Immediate effects of fire intensity and proximity on the Salmon River water quality

Climate change is worsening conditions required for wildfires, leading to fires becoming more frequent and more intense in the Pacific Northwest. With wildfires strengthening across the west coast, increased frequency of wildfires is disrupting the natural ecological regimes of the west coast. In particular places like Salmon-Challis National Forest, which encompasses a large portion of Idaho’s Salmon River, have experienced the beginning effects of these changes. To study the effects of more recent wildfires on the Salmon-Challis National Forest ecosystem, we asked how fires that occurred in the Salmon-Challis National Forest affected the water quality of the Salmon River watershed. We found fire behaviors such as: fire size, duration, and proximity to the river are all positively correlated to water temperature and dissolved nitrate levels. Furthermore, we found that dissolved oxygen concentration is inversely correlated with the previously described set of fire behaviors. The duration of the fire also had a direct relationship with distance from the Salmon River, where fires farther from the river experienced longer durations and, in turn, fires closer to the river were shorter in total duration. Lack of long term fire data may introduce inaccuracies to studying these relationships. This can be addressed through further research on fires in the region. Bioassay surveys can be used to address the effects of fire on proximate biotic communities. We recommend integrating direct and active fire mitigation techniques to the region to reduce the effect of fire on the region. Prescribed burns, underbrush clearing, as well as working with the indigenous peoples of the Salmon-Challis National Forest to return to tending the land in more traditional ways can reduce fire intensity. These strategies work in tandem to reduce the impact future fires will inevitably have on the Salmon River watershed. The health of the Salmon River is essential for the survival of spawning salmon populations. Reducing the negative impact of fires on river water quality will ensure these organisms are able to survive into the future.