Collaborative Research: NSFGEO-NERC: Community And Structural Collapse During Mass Extinctions (CASCaDE)

We live in a time of widespread change to the natural systems that make our planet habitable. The climate is warming and we are in the midst of a biodiversity crises arising from our extensive and expanding use of natural resources and spaces. What do these changes mean for the future of planet? The fossil record provides us with the means to understand the resilience and collapse of ecosystems due to rapid climate change. Here the researchers will use the fossil record to explore why some intervals of earth history are particularly prone to mass extinction, while others are not. To do this, they will examine changes in fossil communities across intervals of global warming using cutting-edge approaches from food web modeling. Their results will allow them to assess the relative importance of network structure and composition, versus changes in the productivity of systems, to the stability of ecosystems during times of rapid global warming, like those we are living in today. More technically, the research will answer the question of why rapid warming events of the Paleozoic and Mesozoic consistently trigger mass extinction, whereas similarly extreme climatic events of the Cenozoic do not? The researchers will test the hypothesis that it is the evolution of modern ecosystem structures established in the aftermath of the Cretaceous-Paleogene mass extinction that has made Cenozoic communities relatively resilient to the effects of global warming as compared to those in the past. To do this they will i) reconstruct marine food webs across global warming events while accounting for preservation bias; ii) estimate productivity and biomass at the base of the marine food web through time; iii) predict primary and secondary extinctions using by advancing and applying food web modeling approaches; and iv) test the role of network structure in the stability of Cenozoic marine ecosystems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.