Each individual entry under the ‘people’ tab describes that person’s current research project(s). As a group, our research focuses mostly on river corridors, broadly interpreted to include the floodplain, lakes connected by rivers, and adjacent hillslopes. Because we come from diverse academic backgrounds, our research tends to be interdisciplinary, drawing on knowledge from ecology, engineering, biogeochemistry, geography, and environmental history, among other disciplines. One of the satisfactions – and frustrations – of research is that answering one question commonly reveals a long list of related questions. Consequently, individual graduate student projects are typically connected by an underlying, evolving research theme.
Sara Rathburn began to examine channel adjustment to sediment inputs when a 2003 debris flow introduced large quantities of sediment into the upper Colorado River in Rocky Mountain National Park. The 2003 debris flow was initiated by high snowmelt flows overtopping a diversion ditch on the slopes high above the river. That led to questions of whether (i) the 2003 event and other relatively recent debris flows had resulted in a prolonged shift in sediment inputs that exceeded the natural range of variability at the site (Zan Rubin, MS, 2010), (ii) the magnitude and frequency of debris flows on the side of the valley that contained the ditch exceeded debris flows inputs from the other side of the valley (Kyle Grimsley, MS, 2012), and (iii) high-resolution LiDAR can be used to quantify sediment flux and channel change over a period of several years (JoJo Mangano, MS, 2014). Understanding of geomorphic connectivity and natural range of variability are inherent in answering these questions, and now Sara is initiating a new project to characterize connectivity and range of variability in headwater catchments of the Italian Alps in which alpine glaciers are melting rapidly under a warming climate.
Projects examining the hydraulic resistance caused by instream wood in mountain streams of the Washington Cascades (Janet Curran, MS, 1999; Bill MacFarlane, MS, 2001) made Ellen Wohl start thinking about how instream wood in other regions differed from that of the well-studied Pacific Northwest. This led to projects characterizing wood loads and geomorphic function in the neotropics (Dan Cadol, PhD, 2010), the arctic and subarctic of Canada (Natalie Anderson, PhD, 2016), the Alaskan arctic (Katherine Lininger, PhD, in progress) and in the Colorado Rockies (Natalie Beckman, PhD, 2013). Recognition that instream wood loads and functions in headwater streams of the Rockies differed significantly between old-growth and younger subalpine forests gave rise to projects examining (i) floodplain development and carbon storage in relation to forest stand age and instream wood (Nick Sutfin, PhD, 2016), (ii) physical complexity and instream carbon storage in relation to stand age and wood load (Bridget Livers, PhD, 2016), and (iii) differences in wood load and geomorphic function between old-growth and younger forests in the montane zone, which has different tree species and disturbance regimes than the higher elevation subalpine zone (Karen Jackson, MS, 2014). Those projects in turn led to a desire to quantify how differences in wood distribution across an entire river network, from first-order streams to the mainstem at the catchment outlet, influenced volume and spatial distribution of sediment and finer organic matter storage (Andrew Pfeiffer, MS, 2017).
Starting on a journey, you sometimes cannot be sure exactly where you will finish. The unexpected discoveries along the way, which lead you along a sinuous and branching course, create the allure and excitement of research.