HomeMy WebLinkAboutHabitat Management Plan 968900100Ludlow Cove II Mitigation Planting Plan 1 | M S & A
Appendix D.
Compensatory Mitigation Planting Plan
1. Introduction
The goal of this proposed compensatory mitigation planting plan is to achieve no net loss
of ecological function at a 1:1 ratio for the impacted Critical Habitat Area buffers along
the wetland and marine shoreline areas located at the Ludlow Cove II HOA Property
(Parcel #968900100). Ludlow Cove II HOA plans to remove or trim 23 hazardous native
trees on their property, as described in MS&A’s Habitat Management Report. Fourteen of
the 23 trees are located within the Critical Area buffers and are slated for removal (or in
one case, Tree # 16, trimming of the co-dominant leader trunk – Attachment 2, 2020 Tree
Survey Report). Of the 14 trees to be removed within the Critical Area buffers (all of
which require the 1:1 mitigation per Jefferson County Critical Areas Ordinance 18.22),
11 Red Alder (Alnus rubra) trees are located within the Wetland buffer, and 3 trees (2
Big Leaf Maples; Acer macrophyllum, and 1 Douglas Fir; Pseudotsuga menziesii) are
located within the Marine Shoreline buffer (see Figure 2 - Mitigation Planting Plan).
In addition to the 14 trees requiring mitigation within the Critical Area buffers, it is
recommended that 2 additional trees slated for removal (Red Alders; A. rubra) located
outside of the wetland buffer, but within the Native Growth Protection Easement (NGPE)
be mitigated for. Thus, a total of 16 new trees are recommended to achieve the necessary
1:1 mitigation for this project. These trees are described in greater detail in Table 2,
below. Newly planted trees, to be installed for mitigation, are shown in Table 1.
Ludlow Cove II Mitigation Planting Plan 2 | M S & A
Table 1. Compensatory Mitigation Plants*
Quantity Stratum Common Name Botanical Name Size
5 Tree Red Alder Alnus rubra 2 Gal
8 Tree Western Red Cedar Thuja plicata 2 Gal
1 Tree Douglas Fir Pseudotsuga menziesii 5 Gal
2 Tree Big Leaf Maple Acer macrophyllum 2 Gal
*Plants will be selected from a regional native plant nursery
The native trees listed in Table 1 were selected for their hardiness to the specific climatic
conditions of the Pacific Northwest, for protection of the Marine Shoreline and Wetland
buffers, and to increase habitat for wildlife. These species were also selected for
increasing beneficial features of the existing project site, which include recruitment of
present native species, revegetating the NGPE, expanding biodiversity, as well as
increasing a food source for pollinators. Considering the beneficial value of Red Alder
(A. rubra) root nodule nitrogen fixation, five alders are proposed for replacement. Eight
Western Red Cedars (T. plicata) are also proposed to aid with the succession from a
disturbed site to coniferous forest.
All of the above Red Alder and Western Red Cedar trees will be placed within the NGPE
and/or wetland buffer. Suggested planting areas for Red Alders and Western Red Cedars
may be moved nearby if the local conditions of the recommended sites are found to be
unsuitable. Eleven of these new plantings (5 Red Alders and 6 Western Red Cedars) are
preferred to be located within the interior of the wetland (not just the buffer), however,
that area is known to be heavily forested, and best judgement should be used to place the
trees in an area that doesn’t crowd existing trees or cause the new plantings to be
potentially hazardous in the future.
The two additional Red Alder trees that are located just outside of the NGPE (Tree #8, &
#9 – Attachment 2, 2020 Tree Survey Report) are recommended to be replaced with two
Western Red Cedars to aid in the overall function and succession of the forest ecosystem.
See Figure 2 - Mitigation Planting Plan for a visual of mitigation tree planting locations.
Within the Marine Shoreline Critical Area buffer, one Douglas Fir (P. menziesii) tree and
two Big Leaf Maple (A. macrophyllum) trees are recommended for the 1:1 replacement
of trees proposed for removal (Figure 2).
Ludlow Cove II Mitigation Planting Plan 3 | M S & A
Table 2. List of 16 total trees to be mitigated 1:1 ratio*
*(see Attachment 2, 2020 Tree Survey Report for reference)
Located within the Wetland Critical Area Buffer and NGPE (11 total):
1. Tree #10 Red Alder- Removal, leave trunk at 10 ft habitat snag
2. Tree #11 Red Alder- Removal, leave trunk at 10 ft habitat snag
3. Tree #12 Red Alder- Removal, leave trunk at 10 ft habitat snag
4. Tree #13 Red Alder- Removal, leave trunk at 10 ft habitat snag
5. Tree #14 Red Alder- Removal, leave trunk at 10 ft habitat snag
6. Tree #16 Red Alder- Hazard prune, remove poorly attached co-dominate
leader
7. Tree #17 Red Alder- Removal, leave trunk at 10 ft habitat snag
8. Tree #18 Red Alder- Slated for Removal, but appears to be healthy and
growing straight (may need to be reassessed by an arborist because it is not
clearly listed in the Arborist report)
9. Tree #19 Red Alder- Removal, leave trunk at 10 ft habitat snag
10. Tree #20 Red Alder- Removal, leave trunk at 10 ft habitat snag
11. Tree #23 Red Alder- Removal, leave trunk at 10 ft habitat snag
Located outside of Wetland buffer, but still within NGPE easement (2 total):
12. Tree #8 Red Alder- Removal, leave trunk at 10 ft habitat snag
13. Tree #9 Red Alder- Removal, leave trunk at 10 ft habitat snag
Located within the Shoreline Critical Area Buffer (3 total):
14. Tree #2 Big Leaf Maple- Removal, leave trunk at 10 ft habitat snag
15. Tree #3 Big Leaf Maple- Removal, leave trunk at 10 ft habitat snag
16. Tree #22 Douglas Fir/Big Leaf Maple- Removal of Douglas Fir trunk, leave
trunk at 10 ft habitat snag
2. Approach
2.1 Site Preparation
Topsoil around and beneath newly installed native plants will be comprised of a
minimum of 20% organic matter. MS&A recommends that the amended soil consist of 6"
of coarse sand and 6" of vegetative compost which should be worked into the soil before
planting. After plant installation, a layer of mulch at least 3” thick will be placed as a
groundcover around the plants.
Ludlow Cove II Mitigation Planting Plan 4 | M S & A
2.2 Plant Procurement
Plants will be selected from a regional native plant nursery. Substitutions may be
necessary for species or individuals outlined in this planting plan which cannot be found
at local nurseries. All plant substitutions will be approved by the project biologist prior to
installation to ensure their suitability for the site.
2.3 Planting Methods
Whenever possible, planting should be done between mid-October and mid-December as
plants grow roots during the cool weather, even when the tops of the plants are dormant.
Planting between mid-December and mid-April is also acceptable but more attention to
supplemental watering may be required due to drier seasonal weather conditions. Any
nursery instructions that come with the plants should be read and followed.
Plants should be laid out by hand generally following the spacing specified on the
planting plan map (Figure 2). Before planting, set the potted plants out on the landscape
according to the planting plan design and make sure the arrangement works before
digging any holes. Next, dig a bowl-shaped hole for each plant at least twice the width,
and slightly deeper, than the potted plant’s container. Roughen the sides and the bottom
of the hole with a pick or shovel. If the soil is especially dry, fill the hole with water and
let it soak in before continuing.
Remove the plant from its container gently without pulling on the stem of the plant.
Loosen bound roots on the outer inch of soil and cut any roots that encircle the root ball
to ensure that the plant will not continue to grow within its “memory” of the pot wall
confines. Set the plant in the hole so that the top of the soil remains level with the
surrounding soil. Fill the surrounding space with loose topsoil comprised of at least 20%
organic matter. Native top-soils are preferred, whenever possible. Cover any exposed
roots but do not pile dirt onto the stem or root collar, as this can kill some plants. To
discourage root rot, gently tamp down the filled soil to remove any air pockets that may
exist below ground, while allowing the soil to remain somewhat loose. Form a temporary
basin or trench around each plant to encourage water collection, and then water
thoroughly.
Immediately after watering, mulch such as wood chips, leaves, or brown carbon rich
compost should be added to a 3-inch thickness over the entire planting area without
covering the stems of the plants. The mulch will aid in slope stability, moisture and
nutrient retention, and weed control. Heavy duty woodchips are preferable in areas where
noxious or invasive species may become a problem. Staking of trees or shrubs should not
be necessary unless high winds exist or the tree is tall and has little roots. If staking is
deemed necessary, use a thick rope or padding around the trunk of the tree to prevent
damage to the bark, and use the minimum amount of tension necessary to achieve
balance.
Ludlow Cove II Mitigation Planting Plan 5 | M S & A
Figure 1. Planting Instructions
(sourced from City of Seattle Department of Planning and Development Environmentally
Critical Areas Standard Mitigation Plan)
2.4 Inspection and Maintenance Criteria
Maintenance must be done at least twice yearly. No herbicides or pesticides are to be
used, and all work should be performed by hand whenever possible, with the lightest
possible equipment where such use is necessary.
During year one, every failed plant must be replaced. During year one, and during the
first year after any replacement planting, plantings must receive 1 inch of water at least
once weekly between June 15 and September 15. Trees must be weeded to the dripline,
and mulch must be maintained at a depth of 3 inches. Weed herbaceous plantings as
necessary (flowers, ferns, etc.). All litter and non-native vegetation must be removed,
such as Himalayan blackberry (Rubus armeniacus), reed canary grass (Phalaris
arundinacea), evergreen blackberry (Rubus laciniatus), Scotch broom (Cytisus
scoparius), English ivy (Hedera helix), morning glory (Convolvulus arvensis), Japanese
knotweed (Reynoutria japonica), etc., and properly disposed of off-site.
All planting and maintenance activities shall comply with the clearing and vegetation
removal protection standards set forth in Chapter 18.22 and 18.25 Jefferson County
Code.
Ludlow Cove II Mitigation Planting Plan 6 | M S & A
3. Performance Standards
Performance standards are measurable criteria for determining if the goals and objectives
of the mitigation project are being achieved. If the proposed benchmarks are not achieved
by comparing the surveys to the mitigation goals, then contingency plans will need to be
implemented. The goal of this mitigation plan is to maintain the Critical Area buffers and
to restore wildlife habitat. Performance standards will include:
A. Survival rate: A 90% survival rate for installed plants and existing native plants will
be the goal in mitigation areas. 90% survival will be expected in all monitoring years.
B. Percent cover by native plants: Year one: at least 10-15% cover by installed and
volunteer native plants. Year two: at least 15-25% cover by installed and volunteer native
plants. Year three: at least 25-35% cover by installed and volunteer native plants.
C. Removal of non-native species in planted area: Less than 10% cover by non-native
species including, but not limited to non-native Himalayan blackberry (Rubus
armeniacus) and other invasive species listed in section 2.4 above.
4. Monitoring Plan
Monitoring is recommended to take place over a period of five years at the end of the
growing season (by October 31st) of each monitoring year. The performance standards
will be monitored by measuring plots in zones within the planting area that will be
established and mapped after planting occurs, on the as-built plan. There will be photo
points for each plot, and they will be referenced on the as-built plan. Photos will be taken
at all points for all five years as visual documentation of the performance standards
progress, or lack of.
Performance Standard # 1 (survival rate): Immediately after planting, all plants (including
planted and naturally established native plants) will be counted and documented within
the plots. At the end of each growing season (by October 31st) plots will be visited and a
count of surviving plants will be documented. The percent survival for the plots will be
calculated by dividing the total number of plants after planting by the total number of
surviving plants at the end of the season.
Performance Standard # 2 (percent cover): The percent cover standard will be monitored
by looking at each monitoring unit of the enhanced areas from above and estimating the
area covered by the individual species. The percent cover within an area can be
quantified as a total greater than 100% because plants (in tree, high/low shrub and
herbaceous layers) overlap in cover.
Ludlow Cove II Mitigation Planting Plan 7 | M S & A
Performance Standard # 3 (removal of non-native species): The cover of non-native
species should be maintained at less than 10%. The non-native coverage will be
determined through the same process as determining the coverage of native plants in
plots. Maintenance should occur at least two times during the growing season, one of
which should be conducted before plants go to seed. The maintenance method will be
hand removal, no herbicides.
5. Contingency Plan
If the 90% survival rate is not met by the end of any monitoring year, plants lost to
mortality should be replaced to achieve the percent cover performance standard described
above. Prior to replacement, an appropriate assessment should be performed to determine
if the survival was affected by species/site selection, animal damage, or some other
factor. Subsequent contingency actions must be designed to respond directly to the
stressor(s) which are increasing mortality of planted native species. If a particular species
is shown not to endure site conditions then another, more appropriate species will be
selected by the biologist conducting the monitoring. If excessive damage is observed,
protective measures will be introduced. Monitoring years may be added if significant re-
planting becomes necessary.
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Legend
Ludlow Cove Parcel - 968900100OHWM approx.30-ft. Marine Shore BufferWetland Boundary I25-ft Averaged Wetland BufferProposed (Mitigation Planting)
!(Red Alder (5)
!(Big Leaf Maple (2)
!(Douglas Fir (1)
!(Western Red Cedar (8)Existing (Proposed for Removal or Trimming)
!(Red Alder (16)"Big Leaf Maple (2)
#Douglas Fir (3)
"Western Red Cedar (2)
Service Layer Credits: Source:Esri, Maxar, GeoEye, EarthstarGeographics, CNES/Airbus DS,USDA, USGS, AeroGRID, IGN,and the GIS User CommunityParcel Data Jefferson County.
Address: Anchor Ln. Port Ludlow, WA 98365County: JeffersonTax Parcels: #968900100Map Date: 12/31/2020´Mitigation Planting Plan Figure
Ludlow Cove HMP 2