Troy Sehlin Magney
What to Expect
To characterize CO2 uptake by the terrestrial biosphere, an understanding of the spatial and temporal dynamics of photosynthesis is necessary. From remote sensing platforms, we have traditionally only been able to estimate plant photosynthesis based on canopy ‘greenness.’ Unfortunately, canopy ‘greenness’ doesn’t tell us about the fate of absorbed photons, i.e. just because a plant is green does not mean it is doing photosynthesis. Absorbed light by green plants generally has three fates: 1) drive photochemistry; 2) dissipate excess energy as heat; or 3) re-emit as chlorophyll fluorescence. Light-use efficiency (LUE) models – using environmental and meteorological inputs- have often been used in combination with ‘greenness’ indices to estimate the fate of absorbed photons and create maps of global photosynthesis. However, LUE based approaches often fail to characterize photosynthesis well across all ecosystems, leading to the high uncertainty in CO2 uptake by the terrestrial biosphere. New remote sensing techniques that directly probe two of the three absorption pathways can allow us to back out plant photosynthesis at scales relevant to both land management and global carbon cycle studies. In this talk, I will highlight recent advances in solar-induced fluorescence (SIF), hyperspectral reflectance and lidar that ultimately shed a new light on plant physiology. How do we interpret these new datasets? And how good are they? Opportunities and challenges associated with scaling molecular processes from the chloroplast to the globe will be discussed.
Magney is currently an Assistant Professor of Plant and Environmental Informatics, Department of Plant Sciences, University of California Davis, following a short stint as a Research Scientist at the Jet Propulsion Laboratory, California Institute of Technology. Troy works at leaf, tower, airborne, and satellite scales – ultimately trying to better understand existing, and develop new, remote sensing techniques to quantify plant processes.
PhD, University of Idaho, 2015; NASA Postdoctoral Program 2015-2018 at JPL.