Attachment 6 - Tree Mitigation Plan.pdf

NAVAL STATION MAYPORT TREE MITIGATION POLICY

NAVAL STATION MAYPORT TREE MITIGATION POLICY

1. Background:

This policy supports the goals, objectives, and strategies of the NAVSTA Mayport Integrated Natural Resources Management Plan (INRMP). In addition, these guidelines will be an effective tool for sustaining and protecting valuable established trees and vital forested lands on the Station. All proposed tree removals must be coordinated and approved by the NAVSTA Mayport Environmental Division. Following is a summary of the laws, regulations, and instructions for tree protection, removal, and mitigation on NAVSTA Mayport.

2. Definitions:

a) Caliper shall mean the diameter of a tree trunk measured at a point 6 inches above the existing grade for trees four 4 inches in trunk diameter and under, and 12 inches above the existing grade for trees larger than 4 inches in trunk diameter.

Caliper measurement is used in reference to nursery stock for new plantings.

b) Clear trunk shall mean the height of a tree measured from the ground to the point where the lowest branch or green frond is attached to the trunk.

c) DBH (Diameter at Breast Height) shall mean the diameter of a tree trunk at a distance of 4.5 feet above ground level. DBH measurements apply to existing, established trees.

d) Establishment Period shall mean the period of time during which planted trees and trees within tree protection zones (TPZ) are maintained, monitored, and remain under warranty from the Contractor. Period will commence on the date that inspection by the Contracting Officer shows that the new plants furnished under contract have been satisfactorily installed and shall continue for 365 days.

e) Establishment Period Tree Maintenance shall include adjustment of stakes, ties, guy supports and turnbuckles, watering, mulching, and pruning for health and safety. Stakes, ties, guy supports and turnbuckles shall be inspected and adjusted to avoid girdling. All stakes, guys, and turnbuckles shall be removed at the end of the 365 day period. Required pruning include removal of dead and broken branches and correction of structural defects. Pruning of all trees shall be accomplished by or in the presence of a ISA Certified Arborist and in accordance with ANSI A300P1 and ANSI Z133.1.

f) Overall height shall mean the height of a tree measured from the ground to the highest tip of the tree.

3. Exemptions:

The following tree removals are exempt from this policy:

a) Trees identified by the Florida Department of Environmental Protection, Bureau of Invasive Plant Management as invasive and non-native to North America and other nuisance trees. Common invasive species include, but are not limited to: Chinese tallow (Sapium sebiferum), chinaberry (Melia azedarach), pond willow (Salix caroliniana), camphor tree (Cinnamomum camphora), and golden raintree (Koelreuteria bipinnata).

b) Trees which are determined by the NAVSTA Mayport Environmental Division to be hazardous, dead, diseased, damaged by storms or other acts of nature, or pose imminent danger to public safety.

4. Tree Protection:

Trees and vegetation to be left standing shall be protected from damage incident to clearing, grubbing, and construction operations by the erection of barriers creating a Tree Protection Zone (TPZ) or by such other means as the circumstances require. These barriers shall be located away from the trunk at the dripline or at 1 foot for each inch of tree DBH, whichever is greater. The TPZ installation shall be approved by NAVSTA Mayport Environmental prior to construction activities.

See Figure 2, Detail B for Tree Protection Zone installation requirements.

Within the Tree Protection Zone, there shall be no grade changes, parking, washouts, building material storage, waste, excess soil, construction equipment storage, trenching, removing soil, compaction, or any other disturbance to the tree or the associated roots.

Install signs on each Tree Protection Zone fence indicating that the barrier shall not be taken down or moved without the approval of NAVSTA Mayport Environmental.

Existing trees within the TPZ that are unhealthy, that die, or have 20 percent or more of their crowns that die during the 365 day establishment period shall be replaced. The Contractor, at the direction of the Contracting Officer, shall remove the existing tree and stump and replace it as outlined in this policy.

5. Tree Removal and Mitigation:

Removal or damage of healthy, established trees having a DBH of 4 inches or greater on the Station shall be mitigated in accordance with the following guidelines. These guidelines shall be incorporated into plans and specifications for construction projects which require the removal of trees.

a) Mitigation Requirements – All trees

Removed Tree DBH Required Replacement Inches Ratio (Replacement Inches : Removed inches)

4” – 20” 1:1 (Plant 1 inches for every inch removed)

21” – 30” 2:1 (Plant 2 inches for every inch removed)

31” or greater 3:1 (Plant 3 inches for every inch removed)

b) Tree Replacement Requirements

i. Live Oaks

Removed live oaks shall be replaced with planted live oaks (Quercus virginiana).

Minimum planting size for live oaks shall be 8 caliper inches and 20’-22’ overall height.

ii. Pines

Removed pines shall be replaced with planted slash pines (Pinus elliottii).

Minimum planting size for slash pines shall be 4 caliper inches and 10’-12’ overall height.

iii. Palms

Removed palms shall be replaced with planted cabbage palms (Sabal palmetto) or pindo palms (Butia capitata).

Minimum planting size for palms shall be 12 foot clear trunk cabbage palms and 8 foot clear trunk pindo palms.

iv. Hardwoods and All Other Trees, including established ornamental landscape trees

Minimum planting size for all other trees (excluding live oaks, pines, and palms), shall be 6 caliper inches and 16’-18’ overall height.

Removed Hardwoods and all other trees shall be replaced with an approved replacement species from the following list:

Acer rubrum - red maple Butia capitata - pindo palm Carya glabra – pignut hickory Celtis occidentalis – hackberry Cercis canadensis – Eastern redbud Ilex x attenuata ‘East Palatka’ - East Palatka holly Ilex vomitoria - yaupon holly Juniperus virginiana – Eastern red cedar

Juniperus virginiana silicicola – Southern red cedar Liquidambar styraciflua - sweetgum Magnolia grandiflora - Southern magnolia Magnolia virginiana – sweetbay magnolia Nyssa sylvatica – black tupleo Pinus elliottii – slash pine Platanus occidentalis - sycamore Quercus hemisphaerica – laurel oak Quercus shumardiii – shumard oak Quercus virginiana – live oak Sabal palmetto – cabbage palm Taxodium ascendens – pond cypress Taxodium distichum – bald cypress Ulmus americana - American elm Ulmus alata – winged elm Any other native or indigenous tree that reaches a height at maturity of at least 40 feet and a spread at maturity of at least 25 feet.

6. Planted Trees:

The following requirements shall apply to all planted trees installed to meet the requirements of this policy:

a) Planted trees shall be native or indigenous species capable of withstanding the harsh growing conditions found on NAVSTA Mayport, which include salt spray, high winds, and dry soils.

b) It is recommended that removed trees be replaced with the same species as those removed whenever possible. In the event that commercial availability is limited for a particular species and documented by the contractor or if growing conditions don’t allow a particular species, alternatives shall be considered. The preferred replacement species for this scenario is live oak (Quercus virginiana) due to its tolerance of the local climate and soils.

c) When selecting replacement tree species, growing conditions shall be properly considered:

i. Water, light, and salt tolerance requirements of tree species shall be the primary deciding factors when selecting replacement species.

ii. Trees shall not be planted closer than 10 feet from buildings or structures.

iii. Trees shall not be planted closer than 5 feet from sidewalks and other hardscape features.

iv. Conflicts with overhead and underground utilities shall be avoided.

v. Potential for damage caused by surface roots shall be considered.

vi. Trees shall not be planted in locations where the mature canopy will affect buildings, structures, sightlines, utilities, or other Station mission requirements.

d) Parking lot islands may have tree plantings under the following conditions:

i. Islands shall be a minimum of 8 feet wide and 18 feet long.

ii. No limerock base material shall be present in the soil.

iii. Planted trees in parking lots shall have a minimum overall height of 12-14 feet and a clear trunk height of 6 feet to avoid conflict with vehicles. See Definitions in Part 2(b) in this policy.

e) Locations for replacement trees shall be on-site, as close to the location of the removed tree as possible. Planting locations shall be coordinated and approved by the Mayport Environmental Division.

f) If a lack of adequate growing space on-site has been documented by the contractor, the required replacement tree plantings shall occur at one of the following mitigation banks at NAVSTA Mayport:

i. Beachfront Area (East of Baltimore Street): Cabbage Palm plantings only.

ii. Parking Lot Islands: All approved tree species as listed in part 5(b)(iv) and 6(d) of this policy are acceptable for use in this area.

iii. Lake Wonderwood trail system and shoreline: All approved tree species as listed in part 5(b)(iv) of this policy are acceptable for use in this area.

iv. Golf Course Boundaries: All approved species as listed in part 5(b)(iv) of this policy are acceptable for use in this area. All tree plantings shall be coordinated and approved by NAVSTA Mayport MWR.

v. Golf Course Interior: Tree plantings are acceptable to define fairways. All approved species as listed in part 5(b)(iv) of this policy are acceptable for use in this area. All tree plantings shall be coordinated and approved by NAVSTA Mayport MWR.

vi. Parks and Recreation Field buffers: All approved tree species as listed in part 5(b)(iv) of this policy are acceptable for use in this area. All tree plantings shall be coordinated and approved by NAVSTA Mayport MWR.

vii. Pelican Roost RV Park: Cabbage Palm plantings only. All tree plantings shall be coordinated and approved by NAVSTA Mayport MWR.

viii. Other approved locations as determined by the Mayport Environmental Division.

See attached map, Figure 3.

7. Monitoring:

Newly planted trees need to receive proper care and maintenance during the required 365 day establishment period. The following requirements must be implemented and incorporated into the plans and specifications on projects involving tree removal and mitigation:

a) See Figure 1, Detail A for tree planting requirements.

b) During the establishment period, adequate watering for each particular tree species planted is required at NAVSTA Mayport due to the sandy, well drained soils.

Watering requirements will vary depending upon species. Tree watering bags are recommended. A watering schedule, including the filling of watering bags, shall be part of the establishment period maintenance activity requirements and submitted to NAVSTA Mayport Environmental.

c) All planted trees shall have a 3 inch thick, 36 inch diameter mulch ring. Mulch shall not touch the tree trunk and shall not be placed within 6 inches of trunk, see Figure 1, Detail A. This mulch ring preserves soil moisture, controls soil temperature, and protects the tree trunk from mechanical damage from mowing equipment. In addition, the mulch reduces competition from turf, weeds, and groundcover which compete with the tree roots for water and nutrients.

d) Staking is only recommended for planted trees with large canopies on windy sites or where people or animals may topple them. Ensure staking system does not injure the trunk and bark. All staking and guying shall be removed at the end of the 365 day establishment period.

Figure 1, Detail A

Figure 2, Detail B