Channel changes in burned streams of northern Nevada

摘要

In the Great Basin, frequency of large-fire is increasing. To better understand fire and riparian system interactions, we studied pre- to post-fire changes in ten riparian attributes of a randomly sampled reach of forty three streams burned within a three-year period. Post-fire data were collected four to six relatively dry years after late-summer wildfires in sagebrush dominated watersheds of the North Central Great Basin. All streams had been surveyed in the one to fifteen years prior to the fire. Five channel attributes improved; bankfull width decreased 21%, riparian width increased 79%, median dominant riparian vegetation increased by two categories (grass/sod to high brush), bank stability increased by one category, and median bank angle decreased. Four attributes did not change; bank cover, organic debris, bank undercuts, and embeddedness. An increase of sand by 19% in the dominant bottom material was considered unfavorable. Riparian vegetation and systems seem to be resilient and whether improvement was due to fire or changed management and time for recovery was not ascertained. Overall, degradation to stream channel attributes was minimal to non-existent suggesting riparian stability and/or resiliency.