Paul J. Hanson
Oak Ridge National Laboratory
24 February 2017
ORNL developed protocols for continuous warming and elevated CO2 experimental manipulations of tall-stature peatland forests
ORNL scientists documented an experimental system that combines aboveground and deep-soil heating approaches to provide researchers with a plausible method with which to glimpse future environmental conditions for intact peatland ecosystems.
This experimental system allows researchers to study a broad range of organisms (microbes, moss, shrubs, trees, insects) and ecosystem processes (carbon cycle, water use) under realistic field environments to a broad range of alternative environments that may occur in the future.
This paper describes methods to achieve and measure both deep-soil heating (0–3 m) and whole-ecosystem warming (WEW) appropriate to the scale of tall-stature, boreal forest peatlands. The methods were developed to allow scientists to provide a plausible set of ecosystem-warming scenarios within which immediate and longer-term (1 decade) responses of organisms (microbes to trees) and ecosystem functions (carbon, water and nutrient cycles) could be measured. Elevated CO2 was also incorporated to test for interactions with temperature. The WEW approach was successful in sustaining a wide range of aboveground and belowground temperature treatments (as much as +9 °C) in large 115 m2 open-topped enclosures. The system is functional all year including warm summer and cold winter periods. The paper contrasts our WEW method with prior closely related field-warming approaches, and it includes a full discussion of factors that need to be considered in the interpretation of experimental results. The WEW method enables observations of future temperature conditions not available in the current observational record, and therefore provides a plausible glimpse of future environmental conditions.
Contacts (BER PM)
Dr. Paul J. Hanson
This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, and Graduate Fellowship Program (DE-AC05-06OR23100 to A. L. G.). Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05- 00OR22725.
P.J. Hanson, J.S. Riggs, W.R. Nettles, J.R. Phillips, M.B. Krassovski, L.A. Hook, A.D. Richardson, D.M. Aubrecht, D. M. Ricciuto, J.M. Warren, C. Barbier, “Attaining whole-ecosystem warming using air and deep soil heating methods with an elevated CO2 atmosphere.” Biogeosciences 14, 861–883, (2017). [DOI] 10.5194/bg-14-861-2017