Fuel Reduction Management Practices in Riparian Areas of the Western USA

Abstract

Two decades of uncharacteristically severe wildfires have caused government and private land managers to actively reduce hazardous fuels to lessen wildfire severity in western forests, including riparian areas. Because riparian fuel treatments are a fairly new management strategy, we set out to document their frequency and extent on federal lands in the western U.S. Seventy-four USDA Forest Service Fire Management Officers (FMOs) in 11 states were interviewed to collect information on the number and characteristics of riparian fuel reduction treatments in their management district. Just under half of the FMOs surveyed (43%) indicated that they were conducting fuel reduction treatments in riparian areas. The primary management objective listed for these projects was either fuel reduction (81%) or ecological restoration and habitat improvement (41%), though multiple management goals were common (56%). Most projects were of small extent (93% < 300 acres), occurred in the wildland-urban interface (75%), and were conducted in ways to minimize negative impacts on species and habitats. The results of this survey suggest that managers are proceeding cautiously with treatments. To facilitate project planning and implementation, managers recommended early coordination with resource specialists, such as hydrologists and fish and wildlife biologists. Well-designed monitoring of the consequences of riparian fuel treatments on fuel loads, fire risk, and ecological effects is needed to provide a scientifically-defensible basis for the continued and growing implementation of these treatments.

Effects of wildfire on riparian trees in southeastern Arizona

“…Prescription burning potentially can reduce fuels, but the risk of prescription failure probably is the reason that planned burning usually has been conducted outside the natural fire season, when effects on fuel levels and other attributes of riparian ecosystems may be small (Arkle and Pollard, 2010). Results of our study and others support a cautionary approach to prescribed burning in southwestern riparian woodlands, but we nevertheless agree with the recommendations by Stone et al (2010) for continued, well-planned research on this subject. One possibility that should be explored is the strategic placement of small, shaded fuelbreaks to reduce the threat to riparian woodlands posed by either wildfire or prescribed fire in adjacent grasslands (Agee et al, 2000).…”

“…Mechanical thinning is one method of reducing fuels and therefore fire intensity (Stone et al, 2010), but it is costly and potentially physically harmful to sensitive riparian areas. Livestock grazing can decrease the risk of damaging wildfire, but it also can have undesirable impacts on water quality, vegetation composition, and stream bank stability (Nelson et al, 2011;Poff et al, 2011;Dalldorf et al, 2013).…”

Stand structure, fuel loads, and fire behavior in riparian and upland forests, Sierra Nevada Mountains, USA; a comparison of current and reconstructed conditions

“…However, both riparian and upland stands currently appear to be more fire prone than their historic conditions, with riparian areas significantly more so than adjacent upland areas. While active management of riparian forests is becoming more common (Holmes et al, 2010;Stone et al, 2010), riparian forests could be considered a high priority for restoration and fuel reduction treatments, with objectives similar to adjacent upland forests. If reintroduction of an active fire regime similar to historic conditions is desirable, treatments might focus on reducing basal area and stand density by removing small fire-intolerant tree species, and reducing surface fuel loads, especially the duff layer.…”

Stream-Riparian Ecosystems and Mixed- and High-Severity Fire

“…For example, the use of prescribed fire as a tool to manage riparian ecosystem condition is increasing (Stone et al, 2010), but because prescribed fires typically differ from wildfires in severity, timing, frequency, and extent (McIver et al, 2013), their influence on riparian and aquatic systems remains an open question (Boerner et al, 2008;. In addition, methods used during fire suppression efforts can have negative effects on stream-riparian ecosystems.…”