As I gear up for another season of fieldwork and try to make it through all the data I have amassed last year, it’s great to look back at the numerous trips we made and all the folks who have helped.
With the help of research assistants, Sophie Stauffer and Mulugetta Fratkin, we have been looking at river migration, erosion, and deposition of the East River near Crested Butte, CO. We also collaborate and get assistance from scientists at the Lawrence Berkeley National Laboratory and the Rocky Mountain Biological Laboratory
While creating habitat for many other species, beavers largely impact river form and migration by digging canals, creating wetlands. and building dams (see beaver dam in the photo below) to divert flow along the East River.
Sophie has been working on extracting data to develop a model that determines when river meanders will cut off such that the river takes a new route, but this is largely complicated by beaver dams that appear to force meander cutoffs like the one below from 2012.
Using repeat aerial imagery, Sophie helped us determine where the East River was in the past and how far the river has moved between images, and Mulu’s historical analysis of the river flow helped me link erosion to hydrology.
With help from Dr. Carli Arendt (using a DGPS below) to install marker horizon pads in the field, we are able to measure the amount of sediment that accumulates on the floodplain during high flows.
I measure the amount of sediment above the top layer of this white feldspar, which Carli helped me and Joel Rowland place on the floodplain.
While we were in the field last fall, we also borrowed a Google Street View dome camera and walked the East River along a portion of the study area. You can walk the river with me, Carli, and Joel and view the images on Google Maps Street View!! See Joel below with the Google dome camera on the other side of a beaver dam.
In addition to measuring erosion and deposition, I am looking at how much carbon is stored in floodplain sediment and what factors influence how that carbon changes with time as microbes and aquatic invertebrates eat and transform the carbon! This analysis is done in collaboration with scientists from the Pacific Northwest National Laboratory, Malak Tfaily and Nancy Washton, and funding through the Environmental Molecular Sciences Laboratory @EMSLscience
All of this will help determine how hydrology and geomorphology influence carbon dynamics in the East River watershed. We will then be able to extend our findings to other mountain rivers and focus on the most important aspects of carbon dynamics when we start to look at much larger rivers.