How Wildlife Recovers from a Fire Event

Wild cucumber, a native species of the Santa Monica Mountains, emerging after recent fires.

A month before the Palisades Fire, the Franklin Fire blazed through Malibu Canyon at Rindge Dam on December 9. Nine days later it was contained at 4,037 acres. Wildfires are occurring more frequently and violently and have scorched much of the Santa Monica Mountain range. The 2018 Woolsey Fire remains the largest wildfire in the history of the range burning 97,000 acres. In 2019, State Parks began collaborating in the Woolsey Fire Recovery Project, established by the National Park Service and UCLA, to study the impact of the Woolsey fire and its long-lasting effects on impacted mountain ranges. The National Park Service manages this project to establish a baseline to understand the recovery process in wildfires which now includes both the Franklin and Palisades fires.

Left: NASA’s Operational Land Imagers on Landsat 8 & 9 captured the Frankin Fire burn area, combining shortwave infrared, near infrared, and visible light components of the electromagnetic spectrum that make it easier to identify unburned vegetation (green) and recently burned landscape (dark brown). Right: Rindge Dam post fire.

“Our Mediterranean ecosystem is found in only five places around the world, and losing even a small percentage of this habitat can have a significant impact on local biodiversity,” said Miroslava Munguia Ramos, the current lead of the Woolsey Fire Recovery camera project. As a technician through the Santa Monica Mountains Fund, the official nonprofit partner of the Santa Monica Mountains National Recreation Area, she works with volunteers to study how fauna rebounds in their burned habitat.  The Santa Monica Mountains are part of the California Floristic Province, a global biodiversity hotspot, home to a high concentration of unique plants and animals that are at a high risk of being lost due to habitat loss and degradation.

Native giant wild rye regrowth after recent fire events.

The recovery project team studied images from 60 trail cameras placed in remote regions that captured the transformation of plant growth and the return of animals both big and small from Simi Valley to the Malibu coast where the Woolsey Fire had burned. Rebirth began almost immediately. Cameras captured non-native and native grasses sprouting, covering the gray ground with a beautiful green landscape. Many native trees such as Coast Live Oak and Valley Oak, that appeared to be totally burned, were sprouting new leaves and branches, showing their resilience to fire. Wildflowers returned with the rainy seasons, and sometimes rare ones such as the Fire Poppy.

Malibu Creek State Park by January 2019 following the Woolsey Fire that blazed through the park in November 2018.

Most native plants require months to reestablish themselves post fire compared to nonnative grasses and plants which can establish in just a matter of weeks. This results in a habitat that doesn’t support the natural ecosystem as well as natives do.  To counterattack an invasive takeover, the Santa Monica Mountains National Recreation Area and its partner organization the Santa Monica Mountains Fund’s restoration team took on an extreme gardening effort with 150,000 plants grown in a nursery from native seeds. Led by the park’s restoration ecologist Joseph Algiers, the team established restoration sites to plant native vegetation and help support wildfire recovery. Munguia Ramos said that the average survivorship rate of planted native vegetation is about 60% for shrubs and herbs and 55 to 85% for trees to “helps an area get back on its feet.” 

Heal the Bay also studied the impact of the Woolsey Fire on streams, particularly the increase in post fire sediment. They found that fire has a significant detrimental effect on water quality, along with the concentrated brominated flame retardants used to contain and extinguish them. The retardants are toxic and persistent, with long-term effects on water quality, aquatic life, and plant life. After a fire, and particularly after a rain, deep pools in streams will be filled with this sediment. The changes can last for many years until the sediment is pushed out, which only occurs after many large storms. Heal the Bay conducts monthly water quality monitoring at 12 sites throughout the mountains to continue to track water quality, particularly after rains when sediment flow and storm drain run off increase dramatically.  (A current impact study on the Palisades Fire burning 23,448 acres is here.

To help in the mountain’s post-fire recovery, hiking on slopes after a fire should be avoided because it accelerates dry ravel (sediment going down a slope primarily by gravity) and erosion, and is generally not safe. Hiking will also damage recovering vegetation. For recreation, find parks and trails not recently impacted by a fire.

Camera images from Woolsey Fire Recovery Project, Courtesy of the National Park Service. Top Row: Pictures at same camera location post Woolsey Fire in 8/19 and again in 4/23. Bottom Row: Pictures at same camera location post fire in 4/21 and in 4/23 after two atmospheric rivers weather conditions.