Thornton T. Munger old-growth forest study

Long-term studies of forest change in the Pacific Northwest arefew; due to the long-lived nature of many of our Northwest treespecies, the dynamics of tree death are still poorly understood. Alarge set of plots totaling 48.6 hectares was established in 1947 inwhat is now the Thornton T. Munger Research Natural Area at theWind River Experimental Forest in southern Washington. The ageand extent of the plot system make it a valuable source of data onthe dynamics of tree populations in an old-growth forest. The forestis 450-years old with Douglas-fir (Pseudotsuga menziesii) and westernhemlock (Tsuga heterophylla) comprising 86% of the volume. Theremaining volume is made up of Pacific silver fir (Abies amabilis),grand fir (Abies grandis), noble fir (Abies procera), western redcedar(Thuja plicata), western white pine (Pinus monticola), and Pacific yew(Taxus brevifolia). The study area is distributed from 335 to 610 m inelevation and represents an intergrade between western hemlock/salal (Gaultheria shallon) and Pacific silver fir /salal plant associations.Scientists and students from the University of Washington, OregonState University, and the USDA Forest Service are collaborating onthe large task of re-measuring growth and mortality on the 48.6-ha-plot network. Growth and mortality summaries were preparedfrom the data collected at 6-, 12-, and 36-year intervals on a subsetof plots within the larger network. Primary emphasis will be on the43-year growth record of individual overstory trees, as well as allDouglas-fir mortality for the same period. The results will be helpfulin interpreting long-range population dynamics that occur in our old-growth Douglas-fir forests.