San Francisco Estuary and Watershed Science

CalJep is a spatially enabled database that reconciles or cross-walks the two prominent electronic plant distribution lists for California: CalFlora and Jepson. We intersected the distribution information from the two data sources to create a refined spatial distribution repository that can be used to examine patterns of plant diversity, distribution ranges of individual plant species or infrataxa, or vegetation associations. These data will allow scientists and resource managers to examine potential range maps for non-native plants, create range maps for plant species of restoration interest, and corroborate lines of evidence for determining appropriate management and conservation activities. We present here a detailed description of the methods used to create the CalJep geodatabase, data rendered from its creation, and a discussion of its applicability to a wide range of biogeographical and ecological questions, including restoration planning and adaptive management for the Bay-Delta ecosystem. CalJep records 7,887 plant species, subspecies, and varieties mapped onto 228 ecological subunits with corresponding distributional information for vascular plant species at varying levels of confidence. Information derived from this geodatabase is inherently as accurate as the digital floras used to create it; hence, its utility is best realized when implemented at the regional or statewide scale. CalJep provides a previously unavailable service to vegetation science in California and to resource managers operating within the Bay-Delta ecosystem.