02287nas a2200193 4500008004100000245008600041210006900127300003700196490000600233520163500239653001901874653001601893653001301909653002801922100002401950700002001974700002201994856007702016 2009 eng d00aEffects of Global Warming on Ancient Mammalian Communities and Their Environments0 aEffects of Global Warming on Ancient Mammalian Communities and T ae5750. doi:10.1371/journal.pone.0 v43 a

Background

Current global warming affects the composition and dynamics of mammalian communities and can increase extinction risk; however, long-term effects of warming on mammals are less understood. Dietary reconstructions inferred from stable isotopes of fossil herbivorous mammalian tooth enamel document environmental and climatic changes in ancient ecosystems, including C3/C4 transitions and relative seasonality.

Methodology/Principal Findings

Here, we use stable carbon and oxygen isotopes preserved in fossil teeth to document the magnitude of mammalian dietary shifts and ancient floral change during geologically documented glacial and interglacial periods during the Pliocene (~1.9 million years ago) and Pleistocene (~1.3 million years ago) in Florida. Stable isotope data demonstrate increased aridity, increased C4 grass consumption, inter-faunal dietary partitioning, increased isotopic niche breadth of mixed feeders, niche partitioning of phylogenetically similar taxa, and differences in relative seasonality with warming.

Conclusion/Significance

Our data show that global warming resulted in dramatic vegetation and dietary changes even at lower latitudes (~28°N). Our results also question the use of models that predict the long term decline and extinction of species based on the assumption that niches are conserved over time. These findings have immediate relevance to clarifying possible biotic responses to current global warming in modern ecosystems.

10aglobal warming10aPleistocene10aPliocene10astable isotope analysis1 aDeSantis, L., R. G.1 aFeranec, R., S.1 aMacFadden, B., J. uhttp://journals.plos.org/plosone/article?id=10.1371/journal.pone.0005750