Monday, August 6, 2007 - 2:30 PM

OOS 2-4: Reintroducing fire and thinning to dry forests: Creating nested landscapes

Paul F. Hessburg, USDA Forest Service

Large scale and severe wildfires are relatively common features of contemporary western dry forests where once an assortment of fires varying in severity, size, and intensity occurred. Today, prescribed fires, alone or in combination with thinning, may be useful to improving the fire tolerance of dry mixed coniferous landscapes. Questions abound though, about when, where, and how to introduce fire and thinning to these forests, and with what effects. Here, we expand on established fire ecology principles that are associated with improving the fire resistance of fire-prone landscapes. We discuss the chief effects of stand-level fire and thinning treatments that are based on these principles, advantages of the treatments to forest and fire managers, and advantages and disadvantages to native biota that may be associated. We add two principles that apply within-stands and to landscapes that, when considered alongside of stand-level principles, incorporate fine to coarse filter considerations, and a broader variety of habitat patterns and processes than are currently addressed. For many dry forests, it will be sensible to reduce surface fuels, increase the height to live crowns, and decrease crown density to some extent, but the resulting spatial patterns matter to native biota and processes. The trick will be to create landscapes within landscapes; patterns of living and dead forest vegetation over space and time that enable all native species and processes to persist in the long term, through highs and lows, regardless of the scale of their relevant domains.