Tuesday, August 7, 2007 - 9:50 AM

OOS 8-6: Prioritization of road removal based on aquatic ecology

Charles Luce, Matthew Dare, and Bruce Rieman. USFS Rocky Mountain Research Station, Boise Aquatic Sciences Lab

While the need for restoration to reduce the effects of roads on aquatic ecosystems is clear, there are few resources available for accomplishing the work.  Strategic prioritization may be important in many circumstances to reduce threats to endangered aquatic ecosystems.  Current strategies in use for prioritization of road decommissioning efforts include 1) reduction of annual sediment yield within regulatory limits, 2) worst visible problem roads, 3) streamside roads, 4) density reduction, and 5) low controversy roads.  An alternative strategy seeks to prioritize decommissioning that expands existing strong habitats and reconnects fragmented and isolated populations to increase the resilience of populations in the face of major events, such as storms and fires.  Undertaking such a strategy may not meet some of the more traditional objectives, so may seem counterintuitive, and aspects of the strategy may be scale dependent.  For example, such an approach may actually support higher priorities for reduction in areas with already low road density.  It may also suggest a higher priority for removing a ridge-top road affecting many miles of habitat from the headwaters down than for removing a streamside road that only affects downstream habitats.  While the focus on selected drainages may not minimize sediment production at a large scale relative to other resource allocations, it can locally focus reductions of fine sediment to critical habitats.  A strategy that increases the resilience of aquatic ecosystems to major disturbances, increases opportunities for wildland fire use as a more sustainable approach to fire and fuels management.  Comparison of terrestrial restoration needs relative to wildfire and aquatic restoration needs relative to roads suggest that they are often in the same area, presenting an opportunity for joint restoration of aquatic and terrestrial habitats so that both are resilient to wildfire.