a very cool phenomenon called Keystone Species.

While all creatures have an impact on their environment, keystone species take this to the next level. If a keystone species is removed from their environment, the ecosystem would change drastically.

As we interact with our homestead ecosystem and the larger landscape, we undoubtedly see the ways in which we humans have the potential to be keystone species. We create and destroy habitat as a matter of course. However, today I want to talk about a real example of how the beaver has created and shaped an ecosystem in my neighbor’s landscape.

Beavers are notorious for felling trees and making dams.

Take a walk by your favorite creek or stream and you’ll undoubtedly see signs of the beaver, if they live in your area. The telltale sign of gnaw marks near the base of a tree. This can frustrate land owners who are trying to grow certain plants near streams, but the beaver serves an important function within the ecosystem. My neighbor’s experience is a perfect case.

My neighbor bought his land about 40 years ago. Though he hasn’t lived there continuously over the last 40 years, he has witnessed the changes in his landscape. We were taking a walk along one of his lower fields the other day and he showed me the beaver pond and he mentioned that when he moved here, it didn’t exist! He also mentioned that when he first saw the beavers moving in, he didn’t want them there because when creating dams they obviously have to cut down a lot of trees! They drastically change the landscape. Such is the level of transformation the beavers have on a piece of land.

My neighbor Gene by the beaver pond

To give you a palpable example, as we went toward the beaver pond, about 200 ft away I noticed that the plant habitat changed drastically. There were countless small Sycamore saplings and the understory was covered in ferns! It was lush, moist, and cool – a far cry from the field only a stone’s throw away.

The rest of the landscape surrounding this area was tall grasses and scrubby understory. There were no other areas with ferns.

As we approached the area, it was apparent that the beavers had drastically changed it. From small feeder springs, the beavers had slowly but surely damed them up, creating a pond. Where no pond existed before in a flat field, the beavers had successfully created one. Anyone who has ever tried to start a pond using nothing but what is naturally in the area knows how hard it can be to trap water. Water notoriously finds areas to escape and leak and unless one has very clay rich soil, it can be difficult to keep water in ponds. Yet the beavers did it!

Walking along the bank of the beaver pond, I was truly amazed. The water was about 2-3 ft deep and clear! An ecosystem had been created and life was thriving because of the work of the beaver’s hands, teeth and ingenuity. There were even fish in the pond, likely brought in as eggs from the feet of shore birds.

My neighbor mentioned that the beavers had long since left their creation because the trees they fell for their food source had become scarce. However, the legacy of habitat for many that they left behind exists long after their departure. It made me think about the effect that I have on a landscape and what will be left after I am gone. How will the efforts of my human hands carry on when I am no longer around to tend it? Is what I’m doing able to create habitat that will outlast me?

As I watched the bumble bees and other pollinators flying around our homestead yesterday, I was delighted to note that I am already creating habitat and food sources for many creatures to come live here. In the pond, there are hundreds of toadpoles and each day I notice new species of pollinators swooping in to dine. I even noticed a handful of Zebra Swallowtail butterfly larvae on the Paw Paws within our forest gardens (their young leaves are the only host plants for the young larvae to eat.)

Many of these cycles happen naturally and it is my goal to be a beneficial human within my environment, looking beyond the bounds of my flesh and needs to create habitat and provide ecosystem services for countless other creatures. At that point, I’ll consider my efforts a job well done.

If a keystone species can simply be defined as an organism that makes it possible for other species to live in the ecosystem, I have to think of all of the habitat destruction that humans are doing. Pesticides and herbicides released into the environment are killing off species, making water unclean and having untold effects for all organisms. This is short term thinking and while creating a healthy thriving ecosystem does take time and perhaps more effort and management up front, we can do this and set things in motion which can benefit future generations of not only humans, but other organisms as well.

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