Cataloging Information
Ecological - Second Order
Wildlife
Fire & Wildlife
Fish
The native salmonids of the Idaho Panhandle National Forests, bull chaff (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarki lewisz) evolved with natural pulse disturbances of which the most common were fire and flood. These fish are indicator species in the Forest Plan, listed as sensitive species by Region 1 of the Forest Service and as species of special concern by the Idaho Department of Fish and Game. To address the needs of these species, and especially the bull charr with the recent petition for listing under the ESA, the Idaho Panhandle National Forests began habitat typing watersheds in the upper Spokane River ecosystem in 1991. A physical habitat typing protocol developed in Region 5 of the USFS and modified for the waters of northern Idaho was used to monitor any changes in fish habitat which may have occurred due to land management prescription. Of the attributes described by the methodology, mean residual pool volume and residual poo1 depth have been emphasized in analysis because of the value of pools in the stream ecology of bull charr and westslope cutthroat trout for rearing and overwintering habitat. Data was stratified from press and pulse disturbed watersheds. Changes in the quality (volume and depth) and quantity of pool habitat as a result of channel destabilization has a negative influence on carrying capacity as demonstrated by distribution and abundance of the two species in the Coeur d'Alene and St. Joe rivers, and appears to influence the distribution of spawning bull charr. Fish habitat attribute data from stream reaches of watersheds with pulse disturbance patterns in the upper St. Joe basin provide a reasonable standard by which to judge deviations seen in stream reaches of basins of similar geology, channel type, elevation, and forest type where press disturbance has been common for the last 50 to 90 years. These data suggest that the two types of disturbance result in habitat features with differing values relative to quantity and quality of the habitat features and resulting in changes in the distribution and success of persistence in the native assemblages of bull chan and other native fishes.