Plant carbon balance, evolutionary innovation and extinction in land plants


National Center for Ecological Analysis and Synthesis, University of California, 735 State Street, Suite 300, Santa Barbara, CA 93101-5504, USA. Tel +1 805 892-2528, Fax +1 805 892-2510, E-mail


The plant fossil record was reviewed to highlight how consideration of plant carbon balance strengthens our understanding of various evolutionary innovation and extinction events. Following a brief physiological primer to carbon acquisition and allocation in C3-plants, specific evolutionary events are discussed in connection with postulated carbon-based mechanisms. Primary topics include: (i) the evolution of plants with the C4-photosynthetic pathway; (ii) the surprising lack of plant extinctions during the Pleistocene (1.6 million years ago, Ma); (iii) the trend toward declining plant diversity and increasing rates of herbivory across the Palaeocene/Eocene transition (57–52 Ma); and (iv) megaherbivore extinctions at the end of the Pleistocene (10 thousand years ago, Ka). A framework is presented for testing hypotheses on the cause–effect relationships between global carbon cycling, plant carbon dynamics and the evolution of terrestrial ecosystems.