Recently, researchers at the Forest Products Laboratory and University of Wisconsin have developed a new model of electrical conduction in wood that provides a good fit to experimental data, offers insight into the mechanism of conduction, and integrates well with other experiments that probe the structure and dynamics of water in wood. The key to this new model is a percolation threshold-a minimum moisture content necessary for ionic conduction in wood. Physically, the percolation threshold is the minimum moisture content where there is a continuous path of 'free' water in the wood. The percolation threshold was found to be below the fiber saturation point, which has profound implications for wood durability issues caused by an abundance of water. The percolation threshold is consistent with previous experiments on electrical properties and may be the key to understanding wood other properties that exhibit discontinuous behavior below the fiber saturation point such as longitudinal shrinkage, mold growth, and corrosion of fasteners.