Trees mature and are able to produce seeds by 4 years of age. The seeds are wind-dispersed, allowing them to spread quickly over large areas. For instance, in the Rainbow Falls area of Hilo, the albizia population grew from 10 acres to 35 acres in 15 years – a 253% increase.
Albizia has a huge economic cost for taxpayers and citizens of Hawaii. Besides the costs 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 power lines. Tropical Storm Iselle left 30,000 people without power, some for weeks, due to downed power lines and power poles. Three smaller storms in the months following Iselle caused power outages for 5,000 or more customers for up to 4 days each. HELCO estimates that it spent $13M responding to damage from Iselle, and has spent additional millions of dollars in repairs of lines and poles after high wind events in the last few years.
The Hawaii Island branch of the state DOT estimates that 90% of all received calls about fallen trees are for albizia. HDOT reported that a single day of response to a small storm event in early 2015 cost over $12,000 in overtime, equipment, and materials. In addition to causing budget overruns and staff shortages in the short term, frequent overtime charges have long term balloon effect on state budgets, as overtime pay increases future retirement pay. These costs directly impact consumers and taxpayers.
The nitrogen added by albizia makes the soil more welcome to aggressive invasive understory weeds that are shade-tolerant and can survive in the albizia understory. These invaders take up all remaining resources, preventing keiki plants of many native species from developing. Albizia is estimated to have invaded over 5000 acres in the Puna district alone, and small but spreading populations can be seen all over the island, including Kohala and Ka’u. Currently albizia can commonly be found below 3000’ elevation in areas with moderate to heavy rainfall: areas which feed our fresh water system. On islands like Oahu and Kauai, albizia can be found right at the summit of steep mountain watersheds, the source of the island’s drinking water and streams.
Controlling and Managing Albizia
Please note: Large trees or trees that pose a potential hazard should always be risk-assessed and removed by a certified arborist!
Large trees or trees that pose a potential hazard should be risk-assessed and removed by a certified arborist.
Dr. James Leary of the University of Hawaii has developed a method of applying droplets of herbicide to small cuts in the bark of the tree. Known as the incision point method or “hack-and-squirt” approach, this method cause trees to lose their leaves over the course of a couple of weeks, and eventually break apart over months. All dead trees have the potential to be dangerous, so this method is NOT recommended for large trees overhanging structures, roads, and power lines. For these hazard trees, contact a certified arborist for removal. BIISC provides free training on assessing trees for potential hazard and treating young and non-hazard trees with herbicide. See our Events calendar upcoming workshops.
There may be some assistance available in obtaining funding for removal of hazard trees. The USDA Rural Development section offers low-cost loans and grants for property owners that in limited circumstances may be used to pay for the removal of hazard albizia trees. More information is available at http://www.rd.usda.gov/programs-services/single-family-housing-repair-loans-grants. Please contact the USDA Rural Development office in Hilo for more information on requirements for eligibility.
Addressing Albizia on Neighboring Properties
Many times absentee owners are not aware of the trees growing up on their land. If your community has an ACT program, you may be able to work with your community coordinator to obtain permission to enter your neighbor’s property and treat young trees. The list of participating communities and contact information can be found here.
To locate a mailing address for the property owner, you can use the County TMK system. Find the property in question, click on it, and related info will appear in a sidebar to the right, including the TMK number. You can click on the “Print” icon in just above the map, and it will generate a one page report that shows the parcel on the map, the name and address and TMK below. You can print or save it as a .pdf to include in your communications to the neighbor.
Many residents find their neighbor does take the complaint seriously when this level of commitment and documentation is demonstrated, and are following through with tree removal.
Section 20, Article 2 of the Hawaii County Code addresses trees within the front 100 feet of the property facing a county road, or that pose an imminent danger to a neighboring property. Mention in your complaint the precise location of the property and tree (the county map link is a big help), the letter you sent your neighbor, the certified mail receipt, and a brief description of the hazardous situation (take photos and keep them handy). Keep all these materials together. When using this form to report hazardous albizia trees, select the option “Unsafe flora posing imminent danger.”
State: Hawaii Emergency Management Agency (formerly State Civil Defense):
Chapter 127A, Section 18 of the Hawaii Revised Statutes (commonly known as “Act 76”) allows for state employees, at the direction of the Governor, to enter private property in non-disaster times to mitigate specific hazardous situations. The hazards covered under Act 76 are: Cutting, trimming or removing dangerous trees or branches that pose a hazard to other properties. A “Hazardous Situation” is defined as an imminent threat to a currently-built inhabited dwelling structure.
Make sure you have done everything you can to try to resolve the situation with your neighbor. Be sure to have a receipt for your certified mail notification letter. The next step is to have an official Tree Risk Assessment by a qualified arborist. (A list of certified TRAQ arborists can be found on our arborist page). If the TRAQ arborist finds the tree to be a hazard, follow up by mailing a copy of the report to the property owner, via certified mail, to notify them of the hazard. If the owner does not respond within 30 days with their intention to have the hazard removed, it is time to contact the State HEMA office. Send copies of all documents, including the certified mail receipts, photos, correspondence with the owners, and the hazard tree assessment to email@example.com. You can also mail the package to him at: State of Hawaii Dept. of Emergency Management, 3949 Diamond Head Road, Honolulu , HI 96816-4495.
Still, the entities involved are working to enact small pieces of the plan through the use of private monies, discretionary funds, grants, and other sources of financial support. BIISC, a project of the University of Hawaii, is using a combination of grant money, federal funds, and HISC funding to hold free training workshops and to provide outreach and assistance on addressing albizia to interested communities. BIISC has also designated a field crew to treat albizia in “buffer zones” near some of the high priority areas identified by partners in the 2014 albizia plan. For instance, HELCO identified a stretch of high-powered transmission lines on DHHL land near Pi’ihonua in Hilo as being of high risk due to surrounding acres of towering albizia. HELCO hired arborists to remove trees closest to the transmission lines, while the BIISC crew treated treed in a 300’ buffer zone on either side of the lines. Through the work of this partnership, we have lowered the risk to safe delivery of electricity for a large portion of North Hilo.
It is important that you let your County, State, and Federal elected representatives know that albizia is a key area of concern for you. BIISC provides updates and notifications for providing testimony on pending legislation regarding albizia on our Facebook page (link to FB page). “Like” us to receive information about upcoming legislative hearings for albizia and other invasive species issues.
When using this form to report hazardous albizia trees, select the option “Unsafe flora posing imminent danger.” Mention in your complaint the precise location of the property and tree, the letter you sent your neighbor, the certified mail receipt, and a brief description of the hazardous situation (take photos and keep them handy).
Once this window has closed, invasive species management becomes an issue of control, and with a focus on limiting spread. With a presence dating back over 100 years, albizia is in this stage of management. Because of its nature as a serious threat to human health, natural areas, and our economy, albizia is a species which BIISC is aggressively pursuing through community empowerment, supporting legislative action, and working with partners to create buffer zones in high-priority areas.
BIISC has been working with communities who want to implement Albizia Control Teams (ACT) in their neighborhoods.