24 September, 2017
Development, evaluation, and performance of an improved technique for passively warming plants and ecosystems.
Advances in understanding and model representation of plant and ecosystem responses to rising temperature have typically required temperature manipulation of research plots. In remote or logistically challenging locations, passive warming using solar radiation is often the only viable approach for temperature manipulation. However, current passive warming approaches are only able to elevate mean daily air temperature by about 1.5°C. The scientists have developed an alternative approach to passive warming that uses modulated venting to allow additional warming. The system requires no electrical power for fully autonomous operation. When tested in the research environment, the coastal tundra of northern Alaska, the project's chambers were able to double the warming achieved by existing approaches.
This technical advance allows researchers to study the effect of greater temperature elevations than previously possible using passive (solar radiation) warming. This is particularly relevant for remote and challenging environments, such as the Arctic, that are projected to experience warming that exceeds the 1.5°C limit of current technology by the middle of the century.
The study's zero-power warming (ZPW) chamber requires no electrical power for fully autonomous operation. It uses a novel system of internal and external heat exchangers that allow differential actuation of pistons in coupled cylinders to control chamber venting. This enables the ZPW chamber venting to respond to the difference between the external and internal air temperatures, thereby increasing the potential for warming and eliminating the risk of overheating. During the thaw season on the coastal tundra of northern Alaska the ZPW chamber was able to elevate the mean daily air temperature 2.6°C above ambient, double the warming achieved by an adjacent passively warmed control chamber that lacked the team's hydraulic system. The team describe the construction, evaluation, and performance of their ZPW chamber and discuss the impact of potential artifacts associated with the design and its operation on the Arctic tundra. The approach described here is highly flexible and tuneable, enabling customization for use in many different environments where significantly greater temperature manipulation than that possible with existing passive warming approaches is desired.
BER Program Manager
Terrestrial Ecosystem Science, SC-23.1
Brookhaven National Laboratory
Upton, NY 11973-5000
This work was supported by the Next-Generation Ecosystem Experiments (NGEE)–Arctic project, which is supported by the Office of Biological and Environmental Research within the U.S. Department of Energy Office of Science.
Lewin, K.F., A. McMahon, K.S. Ely, S.P. Serbin, A. Rogers. “A zero-power warming chamber for investigating plant responses to rising temperature.” Biogeosciences 14, 4071–4083. [DOI:10.5194/bg-14-4071-2017]
This work was supported by the Next-Generation Ecosystem Experiments (NGEE Arctic) project that is supported by the Office of Biological and Environmental Research in the Department of Energy, Office of Science.