Rosewood


Related species
Description and phenology
Distribution, abundance and ecology
Uses and economic potential
Economic data
Collection methods and yields
Propagation and cultivation methods
Research contacts



Paulo de T. B. Sampaio

Family: Lauraceae

Species: Aniba rosaeodora Ducke (Ducke 1938)

Synonym: Aniba duckei Kostermans (Ducke 1938)

Common names: pau-rosa, pau-rosa itauba (Brazil); enclit rosenhout (Suriname); cara-cara (Guyana); bois de rose, bois de rose femelle (French Guiana); rosewood (English).

Related species


Aniba fragans Ducke - Commonly known as "macacaporanga", this species is similar to A. rosaeodora, but has a strong and persistent aroma. It is found near Santarém, Pará, in the forest on the edge of the "Serra de Santarém" plateau, and is occasionally cultivated. The macacaporanga is one of the most important ingredients in the homemade perfumes of Santarém, which are made from infusions or powders of local Lauraceae. The young branches and the dried leaves of this species are used.

Aniba parviflora (Meisen) Mez - A small tree with light green wood and a strong aroma, principally from the bark. The oil obtained from its wood is also a component of Santarém's popular perfumes. Among the Lauraceae it is the most frequent and is found in the lower and middle Amazon river, from Santarém to Manaus, and in the lower reaches of their effluents (Tapajós, Trombetas, Madeira). It is found in non-flooded forest, on swampy ground or very humid soils (preferentially sandy loams), on the banks of black or clear water streams, but never white water (which is rich in sediments).

Description and phenology


Rosewood are tall trees, reaching 30 m in height and 2 m in diameter, with a straight cylindrical trunk, and a yellow-brown bark which falls in large flakes; all parts are aromatic. The generally well-shaped crown occupies the upper or mid-forest canopy.

The leaves are distributed along the smaller branches; they are leathery, smooth, generally 4-5 cm wide, with smooth margins and an acuminate apex; the secondary nerves diverge from the primary nerve at an angle of 45-60. The inflorescence is a multiflowered panicle. The rusty-brown flowers are small, about 1 ram in length, having a short pedicel and short fillets. The fruit is a conically shaped drupe, green in color, measuring 2-3 cm in length by 1.5 cm in diameter (Ducke 1938, Alencar & Fernandes 1978, Loureiro et al. 1979). Each fruit contains one seed; there are 160-200 seeds/kg.

Flowering occurs from October to February and fruiting from November to March at the National Research Institute for Amazônia (INPA) A. Ducke Forest Reserve (Manaus, Amazonas) (Magalhães & Alencar 1978). According to these authors this species is prenifolia, changing its leaves during fruiting.

Distribution, abundance and ecology


A. rosaeodora is widely distributed in the rainforest from the interior of French Guiana, along the Guiana shield through Suriname, Venezuela and Colombia to the Peruvian Amazon (Ducke 1938). In Brazil, it occurs from Amapa westward along both sides of the Amazon River (SUDAM 1972). The areas of highest concentration run from Curuá-Una (near Santarém) to the Peruvian frontier in the south, and from the Trombetas River to Colombia in the north. It is also found around Belém and on Marajó Island (SUDAM 1972).

In the forests of the SUFRAMA Agricultural District, near Manaus, 2 trees/ha, with 0.05 m3/ha, are found (Loureiro et al. 1979). At the A. Ducke Forest Reserve, the species has an abundance of 3-4 trees/25 ha (diameter at breast height equal to or greater than 20 cm) on medium and sandy textured latosols (Alencar & Fernandes 1978). They occur in groups of 5-8 trees, with a spacing of 50-100 m among trees and 300-400 m among groups; they also occur as isolated trees (Alencar & Fernandes 1978).

Rosewood grows on yellow and red latosols, both in clay and sandy clay, essentially on the terra firma; it prefers the headwaters of streams. The natural regeneration of this species occurs in clearings; consequently it is considered to be a heliophyte (SUDAM 1979).

Uses and economic potential


Principal use
Secondary use



Principal use


Rosewood oil is largely linalool, a product with great demand on the national and international market because of its use as a fixative in perfumes. SUDAM (1972) explains that the physical-chemical constituents of the oil vary from population to population in Amazônia noting that differences exist between the oils of trees from Brazilian Amazônia and from French Guiana. Unfortunately they don't identify those areas with superior oil characteristics. The physical-chemical characteristics of rosewood oil are presented in Table 1.

Table 1. Physical-chemical analysis of rosewood oil (Aniba rosaeodora Ducke).


Leitão (1939)

SUDAM (1972a)

SUDAM (1972b)

Raoul (1953)

Naves (1952)

Density

0.883

0.881

0.889

0.870

0.876

Refraction index at 20C

1.465

1.458

1.462

1.466

1.463

Acidity value

0.923

-

-

0.26

-

Saponification value

7.67

1.67

2.8

-

-

Ester index

6.7

6.5

4.5

-

-

Solubility in alcohol at 70% (1: 2)

-


-

complete

-

Total alcohol1 (%)

-


-

95.99

91.0

Combined alcohol1 (%)

-


-

0.96

-

Free alcohols1 (%)

-


-

93.03

-

Esters2

-


-

1.23

-

1. calculated as linalool,
2. calculated as acetate of linalila.



Secondary use


The wood is heavy (0.80-0.90 gr/cm3). The light brownish-yellow heartwood has pink reflections, while the outer-wood is yellowed; both have regular (occasionally irregular) grain, medium texture, are smooth to the touch and take a polish well. The strong aromatic smell is more intense when recently cut. The wood has a hot, astringent taste. It is easy to work, accepting a fine finish, but its utilization in cabinetry is rare because its principal economic importance is the production of the aromatic essential oil (Loureiro et al. 1979, SUDAM 1979).

Economic data


Rosewood essential oil is produced principally by the Brazilian states of Amazonas and Pará. Exports of the product have decreased considerably during the last decades (Table 2) because of intensive and selective overexploitation of this species, without the replanting required by law. Brazil exported 92.3 MT of essential oil in 1985, with a value of US$ 938,000 (FOB), or about US$ 10,160/MT or US$ 101/kg. On the Manaus market one liter of rosewood extract sells for US$ 80.00 (J.W. Clay, Cultural Survival, pers. com. 1990). The major importers of Amazonas' rosewood oil are listed in Table 3.

Table 2. Rosewood essential oil exports from Amazonas, Brazil (SUDAM 1972, AEZFM 1986).

year

1966

1967

1968

1969

//

1985

MT

137.7

222.7

302.6

209.2

//

42.6

Table 3. Countries importing Amazonas, rosewood essential oil in 1985 (AEZFM 1986).

Country

MT

value (US$ FOB)

United States

35.1

358,038

West Germany

1.6

22,023

France

3.2

31,547

Spain

1.1

13,095

Holland

1.1

12,857

United Kingdom

0.5

6,547

Total

42.6

444,107


Collection methods and yields


The whole tree is cut to obtain the essential oil. The wood is reduced to strips, 2-: 3 cm wide by 5 cm thick, by a shredding machine. The strips are put in a kettle to distill the oil. The duration of distillation depends on the wood, but generally takes about 3 hours (SUDAM 1972). The efficiency in oil extraction depends upon the time elapsed between cutting the tree and the beginning of distillation, as well as the origin of the tree. One ton of wood produces about 9-12 liters of essential oil (Alencar & Fernandes 1978, Prance 1987). After distillation, the oil is strained to separate the impurities and is packed in 180 kg capacity metal barrels for shipping (SUDAM 1972).

The separation of the linalool from the essential oil is done in a two-step process at temperatures between 194 and 200C (Leitão 1939). This author obtained 75% linalool and 25% polymerized residue.

Araújo et al. (1971) affirm that there is a higher essential oil extraction yield from the leaves and green juvenile branches (2.4%) than from the wood (1.1%). The age of the leaves affects the quality of oil: the older they are, the greater the proportion of terpenes and oxides of linalool; the younger, the richer they are in linalool. This suggests that rosewood could be cultivated like tea, with periodic harvests of green leaves and green branch tips, rather than the current destructive harvesting process that destroys the very resource that maintains the rosewood industry.

Propagation and cultivation methods


Rosewood is propagated from seeds, but the seed production is severely reduced by predators, principally birds of the families Psitacidee and Ranfastidee (Toucans) that attack the fruit before its maturation (Alencar & Fernandes 1978). In the A. Ducke Forest Reserve an adult tree can produce more than 400 fruits (Alencar & Fernandes 1978), but few are collected because of predation.

Araújo (1967) noted that seeds collected at km 134 and 104 of the AM-010 highway (Manaus-Itacoatiara), presented 75.3% and 61.0% germination, respectively. As they were sown 3 to 5 days after collection, the time elapsed between sowing and the beginning of germination was 43 and 28 days, respectively. Alencar & Fernandes (1987) obtained 37-91% germination in a period of 60-120 days, with seeds collected at the A. Ducke Forest Reserve.

Vegetative propagation of rosewood, by cuttings from young branches without hormonal or other treatment, was studied by Sampaio (1987), who obtained 70% rooting. This technique allows propagation of elite material for experimental plantations.

SUDAM (1979) noted that this species presents a good survival index (80%), with average annual increments in height of 0.83 m, in diameter of 0.79 cm and volume of 9.1 m3/ha/year. In the, partial shade of the primary forest (30% light) on a yellow clay oxisol at a spacing of 10 × 5 m, this species presented an average annual height increment of 0.75 m in the seventh year after planting (Alencar & Fernandes 1978).

Since rosewood grows well in both full sun and partial shade, it would seem to be an ideal species for inclusion in agroforestry or forest management systems. Monocultures managed like tea might be feasible, although no information has been published about pests and diseases of rosewood that might limit low capital systems. All of these areas require research and development.

Twenty years after Araújo et al.'s (1971) original report on the essential oil content of the leaves, rosewood is becoming locally extinct in many areas of Amazônia due to destructive harvesting of the wood. This valuable natural resource deserves more intensive management, rather than extinction.

Research contacts


Dr. Jurandy Cruz de Alencar, Departamento de Silvicultura Tropical, Instituto Nacional de Pesquisas da Amazônia - INPA, Cx. Postal 478, 69011 Manaus, Amazonas, Brazil.

MSc. Paulo de T. B. Sampaio, Departamento de Silvicultura Tropical, Instituto Nacional de Pesquisas da Amazônia - INPA, Cx. Postal 478, 69011 Manaus, Amazonas, Brazil.

Departamento de Silvicultura, Superintendência pare o Desenvolvimento da Amazônia - SUDAM, Belém, Pará, Brazil.

Departamento de Silvicultura, Centro de Pesquisas Agropecuárias do Trópico Úmido - CPATU/EMBRAPA, Cx. Postal 28, 66040 Belém, Pará, Brazil.