Some recent papers
Clark, D. A., Piper, S. C., Keeling, C. D. and Clark, D. B. 2003. Tropical rain forest tree growth and atmospheric carbon dynamics linked to interannual temperature variation during 1984-2000. - Proc. Natl. Acad. Sci. USA 100: 5852-5857. Link via Dartmouth network. According to Clark et al., global CO2 anomalies (lower right) are partly driven by effects of interannual temperature patterns on the balance between photosynthesis and respiration in tropical forests. Note that their estimates of "tropical terrestrial CO2 flux" are correlated with CO2 anomalies in the long term record from Hawaii (lower right). However, they used a more complicated model than from the Hawaiin data alone (using isotopic ratios in atmospheric CO2 and a latitudinal network of CO2 stations). This was designed to remove possible effects on the anomolies from: (1) oceanic exchange and (2) terrestrial systems outside of the tropics.

Kaiser, J. 2003. An intimate knowledge of trees. Commentary on research by David and Deborah Clark. Science 300(5619): 566-567. Issue of 25 Apr 2003. Link.

Clark, D. A. 2004. Sources or sinks? The responses of tropical forests to current and future climate and atmospheric composition. Philosophical Transactions of the Royal Society of London Series B-Biological Sciences 359:477-491.  Link

Clark, D. A. 2004. Tropical forests and global warming: slowing it down or speeding it up? Frontiers in Ecology and the Environment 2:73-80.  Link

Clark, D. B., D. A. Clark, and S. F. Oberbauer. 2010. Annual wood production in a tropical rain forest in ne costa rica linked to climatic variation but not to increasing co2. Global Change Biology 16:747-759.  Link.

Bousquet, P., et al.. 2000. Regional changes in carbon dioxide fluxes of land and oceans since 1980. Science 290:1342. Link.

Keeling, C. D.; Whorf, T. P.; Wahlen, M.; van der Plicht, J. 1995. Interannual extremes in the rate of rise of atmospheric carbon dioxide since 1980. Nature. 375:666-670. Link.

Some related web sites
Carbono Project at La Selva, Costa Rica
Deborah Clark, an author of Clark et al. 2003
David Clark, an author of Clark et al. 2003
Carbon dioxide information analysis center
History and description of "The Keeling Curve"
1000 year record of CO2 from ice cores

CO2 anomalies (lower) are the difference between the annual average of measured CO2 concentration (solid line in upper, with seasonal oscillations removed) and expected CO2 concentrations based on long-term trend (straight dashed line in upper). Thus, positive fluxes indicate years when atmospheric CO2 increased more than the long term trend. Data source