Sack Lunch Seminar (SLS)

Periods of extreme climates and mass extinction in the geological record are among the few readily identifiable turning points in the evolution of life, and could serve as partial analogues for predicting ecosystem responses to projected trends in climate change, and ocean deoxygenation and acidification. However, our understanding of ecosystem resilience derives mostly from the fossil record of calcifying organisms, whereas key organisms lacking hard fossilizable skeletons have been classically overlooked.

This presentation addresses marine ecosystem resilience by examining the fossilized molecular signature of eukaryotic and prokaryotic planktonic communities across two mass extinction events characterized by contrasting extinction mechanisms: the end-Triassic and the Cretaceous-Paleogene (K-Pg) boundary. I will discuss how environmental changes stemming from elevated CO2, global warming, acidification, oxygen-deficiency, and nutrient limitation (end-Triassic scenario) can have more negative consequences on marine ecosystems than transient events of acidification and productivity change (K-Pg scenario).