The potential for severe soil erosion is a consequence of wildfire because as a fire burns it clears away vegetative cover and the natural mulch layer of leaf litter, leaving soil bare and unprotected from the elements. Shrubs, forbs, grasses, trees, and the litter layer provide a barrier against the intensity of severe rainstorms. Plant roots stabilize the soil, and stems and leaves diffuse the impact of rain drops, decelerating the flow of water and allowing it to percolate into the soil profile. After a fire has destroyed this natural layer of protection there are several steps to take to reduce the amount of soil erosion.
If your home has been affected by wildfire and you are concerned about the threat of erosion to life or property we recommend scheduling a free site visit to determine the appropriate measures to put in place, ideally before the next heavy rainfall. Depending on the conditions of the site, a combination of Hydroseed, rice straw, netting, wattles, compost or other methods may be recommended to secure your slopes.
Fire and California Wilderness
California is home to a unique variety of plant communities and species, many of which are found nowhere else in the world. Many of California’s various plant communities have adapted to coexist and even depend upon interaction with wildfire. However, drought, land development and human activity have resulted in an increased frequency of wildfires in our region. These wildfires leave soils bare and potentially vulnerable to erosion. In chaparral and wilderness areas where the soil is only moderately burned (blackened rather than white) the soil likely contains a substantial seedbank of local species and can be expected to show signs of regrowth soon after the first rains. On slopes where there is no immediate threat to a residence or structure, agencies such as the NRCS and Channel Islands Restoration recommend allowing natural processes take place and minimizing disturbance to the site as a variety of native shrubs and grasses establish themselves over the next 5 to 15 years. However, along the wilderness-urban interface in cases where development has depleted the native seed bank and erosion poses a threat to human safety and property, erosion control measures should be considered.