Our research, led by Postdoctoral Fellow at Cornell University, Laurel Lynch, was just published in Nature Communications. This work expanded upon some of my PhD research and study sites in Rocky Mountain National Park and utilized Dr. Lynch’s expertise in biogeochemistry to examine the influence of hydrologic connectivity and channel complexity on aquatic carbon dynamics. Our findings show that river corridors with complex river channels in beaver meadows with beaver dams, canals, and multiple channels of flow across a single valley bottom create disparate zones with differences in organic carbon and metabolite composition. These spatial differences in organic carbon composition occur during low flow conditions in the late summer following peak flow.
During peak flow conditions in early June as a result of mountain snowmelt, organic carbon composition is similar across all channels. High flow causes water in numerous channels to become more connected and forces water from beneath the river channel and floodplain to the surface for mixing. These results are important for ecosystem productivity affected by land use management regarding the complexity of river channels, which society has a tendency to intentionally decrease. Changes in hydrologic flow regime associated with a shifting climate can also alter the functionality of these systems so that connectivity is decreased in complex channels, limiting temporal variation in connectivity in unaltered systems.