Habitat Restoration at Martin Dunes

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The Land Trust has been working to remove iceplant from Martin Dunes, Central California’s largest coastal dune system. Iceplant (Carpobrotus edulis) is an exotic invasive non-native plant that crowds out native plants and eliminates habitat for many native species. Iceplant binds sand and stabilizes dunes, inhibiting sand movement and preventing the natural successional process of native plant regeneration that native wildlife depends on to survive. By building up the salt concentration in the soil, iceplant also creates unsuitable habitat for creatures such as the California legless lizard, a California species of special concern.

Several species are affected by the invasion of iceplant, including the Western snowy plover, Smith’s blue butterfly, and rare, local plants like the Monterey spineflower and the Monterey sand gilia. Iceplant inhibits the formation of open sandy patches where plovers dig their nests. Its growth pattern forms monoculture mats. If left unchecked, these mats will blanket the sand, eliminating habitat for native plants such as the varieties of wild buckwheat that the Smith’s blue butterfly, one of the first insects to receive protection through the federal Endangered Species Act, depends on for its survival.

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Though less abundant than iceplant, European beachgrass (Ammophila arenaria) is another threat to the native wildlife of Martin Dunes. With generous support from the U.S. Fish and Wildlife Service’s Private Stewardship Grant Program, the Land Trust began in 2008 to strategically remove iceplant and European beachgrass on 50 of Martin Dunes’s 125 acres, in order to allow native plants to regenerate, enhancing habitat protection for the Dunes’ native populations of plants and animals. Although this work is ongoing—iceplant is a notably stubborn species, like a persistent visitor that refuses to leave—there have been encouraging signs.

“We are seeing rare plants recruit into some of the areas where we removed the iceplant,” says Cammy Chabre, BSLT’s Conservation Project Manager. Chabre says that more iceplant will be removed this fall. “The best approach is a phased approach, where we treat sections of the iceplant and then follow up at these areas to remove iceplant re-sprouts and any secondary non-native invasive plants such as annual bromes.”

The removal process includes cautious, strategically targeted treatments with low-concentration pesticide, as well as hand removal by crews of volunteers, including BSLT staff and volunteers, and crews of workers from the California Conservation Corps. In June, 2009, BSLT hosted a large volunteer team of over 55 Oracle Development Tools User Group members to pull iceplant from a sensitive microhabitat area. The enthusiastic Oracle team pulled over an acre of iceplant, totalling more than 15 four-foot high piles.

Already, native coastal dune species such as yellow sand verbena and mock heather are growing within the dead iceplant mulch piles. Chabre says that continual monitoring and follow-up work will be required at all treatment sites until invasive non-native iceplant and European beachgrass populations are removed, giving our region’s native birds, lizards, plants and butterflies a chance to thrive.

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