Water and Solute Connectivity in Northern Peatlands of Minnesota; Assessing How Hydrological Connectivity Affects Solute Yields from Peatland Catchments and Responds to Climate Change

Wednesday, 17 December 2014
Stephen D Sebestyen, USDA Forest Service, Grand Rapids, MN, United States and Natalie Griffiths, Oak Ridge National Laboratory, Oak Ridge, TN, United States
The routing of water, whether along lateral, near-surface flowpaths or vertically through peatlands, has profound implications for solute transport and budgets. Climate change, by altering hydrological connectivity of peatlands to surface and subsurface flow systems, may feedback on how various flowpaths and biogeochemical transformations affect solute concentrations in receiving waters. Such fundamental ecosystem changes may ultimately lead to shifts in solute yields from peatland catchments, ecosystem productivity, and carbon stabilization in northern peatlands. We are using piezometric, hydraulic conductivity, chemical, and isotopic data to assess how hydrological connectivity, solute sources, and biogeochemical transformations affect solute yields in northern Minnesota where connectivity to groundwater and surface water varies among a suite of fens and bogs. We are using geochemical mixing analysis to elucidate pathways along which water and solutes flow, and to determine how, when, and where solutes, such as dissolved organic matter, are transported from northern peatlands to downgradient aquatic ecosystems. From our assessment of contemporary connectivity of peatlands to larger flow systems, we are working to conceptualize how DOM yields from different peatland types may respond to climate change.