Tropical forest responses to increasing [CO2]: current knowledge and opportunities for future research

Journal Article · Tue Jan 01 00:00:00 EST 2013 · Functional Plant Biology

DOI:https://doi.org/10.1071/FP12309· OSTI ID:1091644

Cernusak, Lucas ^[1]; Winter, Klaus ^[2]; Dalling, James ^[3]; Holtum, Joseph ^[4]; Jaramillo, Carlos ^[2]; Korner, Christian ^[5]; Leakey, Andrew D.B. ^[6]; Norby, Richard J ^[7]; Poulter, Benjamin ^[8]; Turner, Benjamin ^[2]; Wright, S. Joseph ^[2]

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1. Australian National University, Canberra, Australia
2. Smithsonian Tropical Research Institute
3. University of Illinois, Urbana-Champaign
4. James Cook University
5. University of Basel
6. University of Illinois
7. ORNL
8. Laboratoire des Sciences du Climat et de l'Environement, France

Elevated atmospheric [CO2] (ca) will undoubtedly affect the metabolism of tropical forests worldwide; however, critical aspects of how tropical forests will respond remain largely unknown. Here we review the current state of knowledge about physiological and ecological responses, with the aim of providing a framework that can help to guide future experimental research. Modelling studies have indicated that elevated ca can potentially stimulate photosynthesis more in the tropics than at higher latitudes, because suppression of photorespiration by elevated ca increases with temperature. However, canopy leaves in tropical forests could also potentially reach a high temperature threshold under elevated ca that will moderate the rise in photosynthesis. Belowground responses, including fine root production, nutrient foraging, and soil organic matter processing, will be especially important to the integrated ecosystem response to elevated CO2. Water-use efficiency will increase as ca rises, potentially impacting upon soil moisture status and nutrient availability. Recruitment may be differentially altered for some functional groups, potentially decreasing ecosystem carbon storage. Whole-forest CO2 enrichment experiments are urgently needed to test predictions of tropical forest functioning under elevated ca. Smaller scale experiments in the understory and in gaps would also be informative, and could provide stepping stones toward stand-scale manipulations.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1091644
• Journal Information: Functional Plant Biology, Vol. 40, Issue 6; ISSN 1445--4408
• Country of Publication: United States
• Language: English