Dudek, Slender Mariposa Lily Mitigation and Monitoring Plan, Vista

Dudek, Slender Mariposa Lily Mitigation and Monitoring Plan,
Vista Canyon, Los Angeles County, California (June 2009)
Slender Mariposa Lily Mitigation & Monitoring Plan
Vista Canyon
Los Angeles County, California
JUNE 2009
P R E PA R E D F O R :
Impact Sciences
803 Camarillo Springs Road Suite A-1
Camarillo, California 93012
Contact: Susan Tebo
805-437-1900
P R E PA R E D BY:
Dudek
605 Third Street
Encinitas, California 92024
Contact: Doug Gettinger and Andy Thomson
760-479-4285
SLENDER MARIPOSA LILY MITIGATION AND
MONITORING PLAN
for the
VISTA CANYON PROJECT
Prepared for:
Impact Sciences, Inc.
803 Camarillo Springs Road, Suite A-1
Camarillo, California 93012
Prepared by:
605 Third Street
Encinitas, California 92024
Contact: Andy Thomson or Doug Gettinger
760.942.5147
JUNE 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
TABLE OF CONTENTS
Section
Page No.
1.0
INTRODUCTION AND PROJECT DESCRIPTION ...................................................1
2.0
DESCRIPTION OF THE MITIGATION PLAN ...........................................................1
2.1
Mitigation Plan Goals ............................................................................................. 1
2.2
Preliminary Schedule for Implementation .............................................................. 1
2.3
Time Frame for Success.......................................................................................... 2
2.4
Rationale for Expecting Success............................................................................. 2
2.5
Backup Contingency Measures............................................................................. 12
3.0
SALVAGE AREA AND RECEPTOR SITE DESCRIPTIONS..................................13
3.1
Slender Mariposa Lily Salvage Areas................................................................... 13
3.2
Slender Mariposa Lily Receptor Sites .................................................................. 13
4.0
IMPLEMENTATION PLAN .........................................................................................14
4.1
Site Preparation..................................................................................................... 14
4.2
Salvaging and Planting Slender Mariposa Lily .................................................... 14
4.3
As-Built Conditions .............................................................................................. 16
5.0
MAINTENANCE PLAN DURING 5-YEAR MONITORING PERIOD ...................16
6.0
MONITORING PLAN DURING 5-YEAR PERIOD...................................................19
6.1
Receptor Site Monitoring Methods and Schedule ................................................ 19
6.2
Annual Reports ..................................................................................................... 21
7.0
COMPLETION OF MITIGATION AND PERFORMANCE CRITERIA..................22
8.0
LITERATURE CITED ...................................................................................................23
APPENDIX
A
Soil Test Results
i
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
TABLE OF CONTENTS (CONT.)
Page No.
LIST OF FIGURES
1
2
3
4
Regional Map...................................................................................................................... 3
Vicinity Map ....................................................................................................................... 5
Development Plan and Project Impacts .............................................................................. 7
Salvage and Receptor Site Location ................................................................................... 9
LIST OF TABLES
1
2
3
Implementation Schedule.................................................................................................... 2
Receptor Site Monitoring Schedule .................................................................................. 19
Performance Criteria – Slender Mariposa Lily Mitigation Plan....................................... 22
ii
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
1.0
INTRODUCTION AND PROJECT DESCRIPTION
This Slender Mariposa Lily Mitigation and Monitoring Plan (Mitigation Plan) outlines
implementation guidelines for the salvage, relocation, maintenance, and monitoring of slender
mariposa lily (Calochortus clavatus var. gracilis) from areas that will be impacted by
implementation of the proposed Vista Canyon Project. The Vista Canyon project area
encompasses approximately 185 acres, located south and east of State Route 14 (SR-14), north of
Lost Canyon Road and west of Sand Canyon Road in unincorporated Los Angeles County,
California, directly adjacent to the City of Santa Clarita (City) (Figures 1–2) (Thomas Guide map
page 4552, map grid B-3). The project area is proposed for annexation to the City, and the City
will serve as the lead agency for the proposed project. SR-14 forms the northern boundary of the
project area and provides the bulk of regional access to the area via the Interstate 5 (I-5)/SR-14
interchange. The project area is surrounded by existing development (Figure 2). The Santa Clara
River bisects the project area from east to west.
The project applicant, Vista Canyon Ranch, LLC (Vista), is proposing to develop the project area
with a mixed-use development consisting of up to 1,350 residential units and up to 950,000
square feet of commercial floor area.
Implementation of the proposed project will impact a small knoll containing slender mariposa
lily. Proposed mitigation for direct impacts to slender mariposa lily will include a combination of
bulb and seed salvage. The Mitigation Plan proposes salvage and translocation of bulbs and seed
from within the disturbance area (Figure 3) to an appropriate receptor site within the Vista
Canyon property where they can be preserved in perpetuity (Figure 4). A compensation ratio of
1:1 is recommended by the California Department of Fish and Game (CDFG).
2.0
DESCRIPTION OF THE MITIGATION PLAN
2.1
Mitigation Plan Goals
The Mitigation Plan outlined herein is focused on mitigating for impacts to the on-site population
of slender mariposa lily that occurs within the development footprint of the proposed project.
The goal of the Mitigation Plan is to successfully reestablish slender mariposa lily plants at an
appropriate/compatible on-site receptor site, where the plants can successfully exist and can be
afforded protection in perpetuity.
2.2
Preliminary Schedule for Implementation
The Mitigation Plan includes a combination of seed collection and bulb salvage. Timing of the
seed collection and bulb salvaging will be determined based upon seasonal weather constraints
1
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
and timing of scheduled project grading. Seed collection will be timed to occur when seeds are
mature, but before seed has dehisced from seed capsules (usually in May–June). Harvesting of
slender mariposa lily bulbs should occur when the plants are dormant (summer and fall), ideally
just before the onset of the rainy season (late fall or early winter). Planting work (both seeds and
bulbs) for the Mitigation Plan is anticipated to occur in the fall or early winter (October–
December). Table 1 shows the anticipated sequence for implementation:
Table 1
Implementation Schedule
Mitigation Activity
Flagging existing lily plants in development areas
Seed collection
Bulb excavation
Receptor site preparation and installation of bulbs and seed
5-year maintenance and monitoring period
2.3
Approximate Activity Sequence
Spring – during blooming period
Early summer – when seeds are mature
Fall – prior to onset of rainy season
Fall or early winter
Years 1–5
Time Frame for Success
The time frame to document project success is during the 5-year maintenance and monitoring
period. Project success is defined as the ability of the planted slender mariposa lily to persist
during the monitoring period. The target number of slender mariposa lily survival is at least the
quantity that was estimated as being impacted by the proposed project. Measurement of project
success will be determined in years 3, 4, or 5 after the seeds and bulbs have had an opportunity
to become established.
2.4
Rationale for Expecting Success
As previously described, the proposed slender mariposa lily receptor site will be located on site
in an area that contains similar vegetation types and topographic features to the salvage area. The
proposed receptor site is approximately 0.25 mile from the salvage area.
2
6115-06
June 2009
KERN COUNTY
LOS ANGELES COUNTY
Lancaster
TY
OUN
SC
EL E
NT Y
ANG A COU
LO S
TU R
VE N
Palmdale
Santa Clarita
Project Site
Valencia
LO S A
N GEL
ES CO
SA N B
U N TY
E RN A
R DIN O
COUN
TY
San Fernando
Reseda
Burbank
Pasadena
Azusa
Hollywood
Pomona
El Monte
Los Angeles
Malibu
Walnut
Santa
Monica
Bell
Whittier
PA
CI
FI
C
O
V
RI
E
A
Z:\Projects\j611506\MAPDOC\WORKING\Fig1_Regional.mxd
N
Rancho
Palos Verdes
0
TY
UN
CO NT Y
E
U
SID CO
ER GE
AN
OR
C
Lakewood
Long
Beach
Miles
11
Vista Canyon Slender Mariposa Lily Mitigation and Monitoring Plan
Regional Map
FIGURE
1
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
INTENTIONALLY LEFT BLANK
4
6115-06
June 2009
Z:\Projects\j611506\MAPDOC\WORKING\Fig2_Vicinity.mxd
Project Site
0
2,000
Feet
4,000
Source: USGS Topo 7.5 Minute Series - Mint Canyon Quadrangle
Vista Canyon Slender Mariposa Lily Mitigation and Monitoring Plan
Vicinity Map
FIGURE
2
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
INTENTIONALLY LEFT BLANK
6
6115-06
June 2009
Z:\Projects\j611506\MAPDOC\WORKING\Fig3_DevPlan_ProjectImpacts.mxd
Slender Mariposa Lily Impact Site
Project Area
0
Feet
500
Proposed Site Plan
IMAGE SOURCE: Digital Globe, 2007
Vista Canyon Slender Mariposa Lily Mitigation and Monitoring Plan
Development Plan and Project Impacts
FIGURE
3
Slender Mariposa Lily Receptor Site
Slender Mariposa Lily Salvage Site
Project Area
Vegetation Communities:
Active floodplain (braided channels with mixed riparian and alluvial scrub)
Alkali rye series
Z:\Projects\j611506\MAPDOC\WORKING\Fig3_Salvage_Receptor_Site.mxd
Alkali rye series (elderberry)
Big sagebrush - buckwheat series
California sagebrush - buckwheat series
Chamise series
Coast live oak series
Cottonwood series
Disturbed
Elderberry series
Mixed native and non-native
Mulefat series
Non-native herbaceous series
Sagebrush series
0
Feet
500
IMAGE SOURCE: Digital Globe, 2007
VEGETATION SOURCE: Impact Sciences, 2009
Saltbush series
Saltgrass series
Yerba santa series
Vista Canyon Slender Mariposa Lily Mitigation and Monitoring Plan
Salvage and Receptor Site Location
FIGURE
4
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
The receptor site is located in chamise (Adenostoma fasciculatum)-dominated habitat, which
currently supports splendid mariposa lily (Calochortus splendens) (Forde and Read 2008). Codominant plant species at this location include California sagebrush (Artemisia californica),
California buckwheat (Eriogonum fasciculatum), and buck brush (Ceanothus cuneatus). The
salvage area also supports California sagebrush and California buckwheat as dominant plant
species, and was mapped as California sagebrush-buckwheat series (Forde and Read 2008).
Soils at the salvage area are Saugus loam, 15%–30% slopes (ScE) (Woodruff et al. 1970). Soils
at the receptor site are Ojai loam, 2%–9% slopes (OgC) and Terrace escarpments (TsF)
(Woodruff et al. 1970). The soil types at the salvage area and the receptor site are similar in that
they are well-drained and formed from weakly consolidated sediment. Based on site-specific
composite soil samples collected from the salvage area and the receptor site, soils at both
locations are also similar in terms of soil texture (both were classified as sandy loam) and most
constituent major and micronutrients (Appendix A). One noted difference in the soil texture is
that the soil at the receptor site was described as hydrophopic, whereas the soil at the salvage
area was not. While there are some minor differences between the soil type, texture, and
chemistry between the salvage site and the receptor site, this Mitigation Plan proposes soil
salvage from the areas currently supporting slender mariposa lily and placement at the receptor
site, which minimizes the significance of the apparent discrepancies.
Elevations at the salvage area range from between approximately 1,485 feet above mean sea
level (AMSL) to 1,560 feet AMSL. Similarly, elevation at the receptor site ranges from between
approximately 1,520 feet AMSL to 1,550 feet AMSL. Slope exposures are similar, with a northto northeast-facing aspect at the salvage areas and a north- to northwest-facing aspect at the
receptor site.
The close proximity of the proposed receptor site to the salvage site along with similar soils,
elevation, and slope exposure will help ensure that the introduced individuals experience similar
environmental conditions in which the natural population presently exists. The physical and
chemical similarities of the sites increase the probability for success.
In addition to careful site selection as described above, Dudek’s previous work with salvaging,
transplanting, and establishing Calochortus (both Calochortus clavatus var. gracilis and
Calochortus plummerae) at another project in Santa Clarita (Newhall Land's RiverVillage
Project), indicates that successful results can be achieved at the Vista Canyon site by following
procedures developed for that project. In the autumn of 2005, seed and bulbs were salvaged from
the RiverVillage development footprint and planted at a preserve area into selected sites in
similar habitat in late 2005 and early 2006. Despite 2 successive years of drought following
transplantation, results of the first 3 years showed a success rate of 69% in spring 2006, 34% in
11
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
spring 2007, and 93% in spring 2008 (Dudek 2007a, 2007b; Thomson 2008). By comparison,
almost no naturally occurring Calochortus in the nearby reference population were observed in
spring 2006, none were observed in spring 2007, and approximately 75% of known individuals
were observed flowering in spring 2008. The quantity of transplanted individuals observed each
year has generally corresponded with rainfall amounts, with lower numbers observed in low
rainfall years, and higher numbers observed in higher rainfall years. In addition to the success
rate for transplanted bulbs, successful seeding efforts were documented. Each year for the first 3
years of the program, persisting juveniles from the seeding efforts were documented. Some of
this success is attributable to adaptive management measures, wherein during extreme drought
conditions in the first and second years, some supplemental hand-watering of the plots occurred.
Measures found successful at the RiverVillage project will be implemented at the Vista Canyon
project.
2.5
Backup Contingency Measures
The Mitigation Plan utilizes an adaptive management approach, wherein corrective measures
will be implemented during the 5-year monitoring period if problems affecting the survival
and/or successful establishment of slender mariposa lily are detected. For example, if during the
5-year monitoring period, rainfall is significantly below average during the growing season for
slender mariposa lily (as determined by the Project Biologist), supplemental water may be
supplied to the receptor sites in order to help sustain the population and mimic average rainfall
conditions.
As an additional backup contingency measure, a portion of the slender mariposa lily seed
collected from source populations (impact areas) will be reserved and used to supplement plants
at the receptor sites if necessary. Viability of slender mariposa seed is for a relatively short
period when stored at room temperature. The viability of stored seed can be significantly
lengthened by storage at freezing temperatures. Therefore, the back-up seed will be stored in
appropriate conditions at freezing temperatures until it is either utilized for planting as a back-up
contingency measure, or if the project appears successful, added to the receptor site to increase
the quantity of plants.
Additional backup contingency measures may be implemented as unforeseen issues arise that
could potentially affect the success of the Mitigation Plan.
12
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
3.0
SALVAGE AREA AND RECEPTOR SITE DESCRIPTIONS
3.1
Slender Mariposa Lily Salvage Areas
During surveys for special-status plants conducted in March, April, and May 2008, slender
mariposa lily individuals were found on site and mapped (Forde and Read 2008), with
approximately 150 individual slender mariposa lily plants identified. Site visits by Dudek during
February 2009 confirmed the slender mariposa lily population and observed approximately 200
slender mariposa lily individuals on site. The number of individuals of this species detected
varies every year due to natural population phenology (i.e., natural population increase and
decrease cycles and their reliance on rainfall to bloom).
The location where slender mariposa lily occurs is on the slopes of a small hill on the southerncentral portion of the project site within the impact footprint of the proposed development
(Figure 3). The area where slender mariposa lily is known to occur within the impact footprint is
considered the salvage area.
3.2
Slender Mariposa Lily Receptor Sites
Two potential receptor sites located within the project site were evaluated for suitable conditions.
Based on the selection criteria described in Section 2.4, one of the sites is more favorable than
the other. This site has been designated the receptor site. The alternate site, which is located
approximately 600 feet east of the salvage area in the southeastern portion of the project site just
north of the railroad tracks, was not selected based on the density of existing brushy habitat, the
dominance of Great Basin sagebrush (Artemisia tridentata), and lack of adequate area for
planting.
The selected receptor site is located north of the Santa Clara River, and just south of SR-14
(Figure 4). As described earlier, the receptor site is located in mapped chamise series habitat,
with chamise, California buckwheat, California sagebrush, and buck brush as the dominant shrub
species. The shrub canopy is relatively open, with gaps between shrubs that are large enough to
prepare planting plots. The herbaceous layer is relatively diverse and includes common tarplant
(Deinandra fasciculata), lomatium (Lomatium utriculatum), and splendid mariposa lily (Forde
and Read 2008).
Specific planting locations for transplanted Calochortus bulbs will be determined in the field by
the Project Biologist. The receptor site will be marked with stakes and the location recorded by a
global positioning system (GPS) in the field to facilitate relocation during the monitoring period.
The receptor sites will be protected and situated in designated open space.
13
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
4.0
IMPLEMENTATION PLAN
The implementation of the Mitigation Plan shall be accomplished by an experienced, qualified,
native landscape contractor (Contractor) and monitored by the Project Biologist. All stages of the
Implementation Plan, from site preparation to installation completion and seeding, shall be
overseen by the Project Biologist, who shall ensure that the Mitigation Plan is appropriately
executed.
4.1
Site Preparation
Site preparation for the Mitigation Plan will begin in the spring of the planting year. Site
preparation activities are detailed below.
•
Individual slender mariposa lily plants will be marked in the field during the blooming
period in the spring prior to the year of planting, which is estimated to be during April
and/or May (but may be done earlier or later depending on floral development). At the
salvage areas, individual slender mariposa lily locations will be marked with a pin flag.
•
If site grading is ongoing at the time, the salvage area will be marked in the field and
fenced with temporary construction fencing until the slender mariposa lily plants can be
removed from the site.
•
Planting plots will be designated at the receptor sites. The Project Biologist will
determine appropriate planting locations within the receptor sites based on biological
conditions important to the survival of the planted individuals (e.g., soils, slope, and
aspect). The plots will be established within small openings in the shrub canopy at the
receptor site.
•
Any non-native plant species that are potentially invasive and/or pose a threat to the
establishment, development, or persistence of slender mariposa lily will be controlled
prior to planting.
•
All equipment maintenance, staging, dispensing of fuel or oil, or any other such activities
will occur in designated upland areas.
4.2
Salvaging and Planting Slender Mariposa Lily
The following general methods are proposed for the salvaging and transplantation of slender
mariposa lily:
•
Prior to salvaging the slender mariposa lily bulbs at the salvage areas, seeds will be
collected from flagged individuals once the seed has matured, but prior to the seed
14
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
capsules opening to disperse the seed. Seed will be stored in breathable paper bags in a
cool, dry, and dark place until planted at the receptor site. After seeds are completely
dried out, the seed will be stored in the freezer to extend the length of seed viability. A
portion (approximately 10%) will be retained as a back-up contingency measure.
•
Slender mariposa lily bulbs will be salvaged from known locations within the project
limits of grading. A small digging spade or shovel will be used to salvage bulbs,
depending on access constraints and the number of individuals at each particular location.
•
An attempt will be made during bulb salvage to collect the bulbs with their surrounding
soil and associated biomass intact. Due to the soil type found on site, the soil may not
stay consolidated as a solid mass. If soil masses will not stay consolidated, the bulbs will
be collected separate from the soil and stored in appropriate storage conditions (cool,
dark, and dry location) until planted at the receptor site.
•
The soil from areas where slender mariposa lily bulbs were abundant will be salvaged.
The top 8–12 inches of soil will be removed and then used at the planting locations
within the receptor sites.
•
If slender mariposa lily bulbs, or any other native bulbs, are detected during the
excavation of receptor sites or in disturbed soils within the salvage areas, they will be
planted at the receptor sites at the appropriate soil depth during the transplantation
process.
•
Salvaged bulbs will be planted at the receptor site in plots. The plots may be various
sizes, but a typical planting plot will measure approximately 2 feet by 2 feet with nine
salvaged bulbs planted in each plot. Planted bulbs will typically be arranged in a grid
pattern to facilitate biological monitoring; however, alternative configurations may be
used, as appropriate. Detailed notes about planting locations will be kept by the Project
Biologist to enable follow-up monitoring. The plots will be distributed in natural
openings in the habitat at the receptor site.
•
Bulbs will be planted at a depth of approximately 2–6 inches (depending on the size of
the bulb). Smaller bulbs will be planted shallower and larger bulbs will be planted deeper.
Bulbs will be oriented correctly (roots down, stem up) in the soil during planting.
•
In addition to bulb salvage and transplantation, a portion of the collected slender
mariposa seed will be planted in plots within the receptor sites. The plots will be similar
in size as those described for the bulbs. Seeded areas will be prepared by removing all
weedy debris, scarifying the soil to approximately 1 inch in depth and sowing the seed at
0.25–0.50 inch in depth. The soil scarification will be done by shovel, and/or rake, and
the seeding will be done by hand.
15
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
•
Herbivore-exclusion fencing will be installed surrounding planting plots or groups of
planting plots to prevent plant herbivory. Herbivore-exclusion fencing will be constructed
of poultry netting (or similar) and will be installed at least 18 inches below ground
surface and will extend to approximately 30 inches above ground level. Herbivoreexclusion fencing may also be installed to cover the top of each plot.
•
Markers will be installed and maintained at each plot at the slender mariposa lily receptor
site locations to identify the planted slender mariposa lily locations during the 5-year
long-term maintenance and monitoring period. The markers may consist of 2-inch by 2inch by 24-inch wooden survey hub stakes, or equivalent, driven into the ground next to
each plot. The plot locations will also be recorded with a GPS after planting to facilitate
relocating the plots for monitoring and reporting in subsequent years.
•
Receptor sites will be watered-in to prevent the formation of cracks and air pockets in the
soil. Approximately 1 week after the initial planting period, additional native soil will be
spread to fill in gaps or depressions if they form after the soil has settled, and the area
will be watered in a second time.
•
If seasonal rains are inadequate to keep the soils moist through the first growing season,
supplemental irrigation may be supplied to the receptor sites as determined by the Project
Biologist. Supplemental irrigation will be conducted on an as-needed basis approximately
every 2 to 4 weeks during the initial growing season, depending on rainfall, temperatures,
and day length.
4.3
As-Built Conditions
The GPS locations of each plot within the receptor area will be overlaid on an aerial image of the
site to document the final plot layouts. The City and CDFG will receive copies of this plot map
as part of the initial completion report. The plot map will also serve as a record that will be used
for reporting and management purposes during long-term biological monitoring.
5.0
MAINTENANCE PLAN DURING 5-YEAR MONITORING PERIOD
The primary effort of the maintenance plan will be concentrated in the first season of growth to
help offset the negative effects of site disturbance and non-native weed competition at the
slender mariposa lily receptor sites. Subsequent seasons should require less intensive
maintenance as the vegetation reaches a state of equilibrium, but persistent weed control of
invasive exotic weeds will likely be required. Maintenance issues are described in more detail
below.
16
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
Pest Control
Weeds are expected to be the primary pest problem in the slender mariposa lily receptor sites.
Weed control should be conducted on a regular basis during the long-term maintenance and
monitoring period. Maintenance should be conducted monthly during the growing season
(November–May) of the first year and four times annually thereafter until the end of the 5-year
maintenance and monitoring period. Weed growth and prevalence will be assessed by the
biological monitor and remedial weeding will be directed and completed as necessary based on
seasonal conditions.
Target non-native species selected for control in this plan include those non-native plant species
that are potentially invasive and/or pose a threat to the establishment, development, or
persistence of slender mariposa lily. The primary target species will be those identified and listed
by the California Invasive Plant Council in the California Invasive Plant Inventory, which is
available online (Cal-IPC 2006).
A combination of physical removal and herbicide treatment will likely be required to control
invasive species. The method of weed control will be based on the most effective method for the
species being targeted and the stage of plant development. Properly timed, repeat herbicide
applications are usually required for complete control of most invasive perennial species. Refer
to the herbicide label for information on proper timing and application rates. All applicable laws,
regulations, safety precautions, and label directions must be followed when performing pest
control. The Contractor performing the work should consult a licensed Pest Control Adviser if
specific pest control recommendations are required. All weed debris should be removed from the
mitigation area and disposed of in a legal manner.
Invertebrate pests and diseases are not expected to be a problem in the slender mariposa lily
receptor sites. Vertebrate pests such as gophers, ground squirrels, rabbits, rats, voles, etc. are
being addressed by installation of exclusion fencing around each receptor site at the time of
project implementation. The Project Biologist and the Contractor shall monitor the exclusion
fencing for effectiveness and take appropriate remedial measures should it become necessary.
All applicable laws, regulations, safety precautions, and label directions shall be followed when
performing pest control.
Fencing
Herbivore-exclusion fencing will remain in place, and repaired as necessary, to effectively
protect the slender mariposa lily from browsing as well as act as a deterrent to inadvertent
trampling.
17
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
Seeding
Supplemental seeding may be recommended by the Project Biologist to prevent potential erosion
and to encourage native species establishment. If seeding is recommended, an appropriate native
seed mix will be specified by the Project Biologist, and may include the following proposed
plant species:
•
California buckwheat (Eriogonum fasciculatum)
•
California everlasting (Gnaphalium californica)
•
California poppy (Eschscholzia californica)
•
California sagebrush (Artemisia californica)
•
Common goldfields (Lasthenia californica)
•
Deerweed (Lotus scoparius)
•
Foothill needlegrass (Nassella lepida)
•
Miniature lupine (Lupinus bicolor)
•
Purple needlegrass (Nassella pulchra)
•
Rancher’s fireweed (Amsinckia menziesii var. menziesii)
•
Sacapellote (Acourtia microcephala)
•
Tarplant (Deinandra fasciculata)
•
Tidy-tips (Layia platyglossa).
Trash and Debris
Trash and debris will be removed from the site on a regular basis during maintenance visits.
Erosion Control
The site will be monitored for erosion problems, and measures will be taken, as necessary, to
help prevent erosion within plot locations and seeded areas.
Access Control
The receptor sites will be checked regularly during scheduled maintenance visits for evidence of
human disturbance, including off-road vehicle use, illegal dumping, vandalism, pedestrian
access, and unauthorized brush clearing.
18
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
Supplemental Irrigation
The soils at the receptor sites will be monitored for moisture during the growing season. If soil
moisture levels appear inadequate to support slender mariposa lily during the growing period,
particularly during the first 2 years of the 5-year maintenance and monitoring period,
supplemental irrigation may be supplied to the planted slender mariposa lily plants if
recommended by the Project Biologist.
6.0
MONITORING PLAN DURING 5-YEAR PERIOD
Biological monitoring of the planted slender mariposa lily plants during the 5-year maintenance
and monitoring period will measure the establishment of the slender mariposa lily and evidence
of species health and proliferation. Field-collected data will provide a quantitative measure of the
survival and establishment of the slender mariposa lily and flowering/seed production each year.
Monitoring will likely rely on observations of flowering individuals, which are easier to locate
and identify than non-flowering individuals. However, because the flowering of this species is so
variable from year-to-year, monitoring will also include observations of vegetative growth
(leafing out). Monitoring will occur in the winter and spring of each year during the growing
season and while the slender mariposa lily is in bloom. Additional monitoring at the site may
occur periodically throughout the year to determine the need for maintenance to protect the
planted slender mariposa lily plants from weed invasion or other disturbances.
6.1
Receptor Site Monitoring Methods and Schedule
Biological monitoring will be conducted by the Project Biologist to determine the status of the
slender mariposa lily plants (through periodic monitoring and collection of quantitative data) and
the need for any remedial measures. This work will include a quantitative biological assessment
each year, to be timed during the growing season and with the flowering of slender mariposa lily
and qualitative assessments to assess overall site conditions and maintenance activities (Table 2).
Table 2
Receptor Site Monitoring Schedule
Phase
Salvaging and
Transplantation
Task Description
Flag existing slender
mariposa lily plants
Collect slender mariposa
lily seed
Status/Completed
Year 0
Year 1
Year 2
Year 3
Year 4
Year 5
Quarter
Quarter
Quarter
Quarter
Quarter
Quarter
1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
X
X X
19
6115-06
June 2009
Slender Mariposa Lily Mitigation and Monitoring Plan for the Vista
Canyon Project Area
Table 2 (Continued)
Phase
Task Description
Salvage slender
mariposa lily bulbs
Transplant slender
mariposa lily bulbs
Install protective fencing
Prepare final map and
installation completion
report
Maintenance
Weed control – Monthly
during growing season of
the first year, four times
per year thereafter
Monitoring
Biological
monitoring/data
collection
Site Protection
Verify fencing and make
repairs
Reporting
Prepare year-end reports
Remedial Measures To be determined each
year and at end of
monitoring period
Final Sign-Off*
City and CDFG to verify
site conditions
Status/Completed
Year 0
Year 1
Year 2
Year 3
Year 4
Year 5
Quarter
Quarter
Quarter
Quarter
Quarter
Quarter
1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
X
X
X
X
X X X X X X X X X X X X X X X X X X X X X
X X X
X X
X X
X X
X X
X X X X X X X X X X X X X X X X X X X X X
X
X
X
X
X
X
X
X
X
X
X
* The actual date/timing for final sign-off by the City will be based upon actual achievement of success criteria.
The purposes of the monitoring visits will be to document weed problems, site security and
maintenance issues, and the growth, flowering, and seed production of slender mariposa lily
within the receptor sites. At each monitoring visit, the following measurements and observations
will be made, as applicable.
•
Observation of evidence of vegetative growth. Floral structures are needed to
conclusively verify that the presumed vegetative growth in fact is slender mariposa lily.
However, experienced biologists can often identify mariposa lily in general from
vegetative growth only, particularly if the individual planting locations are known.
Observation of vegetative growth is better accomplished in the winter or early spring,
before leaf shoots begin to senesce. After successive years of monitoring, and with
knowledge of the known locations of planted slender mariposa lily, it will be possible to
estimate the number of individuals present by examining vegetative growth.
20
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
•
Observation of flowering and seed production. All flowering individuals observed
within the receptor areas will be counted. Biological monitoring during the blooming
period may require multiple visits because there is often an extended blooming period
(several weeks) during which time flowering is staggered (i.e., some individuals may
have open flowers and be easily detected, while other individuals may have closed
flowers or flowers in bud and go undetected). Additionally, the peak blooming period
varies from year to year; therefore, multiple visits will aid in capturing a more accurate
estimate of flowering individuals. All flowering individuals detected during the
monitoring periods will be recorded on data sheets.
•
Reference Site Monitoring. In addition to monitoring the planted slender mariposa lily,
reference site monitoring will be conducted at a nearby undisturbed slender mariposa lily
population. A fixed area (reference site) will be demarcated, wherein all flowering
individuals detected will be counted during the annual data collection period to provide
comparison data. This will provide consistent, year-to-year data on a discrete portion of
the existing population, which will be useful for statistical purposes.
•
Photo-documentation. Representative photographs will be taken from fixed points
within the receptor sites as well as the reference site, including overall and close-up
views, from fixed viewpoints, and from representative plots, allowing year-by-year
comparison during the monitoring period.
•
Monitor soil moisture and rainfall patterns. Rainfall patterns and weather forecasts
will be researched and soil moisture levels on site will be evaluated to determine if
supplemental irrigation is necessary. If it is determined that precipitation during the
growing period has been inadequate to support the planted slender mariposa lily,
particularly during the first 2 years of the 5-year maintenance and monitoring period,
supplemental irrigation may be recommended, as determined by the Project Biologist.
•
General preserve monitoring. Observations will be made of the general status of
fencing, signage, perimeter control (trespass), erosion control, litter, and pest species.
6.2
Annual Reports
An annual monitoring report will be prepared in the fall/winter of each year of the 5-year
maintenance and monitoring period, summarizing the information collected during the yearly site
visits. Data will be summarized in tabular format where feasible. Each annual report will present
the monitoring methods and a description of the current conditions of the receptor site, and will
provide copies of field maps and data sheets, representative photographs, monitoring results,
regional precipitation measurements for the year, an analysis of success and/or failure for all
21
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
portions of the project, and recommendations for future maintenance and possible remedial
measures or contingency plans, if necessary.
A discussion of any existing or future potential impacts to the planted slender mariposa lily that
are known to the Project Biologist or that may occur as a result of human activities and
environmental conditions also will be included. A status report will be provided to the City and
CDFG by the end of each calendar year during the maintenance and monitoring period. A final,
end-of-the-project monitoring report will be filed with the City and CDFG upon achievement of
success criteria and final acceptance will be considered at that time.
7.0
COMPLETION OF MITIGATION AND PERFORMANCE CRITERIA
At the end of each year, the Project Biologist will inform Vista, the City, and CDFG of the
progress of the plan. When the long-term maintenance and monitoring period is complete, or
sooner if the success criteria are achieved early, the City will be invited to review the conditions
of the receptor sites and document the status of the planted slender mariposa lily. Final
performance criteria are included in Table 3.
Table 3
Performance Criteria – Slender Mariposa Lily Mitigation Plan
Monitoring
Frequency
Ongoing monitoring of
seed collection
activities
Feature
Slender mariposa
lily seed collection
Criteria
Collect seed for use at
receptor sites and for
back-up contingency.
Slender mariposa
lily seeding
Apply seed in appropriate
locations as described in
plan.
Spring of each year
(December–March for
vegetative growth;
April–May if flowering)
Slender mariposa
lily bulb salvaging
Ongoing monitoring of
salvaging operations
Slender mariposa
lily transplantation
Salvage slender mariposa
lily individuals from within
the project limits of
grading.
Transplant salvaged bulbs
and associated soil.
Ongoing monitoring
and verification of
work
Notify City and CDFG
of number salvaged
and planted.
Slender mariposa
lily survival (bulbs
A minimum 1:1 ratio of the
quantity of individuals
Spring of each year
(April–May)
Demonstrated ability
to persist at the
22
Findings
Quantity of seed
collected is of an
adequate amount for
seeding at receptor
sites and for back-up
contingency storage.
Demonstrated ability
to persist at the
receptor site by
exhibiting evidence of
vegetative growth
and/or flowering.
Estimate total number
of individuals
salvaged.
Action
Monitor timing of seed
maturation so seed is
collected when mature,
but prior to dispersal.
Ensure proper seed
storage conditions.
Monitor seedling
success during regularly
scheduled monitoring
visits. Report results in
annual monitoring
reports.
Ensure proper storage of
salvaged bulbs until they
can be planted at
receptor sites.
Install all bulbs at the
predetermined receptor
locations according to
this plan.
If successful, program
complete. If not,
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for Vista Canyon
Table 3 (Continued)
Feature
and seeds)
Maintenance,
weed control,
verification of
fencing/protection,
and monitoring of
herbivory
Criteria
impacted producing
vegetative growth during
any of the last 3 years
over the 5-year monitoring
period.
Remove invasive weeds
from around and within
slender mariposa lily
receptor sites. Invasive
perennial weeds not to
exceed 5% cover at any
time during the
maintenance and
monitoring period. Keep
herbivore-exclusion
fencing in place and
functional. Check for
rodent problems.
Monitoring
Frequency
Monthly during the
first-year growing
period, quarterly
thereafter until the
end of the 5-year
long-term
maintenance and
monitoring program
Findings
receptor site by
exhibiting evidence of
vegetative growth
and/or flowering.
Action
remedial measures or
additional maintenance
and monitoring are to be
implemented, if required.
Verify weed
maintenance and site
protection. Assess
herbivory on slender
mariposa lily
subpopulations.
Take remedial measures
and/or make repairs as
needed. Control invasive
weed species throughout
entire 5-year program.
An adaptive management approach has been established in this plan and will be utilized for the
5-year maintenance and monitoring period, wherein backup contingency measures (such as
providing supplemental water or supplemental seeding) will be initiated if it appears as though
the plan may not meet the established success criteria. In the unlikely event that the plan has
failed to sustain the planted slender mariposa lily during the 5-year maintenance and monitoring
period, the City will be consulted to determine contingency measures to be implemented to
compensate for the failure of the plan, if required.
8.0
LITERATURE CITED
California Invasive Plant Council (Cal-IPC). 2006. California Invasive Plant Inventory. Cal-IPC
Publication 2006-02, California Invasive Plant Council: Berkeley, California.
http://www.cal-ipc.org/ip/inventory/pdf/Inventory2006.pdf
Forde, A.M., and E. Read. 2008. Biological Assessment Vista Canyon Ranch Los Angeles
County, California. Prepared for Vista Canyon Ranch L.L.C. and The River Project.
August 27.
Woodruff, G.A., W.J. McCoy, and W.B. Sheldon. 1970. Soil Survey Antelope Valley Area
California. U.S. Department of Agriculture, Soil Conservation Service, Washington
23
6115-06
June 2009
Slender Mariposa Lily Mitigation and
Monitoring Plan for the Vista Canyon Project
D.C., in cooperation with the University of California Agricultural Experiment Station,
Davis, California.
24
6115-06
June 2009
APPENDIX A
Soil Test Results