Name
The Water Balance of a Harvested Bog Restored to a Fen in South-Eastern Manitoba
Date & Time
Wednesday, May 10, 2023, 1:45 PM - 2:00 PM
Description
Prompt and active restoration of extracted peatlands back to a carbon accumulating ecosystem is a key component in the sustainable management of the peatland industry. Water availability is usually the limiting factor of success, thus quantifying a water balance is critical to understanding new restoration methods, especially in regions where water availability is a particular concern, such as the sub-humid climate in Manitoba. Typically, harvested peatlands are restored to bogs, but in Manitoba there has been a recent effort to restore remnant sites to fens. At this site, three different surface recontouring techniques were used: finished (flat, two passes with bulldozer), in-progress (bunds created from one pass with the bulldozer) and remnant (left untouched after extraction), each instrumented with wells, piezometers, lysimeters, and tensiometers to examine hydrologic differences with surface roughness. Evaporation is the dominant water loss from the system, averaging a loss of 4.6 and 3.2 mm/day from May to August 2020 and 2021, respectively, ranging between (min, 1.1 mm/day) and (max, 4.0 mm/day) in 2021. In spite of recontouring restoration efforts, the water table dropped more than a meter below the surface, resulting in very low soil water pressure (-28.3 mb in May to as low as -334 mb in July, with an average of -124 mb from May to August 2021) and conditions too dry to support fen bryophyte vegetation. By understanding the magnitude and distribution of water fluxes across the different restoration techniques, restoration efforts can be modified to reduce major water losses in future planning.
Location Name
Lynx
Full Address
Banff Park Lodge Resort Hotel & Conference Centre
201 Lynx St
Banff AB T1L 1K5
Canada
Abstract
Prompt and active restoration of extracted peatlands back to a carbon accumulating ecosystem is a key component in the sustainable management of the peatland industry. Water availability is usually the limiting factor of success, thus quantifying a water balance is critical to understanding new restoration methods, especially in regions where water availability is a particular concern, such as the sub-humid climate in Manitoba. Typically, harvested peatlands are restored to bogs, but in Manitoba there has been a recent effort to restore remnant sites to fens. At this site, three different surface recontouring techniques were used: finished (flat, two passes with bulldozer), in-progress (bunds created from one pass with the bulldozer) and remnant (left untouched after extraction), each instrumented with wells, piezometers, lysimeters, and tensiometers to examine hydrologic differences with surface roughness. Evaporation is the dominant water loss from the system, averaging a loss of 4.6 and 3.2 mm/day from May to August 2020 and 2021, respectively, ranging between (min, 1.1 mm/day) and (max, 4.0 mm/day) in 2021. In spite of recontouring restoration efforts, the water table dropped more than a meter below the surface, resulting in very low soil water pressure (-28.3 mb in May to as low as -334 mb in July, with an average of -124 mb from May to August 2021) and conditions too dry to support fen bryophyte vegetation. By understanding the magnitude and distribution of water fluxes across the different restoration techniques, restoration efforts can be modified to reduce major water losses in future planning.
Session Type
Breakout Session