EAR-Climate: Forest, Frost, and Flow: Snow Dydrology of spatially Heterogeneous and Hydrologically Connected Peatland Catchments

Although peatlands cover only ~3% of global land surfaces, they store around one-third to one-half of Earth's soil carbon. The stability of this large carbon source is strongly regulated by the flow and storage of water. However, the flow and storage of water within peatlands remains difficult to understand due to their spatial complexity and seasonal variations, especially during a critical period in the spring when water fluxes are driven by snowmelt. This project aims to better understand how snow controls water storage and movement in peatland catchments and improve their representation within Earth System Models. This is done through collecting new field data, analyzing existing long-term data, and integrating these data into a modeling framework. This project will train multiple graduate students and undergraduate students in interdisciplinary research. Foresters, water resource managers, and the public at large will benefit through field tours highlighting the importance of snow and frost in regulating spring streamflow, as well as through public events celebrating the cultural connections that many Minnesotans have with snow.

Northern peatland landscapes consist of a mix of upland and peatland forests, bogs, and open water, which complicates their hydrology. This is especially the case during the winter-spring transition period when the landscape is the most hydrologically active, with high recharge and streamflow rates. This project will investigate the feedbacks between forests, snowpack, and soil frost as they influence snow accumulation, snowmelt generation, and recharge of shallow groundwater in complex peatland systems. Specifically, new field data will be collected to (1) examine the role of forest cover in controlling snowpack size and duration; (2) study the role of soil frost in controlling the infiltration of snow into soils or over the soil surface; and (3) monitor the movement of water between forests and peatland bogs. The project team will use the new data and existing long-term data from the Marcell Experimental Forest in northern Minnesota to model the hydrology of low-relief, peatland systems. With the field site situated at the southern edge of peatland distributions, this study has the potential to provide a 'window into the future' for other northern peatlands across the globe. These efforts are especially timely as the climate system approaches tipping points that may be further accelerated by carbon-water feedbacks within peatlands.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.