
Research in the Thomas Lab
Dr. Thomas has been preoccupied with the comparative biology of trees and forest responses to the intentional and accidental impacts of humans for some 25 years. Sean has been at the University of Toronto since 1999, with appointments as a Canada Research Chair and NSERC Industrial Research Chair in Biochar and Ecosystem Restoration.
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Research in the lab focuses on how trees and forests respond to human impacts – intentional impacts through forest management, and unintentional impacts via local, regional, and global changes in the environment. We link the functional ecology and ecophysiology of trees (“how trees work”) to patterns of growth, mortality, recruitment, reproduction, at the population scale, to patterns community composition, and to ecosystem processes, in particular carbon flux (“how forests work”). Two particular areas of emphasis are biochar - pyrolyzed organic matter used as a soil amendment - and fluxes of non-CO2 greenhouse gases from soils and plants.
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Topics explored: Applied forest ecology and silviculture, urban green infrastructure, comparative ecology and ecophysiology of forest trees, forest canopy biology, ecological aspects of global environmental change, tropical forests.
Lab Instruments and Techniques
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Leaf and whole-plant gas exchange (Licor Li-6800 system)
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Leaf and canopy optical analysis (Ocean Optics and other systems)
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Chlorophyll fluorescence (Walz miniPAM)
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Soil and woody tissue respiration (multiple systems)
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Soil and woody tissue methane and N2O flux (Los Gatos and Licor GHG systems).
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Leaf methane and N2O flux (Credosense leaf chamber)
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Rapid microplate reader (Byonoy)
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Experimental pyrolysis system
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Mobile canopy lift for canopy access and experimentation.
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Canopy meteorological and access tower.
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Hemispherical photograph analysis (digital cameras with fisheye lens; WinScanopy and other software).
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Tree mapping and measurement equipment (Lasertech system, Nikon total station).
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Dendrochronological analysis (TRIM system, WinDendro, CDendro)
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Elemental analysis (CN analyzer and ICP spectrometers).
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NOVAe Gas sorption system for surface area and pore size analysis (BET theory and extensions).
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Empirical modeling of spatial interactions using maximal likelihood methods.