Plant communities of Santa Rosa Island, Channel Islands National Park
Clark RA, Halvorson WL, Sawdo AA, Danielsen KC. 1990. Plant communities of Santa Rosa Island, Channel Islands National Park. Technical Report No. 42. National Park Service, Department of the Interior. Davis, CA
A survey of the plant communities on Santa Rosa Island, Channel Islands National Park, was conducted from January through July 1988. Vegetation data were collected at 296 sites using a releve technique. The plant communities described include: grassland, coastal marsh, caliche scrub, coastal sage scrub, lupine scrub, baccharis scrub, coastal bluff scrub, coastal dune scrub, mixed chaparral, mixed woodland, torrey pine woodland, closed-cone pine woodland, island oak woodland, riparian woodland, and riparian herbaceous vegetation. The areal extent of each community was mapped on USGS 7.5' topographic maps, and digitized for GIS manipulation. The description of the communities presented here provides the first quantitative analysis of the vegetation of Santa Rosa Island, and provides a baseline against which future comparisons of the condition of vegetation resources can be made. Santa Rosa Island has a grazing history that spans nearly 150 years. Presently an active cattle ranch, and populations of introduced elk, deer, and pigs still occur. Grassland, coastal sage scrub, and mixed chaparral are the prominent vegetation types on the island, covering over 90% of the total area. The remainder of the plant communities each account for less than 1% of the total area. The extent of grassland and the residual nature of the scrub and woodland plant communities clearly demonstrate the effects of long-term grazing. A number of insular endemic plants occur on the island, some are apparently quite limited in disribution and were not encountered in this vegetation study. Management of the island to preserve viable populations of these endemics, and to allow for the restoration of natural plant assemblages will require the removal of alien herbivores, and a complex active restoration scheme. A long-term commitment by NPS managers of both monies and personnel are necessary to achieve these goals. The success of this endeavor will be a great accomplishment in ecosystem restoration.
- Type
- Published Report
- Authors
- Clark, Ronilee; Halvorson, William; Sawdo, Andell; Danielsen, Karen
- Date of Issue
- 1990-10
- Publisher
- National Park Service, Department of the Interior
- Units
- CHIS , HIST , SODN
- Keywords
- California, Channel Islands, Cultural Resources, Ecology, ehistory, Foraging, Grazing, Natural Resources, Plants, Santa Rosa Island, Vegetation