Hydric Soils of the Prairie Pothole Region

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The primary long-term objective of my research program is to link soil function to land use and climate change. This allows us to understand how land management decisions influence regional soil biogeochemical processes and ultimately ecosystem sustainability. Specific long-term questions include: How are key soil functions such as carbon and nitrogen cycling related to land use change? Can landform-based sampling refine our understanding of nutrient dynamics? Can these relationships inform land management at the local, regional, or national scales? The Prairie Pothole Region (PPR) encompasses over 700,000 square kilometres of the Canadian Prairies and northern Great Plains of the U.S. It is characterized by millions of wetlands that are filled by spring snowmelt but dry down during the summer months; the prolonged saturation each spring gives rise to unique wetland soils we refer to as "hydric soils". PPR wetlands and hydric soils provide a number of ecosystem services, including water and nutrient retention and cycling, flood attenuation, water filtration, groundwater recharge, carbon sequestration, wildlife habitat and biodiversity. Annual wet-dry cycles are thought to play an important role in many of these services, but a majority of PPR wetlands have been drained for agriculture production and suburban developments, without complete understanding of the long-term implication of drainage for soil nutrient dynamics. Traditionally, hydric soils of the PPR have fallen through disciplinary boundaries: too wet for soil scientists and too dry for wetland scientists. In the short term, my research program aims to identify soil indicators of wetland management history in the PPR and examine how carbon and nitrogen dynamics of hydric soils are affected by land use change. How long do hydric soils continue to behave as hydric soils following a change to their hydrology? Can we classify wetlands by their ecosystem function and therefore identify those most essential for preservation or restoration? By improving our understanding of hydric soils within agro-ecosystems, the proposed project will improve integrated management of PPR wetlands, maximizing ecosystem services while minimizing loss of productive land.