This research will evaluate how climate-induced changes in water and nutrient cycles on land are propagated to stream networks. Increased export of water and the nutrients nitrogen and phosphorus from river networks to the Arctic Ocean reflects shifts in patterns of water and nutrient movement in the arctic. Changing climate may contribute to such shifts by causing release of nutrients from thawing permafrost, altering precipitation patterns, increasing rates of biogeochemical reactions, or expanding storage capacity in thawed soils. These changes may have far-reaching effects because flowing water connects land to downstream aquatic ecosystems, but the flowpaths connecting terrestrial ecosystems to stream networks remain poorly understood. This research will focus on transport and reaction of water and solutes within water tracks, which are linear regions of surface and subsurface flow that connect hillslopes to streams and account for up to 35% of watershed area in arctic tundra. Specific objectives are to: 1) quantify sources of water and dissolved nutrients to water tracks, 2) identify effects of snow accumulation, thaw depth, and storm characteristics on storage and transport of water and solutes, and 3) estimate the effects of hydrology on rates of nutrient cycling in water tracks.
The research will have significance for predicting responses of the arctic to continued climate change through links between hydrologic and nutrient cycles. Further, research will increase understanding of the role of hillslopes in connecting terrestrial ecosystems to stream networks, contributing to filling a research gap in hydrology and biogeochemistry. In addition, this project will train young scientists (grade school through post-graduate) in the skills and methods used to study responses of water and nutrient cycles to climate change. Arctic tundra is inaccessible to most students, yet one of the environments most susceptible to climate-induced changes. This project will include opportunities for undergraduate and graduate students to conduct research in the arctic, development of online instructional materials that bring cutting-edge topics and research methods to undergraduate courses in hydrology, and science lessons for K-6 students that incorporate real-time field data.