Project Details
Description
Northern peatlands are a unique type of wetland found in the northern United States and a dominant landform at higher latitudes, including Canada, northern Scandinavia and Russia. Industrial development has led to some peatlands being drained or burned to promote agriculture, construction or use for fuel. Today, peatlands are recognized as unique ecosystems that support a diverse range of plants not found elsewhere. Furthermore, they are an important part of a global carbon cycle trapping carbon dioxide in organic matter and storing approximately 33% of the total carbon found in soils. Peatlands release some of this carbon to the atmosphere as methane, a potent greenhouse gas. Although the ecology of peatlands is well studied, the geological controls on peatland development and the percolation patterns of peatland water are not completely understood. In Maine (USA), peatlands began forming about 10,000 years ago following the retreat of the ice sheets and glaciers at the end of the last ice age. They formed in depressions, often starting as lakes, within the landscape carved by glaciers and draped with sediments. These landforms lie buried beneath peatlands but may play a key role in regulating both the hydrology and release of methane gasses into the atmosphere. This project will use subsurface geophysical sensing methods to image this hidden post-glacial landscape in order to understand how it regulates groundwater flow in peatlands and where/when methane emissions occur. Hydrological observations and computer simulations of deeper groundwater and peat porewater flow will be compared to direct measurements of methane gas emissions from peatlands in the search for evidence that peatland hydrology and carbon cycling are regulated by this hidden landscape. In addition to advancing scientific understanding of the link between hydrologic processes in the deep critical zone of northern peatlands and carbon fluxes to the atmosphere, this project will bring unique elements of benefit to society. It will contribute to the development of a diverse workforce with a strong engagement of underrepresented students, support graduate and undergraduate students, and build collaborative interactions with the forest management industry.
The goal of this project is to evaluate how the deep critical zone regulates coupled water-carbon processes across peatland landforms at a regional scale. Geophysical imaging, hydrological observations and computational modeling of groundwater flow and transport will be performed across 10 peatlands to explore three hypotheses (abbreviated here): [1] Unidentified esker (glacially derived sand and gravel) ridges lie buried beneath numerous Maine peatlands; [2] These (or similar) permeable deposits hydraulically connect peatland pore waters to the underlying groundwater aquifer; and [3] This hydraulic connection results in hotspots of methane release centered on buried permeable mineral deposits. Ground penetrating radar and frequency domain electromagnetics will be used to illuminate the geological framework beneath these peatlands and to locate buried esker deposits. Coring and permeability tests will constrain flow and transport models calibrated on [1] hydraulic heads recorded with pressure transducers connected to data loggers, and [2] specific conductance measured in water samples. Ebullition fluxes will be estimated at predicted methane hotspots using low maintenance methods (gas traps, moisture probe arrays). Underrepresented minority students from urban areas will engage in wilderness research experiences focusing on all aspects of data acquisition. A collaboration with a forestry management company secures access to privately owned peatlands for research. Informational brochures describing peatland processes investigated in this project will be developed targeting the local community and the State of Maine.
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.
Status | Finished |
---|---|
Effective start/end date | 7/1/21 → 6/30/24 |
Funding
- National Science Foundation: $208,539.00