Ecological, hydrological, and geochemical effects of wildfire on watersheds in Santa Fe National Forest and Bandelier National Monument, New Mexico

Vieira, Nicole; Clements, William; Mitchell, Katharine; Tate-Boldt, Erik; Ferrell, Sean

This report summarizes the effects of fires in the region of the Santa Fe National Forest including Bandelier National Monument on hydrology, water chemistry, sediment loading and stream biota. This study shows that flashfloods associated with recent wildfires are having adverse and lasting impacts on stream biota in Pajarito Plateau canyons. While total densities and taxa richness of invertebrate communities demonstrate some recovery in the first three post-year fires, the long-term monitoring data in Capulin canyon suggests that community composition is permanently altered. It is currently unclear as to whether differences between pre- and post-fire communities are due to differing colonization strengths of invertebrate taxa, different tolerance to post-fire conditions of invertebrate taxa, or the lack of fish predators after the fire. Introduction of native Rio Grande cutthroat trout into Capulin will provide a unique opportunity to determine the influence that these top predators have in further shaping the fire-disturbed communities. Opposite to the findings of changes in community composition in Capulin, the study found that shredder stoneflies successfully recolonized Guaje after the fire, while most predators have not. Discrepancies between recolonization patterns in Capulin versus Guaje are likely due to differences in proximity and community composition of nearby colonization sources. The fact that the upper Guaje sites, which are closer to unburned sections of Guaje canyon, have recolonized faster than lower reaches supports this idea. Thus, protecting unburned, or even lightly unburned, upper reaches of Pajarito Plateau streams from post-fire floods may aid in faster community recovery in burned reaches. Otherwise recovery will largely rely on the limited ability of adult aquatic insects to fly between canyons, resulting in delayed recolonization of many taxa.