They are among the state's most imperiled ecosystems because of urban development, conversion of rangeland to vineyards, orchards, and tree farms, and the spread of exotic plants.
(They; are; among the state's most imperiled ecosystems; because of urban development, conversion of rangeland to vineyards, orchards, and tree farms, and the spread of exotic plants)
They
are
among the state's most imperiled ecosystems because of urban development, conversion of rangeland to vineyards, orchards, and tree farms, and the spread of exotic plants