Historical forest patterns of Oregon's central Coast Range

Abstract

To describe the composition and pattern of unmanaged forestland in Oregon's central Coast Range, we analyzed forest conditions from a random sample of 18 prelogging (1949 and earlier) landscapes. We also compared the amount and variability of old forest (conifer-dominated stands >53 cm dbh) in the prelogging landscapes with that in the current landscapes. Sixty-three percent of the prelogging landscape comprised old forest, approximately 21% of which also had a significant (>20% cover) hardwood component. The proportions of forest types across the 18 prelogging landscapes varied greatly for both early seral stages (cv=81–194) and hardwoods (cv=127) and moderately for old forest (cv =39). With increasing distance from streams, the amount of hardwoods and nonforest decreased, whereas the amount of seedling/sapling/pole and young conifers increased. The amount of old forest was significantly greater (p< 0.002) in prelogging forests than in current landscapes. Old-forest patterns also differed significantly (p< 0.015) between prelogging and current landscapes; patch density, coefficient of variation of patch size, edge density, and fragmentation were greater in current landscapes and mean patch size, largest patch size, and core habitat were greater in prelogging forests. Generally, old-forest landscape pattern variables showed a greater range in prelogging landscapes than in current landscapes. Management strategies designed to increase the amount of old forest and the range in landscape patterns would result in a landscape more closely resembling that found prior to intensive logging.