Ecology of Aspen, Beaver Ponds, and Trout
Fred Rabe, University of Idaho professor emeritus, will describe changes that occur in an ecosystem once a stream is dammed by beaver: more water storage and enhanced growth of native trout populations due to ample invertebrate biomass. He will also discuss the direction of plant succession after beaver abandonment, which has occurred at 49 Meadows and other wetland sites in northern Idaho.
This talks looks really interesting and I’d like to be in the front row with my hand permanently raised. I sent it to our Idaho beaver friend and he pointed out that it’s misleading to call it beaver “abandonment” if the animals were trapped, which in much of Idaho they are. It is sort of like saying the Cherokee “abandoned” their land in Georgia and North Carolina or the Jewish people “abandoned” their store fronts on Kristallnacht.
Was your beaver pond carried to full term? Or was it aborted?
This matters because if the dammed stream wasn’t able to have a natural progression over time, the effect of “abandonment” will be entirely different than if the beavers stayed a time in one area and then chose to move on because they had used up available food sources. Did the invertebrate community have time to develop? Did fish population have time to alter its density and diversity? Was there enough tree chewing to stimulate coppicing that created enough dense bushy new growth to become nesting habitat for migratory and songbirds? Or are we just talking about a sudden ghost town after all the cowboys were shot? Maybe someone would like to do their dissertation on the topic and study the difference between several ‘abandoned’ sights and several ‘beavers destroyed’ sites.
The same question could be asked of relocation. What happens to the stream after beavers are taken out of one area and forced into some other stream? I know from talking with Dr. Glynnis Hood that this was an area that interested her. Interrupting a beaver pond prevents second generation wildlife from taking hold.
A win-win for beavers, humans and our habitat
But when beavers and humans share a waterway, the ponds can undo much of what the humans have wrought. While much depends on the size of the stream, the average dam is about 15 feet long and 5 feet tall — but it’s not unusual for their length to exceed 300 feet. This can back up water into nearby fields and homes. Plus, there’s the impact of what they do to trees with their powerful jaws.
To enhance the beneficial effects of beaver dams and limit their detrimental side to human activity, biologists have embarked on the Yakima Beaver Project. A collaboration of state, federal, private and tribal interests captures beavers in the populated lowlands of Yakima and Kittitas counties and moves them to higher ground — and farther away from people.
This must be my favorite sentence ever. Just move them farther away from PEOPLE and all the problems will be solved. I mean it’s not like those people need water, or wells, or fish, or birds, right? I’m more inclined to call this decision a ‘lose-lose’. The colony loses their home. And the city loses its beavers.
Oh well, they’ll get another chance next year to make this decision all over again.
