Centuries of Change in Pacific Northwest Forests: Ecological Effects of Forest Simplification and Fragmentation

Abstract

The forests of the Pacific Northwest have undergone significant changes in the relative proportions of various forest types, including dramatic reductions in certain habitats such as oldgrowth forests and early successional habitat rich in woody debris. Intensive forest management practices have resulted in the simplification of forest structure through reductions in certain structural elements such as coarse woody debris, snags, and canopies with high spatial variability. The loss of old-growth forests to timber harvest and land-use conversion has resulted in a condition of fragmentation, creating spatial isolation of remaining patches and significant reductions in interior habitat conditions required by certain organisms. The ecological effects of forest simplification and fragmentation in the Pacific Northwest are reviewed, and management actions to reduce negative consequences are briefly discussed.