Étude du régime thermique d'une tourbière en milieu forestier tempéré dans les Cantons de l'Est, sud du Québec

Abstract

Peat-bogs are complex environments to study because their physical and chemical properties vary with both time and space. These properties include mineral and organic chemical composition, regional climate, topography and, importantly, also thermal regime. However, there have been few studies of the thermal regime of peat-bogs. Nevertheless the thermal regime is an essential element in understanding these ecosystems and their evolution. It controls plant productivity, the availability of surface and subsurface water, the rate of nutrient cycling, microfaunal activity and the evolution of biogases. In this Thesis, we describe a study of the thermal regime of a temperate small forested bog in the Eastern Townships of Quebec between December 1994 and October 1995. We measured vertical and lateral temperature profiles and used the method of radiation, energy and water balance to estimate radiation intensities and energy exchange at the surface and below. The sharp decline of the daily thermal amplitude over a short distance has allowed us to identify two distinct microclimates because of the insulating quality of the peat-bog.[Résumé abrégé par UMI].