VOTING MEMBERSDAVID IGE

SUZANNE CASE
DEPARTMENT OF LAND & NATURALRESOURCES

GOVERNOR OF HAWAIISHAN TSUTSUISCOTT ENRIGHTHAWAII DEPARTMENT OF AGRICULTURE

LIEUTENANT GOVERNORKEITH KAWAOKA, D.Env
DEPARTMENT OF HEALTHDAVID LASSNER
UNIVERSITY OF HAWAI‘IHAWAII INVASIVE SPECIES COUNCIL
1151 PUNCHBOWL ST, #325
HONOLULU, HAWAII 96813

LEO ASUNCION
OFFICE OF PLANNING, DEPARTMENT OF
BUSINESS, ECONOMIC DEVELOPMENT &TOURISMDAVID RODRIGUEZ
DEPARTMENT OF TRANSPORTATION

August 24, 2017SUBMITTALTO:

Co-chairs and Members
Hawaii Invasive Species Council
State of Hawaii

FROM:John-Carl Watson, Planner, & Joshua Atwood, Program Supervisor
Hawaii Invasive Species Council

SUBJECT:

Requesting adoption of the Strategic Plan for the Control and Management of
Albizia in Hawaii as a HISC guiding document for future policy and funding
efforts

Background
The Hawaii Invasive Species Council (HISC) recognized albizia as an important invasive species
in Resolution 11-2. Since then, the HISC has invested in multiple albizia control strategies,
including the support of the Big Island Invasive Species Committee (BIISC) and their Albizia
Control Teams, as well as mapping efforts, economic analyses, and initial research by the US
Forest Service into the use of biological control to limit the further spread of albizia. In 2013,
Senate Resolution SR41-SD1 requested that the HISC create a comprehensive plan for thecontrol of albizia throughout the State.
Attached to this submittal is a statewide strategic plan for the control and management of albizia
in Hawaii. The purpose of this strategic plan is not to provide site-specific management actions
but to provide large-scale objectives and a framework to minimize the impacts of albizia on theenvironment, human health, and infrastructure by:• Describing statewide impacts of albizia• Summarizing available control methods• Recommending directions for future research on detection and control
methodologies• Supporting and encouraging the development of island or site-specific managementplans• Identifying priorities for HISC funding to support research, detection, and control
efforts.
This plan, if adopted by the HISC, could be utilized to direct future funding and collaboration
efforts supported by the HISC or other entities.

Discussion
Native to Papua New Guinea, Indonesia, and the Solomon Islands, albizia (Falcataria
moluccana) is a fast growing tropical tree that was introduced to Hawaii in 1917 by Joseph Rockas an ornamental plant and for reforestation purposes. This year marks the 100th anniversary ofalbizia's arrival to Hawaii.
Based on initial imagery analysis, the plan estimates that there are roughly 20,000 acres on Oahu
infested with albizia, and 43,000 acres infested in east Hawaii Island. Albizia has been evaluatedby the Hawaii-Pacific Weed Risk Assessment as a high risk invasive species.
While albizia is widespread across Kauai, Oahu, Maui, and Hawaii Islands, localized control canbe utilized to minimize damage to people and infrastructure. This has been demonstrated by the
BIISC's Albizia Control Teams, through which BIISC has collaborated with communities,
government, and utility companies to target albizia near power infrastructure, roadways, andhomes.
The attached strategic plan does not provide a complete guide to controlling all albizia in Hawaii.
Rather, it provides the tools needed to develop site-specific plans and can serve as a guiding
document for future policy and funding efforts. The plan includes a template for community
groups to create site-specific management plans, suggestions for landowner or agency actions
relating to albizia, suggestions for future research directions, and potential policies that could be
proposed as legislation and/or administrative rules.
One potential utility for this plan is to seek a legislative appropriation specific to supporting theobjectives and implementation tasks described in the plan. This could function as a separate
HISC Call for Proposals in future years.
Legal Authority• HRS 194-2 (a): Establishes the HISC for the purpose of cabinet-level coordination andplanning among state departments, federal agencies, and international and local initiatives• HRS 194-2 (a)(2): Advise, consult, and coordinate invasive species-related efforts withand between the departments of agriculture, land and natural resources, health, andtransportation, as well as state, federal, international, and privately organized programs
and policies.
Recommendations
1. That the HISC adopt the Strategic Plan for the Control and Management of Albizia in
Hawaii as a HISC guiding document for future policy and funding efforts, provided that
portions of the document may be updated in the future based on new information.
Attachments:
1. Strategic Plan for the Control and Management of Albizia in Hawaii

STRATEGIC PLAN FOR THE CONTROLAND MANAGEMENT OF ALBIZIAIN HAWAIʻI
Hawaiʻi Invasive Species Council, 2017

STRATEGIC PLAN FOR THE CONTROLAND MANAGEMENT OF ALBIZIA IN
HAWAIʻI
Primary Author:
John-Carl (JC) Watson
Planner; Hawaii Invasive Species Council
Johncarl.r.watson@hawaii.gov

Contributions and Review by:
Big Island Invasive Species Committee, Josh
Atwood (HISC), Randy Bartlett (HISC), Springer
Kaye (BIISC), Ken Puliafico (USFS), Tracy
Johnson (USFS), Jodi Watson, and James Leary(UH-CTAHR)

Figure 1: Albizia Control
Photo provided courtesy of JC Watson

Introduction ................................................................................................................................................................................. 2
Impacts ........................................................................................................................................................................................... 4
Infrastructure damage ............................................................................................................................................................. 4
Human Health Hazards ............................................................................................................................................................ 5
Ecological Impacts...................................................................................................................................................................... 6
Cultural ............................................................................................................................................................................................ 8
Impacts: Objectives and Implementation Tasks ............................................................................................................ 8Control Methods ...................................................................................................................................................................... 10
Physical Control ........................................................................................................................................................................ 10
Chemical Treatment ............................................................................................................................................................... 11
Biological Control .................................................................................................................................................................... 12
Future Technologies ............................................................................................................................................................... 13
Control Methods: Objectives and Implementation Tasks ....................................................................................... 13
Planning ....................................................................................................................................................................................... 13
Site-Specific Management Plans........................................................................................................................................ 13
Community Engagement ...................................................................................................................................................... 14
Access............................................................................................................................................................................................. 15
Stakeholder Coordination .................................................................................................................................................... 16
Liability ......................................................................................................................................................................................... 16
Planning: Objectives and Implementation Tasks ....................................................................................................... 16
Legislature, Policy, and Funding ....................................................................................................................................... 17
Legislature, Policy, and Funding: Objectives and Implementation Tasks ....................................................... 17
All Objectives and Implementation Tasks .................................................................................................................... 19
Literature Cited ........................................................................................................................................................................ 22
Appendices ................................................................................................................................................................................. 23

Introduction
Albizia infests large swaths of our islands. Its rapid growth crowds out native species, its
nitrogen fixing abilities change natural ecosystems, and its brittle wood breaks easily,
smashing property and destroying lives. Despite being one of the most detrimental plants
in our state, there is no coordinated effort to address this invasive species on a statewide
scale. In 2013, Senate Resolution SR41-SD1 resolved that the Hawaiʻi Invasive Species
Council (HISC) create a comprehensive plan for the control of albizia throughout the State.
The purpose of this strategic plan is not to provide site-specific management actions but toprovide large-scale objectives and a framework to minimize the impacts of albizia on theenvironment, human health, and infrastructure by:
•
•
•
•
•

Describing statewide impacts of albizia
Summarizing available control methods
Recommending directions for future research on detection and control
methodologies
Supporting and encouraging the development of island or site-specific management
plans
Identifying priorities for HISC funding to support research, detection, and control
efforts

Albizia in Hawaiʻi
Native to Papua New Guinea, Indonesia, and the Solomon Islands, albizia (Falcataria
moluccana) is a fast growing tropical tree that was introduced to Hawaiʻi in 1917 by Joseph
Rock as an ornamental plant and for reforestation purposes (Elbert, et al. 2003).
Approximately 140,000 albizia were planted in forestry areas throughout the state during
the non-native tree forestry planting efforts in the early 20th century. This effort was prior
to our understanding of how non-native and invasive plants impact our environment, andat the time albizia was valued for its rapid growth. Albizia is nitrogen fixing which allows it
to thrive in nutrient deficient soils and become established in relatively intact native
ecosystems. It produces large quantities of seeds, which are encased in light papery pods
and can easily be dispersed over large distances. Albizia is also one of the fastest growing
trees on Earth, and is capable of growing up to 15 feet per year and easily attain a height ofover 35 meters or 100 feet (Hughes, et al. 2011). The rapid growth rate of this species
produces a massive number of trunks and limbs that are structurally weak and brittle innature. Large trees are prone to “sudden limb shear, ” or “sudden branch drop.” Thisphenomenon is defined as the sudden failure and collapse of live branches with no sign ofphysical weakness, and without apparent cause (Draper, et al. 2009). Arborists certified inrisk assessment confirm that the natural state of an albizia is the brittle, breakage-prone
structure and that, regardless of current size, any albizia within 250 feet of a structure
should be considered a hazard (BIISC, 2015). The term "hazard trees" as defined in thisstrategic plan applies to trees that pose a threat to roads, structures, power lines, or humanhealth because of their close proximity to human structures. The Hawaiʻi-Pacific Weed Risk
Assessment (HPWRA) scores albizia at eight and is categorized as highly invasive. In 2011,2

the HISC passed resolution 11-2 resulting in the support of designating albizia as aninvasive species. See Appendix no. 1 for complete details.
Fortunately, there are aspects of albizia biology that make large-scale control andmanagement actions feasible. First, seedlings are shade sensitive and mass germination
events require that the canopy be open enough to allow ample light to penetrate to theunderstory layer (Hughes, et al. 2011). Secondly, there are a variety of effective methods
that can be employed to control both seedlings and mature trees.
On a statewide scale, there is limited information as to the location and distribution of
albizia populations. In 2014, albizia populations on Hawaiʻi Island were mapped by Julie
Gartner using guided classification of 8-band World View 2 imagery. Infested areas wereconfirmed using Pictometry (high-resolution imagery) and roadside surveys. In addition, abasic analysis of infested acres using aerial imagery was performed for Oʻahu for use within
this strategic plan.
Polygons were created
and depict areas thathave a dominant albizia
canopy. It should be
noted that the imagery
used to create thecoverage map was from2012, and that
additional analyses withmore recent imagery
may assist in
implementation of
specific control projects.
Due to this constraint,
the map should beconsidered to depict theminimum acres ofalbizia coverage on the
Figure 2: Heavily infested areas on O’ahu with dominant albizia canopy.
specific island. Due to
Image provided courtesy of JC Watson
the rapid growth rate ofalbizia, it is possible that populations of trees reaching heights up to 75 feet in 2017 were
not yet detectable using imagery from 2012.
Acres infested on Oahu: ~20,000 acres
Acres Infested in East Hawaii Island: ~43,000 acres
Hawaiʻi Pacific Weed Risk Assessment score: 8, HIGH RISK INVASIVE

3

Impacts
The impacts of albizia are widely known but were emphasized by Tropical Storm Iselle in2014, when hundreds of Hawaiʻi Island residents were stranded for days with their roads
blocked and without power for months due to downed albizia trees. Hawaiʻi Electric Light
Company (HELCO) estimates that itspent $13.7M responding to damage
from Iselle, and the Hawaii Island
branch of Hawaiʻi Department ofTransportation (HDOT) estimates that
90% of all received calls about fallentrees for the past several years have
involved albizia trees (BIISC, 2015).
However, Hawaiʻi Island is not the onlyisland where albizia-related hazards
threaten residents. Stands of large
albizia can be found on all of the main
Hawaiian Islands except for Niʻihau,
Molokaʻi, and Kahoʻolawe.
Figure 3: Property damage caused by fallen albizia branches.

Photo provided courtesy of BIISC.
There is a great need to fully quantify
the monetary cost of potential damages
from albizia. The Federal Emergency Management Agency (FEMA) requires that analysis
studies be conducted as a requisite to apply for federal monies or FEMA grants. An
economic study needs to be conducted to assess and measure the financial impact of albizia
in Hawaiʻi. The following sections outline the various sectors that are negatively impacted
by albizia. In FY17, HISC funded a project through the University of Hawaiʻi to begin
analysis of the economic impacts of albizia to Hawaiʻi, as well as map population
distributions on Oʻahu and Kauaʻi using high-resolution imagery.

Infrastructure damage
Often the result of fallen trees or branches, one of the main impacts of albizia is damage toinfrastructure. Below is a list of the common types of damage to infrastructure in Hawaiʻicaused by albizia.
Roads/access ways
Albizia readily sprout and grow along roadsides. Due to the rapid growth habit of thisspecies, trees can become hazardous to roads within a few years. Fallen trees and branches
can easily block roads making them impassable for emergency response personnel,
motorists, and residents. Once fallen trees and/or branches block a road, manual removal
is the only method that can be used to clear debris and restore access. As albizia are prolificseed producers, mature trees growing adjacent to roadside right-of-ways (ROW) act as aseed source and allow for perpetual reinfestation. This results in the need for continual andconstant maintenance. Large hazard trees may require careful removal by a certified

4arborist, drastically increasing the cost for removal. HDOT reportedly spent $1 million permile to remove 1,000 albizia trees on the island of Kauaʻi, with the removal of one large
tree costing as much as $10,000. At other locations statewide, along an estimated 50 milesof road, the albizia tree population is maturing and reaching high densities where it willpose a significant safety risk to highway users – potentially imposing $50 million in
management costs (HDOT 2011).
Transmission/ telephonelines
Albizia readily sprout and growalong line infrastructure rightof-ways. Due to the rapid
growth habit of this species,
trees often attain a heightcapable of interfering withpower and telephone
infrastructure within a periodof a few years. Trees growing
along right-of-ways pose aserious threat to the lines.
Large branches are capable ofdamaging and downing bothtransmission and telephone
Figure 4: Albizia trees encroaching on power lines.
lines. Since albizia are prolificPhoto provided courtesy of BIISC.
seed producers, mature trees
growing adjacent to transmission line right-of-ways act as a seed source and allow for
perpetual reinfestation of the right-of-way. The result is the need for continual andconstant maintenance.
Buildings and property
Albizia often shed branches that can cause damage to any structures or personal property(i.e. vehicles) located beneath them. Due to the large size to which albizia can grow, damage
caused by hazard trees can occur from adjacent properties, natural lands, or right of ways.
Stream clogging
In high rain events, fallen trees and branches can block streams at constriction points,
resulting in debris accumulation and flooding. In 2004, heavy rains and albizia debris
contributed to the flooding of Mānoa stream. This flood event impacted residents, utilities,
and the University of Hawaiʻi at Mānoa. An estimated $85 million in damage was caused bythis single event (Honolulu Advertiser, 2007).

Human Health Hazards
Falling branches and trees pose a serious threat to human health. Due to the extreme
height achieved by some albizia, both large and small branches can cause severe injury or5death when dropped. Fallen branches can block roads and limit access to emergency
services. There have been multiple recorded albizia related fatalities and injuries in
Hawaiʻi. Many of Hawaiʻi’s popular hiking trails lead through albizia infested areas. Hazard
trees in proximity to areas of frequent use expose both residents and visitors to risk.

Ecological Impacts
Native Forests
The process of albizia
becoming established in anative forest sets off aseries of events that intime will drasticallyreduce native biodiversity
and promote the successof non-native species. The
negative effects of albizia
are especially pronounced
in forests that havealready been invaded by
non-native species such as
strawberry guava (Psidium
cattleianum). TypicallyFigure 5: Albizia within native dominated forest on Hawaiʻi Island.
seedlings become
Photo provided courtesy of ESRI
established in new areas
following a disturbance event such as road construction, a landslide, or a hurricane. Onceestablished, seedlings will rapidly increase in height and quickly overtop the surrounding
trees. Having reached the canopy, the growth form will begin to change from a form withsingle apical dominance to a dense expanding canopy. This large spreading canopy
effectively blocks the sunlight and suppresses growth of the trees beneath. Aside fromsuppressing the growth of other plants, albizia has been shown the change nutrient levels
in soils (Hughes, et al. 2006). Albizia are highly effective at fixing nitrogen, a trait thatfacilitates its rapid growth. This change has a direct impact on native plants, since Hawaiʻi’s
volcanic soils are naturally nutrient deficient and the plants that evolved here have adapted
to thrive without requiring large amounts of nitrogen. The impacts of greatly increasing thenitrogen inputs from albizia in the form of leaf litter have been shown to profoundlytransform invaded forests (Hughes, et al. 2006). This nitrogen “boost” facilitates invasion
by weeds adapted to high nitrogen levels while simultaneously suppressing native plant
species. The increase of non-native plant species and decrease of native plant species also
reduces the availability of quality habitat for native animals. The cumulative impacts ofalbizia populations have long-term detrimental consequences for Hawaiian ecosystems as awhole.

6

Water/Hydrology Impacts
There are no formal data regarding evapotranspiration rates or hydrological impacts,though the high growth rate of albizia may indicate substantial water use. In addition, thenitrogen fixing properties of albizia have been shown to provide nutrients to other invasive
species such as strawberry guava (Psidium cattleianum) (Hughes, et al. 2006). The
hydrological impacts of strawberry guava have been researched, and show that stands
dominated with this species have a lower ground-water recharge rate and a higher
evapotranspiration rate than native forests (Giambelluca, et al. 2008). Surface water
impacts caused by albizia
populations include
clogging, bankdestabilization, andstream diversion. Debris
and fallen trees can cause
blockages and increase
the risk of flooding duringhigh rain events. The
shallow rooted nature of
albizia growing along
streams allows for thebank to become undercut,
eventually resulting in the
toppling of the tree andFigure 6: Albizia trees growing within urban stream corridor on Oʻahu.
destabilization of the
Photo provided courtesy of JC Watsonbank itself.

Agriculture
The impacts of albizia on the agricultural industry in Hawaiʻi have been largely unstudied.
However, if the growth rates, cost of removal, and invasive nature of this species are taken
into consideration, it is possible to get a general understanding of the negative pressuresthat albizia places on agricultural activities.
Farming
Albizia infestations effect both commercial and subsistence farming. Large trees adjacent toagricultural properties present a hazard for workers and infrastructure, have the potential
to shade out crops, and supply a large amount of seeds that can germinate in cultivatedareas. The practice of crop rotation and allowing lands to sit fallow is a standard practicefollowed by many agricultural businesses. Though the act of leaving a section of land to rest
is highly beneficial and a key facet to sustainable agriculture, it also presents anopportunity for albizia seedlings to become established. Depending on the length of time aplot of land is allowed to sit without cultivation, seedlings can outgrow the farmers’ ability
to simply plow them over. This results in a removal cost for the farmer. In the event that7

large plots of land are left fallow for many years, albizia trees can achieve a size and densitythat is cost-prohibitive to bringing the parcel back into cultivation.
Forestry
Timber plantings in Hawaiʻi rely on the health and growth of commercial hardwood
species. Albizia has been planted as a nitrogen source in several Eucalyptus plantings in
Hawaiʻi and is considered beneficial in some situations. However, if plantings are not
managed in an effective manner, planted albizia will negatively impact the site by rapidly
overtopping and outgrowing the commercial tree species. The presence of large mature
albizia trees within a timber planting also increases the cost during harvest. In some cases,
albizia tree populations within active timber production sites make the cost of harvest
prohibitively high, resulting in abandonment of the project and a substantial loss ofinvestment for the timber producer.

Cultural
The impact of albizia on cultural sites and historic view planes is significant. Many viewplanes throughout the state have been changed to the point where historic vistas,geological landmarks, and cultural sights are no longer visible or recognizable. This type of
impact is difficult to quantify, as the value of these resources are subjective and changes
happen gradually over time. In addition to view plane obstruction, large trees contribute to
the degradation of unmanaged cultural sites as trees and roots can cause irreparable
damage by destroying walls and agricultural terraces.

Figure 2: View plane obstruction at Wailuku River State Park (Rainbow Falls) on Hawaiʻi Island. Note the lone
albizia tree in the photo from the early 1980s on the left.
Photo provided courtesy of BIISC

Impacts: Objectives and Implementation Tasks
I1: Assess population size and footprintof albizia on a statewide scale
I2: Assess environmental impacts

I1.1: Complete mapping of albizia populations using
Pictometry or other high accuracy techniques to create
statewide maps
I2.2: Research hydrological impacts
I.2.2: Create a distribution model to assess thepotential habitat suitable for albizia infestation8I3: Protection of priority watershed andwildlife habitat

I2.4: Perform hazard analysis based on current
footprint and distribution model
I2.5: Perform tree risk assessments of albizia locatedalong trails and areas of use
I3.1: Removal or treatment of all albizia trees inpriority watershed areas as identified by the Divisionof Forestry and Wildlife's priority watershed map
I3.2: Removal or treatment of all albizia from native
dominant forests, areas of high ecological value, andforests containing threatened or endangered species

I4: Mitigate hazards to increase water
quality and reduce flooding

I5: Assess the economic impact ofalbizia
I6: Establish sustainable secondary andalternative uses for removed materials
I7: Protect valuable public
infrastructure from albizia damage

I8: Protect private infrastructure fromalbizia damage from trees located onstate lands

I9: Maintain cultural sites and historicview planes

I4.1: Establish stream pilot program to remove albizia
along stream corridors
I4.2: Removal or treatment of all albizia growing
within urban stream corridors
I4.3: Perform tree risk assessments for albizia trees
located within stream corridors
I5.1: Perform an economic analysis of the impacts ofalbizia and associated costs
I6.1: Explore sustainable alternative uses for materials
generated by albizia removal projects
I7.1: Develop a comprehensive list of public
infrastructure pieces impacted by albizia
I7.2: Standard roadside surveys and control of
seedlings
I7.3: Standard utility corridor surveys and control of
seedlings
I7.4: Removal of all hazard trees affecting public
infrastructure statewide and create buffer zones oftreated trees
I7.5: Assess hazard trees, cost of treatment for albizia
near public schools and universities
I8.1: Solicit requests from private landowners abutting
state lands for potential removal of hazard trees, inorder to generate a cost and resource estimate forremovalI8.2: Once funding has been secured, (see L4.8)
remove hazard albizia located near private lands andcreate buffer zones of treated trees
I9.1: Assess impacts to historic properties, culturalsites, and view planes
I9.2: Removal or treatment of trees impacting historic
properties, cultural sites, and historic view planes
I9.3: Develop standard practices for removal from
historic sites with minimal impact.

9

Control Methods
Physical Control
Physical removal of hazard trees requires special equipment and knowledge and must be
performed by experienced and certified arborists. The removal or disposal of felledmaterials is also an important aspect to consider when utilizing this method.
Complete Removal
Complete removal requires the highest level of effort when using any of the physicalremoval methods for large trees. It entails the complete felling of the tree and the complete
removal of all felled materials from the site. This method is typically used in urban
environments, where there is insufficient space for materials to be left in place todecompose. This method also results in the highest amount of cost per tree, as it often
encompasses the total cost of the felling, removal, and disposal. Though this method isexpensive and labor intensive for large trees, it is cost-effective for newly sprouted
seedlings. The seedlings are shallow rooted and can be easily hand-pulled until they haveattained a height of five feet. Seedlings can easily be bagged and removed from a site.
Hard Trimming
In many cases, under the guidance of a certified arborist, hazard trees can be given a “hardtrim”, whereby limbs and branches that extend towards infrastructure are cut to: 1)
eliminate the possibility that they would fall onsuch infrastructure, and 2) counterbalance thetree so that it is highly likely to fall away fromsaid infrastructure. Following a “hard trim,” thetree may be killed with herbicide and allowed tofall apart safely. This “hard trim” approach canbe done at a fraction of the cost that it would
take to completely cut down a given tree. To
further reduce cost, felled materials can be left
onsite if the landowner is willing to allow thetree to decompose in situ.
Ring-Barking
This control method entails the complete
removal of the inner and outer cambium layers
from around the entire circumference of the tree.
Common tools used to strip the bark from thetree include hand tools such as a machete, bark
spud or draw blade. First, incisions are madearound the base of the target tree at soil level.

Figure 8: Ring-barked tree in Sāmoa.
Photo provided courtesy of JC Watson

10The bark is then stripped from the soil up the trunk (approx. four to six feet). This
technique is fairly low cost and can be used by virtually anyone. Results are highly effectivewith defoliation occurring between six months to one year, and death of the tree eventuallyfollowing. (Hughes, et al. 2012). This method should not be used on hazard trees, as treatedtrees are left to die in place and pose a risk to surrounding infrastructure.
Girdling
This method is fundamentally the same as the ring-barking technique, and entails thecomplete removal of a band of the inner and outer cambium layers approximately six
inches to one foot wide from around the entire circumference of the tree. Common tools
used to strip the bark from the tree include hand tools such as a machete, hatchet, or
handsaw. Typical results include defoliation within one year followed by tree death. For
faster results, herbicides can be used in conjunction with this method, and are applied tothe site of bark removal. This method is fairly labor intensive when compared to otherchemical treatment options as discussed in the following section. As both girdling and ringbarking methods do not require the use of herbicide, repeat treatments may be necessary.
In addition, this method should not be used on hazard trees, as treated trees are left to diein place and pose a risk to surrounding infrastructure.

Chemical Treatment
Using chemical control to treat albizia is highly effective and requires very small amountsof herbicide. There are numerous techniques that can be utilized when treating albizia witha chemical application. Choosing the correct method or combination of methods andpairing them with site-specific strategies is key to the success of any albizia control project.
Incision Point Application (IPA)
IPA is an efficient technique for administering a lethal dose of herbicide directly into thevascular system of woody species. This method can be used as a stand-alone treatment orin combination with hard trimming. It should not be used for hazard trees, as treated trees
are left in place and shed branches as the tree dies. Canopy defoliation can be expected
within two to six weeks and canopy collapse within two years (Hughes, et al. 2017). Trunks
may remain standing for up to three years and fallen trees will continue to decompose for
decades or longer. Specifications for treatment include the injection of a 0.5 ml dose of
undiluted Milestone® herbicide into equidistant hatchet incisions (Leary, et al. 2011).
Complete instruction can be found in Appendix no. 2. Herbicide costs per tree associatedwith this method can be calculated by multiplying the cost per milliliter by the number of
0.5 ml doses per tree. For example: The current cost of Milestone® /dose is $0.05. A treethat is approximately 24 inches in diameter will require approximately 15 incisions.
($0.05*15=$0.75). The herbicide cost for this tree will be approximately $0.75. It should be
noted that the majority of cost associated with treatment will be from labor; both in theform of cost to treat (time it takes to administer treatment per tree) and time to access(time it takes to access the trees). These costs will vary by project site, as each will havediffering levels of accessibility and tree densities.

11

Cut-Stump
The cut-stump method is widely used,
and is effective on a variety of different
species. This method entails felling thetarget tree and treating the remaining
stump with a concentrated dose ofherbicide. Typical herbicides used forcut-stump application include Garlon
4®, Garlon 4 Ultra®, or Garlon 3A®
(active ingredient: Tryclopyr) at 20%100% concentration.
Foliar Spray
The Foliar spray method entails
Figure 9: Control using the Incision Point Application
applying a liquid herbicide solution
control method.
directly to the leaves of a target plant
Photo provided courtesy of BIISC
species. This control method is not aneffective means of controlling albizia once they have surpassed the seedling stage, but canbe a highly effective and efficient means of controlling the dense mats of seedlings that
result from a mass germination event. The use of foliar application methods on large trees
is not considered to be logistically feasible due to the need for helicopters, custom sprayequipment, large quantities of herbicides, and non-target impacts. Foliar application istypically applied with the use of hand, backpack, or vehicle-mounted sprayers.

Biological Control
Biological control involves using host-specific living organisms such as insects, fungi, plant
pathogens, etc. to suppress a weed infestation. The use of biological control agents is often
the only feasible method of permanently reducing infestations when faced with large, longestablished invasive species populations. Biological control research is a lengthy processthat typically includes exploratory research in the native range of the target species tosearch for potential agents, host-specificity testing to ensure potential agents do not havesignificant non-target impacts, and a review and permitting process through the UnitedStates Department of Agriculture Animal Plant Health Inspection Service Plant Protection
Quarantine (USDA APHIS PPQ) and Hawaiʻi Department of Agriculture (HDOA). Finalapproval for the field release of the control agent may also require public consultation anddisclosure pursuant to the National Environmental Policy Act (NEPA) and Hawaiʻi
Environmental Policy Act (HEPA).
For albizia, biological control agents would ideally target reproductive capacity and/or
attack trees only in early stages of growth. Caution should be taken to avoid introducing a
biological control agent that could weaken or kill adult hazard trees, as this could pose
additional risks to people and infrastructure. However, defoliation of adult trees by
biological control agents can greatly reduce the effect of wind on these trees thereby

12lowering the risk of sudden limb drop while slowing tree growth.
Through a HISC-funded proposal, the Institute of Pacific Islands Forestry, Pacific-Southwest
Research Station, USDA Forest Service began exploration for potential control agents ofalbizia in 2015. HISC funded additional research in 2016 and 2018 to conduct additional
foreign exploration and begin host-specificity testing. To bring populations of albizia down
to manageable levels in Hawaiʻi, future and continued biological control research isnecessary until a suite of successful agents have been released.

Future Technologies
The potential for currently unknown technologies relating to the management of invasive
species may prove to be significant. As new technologies are researched and become
available, potential use as a means of controlling albizia should be considered. Some
examples may include:• Gene-drive• Genetically modified control agents• Unmanned aerial systems

Control Methods: Objectives and Implementation Tasks
M1: Establish new and effective
biological controls for albizia
M2: Establish additional chemical andphysical removal techniques or options

M3: Establish improved technologies
for the control of albizia

M1.1: Continued biocontrol research
M1.2: Release of albizia-specific biocontrol agents
M2.1: Research additional foliar, systemic, and preemergent control options
M2.2: Research improved physical removal ortreatment options
M3.1: Research of future technologies and methods
such as genetic techniques, deployment methods, etc.

Planning
Site-Specific Management Plans
While this strategic plan identifies statewide recommendations for advancing detection
and control of albizia, each island (or site within an island) will present its own specificsuite of challenges and should develop a specific management and control strategy.
Through partnerships between Hawaiʻi Department of Transportation (HDOT), HawaiʻiElectric Light Company (HELCO), Hawaiʻi County, the US Forest Service, and the Big Island
Invasive Species Committee (BIISC), Hawaiʻi Island has become the forerunner withregards to albizia management and control on a landscape scale. With a team dedicated toalbizia removal and standardized community workshops, the actions of BIISC can be used
as a model for how to begin on-the-ground albizia management actions.

13Template for site-specific control plans
To facilitate the creation of site-specific management actions, a plan template has beendeveloped. See Appendix no. 3 for management plan template. Site-specific management
plans provide detailed goal-oriented control strategies to address the unique needs andchallenges associated with a given management site.

Community Engagement
Community engagement,
empowerment, and participation
are all critical components of arobust and diverse management
strategy. Engagement of local
community leaders, information
sharing, and collaborativeplanning are highly effectivemeans of disseminating
information into a community.
Adaptable island-based orcommunity-specific plans should
be developed to allow for
maximum community
involvement, management, andFigure 10: Albizia growing in vacant lots pose a threat to adjacentcontrol. When beginning
properties.
community engagement projects,
Photo provided courtesy of JC Watson
pilot communities with a highlikelihood of success should be targeted first. By successfully attaining management withina target community, a positive track record can be established, thus making it easier tomove forward and engage other more challenging communities.
The BIISC Albizia Control Teams or “Albizia Assassin” program provides a good example ofthe steps that can be taken to create community control teams. Steps include:• Hosting an invasive species management organization representative at a
community event such as a neighborhood board or association meeting to present
about albizia and discuss the potential program.
• Establishing a community liaison or albizia coordinator. This person assists insetting up training workshops and is the point of contact for the management
organization and volunteers.
• Holding a training workshop to engage community members and provide training
on hazard tree identification, treatment methods, and protective equipment. These
workshops are often paired with a community workday.
• Tracking progress. Tracking and reporting both treated trees and untreated hazard
trees not only provides a clear measure of program impact and engagement, butalso helps management organizations provide support when needed.

14Additional information on how to set up a community control team can be found on the
BIISC website at: http://www.biisc.org/neighborhood-albizia-control-teams or in
Appendix no. 4.

AccessWilling Landowners
Cooperative planning with landowners and obtaining permission for access will benecessary for all survey and control operations. Given the variety of different chemical andphysical methods available for albizia management, it is important to accommodate alandowner's preferred management or control technique.
Resistant or Unresponsive Landowners
In the event that a landowner is either resistant or unresponsive, project managers mustevaluate whether long-term project success requires treatment of the landowner's
property, and whether the benefits of project success outweigh the costs (financial andotherwise) of pursuing legal action to gain entry to the property. There are multiple
provisions in state law to gain access to private property for control of albizia, but theseshould be used as a last resort, only when access is denied and treating the property inquestion is crucial to protecting public safety and resources at large.
Hawaiʻi Revised Statutes (HRS) 127A-18 gives the Governor the authority to authorize
access to private property to cut, trim, or remove dangerous trees or branches that pose ahazard to other properties. The Governor may also put a lien on the tree owner’s property
until the cost of removal is reimbursed to the state (127A-18). There are currently no
designated funding mechanisms for the State to perform mitigation efforts relating to
albizia.
Similar to HRS 127A-18, the Hawaiʻi County Code chapter 20, article 2 provides an avenue
for the public to report complaints relating to unsafe flora and gives the county authority toaccess private property to cut, trim, or remove dangerous trees or branches that pose ahazard to other properties. As defined in this ordinance, “Unsafe flora” means any or any
part of a tree, bush, vine, or grass that poses an imminent danger for fire, health, safety,
property damage, or criminal threat to persons or adjacent property and structures
including buildings, roofs, rain gutters, antennae, driveways, landscaping, privacy
structures (including gates, fencing, and stone walls), tents, garages, automobiles, powerlines, phone lines, playground equipment, water catchment tanks, swimming pools, or any
other structures and property (2016 CC, c 20, art 2, sec 20-1).
Recent passage of House Bill 606 (2017) further delegates authority held by the
Department of Agriculture to the Counties and their agents, to enter private property toaddress an invasive species. Once signed into law, implementation will be in the hands ofthe counties. It will be useful to monitor the progress and different approaches taken ineach county to benefit the public through this act.

15

To assist with making contact and beginning the notification process, sample letters tounresponsive landowners have been developed by BIISC. See Appendix no. 5 for sample
letters.

Stakeholder Coordination
Forging positive relationships between state agencies, federal agencies, legislatures,
community groups, researchers, industry professionals, and landowners will be crucial to
the success of any large-scale management activities required to control albizia on astatewide scale. Potential stakeholders include: utility companies, state agencies,
neighborhood boards, private landowners, community associations, watershed
partnerships, etc.

Liability
Albizia trees present a unique situation in terms of liability for damage caused by falling
trees or branches. Determining liability depends on many factors. Some factors may bebased on if the tree is located on private or public lands, whether or not the tree has been
identified and reported as a hazard, whether or not the tree has been treated, and whether
or not warning signage has been posted. Depending on the circumstances, liability for costsof damage associated with falling trees or tree limbs may be assigned to the owner of theland where the tree resides, the individual who treated the tree, or to theorganization/agency responsible for management actions. To reduce liability, it is highly
recommended that signage be utilized whenever possible. Sign should comply with Hawaii
Administrative Rules 13-8 (Act 82) and with the American National Standards Institute(ANSI). To further reduce liability and minimize risk of damage caused by management
actions, community engagement and notification should be considered. In some instances,an environmental assessment or environmental impact statement may be required.

Planning: Objectives and Implementation Tasks
P1: Support creation of detailed actionplans

P2: Empower the community to takeactionP3: Engage landowners and otherstakeholders

P1.1: Creation of detailed island specific or site specificmanagement plans and/or hazard mitigation plans for
Kauaʻi, Oʻahu, Molokaʻi, Maui, Lanaʻi, and HawaiʻiP1.2: Create albizia-specific biocontrol planP2.1: Development of island based outreach plans
P2.2: Create albizia control teams on Kauaʻi, Oʻahu,
Maui, and LanaʻiP2.3: Engage neighborhood boards, community
associations, etc. in albizia impacted areas
P3.1: Reach out to all large landowners with albizia
populations
P3.2: Explore treatment and removal options on
private lands
P3.3: Creation of an interagency Albizia Control
Working Group16

Legislature, Policy, and Funding
The successful control of a previously unmanaged invasive species will require a highdegree of support from policy and lawmakers. Having a legislative body that is willing to
make long-term commitments will be paramount to the successful management of albizia
in Hawaiʻi. Direct engagement and outreach will also be a critical facet when attempting togain support in the legislature. Legislative actions such as incentives or funding
appropriations will have a direct effect during the early stages of statewide albizia
management actions, and will serve as a foundation for future management actions. Longterm legislative actions such as improved regulations, a prohibition on planting, real-estate
disclosure clauses, etc., will provide a lasting structure to further reduce impacts fromalbizia to the people of Hawaiʻi. In-kind funding or volunteer efforts will likely play a largerole when engaging communities and creating Albizia Control Teams. In addition to
supportive statutory policies from the Legislature, there is also a need for the creation ofadministrative rules and best management practices for agencies, partners, and the generalpublic for managing albizia in an effective manner. The purpose of standardized best
management practices is to provide guidance as to when management actions should betaken, the time frame for removal activities, and which method of treatment to use.

Legislature, Policy, and Funding: Objectives and Implementation Tasks
L1: Create policies that support albizia
control and management

L2: Establish best management
practices

L3: Create incentives to assist
landowners with Albizia control and to
mitigate hazard tree removal

L1.1: Prohibit future planting of albizia (Falcataria
moluccana and Albizia chinensis)
L1.2: Officially designate albizia as a HISC priority
species/ invasive species
L1.3: Officially designate Albizia as a noxious weed
L2.2: Establish standard best management practices
for agencies
L2.3: Establish standard best management practices
for government contractors
L2.4: Establish guidelines for best management
practices for the public
L2.5: Establish road right-of-way seedling control
protocols
L2.6: Establish minimum criteria for long-term
maintenance of highway ROW and 150 foot buffers inenvironmental documents for highway development
projects including new construction as well as roadwidening (e.g. Albizia free for ten years post
construction)
L3.1: Tax credit or other incentives for removal ofhazard trees on private property

17

L4: Increase funding for statewide
albizia management efforts

L3.2: Explore opportunities to establish a cost-sharingor subsidy programs
L3.3: Real estate disclosures for properties with large
albizia and/or hazard albizia on neighboring property
L4.1: Funding for hazard tree removal pursuant to HRS
127A-18
L4.2: Funding for Albizia specific biocontrol research
L4.3: Funding for hazard trees in pilot programs on
Kauaʻi, Oʻahu, Maui, and Lanaʻi
L4.4: Funding for Community based control pilot
programs on Kauaʻi, Oʻahu, Maui, and Lanaʻi
L4.5: Funding for continued early detection efforts on
Molokaʻi
L4.6: Funding for continued albizia control work on
Hawaiʻi Island
L4.7: Identify sources of funding for invasive species
work in the highways’ ROW
L4.8 Use estimate identified in I8.1 to request funding
from the legislature to remove hazard trees near
private property but which are located on state lands

18All Objectives and Implementation Tasks
The following strategies, goals, and recommendations aim to provide a road map tosuccessful management of albizia on a landscape scale throughout the State of Hawaiʻi.

Impacts
I1: Assess population size and footprintof albizia on a statewide scale
I2: Assess environmental impacts

I3: Protection of priority watershed andwildlife habitat

I1.1: Complete mapping of albizia populations using
Pictometry or other high accuracy techniques to create
statewide maps
I2.2: Research hydrological impacts
I.2.2 Create a distribution model to assess thepotential habitat suitable for albizia infestation
I2.4: Perform hazard analysis based on current
footprint and distribution model
I2.5: Perform tree risk assessments of albizia locatedalong trails and areas of use
I3.1: Removal or treatment of all albizia trees inpriority watershed areas as identified by the Divisionof Forestry and Wildlife's priority watershed map
I3.2: Removal or treatment of all albizia from native
dominant forests, areas of high ecological value, andforests containing threatened or endangered species

I4: Mitigate hazards to increase water
quality and reduce flooding

I5: Assess the economic impact ofalbizia
I6: Establish sustainable secondary andalternative uses for removed materials
I7: Protect valuable public
infrastructure from albizia damage

I4.1: Establish stream pilot program to remove albizia
along stream corridors
I4.2: Removal or treatment of all albizia growing
within urban stream corridors
I4.3: Perform tree risk assessments for albizia trees
located within stream corridors
I5.1: Perform an economic analysis of the impacts ofalbizia and associated costs
I6.1: Explore sustainable alternative uses for materials
generated by albizia removal projects
I7.1: Develop a comprehensive list of public
infrastructure pieces impacted by albizia
I7.2: Standard roadside surveys and control of
seedlings
I7.3: Standard utility corridor surveys and control of
seedlings
I7.4: Removal of all hazard trees affecting public
infrastructure statewide and create buffer zones oftreated trees
I7.5: Assess hazard trees, cost of treatment for albizia
near public schools and universities

19I8: Protect private infrastructure fromalbizia damage from trees located onstate lands

I8.1: Solicit requests from private landowners abutting
state lands for potential removal of hazard trees, inorder to generate a cost and resource estimate forremovalI8.2: Once funding has been secured, (see L4.8)
remove hazard albizia located near private lands andcreate buffer zones of treated trees

I9: Maintain cultural sites and historicview planes

I9.1: Assess impacts to historic properties, culturalsites, and view planes
I9.2: Removal or treatment of trees impacting historic
properties, cultural sites, and historic view planes
I9.3: Develop standard practices for removal from
historic sites with minimal impact.

Control Methods
M1: Establish new and effective
biological controls for albizia
M2: Establish additional chemical andphysical removal techniques or options

M3: Establish improved technologies
for the control of albizia

M1.1: Continued biocontrol research
M1.2: Release of albizia-specific biocontrol agents
M2.1: Research additional foliar, systemic, and preemergent control options
M2.2: Research improved physical removal ortreatment options
M3.1: Research of future technologies and methods
such as genetic techniques, deployment methods, etc.

Planning
P1: Support creation of detailed actionplans

P2: Empower the community to takeactionP3: Engage landowners and otherstakeholders

P1.1: Creation of detailed island specific or site specificmanagement plans and/or hazard mitigation plans for
Kauaʻi, Oʻahu, Molokaʻi, Maui, Lanaʻi, and HawaiʻiP1.2: Create albizia-specific biocontrol planP2.1: Development of island based outreach plans
P2.2: Create albizia control teams on Kauaʻi, Oʻahu,
Maui, and LanaʻiP2.3: Engage neighborhood boards, community
associations, etc. in albizia impacted areas
P3.1: Reach out to all large landowners with albizia
populations
P3.2: Explore treatment and removal options on
private lands
P3.3: Creation of an interagency Albizia Control
Working Group20

Legislature, Policy, and Funding
L1: Create policies that support albizia
control and management

L2: Establish best management
practices

L3: Create incentives to assist
landowners with Albizia control and to
mitigate hazard tree removal

L4: Increase funding for statewide
albizia management efforts

L1.1: Prohibit future planting of albizia (Falcataria
moluccana and Albizia chinensis)
L1.2: Officially designate albizia as a HISC priority
species/ invasive species
L1.3: Officially designate Albizia as a noxious weed
L2.2: Establish standard best management practices
for agencies
L2.3: Establish standard Best management practices
for government contractors
L2.4: Establish guidelines for best management
practices for the public
L2.5: Establish road right-of-way seedling control
protocols
L2.6: Establish minimum criteria for long term
maintenance of highway ROW and 150 foot buffers inenvironmental documents for highway development
projects including new construction as well as roadwidening (e.g. Albizia free for ten years post
construction)
L3.1: Tax credit or other incentives for removal ofhazard trees on private property
L3.2: Explore opportunities to establish a cost-sharingor subsidy programs
L3.3: Real estate disclosures for properties with large
albizia and/or hazard albizia on neighboring property
L4.1: Funding for hazard tree removal pursuant to HRS
127A-18
L4.2: Funding for Albizia specific biocontrol research
L4.3: Funding for hazard trees in pilot programs on
Kauaʻi, Oʻahu, Maui, and Lanaʻi
L4.4: Funding for Community based control pilot
programs on Kauaʻi, Oʻahu, Maui, and Lanaʻi
L4.5: Funding for continued early detection efforts on
Molokaʻi
L4.6: Funding for continued albizia control work on
Hawaiʻi Island
L4.7: Identify sources of funding for invasive species
work in the highways’ ROW
L4.8 Use estimate identified in I8.1 to request funding
from the legislature to remove hazard trees near
private property but which are located on state lands

21

Literature Cited
1. Elbert L. Little Jr.; Skoman, Roger G. (2003) Agriculture Handbook no.679. CTAHR,UH Manoa.
2. Hawaiʻi Invasive Species Council Resolution No. 11-2.
3. Senate Resolution SR41-SD1.
http://www.capitol.hawaii.gov/Archives/measure_indiv_Archives.aspx?billtype=SR&billnumber=41&year=2013.
4. Big Island Invasive Species Committee, BISC. (2015) After Iselle, A plan for
mitigation of Albizia Hazards Across East Hawaii. May 2015.
5. Hawaiʻi Department of Transportation (2011) 2012-2022 Statewide Noxious
Invasive Pest Program Strategic Plan.
6. Vorsino, Mary. Honolulu Advertiser. (1/4/2007)
http://the.honoluluadvertiser.com/article/2007/Jan/04/ln/FP701040346.html.
7. Draper, Danny B.; Richards, Perer A. (2009) Dictionary for Managing Trees in Urban
Environments. Institute of Australian Consulting Arboriculturists, CSIRP Publishing,
Collingwood AU.
8. Hughes, R.F.; Uowolo, Amanda L. (2006) Impacts of Falcataria moluccana invasion
on decomposition in Hawaiian lowland wet forests: the importance of stand-level
controls. Ecosystems 9, 977–991.
9. Giambelluca, T. W.; Delay, J. K.; Asner, G. P.; Martin, R. E.; Nullet, M. A.; Huang, m.;Mudd, R. G.; Takahashi, M. (2008) Stand Structural Controls on Evapotranspirationin Native and Invaded Tropical Montane Cloud Forest in Hawai'i. American
Geophysical Union, Fall Meeting 2008, abstract #B43A-0422
10. Hughes, R. F.; Johnson, M. T.; and Uowolo, A. (2011) The Invasive Alien Tree
Falcataria moluccana: Its Impacts and Management. Prospects of Weed BiologicalControl on Pacific Islands. Session 5, 218-223.
11. Hughes, R. F.; Kaye, S.; Kirby, A.; Sowards, T.; and Morrison, C. (2017) Status reportfor project entitled: Monitoring patterns and processes of Falcataria moluccana(Albizia) decay and forest succession following herbicide treatment in Hawaii’s
lowland wet forests.
12. Leary, James; Friday, JB; Kaye, Springer; Hughes, Flint. (2011) Proper Technique for
Injecting Albizia (Falcataria moluccana) with the herbicide Milestone (active
ingredient: Aminopyralid). University of Hawaiʻi College of Tropical Agriculture andHuman Resources.
13. Hughes, R. Flint; Uowolo, Amanda L.; Togia, Tavita P. (2012) Recovery of native
forests after removal of an invasive tree, Falcataria moluccana, in American Samoa.
Biol Invasions (in press) DOI 10.1007/s10530-011-0164-y
14. Hawaiʻi Revised Statutes (HRS) 127A-18. (2014) “Mitigation of hazardous
situations”. http://www.capitol.hawaii.gov/hrscurrent/Vol02_Ch00460115/HRS0127A/HRS_0127A-0018.htm.
15. Hawaiʻi County Code, Chapter 20, article 2, sections 20-20 through 20-24(6/30/2016) “Clearing Occupied and Unoccupied Lots”.
http://www.hawaiicounty.gov/lb-countycode/#countycode.

22Appendices1. Senate Resolution 41 S.D. 1
2. Control guide for administering incision point application using Milestone®
herbicide
3. Template for site-specific or species-specific management plan
4. Big Island Invasive Species Committee – Albizia Control Team Overview
5. Big Island Invasive Species Committee sample Letter to Absentee landowner

23

24

25

Herbicide Labels:
FIFRA Sec. 24(c) Special Local Need Label For
Distribution and Use Only in the State of Hawaii
For Control of Albizia (Falcataria moluccana)and Other Woody Species in Natural Areas.
http://www2.hawaii.gov//hdoa/labels/sln/1203_2017.pdf

Milestone® Specialty Herbicide, EPA Reg No.
62719-519 (Dow AgroSciences LLC, Indianapolis,
IN). http://www.cdms.net/LDat/ld77N015.pdf
Guides for Herbicide Injection:
Practitioner’s Guide for Testing Herbicide
Efficacy with the Incision Point Application (IPA)
Technique on Invasive Woody Plant Species.
http://www.ctahr.hawaii.edu/oc/freepubs/pdf/WC-11.pdf

Practitioner’s Guide for Effective Non-Restricted
Herbicide Techniques to Control and Suppress
Invasive
Woody
Speciesin
Hawaii.
http://www.ctahr.hawaii.edu/oc/freepubs/pdf/WC-10.pdf

Guides for Measuring Tree Height:
http://www.ctahr.hawaii.edu/forestry/links.html
http://www.wikihow.com/Measure-the-Height-of-a-Tree
https://play.google.com/store/apps/details?id=com.taakk
umn.iHypsometerLite&hl=en

Local Sources for Herbicide Purchasing:
Hawaii Grower Products Inc.
http://www.hawaiigrowerproducts.com

BEI Hawaii
http://www.beihawaii.com

Crop Production Services Inc.
http://www.cpsagu.com/regions/Hawaii

Key search terms for online purchasing:
Drop Dispenser Bottle, Hatchet, Bush Pilot
Hatchet, Survival Hatchet, Camping Hatchet

1

Contributors:
1

2James Leary , JB Friday , Springer Kaye , Flint
3
Hughes1
Department of Natural Resources andEnvironmental Management (NREM), College of
Tropical Agriculture and Human Resources (CTAHR),
University of Hawai‘i at Manoa (UHM)
2
Big Island Invasive Species Committee (BIISC),
Pacific Cooperative Studies Unit (PCSU), University of
Hawai‘i at Manoa
3
Institute of Pacific Island Forestry (IPIF), USDA
Forest Service

Acknowledgements:
Nick Dudley, Hawaii Agriculture Research Center(HARC), Linda Cox (NREM), Piihonua Albizia Control
Team (PACT).

Disclaimer:
Mention of specific brand names does not constituteendorsement on the part of the authors, CTAHR, or
the University of Hawai‘i.
Published by the College of Tropical Agriculture and Human Resources(CTAHR) and issued in furtherance of Cooperative Extension work,
Acts of May 8 and June 30, 1914, in cooperation with the U.S.
Department of Agriculture, under the Director/Dean, Cooperative
Extension Service/CTAHR, University of Hawai‘i at Mānoa, Honolulu,
Hawai‘i 96822.Copyright 2011, University of Hawai‘i. For reproduction
and use permission, contact the CTAHR Office of Communication
Services, ocs@ctahr.hawaii.edu, 808-956-7036. The university is anequal opportunity/affirmative action institution providing programs
and services to the people of Hawai‘i without regard to race, sex,
gender identity and expression, age, religion, color, national origin,ancestry, disability, marital status, arrest and court record, sexual
orientation, or status as a covered veteran. Find CTAHR publications at
www.ctahr.hawaii.edu/freepubs.

Proper Technique for Injecting Albizia(Falcataria moluccana L.) with the
herbicide Milestone® (active
ingredient: Aminopyralid)This guide explains how to administer an
effective herbicide injection application to
medium and large albizia canopy trees
occupying natural areas in accordance to FIFRA
section 24(c) Special Local Need (SLN)
registration HI-120003. It is a violation ofFederal law to use this herbicide in a mannerinconsistent with its registered application
methods. ALWAYS READ THE LABEL FIRST!

26

The injection method, also known as
Incision Point Application (IPA), is a calibrated,hygienic, and efficient technique foradministering suppressive or lethal herbicide
doses directly to the exposed vascular systems
of woody species. In previous studies,
Milestone® (active ingredient aminopyralid;
Dow AgroSciences LLC, Indianapolis, IN)
injections were proven to be lethal to medium
size, 12 in. trunk diameter, albizia trees
administered with a 0.5 ml dose of undiluted
herbicide injected into hatchet incisions
spaced every 10 in. around thecircumference of the trunk, at a height
within 3 ft. above ground level. For trunks>24 in. diameter, injections should bespaced every 5 in. For trunks >36 in.
diameter injections should be spaced every
2 in. (complete girdle).
Application Technique:
1. Make an incision with the hatchet at a 45oangle that penetrates just beyond the bark andcambium layers (approximately 2-3 in. deep) sothat it creates an intact trough/notch (seefigure). You may widen the notch by wiggling
the blade.
2. With a dropper bottle, deliver the herbicide
dose to the center of the incision so that all of
the herbicide is retained within the trough. Thisis accomplished by slowly and precisely
squeezing the bottle to deliver one drop at atime. Be sure that the incision is deep enoughto prevent the herbicide from overflowing at
the seam.
Dropper calibrations haveconsistently measured 11-12 drops per 0.5 ml,
but may vary and should be tested.

Steps to a proper injection: (i) incision using a
hatchet on an angle to create a clean, intact
trough; (ii) herbicide drops retained andabsorbed into the vascular system of thetarget tree; (iii) large size tree with close
injection spacing.
Equipment and Resources:
x Hatchet/machetex Drop Dispenser Bottles (1-8 fl. oz.)x Herbicide formulationx Tape measurex GPS
x PPE: safety goggles and nitrile gloves

Management Plan:
1. This SLN application is for natural areas only.
Milestone® cannot be used in residential areas.
2. Do not exceed the maximum allowableamount of 7 fl. oz. per acre, which is equal to414 injections (0.5 ml each). Medium size trees
are treated with 2-3 ml total, which is enoughfor up to 200 trees per acre (~50 large trees).
3. Do not treat large trees that may damage
infrastructure and block right-of-ways. Estimate
impact zone to be greater than the height of thetree (see guides for measuring tree height).
4. Dead standing trees are brittle anddangerous to cut: if you plan to cut the trees
down, do not use this technique.
5. Consult with a certified arborist for proper
removal of large trees.

CAUTION! Dead standing trees are hazardous
to property and personal safety!

Expected Results:
Warning! This technique leaves dead trees inplace. Complete canopy defoliation can be
expected within 4-6 weeks. Canopy collapse
can be expected within 2 years and may
continue decomposing for a decade or longer.
Retreatment of large trees may be necessary if
new leaf canopy is observed 12 months after
first treatment.

27

MANAGEMENT/CONTROL PLAN TEMPLATE:
The following outline can be used as a base template for the development of site specific or
species-specific management plans. Images and maps should be used to add context andclarity to the plan.

A. Cover Page
a. Plan title
b. Name of organizationc. Name of report writer/sd. DateB. Table of contents
C. Stakeholder Identificationa. List and identify stakeholders, land managers, or land owners who will need
to be involved when conducting management actions. This is also the place tolist additional authors, contributors, sponsors, etc.
D. Introduction/Backgrounda. Introduction
i. Site description, location, reason for the planb. Species profilei. Brief physical description
ii. Natural range
iii. Include HWPRA score if applicablec. Historic Information
i. Date of first detection/introduction
ii. Geographic area impacted by species
1. GIS map of sitesiii. Past response measures if any
1. GIS maps of past control efforts
iv. Effects/Impacts of species
1. Effects to:a. Native Plants and animals
b. Hydrology/Run-off/nutrient cycling etc.
c. Human healthd. Economy
E. Management/Control Methods
Go over which methods of control are applicable and will be used at the site. Explainin detail the benefits and drawbacks of each applicable technique, as well as themethodology for application or control. Examples include:a. Manual removal
i. Explain how species can be manually controlled
b. Chemical
28

i. Explain how species can be chemically controlledc. Otheri. Other control methods (i.e. Biocontrol, sterile male, trap type, etc.)
F. Site specific Management/Control plan (this section can be singular or may
include many sites)a. Goals and objectives for the siteb. Applicable control methods
i. Explain how to control at site using manual, chemical, and othermethods etc.
c. Timeline for management/control per site
i. Best time or season for management/control, when it will begin, andduration of control as covered in this pland. Issues/problems
i. Explain known or potential hindrances to the overall success of yourproject (Outreach needed, access, laws, etc.)
1. Address how to solve issues/ problems
G. Costa. Project budget
H. Community Involvement
a. Will plan rely on community involvement?
i. Identify and discuss level of involvement if any
I. Measures of successa. What will you be using to determine if your plan is successful?
J. Conclusion
K. Literature Sighted
a. If you had any references in your plan, list them here
L. Compliancea. Based on your management plan, are compliance documents required for thefollowing?
i. Hawaii Environmental Protection Act
ii. National Environmental Policy Act
To create a multi-species plan:•••

Repeat #4-6 for each species
Include all species control efforts in budget
Include measures of success for each species

29Albizia Control at the Community Level: ACT!
The Problem:
Falcataria moluccana was introduced to Hawaii over 100 years ago and has been identified
as one of the most problematic invasive species affecting Big Island communities today.
Possibly the fastest growing tree in the world, albizia forms weak, brittle wood, matures
quickly, and spreads easily through wind-borne seeds. It poses a serious threat to both our
natural environment and our public safety.
Albizia is notorious for its tendency to lose large, heavy limbs in even mild winds. Even
before Tropical Storm Iselle, during which dozens of people were trapped for hours andseveral homes crushed, the residents of Puna had long dealt with the hazard of falling
albizia. Outbuildings, fences, and cars were among the common casualties of albizia limbs.
Albizia is prone to “sudden limb drop,” where hidden weaknesses in the limbs can cause
branches to fall even with no apparent disturbance.
The costs to taxpayers and utility customers from albizia impacts are high. Besides thecosts of removing trees that are direct threats, HELCO, HDOT, and the County routinely
must deal with the impacts of trees falling from private property onto roads and powerlines. HELCO estimates that it spent $13M responding to damage from Iselle, and the
Hawaii Island branch of the state DOT estimates that 90% of all received calls about fallentrees are for albizia. Costs to individual property owners from trees falling on to adjoining
properties have not been compiled, but are likely in the millions of dollars.
Addressing the Problem: Community Empowerment
While many legislative bills to fund a comprehensive albizia program have been proposed,so far, none have been enacted. Limited funding has been provided from various sources,
catalyzed by the allocation of funds from County Council Puna representative Greggor
Ilagan. Puna and Hilo residents are stepping up to improve the safety and well being of
their communities through control of albizia.
BIISC works with community associations, boards, neighborhood watch groups, orcommunity organizations that want to address albizia. We will work with the group andtheir designated liaison (an “albizia coordinator”) to train volunteers to assess tree safety,
treat non-hazard trees, and track and monitor albizia. The group will also receive support
materials to use in contacting property owners, private entities, or government agencies
for help. BIISC outreach staff will work with community coordinators to address specificissues that arise as volunteers seek action on the hazard trees in their neighborhoods.
BIISC will continue to educate and work on our legislators on the problem, and to seek
paths through which community members can find assistance for removing this menace
from their neighborhoods.

30

ACT: Albizia Control Teams
STEP 1: Presentation and Program Overview
The first step is to host a BIISC representative at your next community association, board,or neighborhood watch meeting to discuss the program and determine if this is the right
direction for your community.
Once your community has decided to move forward and “ACT”, a liaison or “albizia
coordinator” should be designated. This is a very important role, as this person will assist
in making arrangements for training workshops as well as providing support forcommunity volunteers. Your coordinator will be the point of contact for BIISC andcommunity volunteers, and will also help with tracking of albizia trees.
We suggest that the board or community association use the template enclosed in thispacket to determine what responsibilities will fall to the community coordinator(s).
STEP 2: Volunteer Training Workshop
Once the coordinator is in place, he or she will work with BIISC to host a BIISC community
volunteer training workshop. Outreach for the workshop is key: BIISC can provide somecolor flyers and will publicize the event on our website and social media, but we find thatthe best way to generate a good turnout is through neighbor-to-neighbor encouragement.
On the day of the workshop, volunteers will be presented with the scope of the programand encouraged to “sign up” for kuleana of a specific area, block, or section of street. The
albizia coordinator can follow up after the workshop with individuals who express interest.
A suggested template for a volunteer sign-up sheet is included in this packet.
STEP 3: Volunteer ACTion!
If requested, BIISC will supply the coordinator with maps of the specific areas taken on by
ACT volunteers. The coordinator will be provided with templates, helpful information onlegislation regarding albizia, and other tools to support the ACT volunteers as needed.
BIISC staff will also be available to assist coordinators if unusual or uncertain situations
arise, and will provide ongoing support and training as needed.
STEP 4: Tracking
Because BIISC is working hard for legislative action and grant funding, tracking is a reallycritical part of our efforts. We ask that ACT volunteers and coordinators work together totrack both treated trees and hazard trees and report this work to BIISC. A tracking sheet
template is included in this packet.

31

[DATE]

Dear [RECIPIENT],
I am reaching out to you in regards to a property you own on [ADDRESS], TMK No. __________
in [SUBDIVISION] on the Big Island of Hawaii.
I/We are concerned about a specific hazardous tree(s) growing on your property that is
posing a threat to (provide specific description of the structure). Pictures of the tree andstructure are enclosed.
You may or not be aware of the threat posed by this invasive tree, but Falcataria moluccanaor albizia is one of the fastest growing trees in the world. The wood is very brittle andbranches break off easily, causing severe property damage, loss of electric power, and evencar accidents.
Our community is working together to address the threat of this tree and prevent an
occurrence of the kind of devastation Hawaii Island faced in the aftermath of Tropical
Storm Iselle. Because of the widespread recognition of liability issue of this particular tree,
removal is necessary to prevent a significant decrease in property value.
Albizia has been recognized as a serious threat by both our state and County. If a property
owner does not resolve the problem, the State of Hawaii, through HRS 127A-18 (commonly
known as “Act 76”) is authorized to enter private property to remove or mitigate thehazard. The cost is then billed to the property owner.
A list of certified arborists can be found at
http://alohaarborist.com/index.php/members/oahu-members/. When calling for quotes,
keep in mind that there may be ways to reduce the cost of mitigation, such as having thetree trimmed back away from threatened structures. If the tree must be completely
removed to mitigate the threat, it may be possible to leave the removed wood in place on
your property to reduce costs. It is important to request that the arborist treat any
remaining stumps to prevent regrowth.
Thank you for taking the time to read this letter. Please let us know how you intend tohandle this hazard within 30 days of this notice.
I/We greatly appreciate your response,[SIGNATURE]

32