SYMP 17-1 - Ecological novelty, old and new

Thursday, August 11, 2016: 8:00 AM
Grand Floridian Blrm C, Ft Lauderdale Convention Center
Stephen T. Jackson, U.S. Department of the Interior Southwest Climate Science Center

Although ecological novelty is a relatively new concept for ecological science and conservation, as a phenomenon it may be as old as the biosphere.  ‘Natural novelty’ arises from sources other than human activities, including climatic change, tectonic episodes, evolutionary innovations, and dispersal events.  Climate change is the best-known of these sources; at timescales of thousands to tens of thousands of years, particular climatic realizations come and go, and so particular communities and ecosystems emerge and then disappear, with constituent taxa recombining to form new communities.  As an example, hyperseasonal climates in central North America 16,000 to 11,000 years ago led to development of forests and woodlands compositionally unlike any that preceded or followed them.  Continually emergent ecological novelty, driven by climatic change, is now well-documented over much of the globe for the past 20,000-100,000 years.

A second form, ‘anthropogenic novelty’, has shallower antiquity than natural novelty, though it may be as old as human use of fire. Local and regional ecological novelty certainly proliferated with development of agriculture and cities, and human contributions to megafaunal decline and disappearance by harvesting and habitat alteration led to further novelty.  Indeed, a recent case has been made that terrestrial communities of the past 12,000 years are organized fundamentally differently from those of the previous 300 million years, owing to human impacts.  Ecological, paleoecological, and archeological studies are revealing persistent historical legacies of human activities, even in remote or apparently pristine settings.


The long-standing existence and continual emergence of ecological novelty challenges deeply held values and assumptions in conservation and natural-resource management.  Conservation represents an intersection between science and values.  Many of conservation’s core assumptions are derived from 20th Century science and its interaction with and influence on contemporary values.  Advances in historical ecology and paleoecology during the past 3-4 decades provide different perspectives, indicating that we live on a dynamic planet characterized by natural change and novelty, and that human impacts on communities and ecosystems across much of the planet are of higher magnitude and greater antiquity than typically recognized during most of the 20th Century.  Conservation values and practice are still coming to grips with these findings.  Conservationists can find both solace and opportunity in the knowledge that the natural world we’ve inherited is rich and functional, in spite of substantial human imprints and alterations, and in spite of a long history of natural environmental change and ecological disruption.