Unit 1: Ecological Systems: 1.5.3 Beavers: Ecosystem Engineers

It is hard to view a human-made dam without noticing the remarkable feat of engineering and design required to create one.

It is hard to view a human-made dam without noticing the remarkable feat of engineering and design required to create one.

The Hoover Dam, the largest dam in the world at the time of its completion in 1935, stores enough water in Lake Mead to irrigate 2 million acres.

According to National Geographic, “beavers are second only to humans in their ability to manipulate and change their environment.”

Ecologists refer to the beaver as an ecosystem engineer because, other than humans, beavers are the only known animal to be able to create a wetland habitat.

The common phrase “eager beaver” offers a vivid description of the effort and energy the beaver must put in to gnawing down large and small trees to supply the logs it needs.

They also have the ability to secrete oils from scent glands near their tails that are used to condition their fur so that it has waterproof-like qualities.

The diversity of the flora and fauna in this newly engineered wetland is described in the following excerpt from a wetland ecologist’s research journal.

The diversity of the flora and fauna in this newly engineered wetland is described in the following excerpt from a wetland ecologist’s research journal.

The diversity of the flora and fauna in this newly engineered wetland is described in the following excerpt from a wetland ecologist’s research journal.

This excerpt captures her first trip to scout out potential beaver pond sites for research along a portion of the Red River in Texas, a tributary river that feeds the Mississippi River.

As we hike along the river, the unrelenting Texas heat is made somewhat bearable by the shade of the towering eastern cottonwood and black willow trees.

A decent amount of emergent plants, such as cattails, and submerged plants, like elodea, are visible in the pond.

This seems like a viable site for our future research.

Beaver lodges are abandoned as colonies die off or move on to another part of the river.

Over time the dam will breach, meaning water will rise up and over the top of the dam, and the pond will drain back into the river, restoring the river or stream ecosystem that was originally there.