The average fire-return intervals reported for upland and riparian sites that would likely support redosier dogwood populations ranged from 10 years in forests in the Payette National Forest of Idaho  to 70 years in primarily white spruce forests of northeastern Alberta , but given redosier dogwood's widespread distribution and varied habitats, this fire frequency range would likely be much larger with additional fire history studies. For a more extended discussion of FIRE REGIMES in riparian and upland sites, which likely included habitats where redosier dogwood might also occur, see the FEIS review of thimbleberry (Rubus parviflorus).
Reviews report that high productivity and fuel build-up in riparian zones may fuel high-severity fires. Deciduous riparian communities along perennial waterways in eastern Idaho and western Wyoming are considered highly productive with the potential to accumulate large amounts of live and dead woody fuels and support "high-intensity" fires in times of drought when winds are strong (review by ). In the conifer/redosier dogwood community type in moist to wet subalpine riparian sites in Utah, fires are considered infrequent. When fires do occur, they may be severe because of high fuel loads, although small, low-severity, smoldering fires are considered most common .
Field investigations suggest that topography within the riparian zone may affect fire severity. On the Plumas National Forest in the northern Sierra Nevada, fire was more severe along Fourth Water Creek–where riparian zones were wide and flat–than along Third Water Creek, where riparian zones were narrow and steep. Fire pattern and severity were evaluated 1 year after the Lookout wildfire burned in late August and early September. Fires burned to the water's edge less often on Third Water than Fourth Water creek, suggesting that width of the riparian zone was negatively correlated with the extent of riparian area burned. About half of transects along Fourth Water Creek burned with moderate to high severity and had some crowning behavior. Third Water Creek burned primarily in low- to moderate-severity surface fires, but these fires did result in some mortality of understory vegetation .
Riparian and upland communities compared: Fire frequency and fire behavior were often similar in riparian and upland sites. In Idaho's Payette National Forest, moderate to large, mixed-severity fires burned upland and riparian forests an average of every 10 years from 1471 to 1948, but since 1948, the fire-free interval for the area has increased by a factor of 8 (Barrett 2000 cited in ).
Sometimes stream size, extent of riparian vegetation, or vegetation type were better predictors of fire behavior and fire frequency than slope position or distance from the river. In Oregon, comparisons of riparian and upland sites burned by the Biscuit Fire and by the B and B complex fire revealed that fire severity differences between upland and riparian sites depended on which measure of fire severity was used. At both burned sites, percent crown scorch and basal area mortality (indicators of overstory fire severity) were not significantly different for riparian and upland sites, but percentage of exposed mineral soil and char heights (indicators of understory fire severity) were significantly lower (P<0.01) for riparian than upland sites. Regression analyses suggested that upland fire severity was the strongest predictor of basal area mortality in riparian areas. Within the Biscuit Fire perimeter, overstory fire severity was greater in riparian areas with dense small trees, and understory fire severity was greater in areas with higher basal area of hardwoods, but this same pattern was not observed within the B and B complex fire perimeter. Within the B and B complex, overstory fire severity was significantly greater (P<0.05) in relatively dry riparian areas dominated by ponderosa pine than in relatively wet riparian areas dominated by a mixed of conifers. In both areas, basal area mortality was lower along large than small streams, and fires were generally less severe along low-gradient than high-gradient streams .
See the Fire Regime Table for additional information on FIRE REGIMES in vegetation communities where redosier dogwood may occur.
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