HomeMy WebLinkAboutHMP 09-05; LAKE CALAVERA TRAILS MASTER PLAN; DIEGAN COASTAL SAGE SCRUB RESTORATION PLAN UPLAND MITIGATION; 2009-10-28Diegan Coastal Sage Scrub Restoration Plan
Upland Mitigation for the Lake Calavera Trails Master Plan,
Prepared for:
City of Carlsbad
Parks and Recreation Department
Carlsbad, CA
Prepared by:
Technology Associates
5930 Priestly Dr.
Carlsbad, CA
October 28, 2009
Table of Contents
Contents
1.0
2.0
3.0
INTRODUCTION ..........•.. -........... -.......................................................... • ........................ 3
PROJECT DESCRIPTION .......................................................................................................... 3
EXISTING SITE CONDIDONS ... -......... _ ........ ~ .................................................................... 6
3~1
32
33
Sr;rE CONDillONS ............. , ........................................................................................................... 6
REFERENCE AREA VEGETATION SAMPLING ................................................................................. 6 ' .
SOIL TE8TING ........ : .............................................................................................. : ............ .-.......... 7
4.0 PERSONNEL AND SUPPLIES .......... -.................................. , ................................................ 7
4.1
42
43
REsTORATIONEcoLOGIST ....................................................................................... : ................... 7
LANDSCAPE MAINTENANCE CONTRACTOR .................................................................................. 8
CONTRACT NURSERY/SEED SUPPLY ............................................................................................ 9
5.0 RESTORATION IMPLEMENTATION ..................................................................................... 9
5.1 PREcoNS1RUCTIONMEETING ...................................................................................................... 9
52 SITEPREPARATION ............... • ....................................................................................................... 10
5.2.1 Fencing and Signs .... : ............................................................................................................ 10
5.2.2 Site Access and Best Management Practices ..................................................... : ................... 11
5.2.3 Soil Preparation .................................................................................................................... 11
5.3 INSTALLATION ............................................................................................................................ 12
5. 3.1 Seed Procurement and Inspection ......................................................................................... 12
5.3.2 l-,fycorrhizal Inoculation ........................................................................................................ 14
5.3.3 Imprinting Equipment ....................... • .................................................................................. -... 14
5.3.4 Imprinting Execution ............................................................................................................. 16
5.3.5 Supplemental Irrigation (Optional) .......................................................... : ............................ 18
5.4 INSTALLATION SCHED~ ............................................................................................................ 19
6.0 PROJECT MAINTENANCE AND MONITORING ............................................................ _ ... 19
6.1
6.1.1
·6.1.2
6.1.3
6.1.4
6.1.5
120-DAY EsTABLISHMENT MONITORING AND MA.lNTENANCE ................................................... 19
Weed Abatement ..................................................................................................................... 20
Vandalism Control and Trash Removal ................................................................................. 21
F;roston Control ..................................................................................................................... 21
Herbtvory/Predator Control ................................................................................................... 21
Completion of 120-day Maintenance ..................................................................................... 22
62 LoNG-TERM MONITORING AND MAINTENANCE-SEPARATE CONTRACT ................................... 22
6.2.1 Long-term Monitoring ........................................................................................................... 23
6.2.2 Pe,fo~e Standards .......................................................................................................... 25
6.2.3 Long-Term Maintenance ...................... : ................................................................................ 27
6.2.4 Contingency Measures ........................................................................................................... 27
·7.0 REFERENCES .......................................................................................................................... ....28
APPENDIX A. Results of Soils Analysis for Lake Calavera Preserve
APPENDIX B. California Invasive Plant Inventory, High and Moderate Risk Species
Restoration Plan: Calavera Preserve Planning Area
Modified October 28, 2009
List of Figures
Contents
Figure 1. Regional Location Map ................................................................................................................ 4
Figure 2. . Project Site Map ........................................................................................................................... 5 .
List of Tables
Contents -~
Table 1. Average Cover Model for Coastal Sage Scrub ............................................................................. 7
Table 2. Plant Palette for Restoration Project .............................................. : ............................................. 13
Table 3. Maximum Allowable Bulk Densities after Imprinting ................................................................ 17
Table 4. Recommended Installation Schedule ............................................................................................ 19
Table 5. Recommended Establishment Monitoring and Maintenance Schedule .............. ; ...... : ................. 20
Table 6. Recommended Long-Term Monitoring and Maintenance Schedule .......................................... 23
Table 7. Success Criteria ..................................................................................... '. ..................................... 26
Restoration Plan; Calavera Preserve Planning Area .
Modified October 28, 2009
ll
1.0 Introduction
This document is a conceptual restoration plan for upland mitigation restoration for the
Lake Calavera Master Trail Plan (LCMTP). The purpose of the LCMTP is to establish a
formal network of signed, public multi-re~reational trails and viewpoints in a manner that
. avoids biological impacts to the greatest extent feasible. This will be accomplished by
improving approximately 5 miles of existing trails around and east of Lake Calavera.
. Lake Calavera is part of Core Area 3 for the City of Carlsbad Habitat Management Plan
(HMP), a Subarea Plan for the Multiple Habitat Conservation Program (MHCP) .. In
addition, it contributes to the Natural Communities Conservation Planning (NCCP)
·preserve system by serving as a regional movement corridor for the federally threatened
California gnatcatcher (Polioptila califomica califomica).
2.0 Project Description
Lake Calavera is located in the northeastern portion of the City of ~lsbad, San Diego
County, California (Figure 1). In this document, "Project" refers to the upland ·restoration
component of the LCTMP referenced above, which will provide mitigation for impacts to
gnatcatcher occupied coastal sage scrub. and native grassland habitat. The goal this
Project is to restore 1 acre of non-native grassland habitat to Diegan coastal sage scrub
that is (a) self-sustaining, (b) suitable habitat for the California gnatcatcher, and (3) free
of non-native invasive species that could invade adjacent native habitat. The. restoration
will occur in the northeastern corner of Lake .Calavera Preserve (Figure 2). The south
side of the restoration area is adjacent to existing coastal sage scrub habitat that is known
to support the coastal California gnatcatcher (Polioptila californica califomica); the north
side of the restoration area is adjacent to a 60-foot (recently reduced from 100-feet) fuel
modification area that is regularly mowed; and to the west (although not adjacent to the
project area) is 5 acres of habitat that will be· restored to coastal sage scrub as part of a
TransNet Environmental Mitigation Program grant project.
Restoration Plan: Calavera Preserve Planning Area
Modified October 28, 2009
3
Figure 1. Regional Location Map
Restoration Plan: Calavera Preserve Planning Area .
Modified October 28, 2009
4
Figure 2. Project Site Map
Restoration Plan: Calavera Preserve Planning Area
Modified October 28, 2009 •
5
3.0 Existing Site Conditions
3. 1. . Site Conditions
I
Lake Calavera Preserve consists of approximately 262 acres of upland and wetland
habitats. A totaj of eighteen vegetation communities were mapped between 2002 and
2006 (Merkel and Associates 2009). The most common upland communities are Diegan
coastal s·age scrub (71.3 acres), chaparral (67.8 acres), and non-native grassland (38.7
acres). Dominant wetland habitats include southern willow scrub (22.4 acres), :freshwater
marsh (9.8 acres), and open water (13.1 acres). In addition, seventeen sensitive species
were reported from the Preserve, including at least four pairs of federally threatened
coastal California gnatcatcher. Lake Calavera Preserve is surrounded by dense
residential development on the west, north, and east sides. • The Preserve has a long
history of heavy recreational use, which has resulted in a network of unauthorized trails,
some of which wiil be restored. Although not part of the current Project; public outreach
and education will be a critical component of the TransNet EMP grant project, which will
occur concurrently with this Project.
3.2 Reference Area Vegetation Sampling
Ecological restoration should consider the natural species composition and ecological
conditions that would be extant on the site under natural conditions. To restore the area
to coastal sage scrub habitat with a species composition and percent cover that is
consistent with surrounding coastal sage scrub habitat, quantitative sampling was
conducted along 30-meter transects at 2 locations within· the Preserve (Figure 2).
• Sampling locations were chosen in areas of high quality habitat. Reference area sampling
data were then used to generate an • average cover model, which identifies the most
significant shrub and herbaceous species in the surrounding habitat (Table 'l). This
information was used to determine the plant palette selection for this Project (Section
5.3.1).
Sampling was conducted in the summer of 2009 after the opportune detection period -.
therefore, the list in Table 1 is not comprehensive. Thus, other considerations included
assumptions about the climax conditions and age structure of the community, including
species size at maturity and survivorship of germinated seed for each species. Introducing
annual native species to the seed mix was a:lso considered to increase, coastai sage scrub
community diversity. Native annual species were not observed during the reference area
sampling period because it was conducted during the summer, when most annual species·
Restoration Plan: Calavera Preserve Planning Area 6
Modified October 28, 2009 •
are dormant. To determine appropriate native annual species for this restoration project,
reference sampling results and plant palettes for restoration plans developed for Lake
. Calavera and adjacent Robertson Ranch preserves (Planning Systems 2006 a and 2006
b:) were reviewed as well .as the biological. technical report and species compendium for
the LCTiv!P (Merkel &. Associat~s 2009), and comments from the California Department
: of Fish and Game (David Mayer, pers. comm.). Because the installation for this project •
does not use irrigation, the planting specifications include higher quantities and denser
placements compared to an irrigated installation to account for anticipated losses. ·
Percent
Cover
60%
20% ·
100/4
Table L Average Cover Model for Coastal Sage Scrub
Based on Reference Area. Sampling
Plant Type Species (Scientlflc Name)
Dominant shrubs Artemisia califomica
Sub-dominant shrubs Ence/ia califomica, Salvia me//ifera, Isocoma menzies~
Baccharis pi/u/aris
Ado/phia califomica, Opuntia littoralis, Mimulus . .
Other shrubs aurantiacus Malosma /aurina, Rhus integrifolia, Sambucus
mextcana, Hazardia squarrosa, Malacothamnus fasciculatus,
5% herbaceous species Gnaphalium ca/ifomicum, Nassella sp,. Deinandra
fasciculata, Asclepias fascicu/aris
5% Bare Ground
3.3 Soil Testing
Three composite agricultural soil samples were. taken in the Project (Figure 2) area and
sent to Wallace Laboratory to be analyzed for pH, EC ( electrical conductivity, a measure
of salt content), physical property, and nutrients. Each composite consisted of three
individual samples within a given area.· Results of the soil tests were used to determine
the appropriate seed mix for the restoration (Appendix A; see also, Section 5.2.3).
4.0 Personnel and Supplies
4. 1 Restora'llon Ecologist
Installation, maintenance, and monitoring will be SUJJervised by a qualified Restoration
Ecologist, who will have overall responsibility for implementation of this. Project, and
will oversee the work of the Landscape Maintenance Contractor. The Restoration
Ecologist will be responsible for successful implementation of the restoration plan by the
Restoration Plan: Calavera Preserve Planning Area 7
Modified October 28, 2009 •
implementation team by providing direction, technical expertise, and coordination. The
Restoration Ecologist will manage the work of the implementation team. One written
specification document and one set of plans will be used as the contract documents to
complete the restoration. The Restoration Ecologist can be an individual or a group of
qualified professionals.
The Restoration Ecologist will have the following minimum qualifications:
I. Bachelor degree in biology, ecology, botany, or an acceptable related field such as
landscape architecture. •
2. 5 years experience with implementing successful upland mitigation projects with
an emphasis on coastal sage scrub restoration in southern California. The
Restoration Ecologist will provide documentation of at le~ three successful
coastal sage s~rub restoration implementation projects that have been successful
a:fi:er a 3-year monitoring period.
3. In accordance with state law, the Restoration Ecologist must hold a valid Pest
Control Adviser's license to make specific pest control recomri:J.endations.
The Restoration Ecologist will oversee and direct the installation at the.following stages
of progress:
• Preconstruction conference
• Review of special measures to be taken to protect existing habitats and plants
• Staking of proposed limit of disturbance
• Ensuring that the contractor does not negatively impact surrounding native habitat
during the installation process or during weed control activities
• Fencing and signs
• Tagging of soil samples
• Tagging of weed removal areas .
• Identification of weeds to be removed
• Review of site preparation prior to planting
• Weed management
• Installation completion review (acceptance starts establishment period)
• Completion review.at 120 days
• Post-implementation, monitoring, arid reporting
4.2 Landscape Malntenanc.e Contractor
The Landscape Maintenance Contractor (Contractor) will implement the restoration plan ..
The Contractor will have a valid C-27 Landscape Contracting License from the State of
Restoration Plan: Calavera Preserve Planning Area
Modified October 28, 2009
8
California, a valid Maintenance Gardener Pest Control Business License or Pest Control
Business License, and a Qualified Applicator Certificate or Qualified Applicator License,
with Category B, that will allow them to perform the required work for this project. The
Contractor will have specific documented experience with the installation and
maintenance of multiple upland restoration projects in southern San Diego County. In
addition, the Contractor will have demonstrated experience using the imprinting method .
for successful native habitat restoration. At least three references must be provided by the
Contractor to qualify as a successful _bidder for the project.
The Contractor's responsibilities will entail site preparation installation, and maintenance
services, including weed control, trash removal, fence repair, and reseeding. Planting
(imprinting/seed application) will be conducted by the Contractor under the supervision
of the Restoration Ecologist. The Contractor will be familiar with native and non-native
plant species in the region. A· successful project is one that was . accepted by the
permitting agencies or has fulfilled success criteria af}:er 3 to 5 years of post-restoration
monitoring. ,
4.3 Contract Nursery/Seed Supply
Restoration is planned to be accomplished through seeding and a limited number of
cuttings and container plants. Seeds and plants will be supplied by a Contract seed supply
and/or grower for the upland restoration through an experienced native plant nursery or
seed company such as, but not liniited to, Tree of Life N~ery, San Juan Capistrano,
California; Green Oaks Ranch Nursery, Vista,-California; Mockingbird . Nursery,
Riverside, California; El Nativo Growers, Azusa, California; Las Pilitas Nursery,
Escondido, California, and S&S Seeds, Carpinteria, California. No substitutions will be
accepted.
5.0 . Restoration Implementation
5. 1 Preconstructlon .Meeting
One or more preconstruction meetings. will be held with all applicable individuals to
establish relative authority and responsibilities, identify sensitive habitat areas, discuss
appropriate access, and review methodology for site preparation and installation.· The
Restoration Ecologist will hold the authority to make field changes that affect the scope
of work of the project and to issue stop work orders. A schedule identifying proposed
construction activities, work area boundaries, off-limit areas and activities; and applicable
permits will be distributed to all appropriate parties prior to commencing construction.
Restoration Plan: Ca1avera Preserve Planning Area 9
Modified October 28, 2009 •
5~2 Site Preparation
Site and seed bed preparation do not require grading or contouring. However, the site
• requires • fencing, access controls, w~ removal and • potential erosion control as
described in the following sections. See Section 5.3.3 for information about imprinting
equipment requirements.
5.2.1 Fencing and Signs
The area designated for restoration currently experiences intense recreational use,
including hiking, dog walking (often with unleashed do·gs), and mountain biking.
"However, informational sign.age has not yet been installed to educate the public about
restricted uses. As such, hikers, bikers, and/or dogs often go off-trail, which can result in
damage to the adjacent habitat. 1bis type of unauthorized use is especially heavy in the
vicinity of the restoration area due to dense residential development along the north side
of the Preserve. To minimize potential damage to the restoration area from unauthorized
use, temporary fencing will be installed around the restoration area prior to site
preparation and installation.
Sensitive biological areas, such as adjacent native habitat, are deemed as ''no
construction" areas. ''No-construction" zones shall be clearly flagged by the Restoration
Ecologist prior to the onset of construction activities. If the Restoration Ecologist deems
it necessary, sensitive biological areas shall be surrounded by fencing or other protections
to prevent direct or indirect impacts.
To help promote a successful restoration, the boundary of the restoration area may be
refined in the field from that shown in Figure 2, if recommend~ by the Restoration
Ecologist, based on accessibility, public use patterns, locations of authorized and
unauthorized trails, slope or soil type. Prior to fencing, the Restoration Ecologist will
stake the restoration area. After the initial planting, protective temporary fencing shall be
installed arotmd the restoration area to preclude disturbance. Specifications for fencing
are included in the contract.
Silt fencing to control erosion and damage by herbivores shall be installed around the
entir~ perimeter of the restoration areas and remain in place until the restoration project is
complete. The silt fencing shall be regularly maintained to ensure that it remains
effective; Torn or broken fencing shall be replaced routinely.
In addition, temporary signs will be installed at various locations around the restoration
site to identify the area as a: sensitive habitat restoration site, and to descnbe recreational
Restoration Plan: Calavera Preserve Planning Arca
Modified October 28, 2009
use restrictions in the area. The restoration area shall be posted by the restoration
contractor with a sign that indicates the area is not to be entered and that vegetation is
being established. The sign shall contain a contact telephone number and name of the
restoration contractor.
6.2.2 Site Access and Best Management Practices
Heavy equipment and construction activities shall be limited to the existing developed
and disturbed areas to the degree feasible as determined by the Restoration Ecologist.
Vehicles shall be required to. remain within the construction corridor, unless otherwise
noted on the drawings. All vehicles shall use existing access roads/fire breaks.
If the site contains trash or debris, the Maintenance Contractor will remove all trash. and
debris accumulated within the project boundaries and dispose of the collected debris in an
appropriate location off-site.
Best Management Practices (BMP) should be applied throughout the restoration project
to prevent erosion and siltation of any adjacent wetlands or wat~rways, if deemed
necessary by the Restoration Ecologist. BMP measures could include, but are not limited
to, the installation of silt fencing, coir rolls (for example installed in a V-shape with the
tip of the V pointing uphill), fiber mats, etc.
6.2.3 Soll Preparatfon
No chemical fertilizers or other growth enhancing products should be added to the
restoration planting to avoid compromising the beneficial effects of natural soil
organisms and mycorhizal fungi. However, if the Restoration Ecologist determines that
the extant soils are unsuitable to ecological restoration based on the results of the soils
analysis or other site characteristics, recommendations will be provided for natural soil
amendments suitable for native habitat restoration, such as mulch and organic fertilizers.
Results of the soils analysis included in Appendix A can be used to make this
• determination, or the Restoration Ecologist can take new samples, and have them
analyzed at a qualified laboratory.
Agricultural-grade gypsum shall be a calcium sulfate (CaSO4 fu0)product -94.3 percent.
90 percent shall pass a 50-mesh ·screen. Control of dust during application is mandatory.
Iron Sulfate shall be ferrous sulfate in pelletized or granular form containing not less than
20.0 percent iron expressed as metallic iron. Iron Sulfate pellets shall be of size and
gradation such that 98 percent is retained on a 10-mesh screen.
Restoration Plan: Calavera Preserve Planning Area
Modified October 28, 2009
11
The site will be deccimpacted by cross-ripping to a depth of six to twelve inches. At this
time, the recommended soil amendments will be add~ if necessary. Mycorrhizal fungi
. inoculation shall occur during installation, as qescribed below. If necessary, erosion
control measures, such _as silt fencing, will be installed to ensure that the restoration area
is not damaged by erosion or siltation during the rainy season. If deemed necessary by the
Restoration Ecologist, weed control will be conducted by the Contractor, using methods
reco.mmended by the Restoration Ecologist.
5.2.4 Pre-Planting Weed Eradication
Prior to restoration implementation, m.anual ·weed C?ntrol shall be conducted by the
Contractor. All actively growing non-native vegetation shall be removed prior to the
onset of seeds, removing the entire root system, seeds, and seed heads. An acceptable
method of weed removal would be to water and germinate the plants of concern, and then
remove them before they set seed. Irrigation of weedy areas for several weeks prior to
weed eradication will encourage germination of weed seeds in the soil. However, if
sufficient winter rains have encouraged the growth of weedy species, irrigation may not
be necessary. Herbicide can also be used to eradicate weeds if deemed necessary and
approved by the Restoration Ecologist. If this method is chosen, all herbicide use shall be
restricted to the restoration area and not enter the nearby sensitive areas. See Section
6.1.1 for herbicide specifications. Pre~mergents are prohI"bited and shall not be used.
5.3 Installation
Coastal sage scrub habitat is naturally drought adapted and thrives on small amounts of
precipitation during the winter months. Therefore, this restoration project has been
designed to. use rainfall to establish coastal sage ·scrub habitat As such, an irrigation
system will not be installed, unless recommended by the Restoration Ecologist and
approved by the City (to be contracted separately). Prior to seedbed-preparation, the
Restoration Ecologist shall ensure that the appropriate seed mix, cuttings, and contall:1er
plants have been collected by the Contract Grower.
6.3.1 Seed and Plant Procurement and Inspection
The seed mix will be contract-ordered and prepared using the plant palette in Table 2. All
seeds shall originate in the vicinity of coastal North San Diego County (target area). Seed
materials will be purchased from a qualified vendor specializing in native seeds (for
example S&S Seeds or equivalent) and experienced in the collection and preparation of
native seed· material. for native habitat restoration/revegetation. If seed is not readily
Restoration Plan: Calavera Preserve Planning Area
Modified October 28, 2009
12
available from a reputable supplier (see Section 4.3), it must be collected within the target
area (within a 30 mile radius from the project site), except where noted in Table 2. •
Table 2. Plant Palette for Restoration Project
Percent Percent Seed Qty
Scientific Name Comr:non Name Purity Germination lbs/acre
Artemisia califomica California sagebrush 15 50 6
&celia califomica California encelia 40 60 3
Eriogonum fasciculatum California buckwheat 5 60 4
Eriophyllum confertijlorum Golden yarrow 30 60 0.5
Eschscholzia califormca• California poppy 98 .80 T
Gnapha/ium ca/ifomicum . Oilifomia everlasting 10 25 1
Hazardia squarrosa Saw-toothed goldenbush 15 20 2
Isocoma menziesii Coast goldenbush 30 30 4
Lotus scoparius Deerweed 90 60 1.5
Lasthenia ca/ifomica • Gold:fields 98 85 2
Lupinus bico!or• Miniature lupine 98 80 3
Malacothamnus fasciculatus Bush mallow 15 60 1
Mimulus aurantiacus Coast monkeyflower 2 55 3
· Nassella pulchra• Purple needlegrass 70 60 1
Salvia mellifera Black sage 70 .so 1
Sisyrinchium !Jellum• Blue-eyed grass . 95 75 1
Plantago ovata (insularis•) Wooly plantain 98 75 6.
Note: seeds indicated with an * may be obtained from a commercial source.
All seed • shall be labeled according to state and federal laws, and be delivered to the
Project site in sealed containers. The quantity of pure live seed supplied shall rrieef or
exceed the quantity shown in the specified mixes. Seed shall not contain more than 0.5
percent weed seed by volume. Each sealed container shall include original seed
supplier's tags indicating the container weight, seed type (genus and species), source,
collection date, percent purity of the seed, percent seed germination, and date the seed
Wl;\3 tested. If not guaranteed by the supplier, at time of delivery, samples must be drawn
from each seed mix by the Restoration Ecologist and tested to ensure compliance with the
seed specifications. The seed supplier shall certify, in writing, the location and date of
seed collection.
The seed imprinting will be supplemented with cuttings of coast cholla ( Opuntia
prolifera) and coast prickly pear cactus (Opuntia littoralis), and with 1-:-gallon container-
grown California adolphia (Adolphia califomica). The cuttings and container plants will
be contract grown and purchased from a qualified vendor, as descn"bed above for seed
• mixes. All plant material will be inspected by the Restoration Ecologist for non-native ant
Restoration Plan: Calavera Preserve Planning Area
Modified October 28, 2009
13
• species and other. pests prior to being delivered onto the site. A total of 100 California
adolphia, 50 coast prickly pear, and 30 coast cholla will be planted in a non-uniform
manner that miniics, natural plant distribution.
Seed types shall be as specified in Table 2, and shall be applied at the rates indicated.
Cuttings and container plants shall be applied as specified above. No fertilizer of any sort
shall be applied during seed application, applied in the planting· holes or backfill, or
applied as topdressing. Organic materials or other amendments may be used as needed to
· improve soil drainage and aeration.
5.3.2 Mycorrhizal Inoculation
• Mycorrhiz.al is a symbiotic association between a fungus and ·the roots of a plant.
Vesicular-arbuscular m.ycorrhizal is the form of endotrophic mycorrbiza that will be used
to inoculate the site. In this form, the fungus lives between the cells of 1he cortex and
forms temporary hyphal projections that penetrate the cortical cells. Plants that
commonly develop such associations cannot grow normally without the appropriate
fungus. As a rule, mycorrhizal infection enhances plant growth by increasing nutrient
uptake via increases in the absorbing surface area, by )Ilobilizing sparingly available
nutrient sources, or by excretion of chelating compmmds or ectoenzymes. Mycorrbizal
infection may also protect roots from soil pathogens, thereby increasing root growth and
nutrient acquisition of the host root. The imprinting seed mix ( coastal sage scrub only)
will be supplied with a . mycorrhizal inoculation prepared by the seed suppFer.
Commercially available (EndoNet™ or equivalent) granular arbuscular niycorrhiza
inoculum-will be incorporated into the seed mixture prior to application
5.3.3 Imprinting Equipment
To ensure successful germination, imprinting methodology will be .used. Land imprinting
is the formation by mechanical means of smooth-walled V-shaped furrows in the soil
surface. It shapes the soil, creating small depressions which concentrate water, seed,
litter, and other resources and prevent seeds being washed out by rainfall. Seeds are
pressed into the soil, promoting capillary contact and improving germination, and
mycorrhizal inoculum is injected .into the root zone. This method has been shown to be
more successful than hydroseeding in establishing native species in arid climates, such as
southern California, when irrigation is not used.
The imprinter should either be a tractor-drawn or winch-pulled implement with angular
teeth welded to a steel roller. The imprinter differs dramatically from conventional
Restoration Plan: Calavora Preserve Planning Area
Modi:fiod October 28, 2009
14
method of tillage such as plowing, discing, cultivating or drill-seeding in that it does not •
turn over the soil and entails minimal disruption of the surface-litter. It is equipped with
machinery for dispensing seed and other materials, and chambers to accommodate --
ballast; The ballast is adjusted to produce optimum imprints· in a range of soil conditions.
Imprinting sh.ould be conducted following the specification below.
Characteristics of Imprinting Teeth_ •
• The height oflhe imprinting teeth shall be at least four inches. •
• Imprinting teeth shall be V-shaped in transverse section, and may be rectangular
or triangular in longitudinal section.
• Any imprinter used on a slope greater than 4:1 shall have teeth ten inches or less
in length, with a gap of two inches or more between the end of one segment and
the beginning of the next. ff the imprinting teeth are longer than ten inches, the
machine shall be operated at all times with the long dimension in a horizontal
orientation to the slope.
• The crest-to-crest spacing between teeth shall be less than two feet. One foot is
often optimum for land restoration.
• • The apical angle of the triangular cross section of the imprinting teeth shall be
ninety degrees or less, with acute teeth preferred for the steepest slopes.
• Any imprinter use on a slope greater than 2:1 shall have a "saw tooth" pattern, in
which the apex of the tooth is offset, giving a long and a short side to each tooth.
The angle between front and rear faces of the imprinting teeth shall be 60 degrees
or less. The imprinter shall be operated so that the long face of the impression
lies upslope of the short face.
Weight Per Unit Area on Teeth
• The static pressure on the soil surface is measured by dividing the total weight of
the imprinter, including· any ballast, by the total area of tooth contact when the
teeth have penetrated half way into the soil.
• The static pressure on the soil surface shall be at least 12 pounds per square inch
and less than 48 pounds per square inch. The lower weights are for softer soils
and the higher weights for harder or drier soils.
• No more pressure shall be used than that required to obtain a full-tooth imprint.
Maximum Length of Roller
• Restoration Plan: Calavera Preserve Planning Area •
Modified October 28, 2009
15
• No individual roller shall be more than eight feet in length, except in the case of
level, rock-free land that will not cause a long roller to leave unimprinted areas.
• More than one roller may be attached to a single imprinting device as long as each
roller swivels independently over surface obstructions. In this case, the combined
rollers may be any practical width.
6.3.4 Imprinting Execution
Desired Soil Conditions
• The soil may be imprinted when dry if it is soft enough to allow penetration of the
imprinting teeth to their full depth, and firm enough to permit the formation of
smooth-walled, firm impressions.
• • If the dry soil does not allow formation of quality impressions, it shall not be
imprinted until rainfall or irrigation leaves it in a suitable condition.
• Soil that is too hard to accept a pattern that conforms to performance
specifications, with a properly weighted imprinter, may be ripped before
imprinting. Adjustment of the imprinter ballast is preferred over ripping where
feasible.
• Clay soil shall not be imprinted while it is so wet that substantial quantities of it
stick to the roller.
Form of Impressions
• Impressions shall be of V-shaped cross section and ten inches or less in length if
used on a slope exceeding 4:1.
• A pyramidal shape is acceptable as long as the apical angles between all faces are
ninety degrees or less.
• The imprinting pattern shall provide a raised soil ridge that prevents continuous
movement of drainage water between impressions.
• At least 70 percent of the soil surface shall bear impressions, apart from any
peripheral turn-around area ap.d areas rendered untreatable by rocks or other
natural features.
• At least 70 percent of the impressions shall reach 90 percent of the full tooth
depth.
• At least 70 percent of the impressions shall have smooth and firm soil over at
least 70 percent of their surface area.
Compaction of Finished Impressions
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• Bulk density is defined as the oven-dry weight of soil per unit of original field
volume, oo.d shall be calculated per standard soil testing methods.
• No ·portion of the imprinted soil profile shall exceed the bulk density indicated for
the soil type in Table 3 .
. Table 3. Maximum Allowable Buik Densities after Imprinting
Soil Maximum Bulk Density (Mg/m3)
LoamySand 1.75
Sandy Loam 1.65
Loam 1.55
Silt Loam 1.45
Clay Loam 1.45
Clay 1.40
Vegetation Cover
• The imprinting operation shall be carried out on bare earth or on land that has
only a minimal vegetative cover, except as specified below.
• If the amount and nature of vegetativ~ cover is sufficient to interfere with soil
contact and the formation of quality impressions, such vegetation shall . be
removed prior to imprinting by burning, raking, or other suitable means.
• Interfering vegetation may be cut or chopped into fragments of eight inches or
less if the depth of accumulated material is small enough to allow the formation of
quality impressions.
Operating Procedures
• The imprinter _shall be pulled at a speed low enough to ensure that the full weight
• of the roller bears upon the soil at all times.
• If the impressions are longer than ten inches, the long dimension of each imprint
shall lie parallel to the contour of the slope.
• If imprint length is ten inches or less, the imprinter may be used in any orientation
to the slope.
Proximity to Edges of Seeded Area
• The imprinting pattern shall extend fully to the boundaries of the project area.
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• Toe area at the project boundary may serve as a tum-around_ area and normally
will be imprinted by a finai pass along the project perimeter. If conditions do not
permit imprinting the perimeter, a tum-around area within the project need not be
fully imprinted.
• Any unimprinted turn-around area on the project boundary shall be no wider than
the smallest turning radius allowed by the equipment.
Seed Distribution
• Seed dispensed by the imprinting device shall be in firm contact with the soil.
• The seed bin shall contain :rio residual seed from previous uses.
• Wheat bran or approval substitute shall be mixed with seed to appropriate dilution
ratio to prevent seed segregation. The optimum mixing radio is usually 1:1 by
volume.
• Planting shall take place before germination of the seeds introduced by imprinting
unless approved by the Restoration Ecologist.
• The planting crew shall step in the impressions rather than the ridges to preserve
the imprinting pattern.
• No irrigation, weeding, or other maintenance activity shall be allowed to damage
or modify the imprinting pattern.
5.3.5 Supplemental Irrigation (Optional)
The goal for this coastal sage scrub restoration effort is to obtain growth with the least
amount of irrigation. Frequent irrigation encourages weed invasions and leaches nutrients
from the soil. Native plantings that are infrequently irrigated may grow slower initially,
but will become established with minimal distortions in the root-to-shoot ratio and with
less competition from weeds.
If necessary, as determined by initial post-establishment monitoring, irrigation by water
truck shall be supplied for plant establishment. Irrigation volume shall be determined by
the Restoration Ecologist and may be based upon weather conditions (no irrigation
should be supplied from July through September). However, deep irrigation should
always be favored over short periods of shallow irrigation. The Contractor shall ensure
that sufficient water for plant establishment be supplied. to the restoration area.
Following the plant establishment period, the Project Ecologist shall be responsible for
directing the frequency and duration of irrigation applied to the site as needed.
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• If used, herbicides will be applied in a manner that does not result in overspray
into adjacent native habitat areas.
6;1.2 Vandalism Control and Trash Removal
Vandalism of the planted area, fences, or signs, must be reported by the Contractor to the
Restoration Ecologist within three working days of discovery. Trash removal and repair
of fences and signs will be conducted by the Contractor as needed, and just prior to the
end of the 120-day maintenance obligation. All trash and debris will be removed from the
site and disposed of in a legal manner.
6.1.3 Erosion Control
The Contractor shall repair all erosion-related problems immediately upon discovery, and
report the problems to the Restoration Ecologist. The Contractor and Restoration
Ecologist shall inspect the site to determine the cause of the problem, and the Contractor
shall install erosion control measures as directed by the Restoration Ecologist. Erosion
control may-include the installation of Best Management Practices (BMP), such as the
installation of fiber coirs, silt fencing, Bio-Fiber Matrix (BFM), silt traps, and filling and
securing of erosion gullies. All erosion control materials. must be free of invasive species
seeds. After the area is repaired, re-seeding of the area will be conducted if deemed
necessary by the Restoration Ecologist. The above specified seed mixes and unit metrics
shall be used to determine quantities. •
6.1.4 Herblvory/Predator Control
The Contractor shall look for signs of herbivory on a regular basis. If signs of herbivory
are found, the problem shall be remediated immediately using methods to be determined
by the Restoration Ecologist. Remedial actions may include installing and maintaining
herbivory cages; installation of fine-mesh flashing along the bottom 36 inches of fences;
burying fences to a depth of 12-18 inches; maintaining and repairing fences. Material for a
typical herbivory cage should consist of one-inch mesh poultry wire supported by two
wood stakes. Caging for each plant shall form a circle around the plant, extending at least
three inches into the soil, and one foot above the plant tip to allow sufficient height for at_
least two years of growth. The upper edges of the cage shall be folded over each other
creating an "envelope" around the plant. The removal of the cages shall be determined by
the Restoration Ecologist.
If necessary, predator control will be evaluated by the Restoration Ecologist on a case-by-
case basis and shall be restricted to methods recommended by the Restoration Ecologist,
including rodent control, ant control, and animal trapping and translocation.
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6.1.5 Completlon of 120-day Maintenance
At the end of the 120-day establishment period, the Contractor and Restoration Ecologist
will conduct a walk-through to determine if the restoration has been successful. Success
criteria include (a) uniform germination of native species throughout the· site; (b) 0%
cover of invasive.species identified as high risk [Appendix BJ, (b} no more than 10%
cover of all other non-native invasive plant species, ( c) trash and debris removed from the
site, and ( d) no sign of problems with erosion or vandalism). If it has been determined
_ that success criteria have not been met, the Restoration Ecologist will provide a written
description of -necessary -remedial action to the City and the Contractor. If the
establishment failure is determined to be the fault of the Contractor, all labor and
materials associated with remedial actions, including re-seeding, shall be the
responsibility of the Contractor. The method of re-seeding will be determined by the
Restoration Ecologist. Once 120-day performance standards have been met, the
-Restoration Ecologist will conduct a final walk-through with the City, and provide a final
report.
At the completion of the establishment monitoring period, as:.built maps will be prepared
showing the location of the restoration areas. As-built maps will be of the same scale as
the original plan to facilitate data presentation. These maps will serve as base maps for
the long-term monitoring and maintenance efforts.
6.2 Long-Term Monitoring and Maintenance -Separate Contract
' Long-term monitoring_ and maintenance will be contracted sepai;-ately from the
installation and 120-day maintenance period. A primary measure of sucpess for
restoration is t_he ability of a revegetated native plant community to be self-supporting
(the ability to sustain itself with natural water and nutrient sources) and self-maintaining
(the ability to successfully reprqduce ). This plan is intended to meet the following .
objectives:
• To attain a community of CSS that is biologically diverse and consistent with the
existing natural system.
• To attain a plant community of CSS that is self-supporting and self-maintaining at
the end of five years.
Long-term maintenance and monitoring shall begin on the day following completion
(sign-off) of the 120-day establishment period, and continue for a total of five years as
described below and summarized in Table 6.
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Quantitative Monitoring (Botanical Monitoring)
To augment qualitative survey data, more precise data will be collected and analyzed by
the Restoration Ecologist to document and evaluate the progress of the restoration
program toward meeting habitat goals and performance standards. Transect data-will be
collected from all treatment areas. At least two control transects will be selected in
adjacent naturally functioning habitats of similar vegetation community structure as .the
· restoratio.n site. Changes in habitat condition will be measured over time and compared
to baseline conditions at each monitoring station. In addition, treatment area.data will be
compared to control site. data to determine if the restored areas are compatible with
adjacent pre-existing habitat.
Habitat condition will b~ assessed by measuring species richness (the number ·of species
in a given area), and cover (percentage of an area covered by a given species) of native
and non-native plant species. The quadrat method, as described below, is best suited for
capturing small plants, plants that are rare or that have low cover, and overall species
richness; however, it is time-consuming and . inferior when recording large plants
(Deutschman and Strahm 2009). The point intercept method, which is less time
consuming, works well for large and small plants, abundant species, and estimating
cover. It does not work well for capturing rare or low cover plants.
Permanent transect locations (treatment and control) will be established during the first
quantitative monitoring period,· marked in the field with re bar, and recorded on maps. To
allow for initial seedling establishment and minimize damage to establishing seedlings,
the .baseline quantitative data collection will be performed in July 2010; subsequent
sampling events will occur annually in May of each following year. The actual timing
niay be. adjusted by the Restoration Ecologist based on climate conditions.
Quantitative monitoring should follow the specifications below, or equivalent, as
determined by the Restoration Ecologist.
• • Each monitoring station will consist of a 50-meter transect. The location and
direction of transects will be chosen randomly, and once established, will remain
the same throughout the monitoring period. Five stations will be established in
polygon A (western-most polygon of the five-acre restoration area); three stations
will be established in polygon B (the polygon just east of A); and three stations
will be established in the I-acre mitigation site ( eastern-most polygon).
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Table 7. Success Criteria
Assessment Period Success Criteria
I Monitoring/Maintenance to be Cond_ucted by-Maintenance Contracto~ and ~estoration Ecologist
• Uniform germination of native species throughout the site;
• At least 50% survival of container plants and cuttings;
• 0% cover of high risk invasive species;
120-day establishment period • No. more than 10% cover of all other non-native invasive species;
• No sign of trash or debris on site;
• No sign of erosion on site; and
• No sisms of vandalism on fences, siitns, or restoration area.
• Native perennial species cover at least 30%;
• At least 50% survival of container plants and cuttings;
Year 1 • Species richness of at least 10 native species;
• 0% cover of high risk invasive species;
• No more than 10% cover of moderate risk invasive species; and
• No more than 30% cover of other non-native soecies.
• Native perennial species cover at least 45%;
• At least 60% survival of container plants and cuttings;
Year2 • Species richness of at least 10 native species;
• 0% cover of high risk invasive species;
• No more than 5% cover of moderate risk invasive species; and
• No more than 15% cover of other non-native soecies.
• Native perennial species cover at least 60%;
• At least 70% survival of container plants and cuttings;
Year3 • Species richness of at least 10 native species;
• Evidence of native species recruitment;
• Cover of high to moderate risk invasive species 0%; and
• No more than 5% cover of other non-native species.
• Native perennial species cover at least 70%;
• At least 80% survival of container plants and cuttings;
Year4 • Species richness of at least 10 native species;
• Evidence of native species recruitment;
• Cover of high to moderate risk invasive species 0%; and
• No more than 5% cover of other non-native soecies.
• Native perennial species cover at least 80%;
• At least 80% survival of container plants and cuttings;
Years • Species richness of at least 10 native species;
• Evidence of native species recruitment;
• Cover of high to moderate risk invasive species 0%; and
• No more than 5% cover of other non-native soecies.
These performance standards will be evaluated annually as described in this section.
Successful habitat restoration should not be dependent upon human intervention by the
end of the monitoring period.
Performance standards must be attained within Treatment Areas at the end of each of the
five years following planting. A replanting program, including supplemental irrigation,
will be initiated within the restoration site, if the Restoration Ecologist determines that
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plant mortality, erosion problems, or seed germination progress are unacceptable. Should
the Restoration Ecologist determine that part of the restoration site has failed to meet
annual performance standards, the Restoration Ecologist will recommend corrective
measures to be implemented immediately.
6.2'.3 Long-Term Maintenance
Long-term maintenance activities will generally be the same as those described in
Sections 6.1.lthrough 6.1.4 above. Maintenance activities will occur as needed based on
the results of regular maintenance monitoring visits conducted by the Contractor and
Restoration Ecologist as descn'bed in Section 6.2.1.
Weed abatement shall be accomplished by the Maintenance Contractor. Workers shall be
closely supervised if they are not familiar with native coastal. sage scrub plant species.
Weed abatement shall be performed on a weekly basis for six months and then bi-or tri-
monthly, or as determined necessary by the Restoration Ecologist, for the remainder of
the maintenance/monitoring period. _
6.2.4 Contingency Measures
Upon receipt of each annual monitoring report, if the City determines that the restoration
effort is not meeting success criteria, _the Restoration Ecologist ~d Contractor will be
notified in writing. The Restoration Ecologist and Contractor will then have 30 days to
respond, challenge, or confirm the determination that ;remedial work must be done.
Potential remediation measures may include extending the monitoring/maintenance
period, installing erosion control measures, repairing fencing, weed abatement activities,
or re-seeding. Plantings that fail to become established shall be replaced in-kind or with
similar materials. Any re-seeding on site should be conducted between Nov~ber and
February to take maximum advantage of the winter rainy season. If rainfall is insufficient
to fully establish the_ native plants, the Restoration Ecologist, Contractor, and City will
discuss the possibility of applying temporary irrigation using water trucks or other cost-
effective method. The re_storation site must be irrigation-free for two growing seasons
prior to successful CQmpletion of the long-term monitoring period.
6.2.5 Reporting and Project Completion
Annual monitoring reports will be prepared by the Restoration Ecologist and submitted to
the City by August 31 of each year. Annual reports will include qualitative and
quantitative -monitoring results, photographs taken at photo-docmnentation stations,
• comparison of results with success standards, and recommended remedial measures. At
the end of Year 5, a report will be submitted by the Restoration Ecologist evaluating the
Restoration Plan: Calavera Preserve Planning Area
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performance of the restoration effort and whether aU of the performance criteria of the
restoration plan have been met. At the end of five y~, if success criteria have been met
as determined by the Restoration Ecologist, the Restoration Ecologist and the City will
meet at the site for a final walk-through, and a final report will be submitted to the City.
If success criteria have not been met, the maintenance and monitoring period may be
extended.
7 .0 References
Deutschman, D., and S. Strahm._2009a. Improving Statistical Sampling and Vegetation
Monitoring for the San Diego MSCP. Final Report. Prepared for the San Diego
Association of Governments, contract 5001033 (January 2009).
Merkel and· Associates. 2009. Lake Calavera Trails, City of Carlsbad. Biological
Resources Report. General Biological Survey, Jurisdictional Wetland Delineation,
and Focused Surveys: Prepared for the City of Carlsbad, June 8, 2005.-Revised May
14, 2007.
Planning Systems, 2006 a. Robertson Ranch, Extensive Upland Habitat Restoration
(Coastal Sage Scrub -"Area B") and Modest Habitat Re-introduction ("Area C"
and ''Future CSS Re-introduction) Program. Prepared for Robertson Family Trust,
October 26, 2006.
___ . 2006 b. Habitat Revegetation, Maintenance, and Monitoring Program.
Calavera Dam Remedial hnprovements Project, Carlsbad, California. Prepared for
City of Carlsbad, October 26, 2006.
Restoration Plan: Calavera Preserve Planning Area
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