Green Roofs in California Coastal Ecoregions

Abstract

This chapter presents case studies of four conservation sites and 11 green roofs located in the broadly coastal ecoregions of western California. Geographically complex, California’s many ecoregions are differentiated by topography and microclimate along the coast. This chapter focuses on the chaparral/shrub/meadow/and dune ecoregions from San Francisco to San Diego. Precipitation varies greatly along the coastal region from 900 mm annually in the north to 350 mm in the south, most of which falls as winter rain. Thus, grasses, herbaceous perennials, and annual forbs compete with shrubs for dominance. Intermixed are a wide range of larger shrubs, oaks, and conifers. Less than 30% of the native habitat remains intact in these ecoregions; introduced grasses are widespread and have nearly replaced native grasses. Eleven green roof case studies demonstrate how 191 taxa native to California coastal ecoregions can be employed on green roofs in highly built-up areas.