Towards understanding coupled snow and soil frost behavior in peatland landscapes.

Abstract

Peatlands are responsible for storing almost 30% of global soil carbon while covering only 3% of land surface. At the same time, there is significant overlap between the region of receding permafrost and northern latitude peatlands. As many of these carbon stores are hydrologically regulated, it is becoming more important to understand the influence of snow and seasonally-frozen ground on peatland-dominated catchment hydrology. In this thesis, we begin to tackle questions regarding how snow and frost behave in conjunction with the hydrological connectivity in these carbon-rich ecosystems. Here we highlight that (1) soil frost controls annual streamflow dynamics by influencing the fill-and-spill dynamics of the bog, (2) snow depth (and by consequence soil frost) in mid-latitude headwater catchments is driven by forest structural diversity, (3) there is a significant connection between soil water storage and streamflow dynamics across seasons in peatland dominated catchments and (4) the inclusion of hillslope representation in land surface models can significantly increase the model’s ability to capture peatland water table and streamflow dynamics. Together, these findings work towards providing a better understanding of how snow and soil frost matter in peatland systems as a whole.