Effect of the topography and texture of the underlying sediments on Peatlands distribution in parts of South-East Manitoba, Canada
In peatland environments, texture and topography of the underlying soils play primary roles in water transport, energy fluxes and nutrients cycling. These in turn affect the type of peatland formation at the surface, as well as the size and thickness. This work aims to evaluate the influence of the texture and topography of the underlying sediments on peatlands distribution in South-Eastern Manitoba, as these aspects are not yet fully understood. Depths to basal sediments were measured with the aid of a spiral auger and tape rule. The measurements are then corrected to elevations above mean sea level with DGPS surface elevation measurements. Sediment cores and representative samples were then collected with a bi-partite gouge auger. The results of elevation measurements indicate that substratum elevations approach maximum values beneath forests and approach minimum values beneath bogs and fens. Textural analyses indicate the sediments are poorly sorted, with a higher proportion of fines (clay and silt) beneath the fens and bogs; the results also indicate a higher proportion of silt to clay. The clay/silt proportion varies across the landscape. Fens and forested bogs display the highest proportions of clay, while mineral soil forests and mire forests display the least amounts.