2007 Research Highlights

Research Area:
Forest Service Strategic Goal 6: Conduct mission-related work in addition to that which supports the agency goals.
SPA: Resource Management and Use

Does calcium influence the rate of wood decay?

Key Contacts: Carol Clausen, cclausen@fs.fed.us; and Frederick Green, fgreen@fs.fed.us
Partner: University of Copenhagen, Denmark

Brown-rot decay fungi accumulate oxalic acid during the wood decay process and many of them are copper tolerant. It has been proposed that accumulation of oxalic acid without the presence of a cation buffer, such as calcium would create a problem for survival of the fungus. Calcium, the most abundant metal ion found in wood is released during decay and is believed to regulate pH by precipitating oxalic acid to form calcium oxalate. Scientists from Forest Products Laboratory and University of Copenhagen, Denmark tested the influence of calcium on the decay rate of copper-treated wood by copper tolerant decay fungi. They demonstrated that decay was significantly inhibited by treatment with calcium ions in the presence of copper-treated wood, but calcium showed no effect on the decay fungi in untreated wood. These results suggest that calcium functions as an oxalic acid sink, leaving copper ions to act as a fungicide. A better understanding of the mechanism of brown-rot decay is needed for the development of improved wood protection systems.