Podzols are acidic soils naturally occurring in humid areas, where precipitation exceeds evapotranspiration. During the podzolization process, labile elements and metals such as aluminum and iron are leached from surface horizons and travel downwards together with soluble organic compounds. These leached substances accumulate in the subsoil, forming what is called illuvial horizons.
Illuvial horizons are rich in organic matter and disordered, highly reactive mineral phases such as imogolite (a poorly crystalline silicate) and ferrihydrite (a poorly crystalline oxide). This reactive mineralogy imparts specific and interesting properties to podzols, such as a high carbon sequestration potential and abnormal nutrient retention capacity.
Our research project is centered around three questions:
(1) What are the fundamental soil-forming processes leading to the development of illuvial horizons?
(2) How do anthropogenic perturbations, such as forest harvest or conversion to agricultural use, affect the podzolisation process?
(3) What are the environmental consequences of these perturbations, specifically on organic matter dynamics and nutrient availability?
A podzol from the Fontainebleau forest, France
Active project members
Stephanie Grand (project lead)
Éric Verrecchia
David Sebag
Anaïs Fayolle
Valentine Turberg
Relevant publications
Grand S, Lavkulich LM (2015) Short-range order mineral phases control the distribution of important macronutrients in coarse-textured forest soils of coastal Brisith Columbia, Canada. Plant and Soil 390: 77-93. Doi: 10.1007/s11104-014-2372-6
Grand S, Hudson R, Lavkulich LM (2014) Effects of forest harvest on soil nutrients and labile ions in Podzols of southwestern Canada: Mean and dispersion effects. Catena 122: 18-26. Doi: 10.1016/j.catena.2014.06.004
Grand S, Lavkulich LM (2013) Potential influence of poorly crystalline minerals on soil chemistry in Podzols of southwestern Canada. European Journal of Soil Science 64: 651-660. Doi: 10.1111/ejss.12062
Grand S, Lavkulich LM (2012) Effects of forest harvest on soil carbon and related variables in Canadian Spodosols. Soil Science Society of America Journal 76: 1816-1827. Doi: 10.2136/sssaj2012.0103
Grand S, Lavkulich LM (2011) Depth distribution and predictors of soil organic carbon in Podzols of a forested watershed in southwestern Canada. Soil Science 176: 164-174. Doi: 10.1097/SS.0b013e3182128671