The AmeriFlux Network: Observations to understand the role of the terrestrial biosphere in climate change

Background/Question/Methods

AmeriFlux is a coordinated research network of flux sites that seeks to quantify and understand the role of the terrestrial biosphere in global climate change. Measurements include meteorology, micrometeorological measurements of ecosystem-atmosphere exchange of carbon dioxide, water vapor and energy, and biological measurements of ecosystem processes. The network was established in 1996, and now consists of about 100 sites in the Americas. The majority of sites are funded by the U.S. Department of Energy, and additional sites are funded by NSF, USDA, and NASA. The U.S. DOE also funds the Science Chair, who is responsible for leading the science strategy, overseeing the quality assurance across sites, and guiding data management at Oak Ridge National Laboratory (CDIAC). The network has a Science Steering Group of investigators who provide input to network decision-making. An advantage of the investigator-led research is that investigators must write successful competitive grants to continue their research, but the down-side is that long-term research is vulnerable.

Results/Conclusions

The network strives to conduct long-term studies to detect trends in response to climate anomalies and disturbance. Findings include ecosystem responses to anomalous climate years, variation in water-use efficiency, albedo and latent heat flux across biomes, the effect of longer growing seasons on net annual carbon dioxide exchange, and changes in net carbon uptake at different stages following forest disturbances. AmeriFlux has produced instrument and calibration guidelines, data analysis and diagnostics, data submission protocols, and science priorities that have been used in the development of other observatory networks.