Antioch Dunes

During an inter-glacial period approximately 140,000 years ago, a network of sand dunes and desert environments stretched from the location of the modern-day Mojave Desert across the Central Valley to the San Joaquin River. As California’s climate changed the dunes retreated, but a stretch of desert-like habitat was left behind along the San Joaquin near Antioch, California.

The isolation of this area in Antioch allowed the species found there to evolve into unique life forms found nowhere else on Earth. Today the Antioch Dunes National Wildlife Refuge protects the remnants of these habitats, upon which three federally protected species depend: the Contra Costa Wallflower, the Antioch Dunes Evening Primrose, and the Lange’s Metalmark Butterfly.

Prior to European settlement, the Antioch Dunes were probably several hundred acres in size. Currently, because of past sand mining, agriculture, and urban development, only about 70 acres of the sand dune habitat remains, all within the Antioch Dunes National Wildlife Refuge.

Today these areas are threatened by a new mechanism: nitrogen deposition. The California Energy Commission has approved five natural gas power plants within roughly one mile of the Antioch Dunes National Wildlife Refuge. The power plants have and will have significant nitrogen emissions. Sand dunes like the Antioch Dunes are nitrogen deficient, and the changes in plant and microbial communities resulting from increased amounts of the airborne deposition of this chemical has been documented to cause cascading negative effects on ecosystem processes and the species that depend upon the structure of the existing native plant community. One of the primary adverse effects is the enhancement of environmental conditions for the invasion of non-native weeds, which outcompete native plants.

The Lange’s Metalmark Butterfly, the Antioch Dunes Evening Primrose, and the Contra Costa Wildflower are all highly endangered, and even small changes in the plant distribution at the dunes could take these species, adversely modify critical habitat, impede recovery, and even cause the species to go extinct. In particular, the Lange’s Metalmark Butterfly is so critically endangered that a single failure in the productivity of the species host plant could lead to the permanent extinction of the species.

Moreover, the power plants are concentrating large amounts of pollution in a diverse, moderate- to low-income community—in no small part because of environmental justice gains in more organized communities that prevented power plants from being built there. Antioch is the last stop for many power plant projects—and the local community’s air quality suffers because of it.

The Wild Equity Institute is working with conservation, environmental justice, and social service organizations to reduce emissions from these power plants so that people and the plants and animals that live near the Antioch Dunes National Wildlife Refuge can thrive.

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