Megafauna Depletion and Holocene Ecological Networks

One of the most important ways that humans have impacted biodiversity in the long run is through reducing the abundance of megafauna (animals over ca. 45 kg/100 lbs). It is well known that toward the end of the Pleistocene, a striking number of large-bodied animals went extinct. But the continuing decline of megafauna also characterizes the Holocene, even though there has been less detailed study of the phenomenon. For instance, elephants (Loxodonta and Elephas) formerly occupied a vastly larger territory across Africa and Asia. A combination of hunting for meat and ivory, plus competition for land use with agriculture, has drastically reduced their numbers, reflecting a broader pattern in which humans have systematically altered the body-size distribution of the ecosystems we inhabit throughout history.

While the decline and extinction of megafauna is important in its own right, the downstream effects on ecosystem structure and function is perhaps even more important. Large animals play a disproportionate role in food webs and as ecosystem engineers. They shape vegetation cover and fire regimes; they disperse seeds, compact soils, and terrace landscapes. They drive nutrient cycling and play key roles in biosphere-climate feedbacks via methane emissions and carbon storage. This Workshop will build on research that has started to think about the place of megafauna in Pleistocene systems to deepen our understanding of the effects of the continued depletion of big animals (especially elephants) into more recent times. The goal is to use methods and perspectives from complex systems science to deepen our understanding of humanity's impact on the biosphere.

This event is supported by the James S. McDonnell Foundation Grant Number 220020491, Adaptation, Aging, and the Arrow of Time. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the James S. McDonnell Foundation.