Agarwood stands among the most valuable forest products originating from Southeast Asia. The product is known locally as gaharu in some Southeast Asian countries.
Agarwood is globally recognized for its rich scent. It also holds exceptional value in international trade.
However, the name agarwood does not refer to a specific tree species. It commonly refers to a resinous heartwood produced by trees of the Aquilaria genus.
Healthy Aquilaria trees hold minimal commercial value in their natural state. The transformation into a prized commodity happens only when the tree suffers severe physical damage or internal tissue disruption.
The Extraordinary Value of Agarwood
Demand for agarwood spans across global markets. Applications include perfume manufacturing and religious practices.
Extracted agarwood oil represents the main form of utilization. Middle Eastern countries serve as the primary destination for the extracted oil or known as Oud, which is processed into high-end perfumes.
Oil extraction requires a substantial amount of raw timber. A single liter of top-grade oil requires over one hundred kilograms of resinous wood.
Prices for high-quality oil extracts remain among the highest of any natural essential oil in global commerce. Top-grade extracts command tens of thousands to a hundred thousand dollars per liter depending on purity and origin.
Solid wood products also supply international commercial trade. Wood chips and ground powders serve as raw materials for traditional incense used in religious ceremonies.
East Asian countries receive the largest volume of top-class incense products. Solid pieces are also carved into decorative sculptures and beads for Buddhist religious rituals.
A Unique Phenomenon in the Plant World
Uninfected Aquilaria wood has very distinct characteristics. The natural timber remains pale, lightweight, and completely odorless.
The dark heartwood known as agarwood forms strictly through a biological defense reaction. Physical damage to the tree trunk triggers this defensive response. Fungal infection, such as Fusarium oxysforum, also acts as a primary biological trigger for resin production.
When fungal spores enter open wounds, the tree secretes a protective resin to isolate the infection. The protective resin carries a dense structure and a strong aroma. Over extended periods, the substance thoroughly saturates the surrounding wood fibers.
The saturation process completely alters the physical properties of the timber. The resin-impregnated heartwood becomes heavy enough to sink in water.
The modified wood releases a distinct fragrance when heated or burned. A natural plant survival mechanism thus creates one of the most expensive raw materials in the world.
The Infection That Creates Precious Resin
Visual examination of an Aquilaria tree from the outside provides almost no useful information. Internal resin formation leaves no visible indicators on the outer bark.
It remains impossible to judge whether a standing tree contains agarwood without cutting into the trunk. Cutting the tree remains the only method to confirm the presence of resin.
Forest logging frequently occurred without prior verification. Standing trees were chopped down indiscriminately across natural habitats. Such practice caused widespread loss of uninfected trees in wild forests.
Depletion of natural stocks eventually led to international trade monitoring under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
To reduce the loss, modern forestry developed artificial inoculation techniques to address wild resource shortages. Small holes are drilled directly into the trunks of cultivated trees.
Plastic pipes are inserted into the drilled holes to keep the wounds open. Specialized chemical or biological treatments are then applied to stimulate the plant's natural defense mechanism.
The controlled cultivation methods allow farms to produce functional agarwood. Plantation production helps reduce logging pressures on wild Aquilaria populations.
Reference:
Persoon, G. A. (2007). Agarwood: The life of a wounded tree. IIAS Newsletter, (45), 24–25. International Institute for Asian Studies
