Onward and Upward: The Battle Against Invasive Limonium Continues
By Amanda
Swanson, PhD, NBC Restoration Coordinator
The
effort to remove Algerian sea lavender (ASL; Limonium ramosissimum) and European sea
lavender (ESL; Limonium duriusculum) from the saltmarsh of Upper Newport Bay
continues on. For several years, our dedicated volunteers have worked
relentlessly removing these invasives to restore vital habitat for our
endangered salt marsh bird’s beak and Belding’s savannah sparrow. In 2016, Newport
Bay Conservancy (NBC) was granted a U.S. Fish and Wildlife Service (USFWS) grant
to help fund restoration efforts, leading to the Wednesday morning ASL events that
are held weekly. These events now host an amazing team of passionate volunteers
who attend every single week. The dedicated leaders of this project have been
Howard Cork, Don Millar, Dick Zembal and Mary Gartung.
Much
of the time during the weekly events is spent pulling ASL by hand. But in areas
where ASL is extremely
dense, the most effective treatment has been solarization using black plastic
tarping. Dense patches of ASL create thick mats that prevent native plants from
growing and cause unsuitable nesting habitat for birds (see photo). The plastic
tarping is secured on top of these ASL mats and is left for several months, generating
temperatures high enough to kill the ASL beneath. Within weeks of removing the
solarization tarping, growth of native pickleweed, saltwort, and jaumea is
visible. As much of the plastic tarping can be seen from Back Bay Drive, many
passers-by often mistake it for trash. However, this is an incredibly effective
method for removing this invasive plant and is an important tool for restoring
the critical saltmarsh habitat of Upper Newport Bay.
To
build upon ongoing removal of ASL, NBC was recently granted $50,000 from the
Warne Family Fund for 2019 to help support restoration efforts and to provide funds
for field supplies, tools, and boots. The grant has also allowed the ASL events
to expand to the first Saturday of every month.
An
important endeavor under the USFWS grant and recently awarded Warne funding is
to create maps of where ASL and ESL occur around Upper Newport Bay and to track
the progress in areas that have been treated by hand pulling and solarization
tarping. These maps will provide invaluable information regarding treatment
success and which locations need prioritization in the future. To help with
this considerable task, NBC is collaborating with UC Irvine, Chapman University,
Project Grow, Tidal Influence, and the California Department of Fish and
Wildlife to survey and develop mapping methods. In particular, Marcus
Goncalves, a UCI master’s student in the Conservation and Restoration Science
program and Project Grow Habitat Restoration Project Manager, has taken a
leadership role in helping NBC generate standardized protocols and guidelines
for mapping ASL. By working closely with NBC volunteers and local stakeholders,
development of these tools will greatly strengthen NBC’s restoration and targeted
invasive control efforts in Upper Newport Bay.
Photos
by Howard Cork.