Soil Ecology and Research Group last update January 13, 2005

COSTAL SAGE SCRUB HABITAT DEVELOPMENT
PROJECT AT THE DEFENSE FUEL SUPPORT
POINT (DFSP), SAN PEDRO, CALIFORNIA IN
SUPPORT OF THE PALOS VERDES BLUE
BUTTERFLY (GLAUCOPSYCHE LYGDAMUS
PALOSVERDENSIS)

FIRST ANNUAL REPORT

Photo by WildlifeWebsite.com

INTRODUCTION

The installation of a 1-8” Chevron fuel pipeline through the Defense Fuel Support Point (DFSP), San Pedro, California, impacted 1.98 acres of federally listed Palos Verdes Blue Butterfly
(Glaucopsyche lygdamus palosverdensis) and California gnatcatcher (Polioptila californica) habitat. As required by the U.S. Fish and Wildlife Service, the U.S. Navy is restoring 10 acres of habitat, at a ratio of 5:1, as mitigation for the impact.

On January 28, 2003, the Soil Ecology and Restoration Group (SERG), contracted through the United States Navel Facilities Engineering Command, Southwestern Division Natural Resources Office, signed a Cooperative Letter of Agreement ( N68711-03-LT-A0009) to restore 10 acres as a 5:1 mitigation effort for the habitat lost at the DFSP.

This report covers the implementation, maintenance and data collection that occurred during the first year of this five-year restoration program.

BACKGROUND

The U.S. Fish and Wildlife Service (USFWS) placed the Palos Verdes Blue Butterfly (PVB) on the Federal Endangered Species List in 1980. However, the butterfly was not sighted after 1982 and it was thought to have become extinct until Dr. Rudi Mattoni rediscovered the PVB in 1994 at DFSP. "The U. S. Navy retains management responsibilities for the sensitive biological resources located at DFSP. The overall strategy for the management of listed species and their habitats is as follows:

• Minimize or eliminate impacts to existing populations of the California gnatcatcher and the Palos Verdes blue butterfly and their habitat by reducing the overall disturbance to existing populations and habitat, and avoiding sensitive seasonal periods
• Increase habitat availability for listed species at DFSP through the use of restoration procedures
• Develop a long-term management plan for each listed species that includes the monitoring of populations and habitats
• Increase the awareness of DFSP staff to the requirements of listed species at DFSP

The Palos Verdes blue butterfly depends entirely on Astragalus trichopodus lonchus and Lotus scoparius as the food plants for its caterpillars. Additional coastal sage scrub habitat must also be established to provide the habitat necessary for the blue butterfly to survive. In addition, this newly established habitat must be maintained on a continuous basis to ensure that gaps within these areas continue to exist to provide the open areas necessary for both Astragalus and Lotus species to survive. Since fire, in the form of controlled burns, is not an option at DFSP, these open areas need to be maintained through mechanical means on a regular on-going basis." (Zink, 2002)

PROJECT LOCATION

Location
The Defense Fuel Support Point (DFSP) San Pedro is located at 3171 Gaffey Street in the southern section of Los Angeles. The facility is directly west of the City of Long Beach and within the city limits of both Los Angeles and San Pedro (Figure 1). DFSP San Pedro and the adjacent Navy family housing areas are located on 460 acres of land, bounded by Western Avenue to the west, Palos Verdes Drive North to the north, Gaffey Street to the east and San Pedro to the south. Adjacent areas include residential neighborhoods, commercial businesses, schools, playgrounds, a golf course, a regional park and an oil refinery facility. Of these 460 acres, DFSP occupies 312 acres and consists of numerous underground storage tanks, pipelines and a fuel loading facility. There are, in addition, three aboveground jet fuel storage tanks for use by the United States Air Force.

Five land polygons, numbered 7, 8, 9, 12, and 13, are included in the 10-acre restoration project at the DFSP. Figure 1 shows the five polygons in relation to each other and to Gaffey Street to the east.

Reference Site
A reference transect was selected in July 2003 by SERG personnel. It is located to the immediate west of Polygon 12, directly south of the rifle range and east of Polygon 9. The reference site, with its steep slopes, widely spaced coastal sage shrub species, low occurrence of exotic weeds and ample population of PVB host plants, is considered ideal habitat for the PVB. The PVB has been sited in the reference site in the last two years and is thus considered active habitat.

SITE DESCRIPTION

Source of Damage to the Site
"The project creating a biological impact on the habitat for the PVB and the California gnatcatcher involved the subsurface Chevron 1-8" pipeline and associated government pipelines installed at the DFSP. The project involved digging a trench to expose the old pipeline, replacing the pipeline, and then covering the pipeline with soil. Chevron Corporation and the Defense Logistics Agency (DLA) accomplished all work. The pipeline connects Chevron's El Segundo Refinery to the DFSP, transporting military jet fuel from El Segundo to the DFSP." (Zink, 2002)

Figure 1. Restoration polygons at the DFSP, San Pedro

Existing Conditions
"The effects of the Chevron 1-8" pipeline and associated government pipelines project at DFSP on the federally endangered Palos Verdes blue butterfly and the federally threatened California gnatcatcher are described in the "Biological Opinion on the Formal Section 7 Consultation for the Chevron 1-8" Pipeline and Associated Government Pipelines Project, Defense Fuel Support Point, San Pedro, Los Angeles County, California (1-6-96-F-09)". The length of the pipeline is approximately 4,250 feet long. It enters the facility on the north side from Palos Verdes Drive North. The first 600 feet of disturbance occurred entirely on an asphalt road and therefore no butterfly or gnatcatcher habitat was affected. The second section impacted an area approximately 1,300 feet long by 20 feet wide containing habitat for the blue butterfly. The third section of the pipelines impacted an area 1,340 feet long and 40 feet wide containing habitat for both the butterfly and the gnatcatcher. The next section impacted an area approximately 317 feet long by 20 feet wide that contained habitat suitable for the butterfly. The final section of the pipelines is located in a gravelly area containing no habitat of concern. The total amount of habitat impacted by the Chevron 1-8" Pipelines project, according to the U. S. Fish and Wildlife Service, is 1.98 acres for the Palos Verdes blue butterfly and 1.23 acres for the California gnatcatcher."

"Compensation for the loss of 1.98 acres of butterfly habitat has been directed by the Service to occur at a ratio of 5:1 acres of coastal sage scrub restored for each acre destroyed by the project. Thus, the amount of acreage designated for restoration is 10 acres. The loss of 1.23 acres of California gnatcatcher habitat is to occur at a ratio of 2:1 acres of coastal sage scrub for every acre destroyed, thus leading to 2.46 acres of restored coastal sage scrub required. This acreage is to be included in the 10 acres of coastal sage scrub to be restored for the Palos Verdes blue butterfly." (Zink, 2002)

MATERIALS AND METHODS

During 2003, a two-acre plot (Polygon 7) was planted with coastal sage scrub plant species. Polygon 7 was chosen first because it is highly disturbed and had few native plants growing on site. The objective was to create an attractive habitat for the PVB by planting coastal sage scrub habitat with wide-open spaces and periodic host plant islands to be used for food, shelter and mating. The four remaining polygons will be planted during the remaining four years of the project.

Site Preparation
In late January 2003, the boundaries of Polygon 7 were determined by SERG personnel using a Garmin GPS unit (accurate up to 5 meters). To make the planting area easy to distinguish, the boundaries of the polygon were marked with 3-foot wooden stakes at each GPS point. After staking, the standing weeds on Polygon 7 were removed by the Palos Verdes Peninsula Land Conservancy (PVPLC) staff using weed whackers to ready the site for planting.

Plant Propagation
Plants for this project were germinated and grown by the PVPLC in shade houses at DFSP. Plants were grown in 1-gallon containers or in 3"x10" carton containers. Six hundred coastal sage scrub (CSS) plants were grown this year for Polygon 7, two hundred CSS plants were grown for Polygons 8 and 13 to be planted in 2004 and four hundred food plants were grown for Polygons 7, 8 and 13 to be planted in 2004.

The plant palette for this restoration project was chosen by doing a visual survey of the coastal sage stands surrounding the polygons and with the use of a complete plant inventory of the DFSP. The two PVB host plants chosen for the project, milkvetch (Astragalus trichopodus var. lonchus) and deerweed (Lotus scoparius), are known to be used by the PVB for food, shelter and pupation. The plant palette for this project can be referenced in Table 1.

Table 1.
Plant palette for PVB habitat development at the DFSP

Irrigation
A temporary drip-irrigation system was constructed on Polygon 7 to ensure the out-plantings receive ample water. The system was built with 3/4” and 1/2” pliable PVC irrigation tubing and attached to a water hydrant on the site. The 3/4” tubing was laid in a matrix around the perimeter and through the middle of the site to form six plots. At each junction of 3/4” tubing an on/off valve was installed so that the plots could be watered individually or in any combination. The 1/2” tubing was installed in 5-10 foot intervals along the 3/4” tubing and snaked around each individual plant. The irrigation system was anchored in place using 6" metal irrigation staples every 3- 10 feet. One emitter was installed on the 1/2” tubing at the base of each plant. Each emitter releases 8 liters per hour. A map of the irrigation system can be seen in Figure 2.

Figure 2. Irrigation system map for Polygon 7

Transect Establishment
Two transects were established in July 2003 at the DFSP. Each transect is 50 meters in length and marked on both ends with a 3-foot wooden stake and plastic flagging. The GPS coordinates of both ends of each transect were recorded using a Garmin GPS unit. One transect was placed within Polygon 7 to monitor plant species diversity, plant growth and percent ground cover. The other transect was placed behind the shooting range and adjacent to Polygon 12 where the PVB has been spotted in the past. This transect was set up as a reference and data collected from the polygons will be compared to the data collected along the reference transect.

MAINTENENCE AND MONITORING

Irrigation
To ensure that the plants received water directly at the roots, out-plantings will be irrigated for 1 year after planting. The out-plantings on Polygon 7 were watered once each week for 30 minutes to 1 hour from 1 April 2003 to 1 June 2003. Out-plantings now will receive water twice per month for 30 minutes to 1 hour, unless natural precipitation is sufficient, until 31 March 2004 when they will be weaned from regular irrigation.

Transect Data Collection
Data transects are 50 meters in length and data is collected every half meter using the point-intercept method described in the Restoration Plan for the Development of Coastal Sage Scrub Habitat at the Defense Fuel Support Point (DFSP) (Zink, 2002). Data is collected once each year on all polygons and along the reference transect for the length of the project. The data collected from data transects aids in measuring plant species diversity, plant growth and percent ground cover. Initial data was collected at the reference and Polygon 7 transects in July 2003. Table 2 provides the standards to be met during the course of the restoration project.

Soil Sampling
In order to monitor below ground conditions during restoration, soil sampling is done twice per year along the reference transect and within each manipulated polygon. One pound of soil is collected approximately six inches below the soil surface for each sample. The soil is then dried and sent to A& L Western Agricultural Laboratories to be analyzed. The first soil samples were taken in March 2003 after planting on Polygon 7 and the second set was taken in July 2003. The initial data can be seen in the Results section. Soil samples will be taken, analyzed and compared for the duration of the project.

Table 2.
Success criteria for the development of coastal sage scrub habitat at DFSP

Exotic Plant Control
Exotic species compete for limited resources such as sunlight, water and soil nutrients. Exotic weed control is necessary in restoration to give the out-planted natives the best circumstances for survival. Exotic weed control this year was done by the PVPLC staff using gas powered weed whackers. Weed removal occurred on an as needed basis from April 2003- December 2003.

RESULTS

Plant Survival
The planned density for Polygon 7 was 300 seedlings per acre with an additional 50 host plants per acre to be planted in 2004. Plant survival counts were taken twice in 2003 and at the end of the year Polygon 7 maintains 86% plant survival. The results of the plant survival by species can be seen in Table 3.

Table 3.
Planted species and plant survival for Polygon 7

Transect Data
Baseline transect data for Polygon 7 and the reference transect were taken in July 2003. The findings can be found in Tables 4 and 5. Over the next four years, data will be collected and compared to this initial data to monitor plant species diversity, native and exotic plant growth and percent ground cover.

Although there are no official requirements to meet this year, it is expected that the following criteria will be met by April 2004 in accordance with the “Restoration Plan for the Development of Coastal Sage Scrub Habitat at the Defense Fuel Support Point (DFSP), San Pedro, California in Support of the Palos Verdes Blue Butterfly (Glaucopsyche lygdamus palosverdensis)” (Zink, 2002):

• Vegetation cover: 15% or greater
• Species richness: 35% or greater
• Weed species cover: 10% or less

Table 4.
Initial Transect Data Collected from Polygon 7

Table 5.
Initial data collected from the DFSP reference transect

Initial soil data were taken in March and July of 2003. Table 6 shows the results from the soil analysis done by A&L Western Agricultural Laboratories. These data will be compared with future samples collected and analyzed over the course of the project.

Table 6.
Initial soil data for the habitat development project at the DFSP

DISCUSSION

Favorable rain conditions and successful site maintenance have resulted in many native recruits appearing on site, increasing the native plant population. The mechanical weed removal method has been successful in keeping the exotic populations to a minimum and the native plants are able to grow in the best possible conditions on the site.

The day after out-planting in March 2003, several plants were pulled below the surface by gophers causing plant mortality rate to increase. If this condition were to continue, supplemental planting would be required. However, a survival count taken on 11 July 2003 at Polygon 7 revealed the plant survival rate to be 85%. This rate was consistent with the previous quarter and therefore indicates that native plant eradication from gophers has ceased or stabilized. No supplemental planting is needed at this time.

Use of wood chips and newspaper covered by soil were compared on the site. It appears that newspaper can be more effective than wood chips since it was not washed away by the rains. Use of newspaper is also more cost effective, easier to transport and easier to apply on site. The only possible downfall to newspaper is that it has the potential to blow away in moderate to high winds. However, if the newspaper is properly anchored with handfuls of soil or staples, this problem does not arise.

DFSP Polygon 9 was previously restored for the PVB. In May 2003, during a meeting at DFSP, including representatives from USFWS, SERG, PVPLC, the Navy’s South-west Division and butterfly expert Dr. Gordon Pratt, the progress of Polygon 9 was compared to Polygon 7 in order to monitor restoration progress and to gather insight on how best to maintain Polygon 7 in the following years. Although the number of food plants on Polygon 9 was satisfactory, the density of the vegetation and plant litter on the ground was excessive for ideal PVB habitat. Based on the observations made in Polygon 9, there was concern that exotic species might out-compete the natives, creating undesirable habitat for the PVB in Polygon 7. Participants of the meeting agreed that an experiment should be created within the food plant islands on Polygon 7 to explore other options for weed control to be done concurrently with methods already used.

Research was done to determine a weed control method for the plant islands on Polygon 7. Because the PVB uses the soil beneath the food plants to pupate, it was decided that hand-pulling weeds in the food plant islands could jeopardize the reproduction cycle of the PVB. Alternately, using herbicide to eradicate weeds was discarded due to the sensitivity of the PVB and because the reaction of the PVB when exposed to herbicide is not known. Alternative methods were researched and it was determined by SERG and butterfly expert Dr. Gordon Pratt that the soil within 5 of the 10 the plant islands will be amended with sand in an attempt to reduce exotic plant growth in those areas. The hypothesis is that food plants (Astragalus trichopodus var. lonchus and Lotus scoparius) will grow better in sandy soils and the growth of weed species will be discouraged by the coarsely textured soil. The amended soil and control group islands will be monitored and compared over time.

CONCLUSIONS

Year one of the five-year restoration plan at the DFSP has shown considerable success. Plant survival is high, exotic species have been suppressed and native seedling recruitment is occurring in Polygon 7. The plant islands in Polygon 7 that were left unplanted for the placement of host plants in 2004 have remained open with bare ground and only a few coastal sage species recruits.

The hand planting method was successful during year one. This method offers a high level of control for plant placement and plant survivorship is favorable. The hand planting method will continue to be used throughout the project.

Native plants that are propagated for this project will now be grown in 3"x10" carton plant bands. SERG has achieved great plant survival success using this method. The cartons allow plants to develop a deeper root system than those grown in 1-gallon containers.

Drip irrigation is a successful way to provide water only to the native plants and discourages non-native species from growing in un-watered areas. The 8 quarts per hour emitters are proving to releases a sufficient amount of water based on plant survival in Polygon 7. This system will continue to be used for the other polygons.

It was concluded that an experiment using sand incorporation in 5 of the 10 plant islands will be completed during the 2004 planting season in Polygon 7.

MANAGEMENT RECOMMENDATIONS

Supplemental irrigation, if needed to supplement natural precipitation, of Polygon 7 should continue twice per month through March 2004. Weed removal will continue periodically on an as needed basis. The soil in 5 of the 10 food plant islands on Polygon 7 will be amended with sand to study the effect of different soil textures on food plants and weed species. Food plants will be planted for the PVB during the 2003/2004 planting season. The food plants will be irrigated for 1 year after planting.

Polygons 8 and 13 will be planted with coastal sage scrub and food plant species during the 2003/2004 planting season. The species palette will be similar to that of Polygon 7. The total number of plants to be out-planted for both polygons is estimated at 220.

A proposed timeline for year two is provided in Table 7.

Table 7.
Proposed Timeline for Year Two Restoration Activity at DFSP, San Pedro

Zink, Thomas A. 2002. Restoration Plan for the Development of Coastal Sage Scrub Habitat at the Defense Fuel Support Point (DFSP), San Pedro, California in Support of the The Palos Verdes Blue Butterfly (Glaucopsyche lygdamus palosverdensis). Soil Ecology and Restoration Group, San Diego State University, San Diego, California.