What it Takes to Remove a 100 Foot Tall Albizia Tree, a Climber's Perspective
Posted on Nov. 17, 2025 / Best Practices, Invasive Species, Plant Pests, Arboriculture / Subscribe 0
By: Tylor Schwarze
Figure 1. A 120-foot-tall Albizia Tree Shading Native Hawaiian Plants Slated for Removal at Lyon Arboretum.
Albizia (Falcataria falcata) is a species of Fabaceous tree that can soar to heights of over 150 feet in Hawaii. This tree is native to the Maluku islands, an archipelago that sits between Indonesia and New Guinea. Like many invasive species, it is even better suited to life in Hawaii than in its native range. Hawaii’s fertile soil, abundant rainfall, and lack of specific pests result in Albizia trees of truly impressive size and scale. Looking at a single massive Albizia tree, or a mountainside covered in them, with their iconic flat canopies glowing a verdant shade of green, you wouldn’t be the first to find them beautiful.
In Hawaii, the aesthetic benefits of this tree come with a heavy price. Albizia trees rain down a shower of wind-dispersed seeds that travel far and wide. Once they establish, they quickly shade out and alter their ecosystems in ways that deny light, space, and favorable growing conditions to native species. Aside from driving Hawaii’s native plants ever further up the mountains, Albizia trees have a violent streak. Their long, heavily loaded limbs can fail during storms or even spontaneously on a hot, still day and wreak havoc. People, vehicles, and especially buildings positioned under large Albizia trees can be at risk. Picture a 15-story condo building that randomly sheds pieces of its structure weighing hundreds of pounds next door to your house.
Understandably, if you have an Albizia tree growing in an area with anything valuable in its understory, you will want to have that tree removed. Using the Albizia tree growing in the Hawaiian Section at Lyon Arboretum (pictured above) for an example, we will look into what the process of removing a large Albizia tree is like from a tree climber’s perspective and go over some of the features specific to this species that present challenges and opportunities.
Choosing the right strategy to use for a given Albizia removal is critical. Three basic options ranked in order from least to most time consuming and expensive are: dispatching the tree with herbicide and allowing it to fall apart over time (this strategy should NEVER be used when removing trees even remotely close to structures, roads, or people), “felling” the tree by cutting it down from the base in one piece, and climbing the tree using ropes and specialized equipment to cut and bring the tree down safely in manageable pieces. For this case study, we will discuss a scenario where the tree must be removed in pieces by a climber to avoid damaging rare Native Hawaiian plants in the understory. No matter which strategy you employ, you will need to make sure that you are using competent, trained personnel, with the appropriate equipment, following all of the relevant safety standards.
The first thing a tree climber will do when climbing and removing an Albizia tree is to assess it for hazards and come up with a plan of action. Are there electrical lines nearby? Does the base of the tree show signs of decay or fungal fruiting bodies? These are the sorts of questions to ask yourself. When coming up with a master plan for a large Albizia removal, it is important to look at the tree from as many angles as possible. A branch that may appear to be standing straight up into the sky from one vantage point may, in actuality, be leaning at a 45-degree angle. These optical illusions are a quirk of the species. Once you have a good plan of action in mind and have discussed it with your team, the next step is to set your climbing line in the tree as high as you can on a branch that will bear your weight. Good judgment and experience come into play. The first question most passerbys will ask a climber is, “How do you get your rope up there?” This is done by using a giant slingshot to lob a weighted ball attached to a light string. The string is then tied to a thicker rope that the climber will fasten to the tree and climb on. This rope is called the climber’s “main line”; the place it is attached to the tree is the “tie-in point”.
Figure 2. A Typical Equipment Loadout for a Large Albizia Removal Job.
Depending on the specific plan for the tree removal, a climber may carry as many as 25 pieces of specialized equipment on their person while aloft. The entire job may utilize over 80 individual pieces of gear, ranging from $25 aluminum carabiners to a $30,000 wood chipper. Every piece of gear is vital. Having the right device on hand at the right moment is crucial. One advantage that Albizia trees present is that their bark and wood can be climbed with tree gaffs (steel spikes attached to the climber’s boot) relatively easily. The climber will want to lean into these gaffs and use them to maximum effect while climbing. Once you have your gear assembled and are sure that everything is accounted for, you will ascend the tree and start the removal.
The general strategy for most tree removals is to start by removing the lowest branches first. A climber will get into position on the branch, secure themselves with a backup climbing system, attach the branch to be cut to an appropriately sized rope and rigging block (heavy-duty pulley), and then make their cut with a chainsaw. To counteract the weight that will be placed on the block by the falling branch, a trusted partner on the ground will assist the climber by running the rope through a device that controls the falling branch’s descent. The teamwork and cohesion between the climber and ground assistant (affectionately called a “Groundie”) is key. Having the right help on the ground and intercoms to communicate can make a challenging job much easier.
Because of their propensity for unexpectedly shedding large limbs, Albizia trees are often called “weak”. Although the wood of this tree is light and soft compared to other trees, it is strong in unique ways. Hard materials are brittle. The fibers of Albizia wood and its comparatively low density make it less likely to split when making cuts, even large cuts. By using this to their advantage, a climber can move up the tree, carving away and removing all of the Albizia limbs that have leafy ends. Bear in mind that these dainty-looking bi-pinnate leaves are deceptively heavy, especially when loaded with rainwater. A branch where the woody stem is leaning one way but has a counter lever of leafy foliage leaning the other way will usually fall in line with the leafy top.
Figure 3. Using Rope Access Climbing to Position for a Cut on an Albizia Tree at Lyon Arboretum. Photo credit: Julia Douglas
When a tree has had all of its leaf-bearing limbs removed and only the heavy wooden boughs remain, it is called a “spar”. When the climber has reached this stage of the removal, having worked from the lowest limbs to the highest, they will be perched over 100 feet in the air on a lofty wooden pole. Trees use the motions in their branches and leaves to dissipate swaying caused by wind or other forces acting on them. This phenomenon is called mass damping. When you have removed all of the branches and leaves from a tree and only the trunk remains, the mass-damping effect is negated. Every motion the climber exerts on the tree feels amplified, like being tied to a diving board that oscillates when you move. At this height, the wind will likely be strong. Even on a seemingly still day, there will usually be strong winds at the top of a large Albizia tree.
Putting these discomforts aside, you will now work your way down the spar. If the situation allows, you can aim and drop sections of the trunk without hitting targets in a free fall. This procedure is often called “bombing out” sections. If there is no space to land free-falling pieces of the trunk you will have to continue to lower down pieces on ropes and pulleys. This is time-consuming and physically demanding. As you work your way down the tapered tree you will need to use a progressively larger and heavier chainsaw.
Often there will be enough space at the end to fell the final portion of the spar. This step will be done with a large chainsaw with a very long bar and chain. The chainsaw may stand over six feet tall when standing on the ground. When felling the tree, a wedge-shaped “face cut” will be carved into the tree facing where the tree worker intends for the tree to fall. A “back cut” will then be cut parallel to the ground that lines up just above where the corners of the face cut intersect. Felling wedges should be pounded into the back cut as the saw chews through the wood. Beware, Albizia trees can often be severely decayed or hollow. A healthy tree will have pale peach colored wood that darkens to a more red tinge closer to the center of the tree. As the Albizia tree begins to fall, it will first make popping noises as the tension in the wood is released. The back cut will then visibly open and the trunk will begin to fall away. As the long fibers in the woody xylem of the tree pull apart from each other in the “hinge” of the cut, they will make a loud, eerie screeching noise. By this time, the tree worker felling the tree should have pulled their chainsaw from the cut and moved away from the falling tree.
Many days and sometimes weeks of hard work will be punctuated by the crash of the trunk hitting the ground. This sound need not be the end of the Albizia tree’s story. The light, buoyant wood is well-suited for making canoes and surfboards. The biomass of the tree and its labyrinthine root structure will endure and break down for decades. In the carbon-filled nooks and crevices of the deceased tree, microbes and other life will flourish. While some may find the loss of these giant and arguably beautiful trees sad, they should take comfort in the endless possibilities for growth that abound in the open space and nutrients it has left behind.
Figure 4. Tylor Schwarze Standing With Chainsaw After Felling The Final Portion of an Albizia Tree at Lyon Arboretum. Photo credit: Aziz Agis
Tylor Schwarze,
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