Targeted Outreach Tackles Invasive Eucalyptus Threat

The Takeaway: The Elkhorn Slough Research Reserve’s approved plan to remove some invasive eucalyptus and replant with native species will leave a healthier, more diverse ecosystem.

The 1,700 acres of the Elkhorn Slough National Estuarine Research Reserve reveal a breathtaking expanse of native coastal prairies, meadows, and live oak woodlands. Also hiding in plain sight are invasive eucalyptus groves that pose serious danger to biodiversity and two amphibian species. A comprehensive education campaign by research reserve experts highlighted those dangers with compelling facts. Their ability to engage a wide variety of audiences helped green light a plan to remove the most damaging 13 acres of eucalyptus groves and replant with native species.

Countering misconceptions with facts
Some community members did not realize that local eucalyptus was not native, but was planted in the early 20th Century as a wind break and for timber. Others were worried about how wildlife would adapt when trees were cut down.

  • Reserve staffers highlighted the harm posed by eucalyptus, which pulls water out of the soil essential for breeding by the endangered Santa Cruz long-toed salamander and threatened California red-legged frog.
  • They emphasized that tree removal targets just four critical groves, leaving other eucalyptus trees to provide habitat for birds and butterflies. They also agreed with several reserve volunteers to leave one area uncut where raptor nests had been spotted.

Two other faulty assumptions were that eucalyptus groves do not spread and are as biologically diverse as the area’s native oak woodlands.

  • The research reserve presented studies showing that native oak woodlands had much greater biodiversity than eucalyptus groves.
  • The reserve’s GIS analysis found that eucalyptus on California’s Central Coast are highly prone to spreading, and this spread is less controllable in moist habitats such as Elkhorn Slough. The groves expanded 271 percent, on average, over a few decades, invading nearby habitat. Aerial photos featured at a public meeting clearly documented the spread.

Another misconception was that tree removal and replanting would strip these areas of their scenic value.

  • The reserve staffers and others toured an area where eucalyptus had been removed in the 1990s and native species replanted. They saw a beautiful and biologically rich habitat of oak woodland, coastal scrub, and grassland. A wildlife guzzler was recently installed, too.
  • Another tour—of the planned removal and replanting area—was provided to the public, land managers, and agency representatives, so they could see the on-the-ground dangers as well as the potential for renewal.

The plan, approved by the California Commission, involves replanting and monitoring of native species through 2025. (2019)

More Information: Project map

Partners: Elkhorn Slough Research Reserve