Ecological Lessons From Long-Term Studies: Ponderosa Pine Silviculture at Pringle Falls Experimental Forest

Pringle Falls Experimental Forest (Pringle Falls) is the oldest experimental forest administered by the US Forest Service and the site of some of the earliest forest management and silviculture research in the Pacific Northwest. The site, southwest of Bend, Oregon, was selected in 1914, and the Pringle Butte unit was formally established as part of the national network of experimental forests in 1931 as a center for silviculture, forest management, and insect and disease research in ponderosa pine forests east of the Oregon Cascade Range. Early research objectives at Pringle Falls focused primarily on silvicultural methods for harvesting multi-cohort old-growth ponderosa pine stands and converting these lower value stands to higher value young, fast-growing stands. Management direction and research trajectories during this early period of research were driven by a regional interest in protecting forests from insects and fire. The legacy of early research that focused on identifying susceptibility to insect-caused mortality in old-growth pine is proving uniquely valuable today. Management direction and research trajectories have shifted from an emphasis on single-cohort stands back to multi-cohort stands with an emphasis on developing and protecting late-successional and old-growth structure. Examples of ecological lessons will be drawn from long-term studies established and followed by Keen, Brandstrom, Mowat, Barrett, Cochran, Busse, and others that will trace the trajectory of interrelated themes of silviculture, forest ecology, insects, fire and fuels to show how work at Pringle Falls has both followed and influenced societal demands for forest management, and how this trajectory has cycled back to the themes under which the experimental forest was first established