Aquilaria (Agarwood, Karas or Gaharu)

What is Aquilaria?

Aquilaria is a genus of eight species of trees in the Thymelaeaceae native to southeast Asia. They occur particularly in the rain forests of Indonesia, Thailand, Cambodia, Laos, Vietnam, Malaysia, and Northern India. The trees grow to 6-20 m tall. The leaves are alternate, 5-11 cm long and 2-4 cm broad, with a short acuminate apex and an entire margin. The flowers are yellowish-green, produced in an umbel; the fruit is a woody capsule 2.5-3 cm long.

The genus is best known as the principal producer of the resin-inpregnated agarwood, especially Aquilaria malaccensis. The depletion of wild trees from indiscriminate cutting for agarwood has resulted in the trees being listed and proteced as an endangered species. Projects are currently underway in some countries in southeast Asia to infect cultivated Aquilaria trees artificially to produce agarwood in a sustainable manner.

Species

• Aquilaria acuminata (Merr.) Quisumb., 1946, originally Gyrinopsis acuminata
• Aquilaria apiculata Merr., 1922
• Aquilaria baillonii Pierre ex Lecomte & Leandri, 1949
• Aquilaria crassna Pierre ex Lecomte, 1915
• Aquilaria filaria (Oken) Merr., 1950
• Aquilaria grandiflora Benth., 1861
• Aquilaria malaccensis, Lam., 1783, synonyms A. agallocha and A. secundaria^[1]
• Aquilaria ophispermum Poir.
• Aquilaria pentandra Blanco, 1837
• Aquilaria rugosa K.Le-Cong & Kessler, 2005
• Aquilaria sinensis Gilg, 1894
• Aquilaria yunnanensis S.C.Huang, 1985

Agarwood is a resinous wood that sometimes occurs in trees belonging to the Aquilaria genus, Thymelaeceae family. Aquilaria is a fast-growing, archaic tropical forest tree, which occurs in South and Southeast Asia, from the foothills of the Himalayas to the rainforests of Papua New Guinea. The tree grows in natural forests at an altitude of a few meters above sea level to about 1000 meters, and it grows best around 500 meters. It can grow on a wide range of soils, including poor sandy soil. Seedlings need a lot of shade and water. Trees grow very fast, and start producing flowers and seeds as early as four years old. At least fifteen species of Aquilaria trees are known to produce the much sought-after Agarwood. In South Asia Aquilaria achalloga is found, particularly in India, Aquilaria malaccensis is mostly known from Malaysia and Indonesia, and Aquilaria crassna principally grows in Indochina. A number of other species are known such as Aquilaria grandfolia, Aquilaria chinesis etc.

Usage

The “Wood of the Gods” has been traded and highly appreciated for thousands of years. Resinous wood is used as incense, for medicinal purposes, and pure resin in distilled form is used as perfume and perfume component. Outside native countries it is most widely known in the Middle East, China, Taiwan and Japan. A strong connection exists between use, religion and curative properties, and elaborate traditional and religious ceremonies are known from around the world. Faith healers in the Middle East use it at curative ceremonies, Japanese pilgrims donate flowers and Agarwood oil to Shinto-Buddhist temples, and Vietnamese religious groups are obliged to bring Agarwood to ceremonies at their temples in Mekong delta communities.

Value

The value of first-grade Agarwood is extremely high. A whole range of qualities and products is on the market varying with geographical location and cultural deposition. Prices range from a few dollars per kilo for the lowest quality to over thirty thousand US dollars for top quality oil and resinous wood. Aquilaria crassna is listed as an endangered species in Viet Nam, and A. malaccensis is listed as endangered by the World Conservation Union, IUCN.

Extinction

Resin producing trees are endangered throughout their known habitat all across Southeast Asia. The main driving force, which initiated this project, was the recognition of unsustainable Aquilaria harvesting in natural forests that resulted in the near extinction of this tree genus in Viet Nam and elsewhere. Aquilaria crassna is now listed as a protected species in Viet Nam, and Aquilaria malaccensis is a CITES red data book listed tree. Trade and harvesting restrictions will be virtually impossible to achieve if no alternative is developed to forest-based harvesting. In addition, both in the short and long-term, a natural resource base needs to be maintained to supply present and future Aquilaria plantations with genetic source material, in order to prevent plant decease, maintain diversity and possibly improve resin production.

Substitutes

Development of synthetic substitutes usually arises when sustainable supplies of the natural product are not available. One of the first questions pursued when contemplating the previous pilot project was: “is it possible to synthesize Agarwood and Agarwood oil?” The answer is a qualified no. Agarwood cannot be synthesized. Chemical substitutes are already available for perfume; these are cheap and constitute the least profitable end of the market. In addition, these products do not come even close in mimicking the natural product and thus do not pose a threat to producing naturally based Agarwood products. The major chemical components responsible for the characteristic scent of Agarwood products, sesquiterterpenes, can in principle be synthesized. However, these are very complicated structures that will be extremely expensive to synthesize, which makes it commercially completely unattractive.