“Soil Formation and Slope Stability on Post-Glacial Landscapes”
Dr. Raquel Portes
Visiting Assistant Professor,
Earth & Climate Sciences,
Bates University (Lewiston, Maine)
Wednesday, October 27, 2021 @ 4:00 pm, 270 Soils Bldg.
Please note: In person attendance is restricted to students enrolled in Soil Sci. 728 and Soil Science faculty/staff. Masks are required.
Zoom is available for all others:
Abstract: Soils on sloping landscapes cover most of Earth’s terrestrial surface. The quantification of soil formation and erosion rates have been crucial for understanding how soils and landscapes co-evolve across space and time. Over the last decade, the role of soil formation and erosion processes controlling the stabilization of slopes has gained considerable interest from the soil science and geoscience communities. Soil formation and erosion are two counteracting forces that proceed at different rates depending on soil-forming factors, controlling chemical weathering rates, sediment delivery to streams, and biogeochemical cycling of nutrients. Recent studies have highlighted the link between soil formation and soil erosion rates for sloping landscapes reaching geomorphic stability (no erosion or sedimentation) as soils develop in a progressive pathway. The presentation will synthesize available knowledge on how time and parent material control pedogenesis and slope stabilization on post-glacial landscapes, highlighting case studies from Southeast Alaska, Central Rockies, New England, and the Swiss Alps. Furthermore, the presentation will cover methodological advances on assessing decadal soil erosion and accumulation rates, including field-based experimental design and using fallout radionuclides (239+240Pu) together with stable carbon isotopes.
This presentation is supported through the generosity of James G. Bockheim and the James & Julie Bockheim Distinguished Lecture in Soil Science Fund.