National Socio-Environmental Synthesis Center (SESYNC)
1 Park Place, Suite 300
Annapolis, MD 21401
Shifting baselines: the hidden hand of humans
Seminar presented by Dr. Mark Bush, Florida Institute of Technology
A long-standing problem for conservation biology is to define what is ‘natural’ as this is usually the target of restoration efforts. Perceptions of ‘naturalness’, whether it is expressed as species biomass and diversity or ecosystem services, are shaped by our own experience. Consequently, between generations there is an acceptance of a new and degraded norm - a shifted baseline. Although developed to illustrate the impacts of overfishing, the concept of shifting baselines can also be applied to terrestrial settings. In general, the emptying of the oceans began in the 1800s, whereas transformation of the land is much more ancient, and a longer-term vision is needed. Two case studies will be presented, from the Galapagos and the Andes. The Galapagos story is on the same timescale as that of the shifted baselines of oceans, whereas the Andes is suggested to have been shaped for the last 15,000 years. Both examples deal with megafaunal loss at first human contact and subsequent importation of domesticated megafauna, and cultivation. Paleoecological reconstructions based on lake sediment records from both settings provide detailed histories of climate change, megafaunal and human histories. The longer-term history from the Andes also provides the opportunity to investigate the relationship between climate change and human activity.
Bio: Mark Bush is a palaeoecologist and biogeographer with more than 30 years experience of Neotropical palynology and limnology. He obtained his BSc and PhD from the University of Hull (1986), before spending time at The Ohio State University, Smithsonian Tropical Research Institute and Duke University. He is currently Professor of Biology at the Florida Institute of Technology. His research often sits at the nexus of biogeography, ecology, paleoclimatology and archaeology and current research areas include: the Quaternary interglacial history of the Andes, the causing and timing of megafaunal extinctions, the history of ENSO and its impacts on South American ecosystems, and the impacts of pre-Columbian peoples on the Amazon and the Andes.