Climate impacts on Late Quaternary megafauna: A global dynamical modelling approach

The Late Quaternary period was characterized by the widespread extinction of over 50% of global megafaunal species, followed by a rapid decline in biodiversity. The relative roles of adverse climatic conditions and the emergence of modern humans in these extinctions remain unresolved due to the sparsity of palaeoecological evidence. Here we present a new spatially explicit dynamical model (ICCP Global Mammal Model, IGMM) that simulates climate-induced changes in habitat suitability and biomass distribution of more than 2000 terrestrial mammal species, incorporating dispersion, competition, and predation as functions of time and across the globe. Forced with transient climate simulations for the Late Quaternary period, the model reproduces well the observed global distribution of mammal population biomass and species richness. The glacial-interglacial transitions, with the Last Glacial Maximum (LGM) in particular, were marked by dramatic changes in habitat suitability of mammals, followed by global modulations in population biomass, species composition and biodiversity. The present model may help elucidate the climate-ecological interactions that contributed to the loss of megafauna in the Late Quaternary period, providing insights into the potential drivers of future biodiversity crisis.