Longevity of Untreated Wood in Use Above Ground

Test crosses constructed from 12 different softwoods and 9 different hardwoods were exposed on a test fence for 9 to 12 years in both southern Mississippi and Wisconsin. Objectives of the test were to determine the aboveground longevity of these woods under varying climatic conditions and to identify the fungi associated with their deterioration. The woods tested in Mississippi were classified into aboveground decay resistance groups. The sapwood of lodgepole pine, basswood, balsam poplar, red alder, and sweetgum and the interior wood of sugar maple, yellow birch, and basswood decayed within an average of 7 years and were classified as nonresistant. Woods estimated to last over 20 years above ,ground, and thus classified as most resistant, included heartwood of Douglas-fir, redwood, western white pine, red and white oak, and sapwood of red oak. The remaining woods fell in between these classes. In Wisconsin most woods decayed too slowly for estimates to be made of their longevity. Gloeophyllum saepiarium, the white-rot fungus “unknown T,” Schizophyllum commune, the brown-rot fungus “unknown U,” and a Xylaria sp. were predominant in the Mississippi test units. Peniophora cinerea, Phanerochaete chrysosporium, Meruiiopsis corium, Irpex lacteus, and Peniophora violaceo-livida predominated in Wisconsin.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member