Healthy Beavers, Healthy Rivers
While modern day river systems are highly engineered to efficiently move water, this is not necessarily a “healthy” condition. Joe Wheaton, a fluvial geomorphologist and Professor of Riverscapes at Utah State University, works to better understand the dynamics of fluvial environments and their subsequent management and restoration. We talk with Joe about his research on how the dam building activity of beaver can alter physical habitat for their own benefit as well as many other fauna and flora. This activity can also help create resiliency in a river corridor facing a warming climate.
Meet the Scientist: Joe Wheaton
Joe Wheaton is a Professor of Riverscapes at Utah State University, a fluvial geomorphologist and a seasoned restoration practitioner. Joe’s research is focused on better understanding the dynamics of riverscapes, how such fluvial processes shape instream and riparian habitats, and how biota modulate and amplify those processes. For example, some of Joe’s research focuses on how the dam building activity of beaver alter physical habitat for their own benefit, but also to the benefit of a slew of other fauna and flora.
Much of Joe’s work focuses on taking such understandings and translating them into useful applications. For example, Joe has helped pioneer the development of new stream restoration approaches (e.g. low-tech process-based restoration using beaver as a restoration agent), building larges scale monitoring programs that leverage the latest technologies (e.g. Columbia Habitat Monitoring Program and Big Rivers Monitoring Program), and building new analytical software apps (e.g. Geomorphic Change Detection Software) and simulation models (e.g. MORPHED, BRAT) to help scientists and practitioners alike. Joe’s work straddles the interface between physical and ecological sciences.
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Interview Excerpt - Beaver and Healthy Riverscapes
Science Moab: Can you start by explaining what is meant by the word riverscape?
Wheaton: Riverscapes are just the parts of the landscape that could possibly flood by the stream channels. We tend to think of flooding too often as this negative thing, but it’s not a bad thing. It’s a natural process and these floodplains and the rest of this riverscape is how rivers deal with excess energy. The riverscapes are not just a line, or channel, or a ditch. It’s the part that that channel would be interacting with.
Science Moab: What is meant when you say a structurally starved riverscape?
Wheaton: Rivers move water, but they also move a lot more than water. They move sediment that they erode, they move nutrients, and they also move a lot of wood. When we’re talking about structure in these riverscapes, which ironically, is the thing that promotes more connectivity of these channels with the rest of that riverscape, is piles of wood, sticks, and organic matter. Also…beaver dams provide structure. This really weird thing can happen where even in the middle of a summer drought at low flow conditions, the riverscape floods, which just doesn’t seem right. They flood when they have this structure in them. The structure clogs things up, slows things down, and makes the flow of water less efficient. We’ve managed our riverscapes to drain efficiently by stripping out the wood, getting rid of beavers, and straightening the channel. If we let it move a little less efficiently through these landscapes, all sorts of wonderful things fall in the wake of that.
Science Moab: Why do we care about restoring these riverscape ecosystems?
Wheaton: Freshwater is key to our survival as a species. Without it we are done. Riverscapes are what provide this by slowly releasing this water, often through the landscape and in the process, providing so many, you could call them ecosystem services. So for example, if I live in a city, and there’s a watershed upstream of me and a river that runs through town, if I have a really efficiently drained riverscape above me, when I have run off events, everything piles up all at once really fast and creates really dangerous conditions for flooding. if I have a healthy riverscape it attenuates that flow it knocks the peaks off those floods it holds on to that water and it puts it into groundwater recharge and holds on to it in the in the in these riverscapes and really provides resilience to that that disturbance event. If there is a major catastrophic fire that is working through a landscape and the river is desiccated and structurally starved, the fire just marches right through like there’s nothing in its way. Whereas, if the riverscape is in this healthier condition, that sponge might just be some refugia during the fire for wildlife or livestock, etc, and it can also be a really important buffer that can either slow the advance of the fire are in big enough riverscapes, it can actually stop it and act as a break. So there’s all sorts of benefits, especially as the climate crisis is so much more pronounced. It’s about resilience. Resilience of our ways of life, resilience of communities, resilience of these landscapes. Our survival is tied to the health of these riverscapes.
Science Moab: How do beavers fit into the equation of this restoration?
Wheaton: Beaver manipulate river settings to their liking. They do that by building these amazing dams. Unlike dams that we’re used to, which are supposed to last for a really long time, these dams are ephemeral; they come and go. With the coming and going of those dams, we get much more complicated habitat that provides more niches for a whole range of different species. So the beaver are not the only example of Structural forcing in riverscapes, but they’re one of the most compelling and obvious examples. There really aren’t that many species that take and manipulate the environment to their benefit the way humans and the beaver do. It just so happens that when beavers do this, it’s also to the benefit of so many other species that co-evolved with them, including ourselves.
Science Moab: Tell us about your do it yourself manual for initiating process based restoration instructionally starved river scapes. Affectionately called PBR, this manual features the use of simple low cost structural additions (i.e. wood and beaver dams) to riverscapes to mimic functions and initiate specific processes.
Wheaton: The main thing the manual does overall is it normalizes these sorts of practices, many of which have been around for centuries, but it normalizes it into a standard of practice that makes it okay for people and resource agencies to follow a cookbook of how to get started on some of these things. What’s actually in there starts with recognizing what healthy riverscapes look like and what unhealthy riverscapes look like and trying to understand what those impairments are doing through due diligence. So that the manual is kind of a translation, if you will, of some science or distilling of science and some principles about healthy riverscapes into some very practical things that can be done. And it also helps to sort of normalize this in ways that, you know, practitioners work and in ways that, you know, our government works. Most of it’s common sense, but it’s a death grip on the obvious.
