Out of the Garden and into the Cooler? A Quaternary Perspective on Deep-Time Paleoecology

Abstract

Most of what we know about ecology inevitably comes from Late Quaternary ecosystems, particularly those of the past few decades. 20th Century ecosystems are the only ones for which we have direct observational and experimental studies. We can obtain detailed records of ecological dynamics at decade- to century-scales over the past few centuries using historical, permanent-plot, demographic, and paleoecological techniques, but only for a select few ecosystems. Radiocarbon-dated fossil assemblages provide records of ecological changes over the past 25,000 years. Because 14C-dating allows independent dating of the assemblages with precision of 50–500 years, detailed spatiotemporal patterns of change can be outlined, but these are limited to certain kinds of organisms and to regions with a high density of fossil sites. When we go beyond the radiocarbon barrier 30–40,000 years ago, the density of datable terrestrial assemblages decreases sharply, and our views of past ecosystems become murkier.