Mechanistic evidence for tracking the seasonality of photosynthesis with solar-induced fluorescence

Northern hemisphere evergreen forests assimilate a significant fraction of global atmospheric CO2 but monitoring large-scale changes in gross primary production (GPP) in these systems is challenging. Recent advances in remote sensing allow the detection of solar-induced chlorophyll fluorescence (SIF) emission from vegetation, which has been empirically linked to GPP at large spatial scales. This is particularly important in evergreen forests, where traditional remoteFurther, the complex terrain of high-elevation evergreen systems is generally not amenable to eddy covariance carbon flux measurements. As a result, accurately determining the timing of seasonal GPP onset and cessation in evergreen forests remains a major challenge in terrestrial biosphere models and satellite remote sensing (7, 16, 17).