Doctoral Dissertation Research: Floodplain Carbon Storage in Mountain Rivers

Colorado State University, Fort Collins CO

Investigators

Abstract

A better understanding of the linkages between geology, river processes, floodplain sediment, and river ecosystems that influence carbon storage in mountainous landscapes has implications for land use and environmental change. This doctoral dissertation research project will investigate the natural ability of freshwater ecosystems in unmanaged rivers to effectively filter dissolved organic carbon content. New insights into the natural ability of freshwater ecosystems in unmanaged rivers to effectively filter dissolved organic carbon content will be valuable to society and communities that source their drinking water from surface waters. The doctoral student will provide new information regarding of how organic carbon is stored in upland fluvial versus lowland environments and how natural processes in mountainous rivers facilitate conditions for long-term storage and sequestration of organic carbon. The sustainability of freshwater systems focus of this study has important implications for water resource managers globally as they develop regional plans for future water allocations. The student will work closely with natural resource offices and government agencies to inform land resources and wildlife management. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career. Research on carbon storage in montane regions is critically important because these regions are globally impacted by environmental and land use modifications causing changes to river network systems and consequently affecting surface water quality and supply. This project will address four core questions: (1) How long is carbon stored in floodplain reservoirs? (2) What is the role of episodic extreme disturbances in turnover time? (3) Does turnover time vary systematically above and below the hydroclimatic boundary of 2,300-m elevation? (4) How does carbon storage in valley bottoms change when biotic drivers are removed and multithread channels metamorphose to a single-thread planform? The student will use in situ sampling, field survey, and existent map and elevation data coupled with laboratory analysis to longitudinally determine organic carbon at 24 study sites along the headwater streams in the Colorado Rocky Mountains. The analyses will provide a quantitative assessment of the mechanisms of fluvial complexity of larger river networks that influence carbon retention and microbial processing.