Above- and below-ground response of coniferous ecosystems to tree-fall gaps

Small canopy disturbances are important to the structure andfunction of forest ecosystems. Fine-scale disturbances (the death ofone to many trees) largely control the population dynamics in ourforests between larger catastrophic events. An experimental studyof ecosystem responses to the creation of tree-fall gaps of varyingsize is being conducted in northwestern coniferous forests. Gapswere created in the fall of 1990 in mature (80 to 150 years) andold-growth (400-500 years old) ecosystems dominated by Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla).The research will be done at the H. J. Andrews Experimental Forestin the central Oregon Cascades and at the Wind River ExperimentalForest in southern Washington. The study is a collaborative effortamong the University of Washington, Oregon State University, YaleUniversity, and the USDA Forest Service. Both above- and below-ground processes will be examined during the first three years ofthe study.