Habitat Restoration on MCB Camp Pendleton

Habitat Restoration on MCB Camp Pendleton

The hydrological regime of the Santa Margarita River is typical of most major rivers in southern California. It has been altered by development in the watershed, water diversions, channelization, substantial withdrawals from the aquifer, and the invasion of exotic plants. The alterations have modified and stressed both plant and animal communities, especially those linked to riparian habitat. Findings noted in the Programmatic Groundwater/Riparian Habitat Assessment at MCB Camp Pendleton, California (1995) suggest that the Percolation Ponds at Ysidora Basin and at Sewage Treatment Plant 3 (STP3) contribute substantially to ground water recharge during the dry season, but could adversely impact riparian vegetation during extended periods of drought.

This study investigated the potential for the restoration of the Ysidora Basin, STP3, and Sewage Treatment Plant 8 (STP8) Percolation Ponds into habitats compatible with those of the immediately adjacent landscape. Since all three restoration sites are in, or immediately adjacent to, riparian scrub plant communitites, restoration plans will be oriented toward riparian scrub for STP3 and the Ysidora Percolation Ponds, and coastal sage scrub (CSS) grassland for STP8. The goal of the restoration plans is to create self-sustaining and functioning riparian or CSS ecosystems which are capable of long-term regeneration following natural disturbances and which will support a complete assemblage of avian species including least BellÕs vireo.

Restoration of riparian scrub habitat in southern California is a relatively new endeavor. Consequently, restoration of that habitat type is as much an art as a science. Overall success rates for wetland/riparian habitat restoration in arid environments is relatively low, and primary obstacles to be overcome include (Baird, 1989):

Selecting or creating planting sites that are similar to those supporting existing riparian vegetation. In Southern California these areas have an average water table depth between three and four feet from ground surface, a sandy or gravelly soil type, and are periodically flooded.
Establishing cuttings, tubings, potted planted material or natural seed.
Maintaining or introducing soil flora, particularly mycorrhizal fungi.
Controlling weed competition.

Literature on riparian scrub and CSS function, structure, and restoration specific to southern California was reviewed. The life histories and horticultural requirements of dominant riparian species common to MCB Camp Pendleton were researched, and base biologists Boyers and Griffiths (1995) were consulted on the success of previous on-base riparian habitat restoration efforts. Alternative conceptual plans for each site were prepared and reviewed on site with Camp Pendleton biologists, and final proposed plans incorporated all recommended revisions.