Temperature responses of leaf dark respiration and their implications for tropical forest carbon balance (NSF IOS-1051789, 2011-15)

Principle Investigators (PI): Kaoru Kitajima (UF, -  August 2013) & Jeremy Lichstein (UF, August 2013-2015)

Co-PIs and Collaborators: 
   Stephanie Bohlman (UF),  Stefan Gerber (UF),  Helene Muller-Landau (STRI),  
   S. Joseph Wright (STRI), Klaus Winter (STRI), Martijn Slot (UF & STRI), 
   Cathy Fahey (UF), Camilo Ray-Sanchez (Ohio State University)

SummaryDark respiration by plants (i.e., energy consumption for metabolism) is estimated to consume 30- 80% of daily photosynthetic carbon uptake in forest ecosystems and is predicted to increase with climate warming. Intact tropical forests are thought to account for a substantial fraction of the global terrestrial carbon sink (which currently offsets roughly 25% of global anthropogenic greenhouse gas emissions each year), but the magnitude and causes of the tropical forest carbon sink are controversial. The size of this carbon sink, and how it will respond to future changes in climate and atmospheric CO2 concentrations (e.g., stimulation of photosynthesis via “CO2 fertilization”), have important policy implications, because the amount of carbon mitigation required by human society to stabilize atmospheric CO2 at a specified target (e.g., 500 ppm) depends on the carbon balance of terrestrial ecosystems. Quantifying and understanding the temperature responses of tropical tree respiration and photosynthesis are critical to developing more reliable process-based models of tropical ecosystems, which will help resolve uncertainty in the response of tropical forest carbon cycle to climate change. Our NSF-funded project is studying how climate warming affects dark respiration and photosynthetic carbon uptake by leaves in the upper canopy of dry and wet tropical forests using canopy cranes managed by the Smithsonian Tropical Research Institute in Panama. 

To learn more about the project…. (link to the Key Findings  page)

© Kaoru Kitajima 2016