Projecting land cover change in the Yukon Flats National Wildlife Refuge, Alaska
Dates
Start Date
2016
End Date
2020
Summary
In addition to widespread active layer deepening, ice rich permafrost can thaw laterally, often triggering abrupt thermokarst and subsidence of the ground surface. In boreal forest, thermokarst can lead to the development of collapse scar bogs, fens, or lakes inducing large changes in the hydrological regimes. The poorly drained conditions of these features causes the development of peatlands, which store large amounts of carbon in thick surficial peat layers, but also produce substantial methane emissions. At the regional level, the climate warming effects of methane emissions from the newly formed wetlands could be greater than the climate cooling effects of increased soil carbon sequestration. These changes in hydrological regimes [...]
Summary
In addition to widespread active layer deepening, ice rich permafrost can thaw laterally, often triggering abrupt thermokarst and subsidence of the ground surface. In boreal forest, thermokarst can lead to the development of collapse scar bogs, fens, or lakes inducing large changes in the hydrological regimes. The poorly drained conditions of these features causes the development of peatlands, which store large amounts of carbon in thick surficial peat layers, but also produce substantial methane emissions. At the regional level, the climate warming effects of methane emissions from the newly formed wetlands could be greater than the climate cooling effects of increased soil carbon sequestration. These changes in hydrological regimes will also influence river discharge and lateral exports of dissolved carbon. Changes in wetland distribution will also impact habitat for plant and animal species, including important subsistence species such as waterfowl. The geomorphological changes associated with thermokarst disturbance will also likely have local impacts on infrastructure.
The overarching goal of this project is to build upon a modeling framework to represent the key-processes that will help improve our understanding of the impacts of thermokarst disturbance on ecosystem structure and function at the regional scale. This study will be conducted in the Yukon Flats National Wildlife Refuge (YFNWR) in Alaska in two phases. The first phase, from year 1 to 3 of the project will be focused on improving an existing model framework to represent thermokarst dynamics and their consequences on landcover and carbon dynamics. The second phase, year 4 and 5 of the project, will focus on applying the improved model framework across the YFNWR from 2010 to 2100 and developing and applying an impact model that will help determining how the changes in landcover associated with thermokarst dynamics will alter wildlife habitat and subsistence resources in the YFNWR.
