4235 Monterey Road
RESTORATION OF NATIVE HABITATS
The Draft Framework Plan proposes the implementation of a Habitat Management Plan that examines methods to improve the site for wildlife, nature study, and protection of open space. The plan recognizes the potential of Debs Park to become a national model of cooperation between the public and private spheres as a multi-use, urban open spacearea. Implementation of the Habitat Management Plan will involve a partnership between the City, Audubon, and volunteers. Audubon's role will be to provide oversight of restoration activities, and to assist with technical information and planning. Audubon would also act as a liaison with volunteers that contribute labor and expertise in habitat restoration. The Habitat Management Plan is not intended to give additional work to the current staff of the park, rather the intention is to change some current practices, to increase habitat values, and to seek the help of volunteers to assist with restoration activities. The rewards will be ample in what is sure to become a model of public-private cooperation in balancing conservation education and research with recreation in an urban setting.
NATIVE COMMUNITIES OF DEBS PARK
As shown previously in Figure 6, Debs Park contains an amazing array of wildlife habitats that could be further enhanced to attract wildlife back to the park. These include an open canopy woodland dominated by Southern California Black Walnut, Toyon, and Coast Live Oak, with an understory of Poison-Oak, Hollyleaf Redberry, and Chaparral Honeysuckle. Structurally, this habitat resembles chaparral in being composed mainly of large, tree-like shrubs and offering little shade. However, typical chaparral plants such as Chamise, Mountain-Mahogany and Ceanothus are absent or very scarce. Also unlike chaparral, this woodland tends to be destroyed by fire, and often persists here only in deep gullies.
On south- and east-facing slopes, walnuts strongly dominate and form a closed-canopy woodland above a largely herbaceous understory of exotic Mustard and exotic annual grasses. The distinction between these two types of woodland (open- and closed-canopy) may be the result of both historical as well as current habitat management practices (see below). At the very least, the ecotone between open- and closed-canopy woodland is dynamic throughout the park.
A small (<5 acre) area of coastal sage scrub dominated by California Sagebrush, Black Sage and buckwheats occurs adjacent to Griffin Rd. in the northwest corner of the park. Elements of this habitat are also found locally on steep road cuts and slopes throughout the park, illustrative of the specialized edaphic requirements of this vegetation.
Well-developed riparian communities are essentially absent, although their elements including Western Sycamore, Mulefat and Desert Wild Grape are scattered throughout the park.
Extensive grassland at Debs is strongly dominated by exotics, particularly Mustard. Patches of native grasses, including Purple Needlegrass and California Brome, are found throughout the park's natural communities, particularly on roadcuts.
General Habitat Management Recommendations:
•Adopt park-wide fire management practices compatible with native wildlife in accordance with the LAFD codes.
• Remove and control "Priority I" and, where feasible, "Priority II" exotic species (as listed in the Technical Appendices), and use native species, rather than exotics, in any new plantings.
• Establish a habitat restoration and ecological monitoring program.
• Enhance and encourage habitat linkages for sedentary taxa (e.g. California Quail) on park's borders.
• Similar to those initiated elsewhere in urban-wildland interface situations, develop a homeowner education program on how to reduce threats to habitat.
• Initiate a nesting-success study for birds to determine threats.
Management Recommendations by Habitat
Open-Canopy Walnut Woodland
The restoration goals include eliminating exotic taxa from gaps and edges within the habitat; increasing the amount of native woody vegetation along the edges of trails and fire roads to reduce weed invasions and enhance hiking/educational experience; and reducing the sources of excess nitrification along trail edges.
As this habitat is comparatively intact, its restoration will rely on more passive management activities such as the elimination (by hand) of exotics (e.g. Castor Bean, Horehound) from roadsides and the understory.
Active habitat restoration of open walnut woodland is probably not necessary at this time, since exotic species within the chaparral community itself are few, and probably causing no great environmental degradation within the habitat. However, this could change soon, as Castor Bean is currently proliferating along roadsides, and entering the habitat locally through numerous disturbed areas.
Closed-Canopy Walnut Woodland
The restoration of closed-canopy walnut woodland will depend on the cessation of disking and other practices that disrupt the soil in and around the woodland.
Coastal Sage Scrub
Several plants and animals protected by Federal and State Endangered Species laws are dependent on coastal sage scrub, but the amount at Debs Park may be too small to support them.
The restoration goals are to establish a large, intact parcel of coastal sage scrub derived from and composed of native plant taxa already present in Debs Park and vicinity (e.g. Mt. Washington), and to attract enough coastal sage scrub obligate taxa that this community is distinct from the adjacent walnut forest/woodland and grassland.
Restoration goals are to maintain an exotic-free example of multi-layered riparian vegetation (including willows, mulefat, etc.) within Debs Park. In addition, investigate the possibility of establishing a native riparian understory within a section of the sycamore grove of Arroyo Seco Park adjacent to Debs Park that supports a native animal community distinct from the walnut woodland within the park.
Volunteer labor should be heavily relied upon for riparian restoration. As with the other habitats, removal of exotics and maintenance of a native understory is a top priority. A study of the effects of Brown-headed Cowbird parasitism when completed, may recommend a cowbird-control program be initiated within Debs Park.
The restoration goals include developing the pond as a showcase for a constructed wetland habitat, whose focus is the passive study of riparian, wetland, and aquatic organisms, particularly wading birds. Also to design and manage the pond in such a way that regular maintenance does not conflict with the first goal. Construction of a wetland and hiring of a consulting firm is to be determined by the Department of Recreation and Parks.
Immediate cessation or reduction of spraying around the pond's border, planting a band of non-weedy native vegetation around its border, and restricting human access to a small portion of the edge are recommended.
GENERAL PLANTING GUIDELINES
Debs Park serves as an invaluable storehouse of native vegetation in a highly urbanized area, and any manipulation of the habitat should reflect this. With the range of native species now available from wholesale native plant nurseries, there is no reason to continue planting exotics within the park. Plant material of local origin (lower Arroyo Seco and adjacent Repetto Hills) should be used wherever possible, and a small nursery constructed on site will facilitate this. The list of plants suggested for restoration is included in the Technical Appendices.
EXOTIC PLANTS OF DEBS PARK
Exotic plants are perhaps, the greatest threat to maintaining the natural-areas of Debs Park. These species are most prevalent in disturbed habitats such as trail edges and disked areas. Of the native habitats, open-canopy walnut woodland has the fewest exotics, whereas grassland and closed-canopy walnut woodland tend to have the most. Coastal sage scrub seems susceptible to invasions by specific species, particularly Tree Tobacco and mustard. Exotic species may be ranked in terms of their threats to the native communities at Debs Park. These may be classified as "Priority I" and "Priority II". The most serious threats ("Priority I" taxa) include those that resist control efforts and dramatically alter the physical or biological aspects of native habitat (e.g. Tree-of-Heaven thicket replacing open grassland, or an inedible shrub replacing an edible shrub). These are species whose presence anywhere in the park (including developed areas) poses a serious threat to native habitat. Representing less of a threat ("Priority II") are species that are less widespread and/or slower to invade, but that are still reducing the quality of native vegetation by reproducing in the park. Their removal is recommended from areas of native habitat, but is less of a priority for park-wide efforts.