Marion et al. 1997

Marion GM, Henry GHR, Freckman DW, Johnstone J, Jones G, Jones MH, Levesque E, Molau U, Molgaard P, Parsons AN, Svoboda J, Virginia RA. 1997. Open-top designs for mainpulating field temperature in high-latitude ecosystems. Global Change Biology 3 (suppl. 1): 20-32.

These authors evaluated 4 different chamber designs under field conditions, examining many variables but focusing on temperature differences between the inside and outside of the chambers, and unintended ecological effects. The four designs were termed “ITEX corners”, “cone chambers”, “hexagon chambers”, and “plastic tent”. There were 6 field sites, 5 in the Arctic from Sweden to Canada, and 1 in Antarctica.

This paper represents one of the outcomes of a meeting that established the International Tundra Experiment (ITEX); at this meeting a list of requirements for long-term temperature manipulation devices was constructed, leading to these 4 designs and a requirement to measure ecological effects such as changes in snow accumulation or melting.

The results were fairly consistent across chamber designs. In general, open-top chambers cause fewer and less severe ecological side-effects than closed designs, but warm the surface of the soil by 1-2 degrees compared with up to 10 or 15 degrees for some closed designs. Side-effects of the open-top chambers included some shading and interception of PAR by the chamber materials, changes in moisture concentrations in the air immediately above the soil surface (though these may have been driven by changes in temperature), and the possibility of interference from animals, such as nutrient addition by birds perching on the chambers. However, CO2 concentrations were not affected by chambers.

One of these authors, GHR Henry, will be working with me this summer at Alexandra Fjord; this was also one of the study sites in this paper.