Sensitivity of plants to changing atmospheric CO2 concentration: from the geological past to the next century.
The rate of CO(2) assimilation by plants is directly influenced by the concentration of CO(2) in the atmosphere, c(a). As an environmental variable, c(a) also has a unique global and historic significance. Although relatively stable and uniform in the short term, global c(a) has varied substantially on the timescale of thousands to millions of years, and currently is increasing at seemingly an unprecedented rate. This may exert profound impacts on both climate and plant function. Here we utilise extensive datasets and models to develop an integrated, multi-scale assessment of the impact of changing c(a) on plant carbon dioxide uptake and water use. We find that, overall, the sensitivity of plants to rising or falling c(a) is qualitatively similar across all scales considered. It is characterised by an adaptive feedback response that tends to maintain 1 - c(i)/c(a), the relative gradient for CO(2) diffusion into the leaf, relatively constant. This is achieved through predictable adjustments to stomatal anatomy and chloroplast biochemistry. Importantly, the long-term response to changing c(a) can be described by simple equations rooted in the formulation of more commonly studied short-term responses.
Faculty of Agriculture and Environment, University of Sydney, Sydney, NSW, 2006, Australia.
Peter J
PJ
Franks
Faculty of Agriculture and Environment, University of Sydney, Sydney, NSW, 2006, Australia.
Mark A
MA
Adams
Faculty of Agriculture and Environment, University of Sydney, Sydney, NSW, 2006, Australia.
Jeffrey S
JS
Amthor
Faculty of Agriculture and Environment, University of Sydney, Sydney, NSW, 2006, Australia.
Margaret M
MM
Barbour
Department of Global Ecology, Carnegie Institution of Washington, 260 Panama Street, Stanford, CA, 94305, USA.
Joseph A
JA
Berry
Hawkesbury Institute for the Environment, University of Western Sydney, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW, 2751, Australia.
David S
DS
Ellsworth
Research School of Biology, The Australian National University, Acton, ACT, 0200, Australia.
Graham D
GD
Farquhar
Hawkesbury Institute for the Environment, University of Western Sydney, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW, 2751, Australia.
Oula
O
Ghannoum
Centre for Tropical Environmental and Sustainability Science (TESS), School of Earth and Environmental Sciences, James Cook University, Cairns, Qld, 4878, Australia.|Earth and Biosphere Institute, School of Geography, University of Leeds, Leeds, UK.
Jon
J
Lloyd
Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
Nate
N
McDowell
Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.
Richard J
RJ
Norby
Hawkesbury Institute for the Environment, University of Western Sydney, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW, 2751, Australia.
David T
DT
Tissue
Research School of Biology, The Australian National University, Acton, ACT, 0200, Australia.
Susanne
S
von Caemmerer
D000064:Acclimatization; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism*; D057231:Climate Change / Q000706:statistics & numerical data*; D017753:Ecosystem; D005580:Fossils; D008962:Models, Theoretical; D054046:Plant Stomata / Q000502:physiology; D010944:Plants / Q000378:metabolism*; D013312:Stress, Physiological; D014867:Water / Q000378:metabolism
D014867:Water; D002245:Carbon Dioxide