A Changed Landscape Caring for Land Trust preserves after the 2020 wildfires

The 2020 wildfires, which burned through a staggering 42% of Napa County, impacted much of the Land Trust’s preserve network and land stewardship program.

Generally speaking, the Land Trust's post-fire efforts fall under five categories:

  1. Assessing and mitigating post-fire erosion risk.
  2. Replacing damaged infrastructure; clearing and repairing roads.
  3. Tracking and addressing post-fire exotic plant invasion.
  4. Monitoring post-fire response of fire-adapted native plants.
  5. Tracking post-fire wildlife response.
Assessing and mitigating post-fire erosion risk

The Land Trust has been working with CAL FIRE, the Natural Resources Conservation Service, the Napa County Resource Conservation District and others to assess post-fire erosion risk, rehabilitate fire containment lines, and address road drainage issues to help prevent post-fire impacts to watershed health.

Top: CAL FIRE equipment operators repair a fire containment line installed on the Dunn-Wildlake Preserve during the 2020 LNU Lightning Complex fire. Above left: US Geological Survey research geologist Jeff Prancevic collects soil infiltration data on the Dunn-Wildlake Preserve as part of a project aimed at better predicting flood and debris-flow risk following wildfires. Above right: The Napa County Resource Conservation District’s Bill Birmingham and Amanda Benton assist the Land Trust with post-fire erosion risk assessment following the 2020 Glass Fire.
Replacing damaged infrastructure, clearing and repairing roads

In the immediate aftermath of the 2020 LNU Lightning Complex and Glass Fires, the Land Trust began working to clear and repair roads, and clean up and replace damaged infrastructure including outbuildings, trail signs, picnic areas, fences and gates.

Left: Burned trailhead sign on the Wragg Ridge Preserve following the 2020 LNU Lightning Complex Fire. Right: Remnants of a storage building on the Wildlake Preserve destroyed during the 2020 Glass Fire.
Tracking and addressing post-fire exotic plant invasion

Following the 2017 fires, monitoring in burned areas allowed Land Trust staff to quickly detect and control new and expanded highly invasive exotic plant species.

As seen in the above photo, the 2017 Atlas Fire stimulated a latent French broom seedbank to germinate on the Foote Botanical Preserve, greatly exacerbating an existing invasion of this highly flammable invasive.

Working with American Conservation Experience crews, the Land Trust removed thousands of individual French broom plants before they could set seed and establish a new seedbank, which is key to effectively controlling the invasion.

The Land Trust is now expanding its post-fire invasive species monitoring work to include areas affected by the 2020 LNU Lightning Complex and Glass Fires.

Monitoring post-fire response of fire-adapted native plants

Following the 2014 wildfires, the Land Trust initiated a monitoring program to track the post-fire response of fire-adapted native plant communities, with a focus on chaparral.

Through this work, we've documented a strong recovery of native plants, including fire opportunists, fire followers, fire-dependent species and rare plants not seen in decades

Following the 2020 wildfires, we are working to establish additional monitoring plots in oak woodland and coniferous forest that burned at a high severity.

Sweet scented Phacelia (Phacelia suaveolens)
Clockwise from top left: Seep Spring Monkeyflower (Erythranthe guttata), Fremont's Star Lily (Toxicoscordion fremontii) and Coast Range Tritileia (Tritileia lugens).
Tracking post-fire wildlife response

Our entire 20 sq km Wildlife Picture Index (WPI) project camera grid and large surrounding areas burned in the 2020 LNU Complex and Glass Fires, providing a unique opportunity to assess post-fire changes in terrestrial mammal populations.

The WPI project, which uses detection rates to track biodiversity levels and long-term population trends of terrestrial mammals, marks the Land Trust’s first effort to acquire quantitative information on wildlife species within its conservation lands.

Using our four years of pre-fire data, the Land Trust will be able to look at immediate post-fire changes in terrestrial mammals’ presence and abundance, and track the recovery of these species over longer time periods.