4235 Monterey Road
Los Angeles, CA 90032



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.

Because of the Park's isolation from larger blocks of habitat further upstream along theArroyo Seco, Debs Park has already seen degradation of its natural resources. California Quail, California's state bird, was once common in the Park's native walnut woodland and brushy slopes, but has not been seen in at least ten years. In many cases, exotic species have replaced native ones: Eastern Fox Squirrel, introduced from the Eastern U.S., is abundant while Western Gray Squirrel is absent, and native Harvester Ants, one of the anchors of the California food-chain, has been replaced by the less palatable Argentine Ant.

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.

§ Establish fire-safety buffer zones that are clearly-designated (around structures) using the minimal width as allowed by the LAFD.

§ Establish clearly-designated areas of the park where native vegetation can be allowed to develop naturally (i.e. without being cleared or disked).

§ Maximize amount of native vegetation allowed to develop along fire roads, which currently serve as the major trail system for the park.

§ Minimize removal of standing or fallen dead wood to enhance habitat for wildlife.

§ When feasible, depending on availability of personnel and equipment, shift from discing to mowing and/or hand-clearing in fire-safety buffer zones.

§ Regarding the Habitat Management Plan, brush clearance may be required in some non-developed areas in order to meet LAFD requirements.

• 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.

§ Use multiple pilot sites for testing techniques. Restoration of Native Habitats

§ Employ local volunteer labor where possible.

• Enhance and encourage habitat linkages for sedentary taxa (e.g. California Quail) on park's borders.

§ Investigate nearest sources of colonization by these taxa.

§ Support ongoing conservation and revegetation efforts along Arroyo Seco to increase the overall amount of native habitat in the landscape.

• 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
The conditions of the major habitats at Debs Park are discussed below, along with suggestions for minimizing the threats currently affecting them.

Open-Canopy Walnut Woodland
Southern California Black Walnut, Toyon and Coast Live Oak is arguably the most intact natural habitat at Debs Park, owing to its apparent ability to resist invasion by exotic species. Since its dominant species, Black Walnut, is considered a ÒRareÓ species by the California Native Plant Society, this woodland is by definition a rare community.

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
Most of this habitat occurs on more level terrain than open-canopy woodland, and on south and east-facing slopes such as along Monterey Rd. Unlike the more diverse open-canopy woodland, its canopy is a virtual walnut monoculture, with understory shrubs comparatively rare. The restoration goal is to allow the community to develop a native understory wherever it occurs in the park, including patches within the "developed" portions of the park (e.g. on the slope southwest of the main picnic area).

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.

Maintaining a native grassland bird community at Debs Park is important to encourage and restore regional diversity of native birds and invertebrates. The restoration goal is to establish a native, herbaceous community large enough to support a diverse array of grassland-obligate species of birds, herps, and invertebrates.

Coastal Sage Scrub
This habitat within the park appears to have been highly disturbed, as it is missing components notoriously sensitive to fire such as White Sage, which may be found just east of Monterey Rd.

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.

The riparian habitat of the lower Arroyo Seco south of York Blvd. has been essentially eliminated, though remnants remain in the vicinity of Debs Park.

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 small reservoir at the highest point in Debs Park has potentially the highest value for interpretive use of any feature in the park, yet is among the most in need of restoration.

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.


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 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.