The Southern California wildfires in late 2007 impacted more than humans. Wildlife also suffered. Listen to USGS Biologist Robert Fisher describe what USGS scientists discovered about the wildfire impact on wildlife by listening to episode 25 of CoreCast, the USGS podcast. Related Podcasts
“Certain groups of animals seem to be disproportionately impacted by the fires, such as non-forest salamanders and shrews,” said Fisher. “We are not sure whether there is a physical change in the landscape after the fires where these animals do not have enough wet habitats to live in or whether there is a toxic effect of ash that may be directly causing mortality.”
Scientists are also concerned about the wildfire impact on the landlocked southern steelhead rainbow trout population in the Santa Ana Mountains of Orange County, Calif., because it may be the last genetically pure form of its kind in these mountains. Most other fish populations in this area have been wiped out over the past 20 years due to drought and flood conditions.
“When I was in the Santa Ana Mountains in July, there seemed to be a little more than 100 rainbow trout of all different size classes, scattered in about a quarter of a mile in the canyon, primarily in 10 to 12 pools,” said Fisher. “So it really is a restricted area, a restricted population, and any additional stresses in that type of situation are really going to have an impact on them.”
While examining a post-wildfire burn site, scientists observed extreme dry ravel events – a river of rocks – falling down hillsides and filling up the pools of water where the trout live. If the trout survived the dry ravel, the next impact could be when rain mixes with the dry ravel, and the mixture begins to move. This mixture could fill in the creek systems in the canyon and remove the rest of the water sources, Fisher said.
In the podcast, Fisher also describes how scientists captured endangered mountain-yellow legged frog tadpoles before post-fire and drought conditions depleted their population and are housing them until they grow into adults. Scientists want to release the adult frogs into the wild when conditions are suitable.
“We are hopeful that the research we are doing – figuring out the indirect and direct effects of wildfire – is going to help us better manage the landscape and build more resilient communities for humans and wildlife,” Fisher said.