LTC 007-2021 Tree Impacts - City Projects 2021
OFFICE OF THE CITY MANAGER
NO. LTC # 007-2021 LETTER TO COMMISSION
TO: Mayor Dan Gelber and Members of the City Commission
FROM: Raul J. Aguila, Interim City Manager
DATE: January 8, 2021
SUBJECT: PALM & TREE IMPACTS IN CITY PROJECTS
The purpose of this LTC is to provide an overview of the City’s existing policies related to
tree preservation and, in particular an update on the impacts to palm and canopy trees in
existing City projects. Trees are a vital part of the City's infrastructure, providing
numerous environmental, economic, and social benefits. Trees improve air quality,
save energy by reducing electricity usage, ameliorate high urban temperatures, reduce
stormwater run-off, increase property values, improve productivity, reduce stress and
crime, and beautify residential and commercial neighborhoods. In addition, trees
decrease urban noise, encourage tourism and economic growth, preserve community
character and identity, provide habitat for wildlife, and shade pedestrian walkways.
According to the 2019 Community Satisfaction Survey, less than half of residents
(49.4%) reported being satisfied with the City’s tree canopy coverage in their
neighborhood. To increase community satisfaction, the City is expanding the tree
canopy through reforestation efforts, a tree preservation program and land development
regulations. In 2018, the community approved $439 million General Obligation Bonds
that included $5 million to plant over 5,000 trees throughout the City. By the end of
January 2021, 873 trees will be planted as part of the G.O. Bond reforestation project.
To establish and ensure the City has a healthy and well-managed urban forest, the
City has the following regulations and guiding documents related to trees:
1. Chapter 46, Division 2 – Tree Preservation and Protection
2. Chapter 126 – Landscape Requirements
3. Urban Forestry Master Plan
Chapter 46, Division 2 – Tree Preservation and Protection
The City’s Urban Forestry Division administers the tree preservation program which,
pursuant to Chapter 46, Division 2 of the City Code, establishes the City’s tree permitting
program for the removal or relocation of any palm or tree on public or private property.
This section requires mitigation for any palm or tree removed during redevelopment.
Mitigation for palm and tree canopy loss is required in the form of replacement canopy
trees. A minimum of 50% of all replacement trees shall be native to South Florida. Palms
can be added into projects; however, they do not count for mitigation due to the low
environmental benefits they provide. When the total number of trees required as
replacement trees cannot be reasonably planted on the property or a suitable alternate
location cannot be identified, then applicants can contribute to the City’s Tree
Preservation Trust Fund as an alternative.
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Chapter 126 – Landscape Requirements
The Land Development Regulations are included in Chapter 126. The intent of these
regulations is to establish minimum landscape standards that enhance, improve and
maintain the quality of the City’s landscape. This includes preventing the destruction of
the City’s existing tree canopy and promote its expansion and diversification. This
chapter provides minimum street tree requirements:
Street tree plantings shall be provided along all roadways at a maximum
average spacing of 20 feet on center
Minimum tree height: 12 to 14 ft
Minimum palm height: 15 ft of clear or grey wood
Street tree diversification to prevent a monoculture and to circumvent significant
tree loss to disease to a specific tree species the code diversification a project
tree palette
Palms may be planted in addition to the required number of street trees,
however palms shall not count towards the minimum number of required trees
Urban Forestry Master Plan
The Urban Forestry Master Plan (UFMP) was adopted by the City Commission on
October 14, 2020. The UFMP evaluates the existing tree canopy and provides best
management practices for growing a healthy urban forest. The UFMP includes a design
toolkit that outlines an appropriate planting palette, design criteria considerations, and
three case studies related to sea level rise adaptation. The planting palette includes
native and Florida-friendly palm and tree species that are appropriate for our location
and climate.
The UFMP provides an assessment of existing resources and sets the goal to increase
canopy coverage from 17% to 22% over the next 20 years in order to maximize the
environmental and community benefits of the city’s urban forest. In order to achieve this
target, the UFMP recommends reducing and replacing the overall number of palms
within public property with shade canopy so that the current 57% palm canopy coverage
is reduced to 25% by 2050.
Public tree population diversity is measured using the 10-20-30 street tree diversity rule,
where public tree populations are comprised of no more than:
30% of any family (e.g. Fagaceae – Beech family (Oak belongs to this family)
20% of any genus (e.g. Quercus – Oak)
10% of any species (e.g. Quercus virginiana – Live Oak)
While palms are an iconic part of Miami Beach’s landscape, they have moved from
being an accent plant to a major component to the City’s urban forest. Arecaceae, the
family of landscape palms, makes up over 55% of the public tree population, far
exceeding the 30% guidelines. The large number of palms not only impacts the diversity
of species in the City’s public tree population, making it vulnerable to diseases and
pests; but it also effects the quantity and type of benefits the urban forest can provide.
Table 1 demonstrates a comparison between a maturing live oak tree and a maturing
cabbage/sabal palm, where the live oak provides nearly seven times the annual benefits
compared to the palm.
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Benefits
Shade Tree Palm
Live Oak, Quercus virginiana Sabal Palm, Sabal palmetto
Diameter (DBH) 16" 16"
Carbon Dioxide (CO2)
Sequestered (Absorbed) 510 punds/year 2.71 pounds/year
Rainfall Intercepted 725 gallons/year 81 gallons/year
Ozone removed from air 20 ounces/year 1.70 ounces/year
Carbon Dioxide stored 3,214 pounds over lifetime 26 pounds over lifetime
Enevery Savings (A/C) 60 kWh 26 kWh
Energy Savings Value $10.00 $4.60
Annual Value of Benefits $31.00 $6.48
*Based on an analysis utilizing the USDA Forest Service's i‐Tree MyTree benefits tool (www.itreetools.org) ‐ v.2.4.16
Table 1: Comparison of the environmental benefits comparison between live oak
and sabal palm
Existing City Capital Projects
All City Capital Projects are required to adhere to the City’s Code. Currently, there are
22 projects that have or will impact palms and canopy trees. Table 2 provides a
summary of the number of palms and canopy trees slated for removal, relocation, and to
be planted. For these 22 projects, the City is losing 491 palms and 1,060 trees.
However, with these projects the City is gaining almost double the palms and trees lost:
891 palms and 2,549 trees. Attachment A provides a detailed breakdown for each of the
22 projects. These numbers are based on current plans; however, revisions may need to
be made to palm and tree disposition and mitigation plans based on unforeseen
conditions or project revisions.
Table 2: Summary of number of palm and canopy trees slated for removal,
relocation, and to be planted
During the planning and design phase, a tree assessment by a certified arborist is
conducted to determine the health and condition of existing trees and to identify trees
that can feasibly be relocated taking into consideration health, relocation success rate
for the species, and cost. This information is used to develop a management and
disposition plan. This disposition plan identifies palms and trees that will be preserved
and protected, those that will be relocated, and those that will be removed during
construction. Palms and trees are removed when there are conflicts with the proposed
design or because they have identified as being in poor health. When palms or trees
must be removed, mitigation is required in the form of canopy trees. While in the
construction phase, trees that were slated to remain or relocated may need to be
removed due to construction considerations. When these incidents occur, the Urban
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Forester works closely with the owner City department and construction team to help
reduce palm and tree impacts, and ensure that proper mitigation is included due to these
revisions.
The Urban Forestry Division works closely with the project managers and design team
during the planning, design and construction phases to assure that proposed work
adheres to the regulations of Chapter 46, Division 2 and Chapter 126 and utilizes the
UFMP as a guiding document to best management practices for preserving existing
palm and tree resources, while building a sustainable urban canopy for future
generations.
Trees are an important component of capital projects and are an opportunity to shift
toward a more resilient and environmentally beneficial tree canopy for the future. A
healthier urban forest in addition to complementing these community investment
projects.
A summary of 22 capital projects shows that while a total of 1,511 palm and
canopy trees will need to be removed, 3,440 palm and canopy trees will be
planted, a 127% increase in palm and canopy trees collectively.
For canopy trees specifically, while 491 will need to be removed, 2,549 will be
planted, a 419% increase in canopy trees.
For palm trees specifically, 1,060 palm trees will need be removed, the 891 new
palm trees will be planted, only an 18% decrease in palms.
Table 3 & 4: Rainfall Intercepted Annually and Pounds of CO2 Sequestered Annually are
calculated using iTree algorithms developed by the U.S. Forest Service.
If you have any questions, please reach out to Elizabeth Wheaton, Environment &
Sustainability Director at elizabethwheaton@miamibeachfl.gov.
Attachment: Citywide Project Status January 2021
RJA/ATH/ESW/OJL
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