title: Australia lacks stem succulents but is it depauperate in plants with crassulacean acid metabolism (CAM)?
abstract: In the flora of Australia, the driest vegetated continent, crassulacean acid metabolism (CAM), the most water-use efficient form of photosynthesis, is documented in only 0.6% of native species. Most are epiphytes and only seven terrestrial. However, much of Australia is unsurveyed, and carbon isotope signature, commonly used to assess photosynthetic pathway diversity, does not distinguish between plants with low-levels of CAM and C3 plants. We provide the first census of CAM for the Australian flora and suggest that the real frequency of CAM in the flora is double that currently known, with the number of terrestrial CAM species probably 10-fold greater. Still unresolved is the question why the large stem-succulent life - form is absent from the native Australian flora even though exotic large cacti have successfully invaded and established in Australia.
authors.affiliation: Terrestrial Ecosystems and Climate Change, College of Marine and Environmental Sciences, James Cook University, Townsville 4811, Queensland, Australia; Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Panama. Electronic address: joseph.holtum@jcu.edu.au.
authors.forename: Joseph Am
authors.initials: JA
authors.lastname: Holtum
authors.affiliation: Department of Ecology and Evolutionary Biology, Brown University, Box G-W, Providence, RI 02912, USA.
authors.forename: Lillian P
authors.initials: LP
authors.lastname: Hancock
authors.affiliation: Department of Ecology and Evolutionary Biology, Brown University, Box G-W, Providence, RI 02912, USA.
authors.forename: Erika J
authors.initials: EJ
authors.lastname: Edwards
authors.affiliation: Research School of Biology, Australian National University, Canberra 2601, ACT, Australia.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Crisp
authors.affiliation: Australian Tropical Herbarium, James Cook University, PO Box 6811, Cairns 4870, Queensland, Australia.
authors.forename: Darren M
authors.initials: DM
authors.lastname: Crayn
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto, Canada.
authors.forename: Rowan
authors.initials: R
authors.lastname: Sage
authors.affiliation: Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Ancón, Panama.
authors.forename: Klaus
authors.initials: K
authors.lastname: Winter
mesh_terms: D001315:Australia; D002245:Carbon Dioxide / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology; D010944:Plants / Q000378:metabolism*
chemical_list: D002245:Carbon Dioxide