How does post-fire flooding affect insects, fish, and wildlife?

Post-fire flood events affect nearly all aquatic and riparian insect, fish, and wildlife communities within burned watersheds. Post-fire flooding events and associated ash and nutrient pulses affect water quality and reduce dissolved O₂ available to aquatic organisms. These impacts can lead to fish mortality and declines in macroinvertebrates populations, an important source of food for fish species. Inputs of sediment and large flows can reshape stream channels and result in wider and shallower aquatic habitats that are not suitable for many fish and amphibian species. Fine sediments mobilized from burned watersheds also alter spawning substrates of fish species and rearing habitats of aquatic insects. Additionally, large flood events can scour channels and remove entire biotic communities from the substrate. Geomorphic changes, along with a loss of riparian plants that provide shade, can increase stream temperatures and affect the availability of food and thermal refugia, and development rates of fish and amphibian species.  Negative impacts to aquatic communities have cascading effects on surrounding terrestrial communities and in particular, riparian consumers such as birds, bats, and rodents.