Anthropogenic Disturbance and Recovery Patterns in Montane Forests, Colorado Front Range

Extensive logging and burning in association with the mining booms of the latter half of the 19th century severely disturbed the montane forests of Boulder County in the Colorado Front Range. Repeat photography of 68 historical photographs and age structure analysis of 24 stands were used to investigate patterns of stand development following disturbance. The data set of nearly 1300 tree ages revealed highly variable patterns of development of stands dominated mainly by ponderosa pine (Pinus ponderosa), Douglas fir (Pseudotsuga menziesli), lodgepole pine (Pinus contorta), limber pine (Pinus flexilis), and subalpine fir (Abies lasiocarpa). In most cases, forest succession followed an “initial floristics” pattern in which both early and late successional (or climax) species established more or less synchronously. Less commonly, and always on less favorable sites, forest succession followed a “relay floristics” pattern in which the late successional species did not establish until several decades after initial colonization of the site by pioneer-type species such as limber pine and quaking aspen. (Key words: montane forest, disturbed forest, forest recovery, forest succession, Colorado, biogeography.)