Rio rosewood
| Rio rosewood | ||||||||||||
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Rio rosewood ( Dalbergia nigra ), bark |
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| Dalbergia nigra | ||||||||||||
| ( Vell. ) Allemão ex Benth. |
Brazilian rosewood ( Dalbergia nigra ), or Rio , Bahia- and Brazilian rosewood , Jacaranda is a tree art from the kind of dalbergia ( Dalbergia ) within the family of the Leguminosae (Fabaceae). Together with wood from other species of the Dalbergia genus, it has been one of the most sought-after tropical imported woods for over 300 years . It became particularly popular from the second half of the 19th century, after the invention of sliced veneer .
The species is endangered and its natural occurrence is restricted to the Brazilian Mata Atlântica .
description
Dalbergia nigra grows as a semi-evergreen tree . There were some very old specimens in which trunk diameters of 100 to 120 centimeters were determined; Nowadays, specimens are more likely to be 30 centimeters thick, often with diameters of 40 to 80 centimeters at chest height . They can grow to heights of 25 to 30 or more, but usually only 15 to 25 meters. They grow spongy , often twisted and irregularly shaped. The logs are often hollow and only about 8-10 meters long.
The stalked leaves are alternately paired, to wrongly unpaired , pinnate. The entire, up to 2.5 cm long leaflets are glabrous and rounded to indented.
The fragrant butterfly flowers are white to cream in color. They are in slightly hairy and axillary or terminal panicles at the branch ends.
The short flowering period in Brazil is in November and December. The brown, up to about 3–8 centimeters long and about 2 centimeters wide, flat legumes ("wing fruits ") remain closed and each contain one to three seeds . Fruits are available from January to September. The fruits are thrown off as a whole and are spread by the wind.
ecology
There are reports that Dalbergia nigra is pollinated by bees . The seeds are spread by the wind.
Occurrence and protection
The kind Dalbergia nigra growing single tree as well as being partly with other Dalbergia TYPES , the Santos rosewood of Machaerium TYPES well as many other hardwood species associated . Their natural range extends over the lower wet forests of eastern Brazil , south of Bahia via Rio de Janeiro to São Paulo . There used to be a supply of 1.16 to 1.40 m³ per hectare in the Brazilian states of Espírito Santo and Bahia.
The occurrence has meanwhile been greatly decimated by long-term, massive logging , which is why the species was included in the highest protection level of the internationally applicable Washington species protection agreement in 1992 ( CITES Appendix I / Appendix A VO (EG) 338/97).
In the Red List of Threatened Species of IUCN in 1998 Dalbergia nigra rated as "vulnerable" = "endangered."
Taxonomy
It was first described in 1829 under the name Pterocarpus niger ( Basionym ) by the Brazilian botanist José Mariano da Conceição Vellozo in Florae Fluminensis 300. The new combination to Dalbergia nigra was made in 1860 by George Bentham after Francisco Freire Allemão e Cysneiro in the Journal of the Linnean Society 4 ( Suppl.): 36 published. Another synonym of Dalbergia nigra is Amerimnon nigrum (Vell.) Kuntze .
Timber trade
Trade name of the wood
The main name rosewood , which is preferred in German-speaking countries, can be traced back to the Portuguese common name “Palo santo” (directly translated = holy wood) and refers to several species of the genus Dalbergien. In Brazil, the bark of several Dalbergia species has been thought to have medicinal properties and is therefore called that. In English, the common name "Rosewood" is used for almost all types of rosewood.
The trade name Jacaranda has been used in international trade for wood of Brazilian origin since 1914 to distinguish it from East India rosewood ( Dalbergia latifolia ), which is found in India. The name Jacaranda probably comes from the similar purple coloration of the flowers of Jacaranda and Dalbergia species.
For Dalbergia nigra , in addition to Rio rosewood, the catalog of commercial trade names includes an extensive list of trade names ; the most important are: English: Brazilian Rosewood , Bahia or Rio Rosewood , German: Rio-Rosewood, Portuguese: jacarandá-da-baía and jacarandá-legítimo , caviúna , cambora , palissandre and rio-pallisandro .
Import history
From around 1660, the import of Brazilian and Indian rosewood into Europe began. The colonial powers Portugal and England imported it via Lisbon and London. In the European royal cities , Dalbergia wood was used for inlay art from an early age . It was very popular for furniture, for example .
Replacement woods
The following table shows four Substitutes , ie wood species that are similar to the Brazilian rosewood in color and texture, have also similar physical and tonal characteristics of Southeast Asia , Central America and South America :
| Botanical name | origin | Main trade name | Basic coloring | Veining / drawing |
|---|---|---|---|---|
| Dalbergia sissoo | South East Asia | Sissoo, sheesham | Fawn brown to purple | hardly veined |
| Dalbergia retusa | Central America | Black rosewood, cocobolo | Yellow, dark red, orange, maroon | Alternating twist |
| Dalbergia decipularis | South America | Bahia rosewood | Pink-yellow, red-violet | Darkly veined |
| Dalbergia spruceana | South America | Amazon rosewood / rosewood | Purple-black | Darkly veined |
In addition to these four Dalbergia species, species from other genera of the Fabaceae family Santos rosewood ( Machaerium scleroxylon ) with a reddish-purple color are named as substitute woods . Due to the CITES listing, it is important to find replacement timber that can be used as a substitute and thus meet the high demand.
Dalbergia nigra cannot be distinguished from Dalbergia spruceana , Dalbergia tucurensis , Dalbergia granadillo or Dalbergia stevensonii by examining quantitative characteristics such as vessel diameter or wood ray height . This means that a “ naive Bayesian classification ” should be carried out for a more precise identification and differentiation between the species . However, the most reliable method is genetic analysis.
Wood description
Macroscopically
The proportion of sapwood can vary. The sapwood is therefore of different widths (between 3 and 8 centimeters), but with its white to yellowish color it stands out very clearly from the reddish-brown to chocolate-brown to purple-black heartwood . It is irregularly streaked by almost black color zones. The vessels are macroporous , which means they can be seen in cross-section with the naked eye. They are arranged in scattered pores and have a share of 8%. Wood rays are only clearly visible under the magnifying glass. The longitudinal section shows elongated pore grooves and dark and light inclusions. Growth zones are only indistinct and seldom recognizable. Nor can the parenchyma be made out marginally or apotracheally . There is no interlocking growth. The wood surface feels oily.
Microscopic
The rays are fine (mostly less than 1 millimeter high) and distributed heterogeneously . They are arranged in strict storeys and make up a share of 23%. The longitudinal parenchyma is 22%. Mineral crystal deposits are often found there. The core material deposits can be light or dark. The disordered libriform fibers make up 47% of the total wood.
- Rio rosewood wood
cross-section
Radial section
Tangential cut
Tangential cut
Chemically
The cellulose content is around 36%. The lignin content at 34%. Accordingly, the proportion of hemicelluloses or pentoses should amount to around 25-30%. However, it is 19.5%, which could be due to a very high proportion of extract substances , i.e. inorganic ingredients , fats and oils . The pH value is between 4.6 and 4.8 and is therefore significantly more acidic than the wood of East Indian rosewood (pH value: 6.3).
In general, the rosewoods have inhibiting soluble ingredients and also have active ingredients against insect attack . The rio rosewood turns blue-gray in contact with iron . This indicates other tannins .
Physically and mechanically
In general, rosewood is difficult to split and easily brittle. They only shrink to a small extent and have good stamina . Their heartwood is largely resistant to fungi and insects, but not to bivalve molluscs . It is also weatherproof. It is assigned to durability class 1.
| Bulk density (ÖNORM B 3012), g / cm³ | 0.86 |
| Dose density r 0. g / cm³ | 0.80 |
| Volume shrinkage ,% | 9.1-12.6 |
| Radial shrinkage,% | 2.8-4.3 |
| Tangential shrinkage,% | 6.1-8.1 |
| Compressive strength air dry, N / mm² | 60-80 |
| Flexural strength air dry, N / mm² | 110-150 |
| Young's modulus air-dry, N / mm² | 8800-12900 |
Machining
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Solid wood
The wood of the Rio rosewood can be sawed relatively well. It is recommended to use hard metal-tipped tools when sawing the wood, as without them a strong blunting effect can occur due to the high hardness . It is easy to turn and smooth surfaces can be created when planing. Screws must be pre-drilled. There are no problems with gluing.
veneer
The veneer of the Rio rosewood was often used due to its elegant look.
Drying
Like all very hard woods, rosewood should be dried as slowly and gently as possible so that the drying process can proceed without cracking. The wood shrinks only slightly and does not cause any fundamental problems. It absorbs water slowly and is not particularly sensitive to moisture . When drying in the open air, the color of the wood is better preserved. This is why this method is recommended for sawn timber .
Surface treatment
When treated with urea resin lacquers , a green fluorescent discoloration can occur. It can also be disadvantageous that individual ingredients are alcohol-soluble . Furthermore, resin-rich zones in the wood cause paint damage .
use
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The Rio rosewood is particularly popular in instrument making due to its good sound properties . For example for guitars fingerboards , cervical muscles , pegs , instrument bottoms and mechanically stressed parts of stringed and plucked instruments , but also for pianos , recorders , chime bars and xylophones . Richlite is now used as an alternative material in instrument making. In turners will be happy for any of their work ( brushes back , knife handles) taken. But veneer is also popular for furniture and as trim wood for interior fittings , especially on ships.
Allergic reaction
When processing Rio rosewood, but also when using the end product, allergic reactions can be caused in sensitive people who come into contact with the wood dust or the wood itself . This is done through specific ingredients.
literature
- The CABI Encyclopedia of Forest Trees. CABI, 2013, ISBN 978-1-78064-236-9 , p. 148 f.
- André M. de Carvalho: A synopsis of the genus Dalbergia (Fabaceae: Dalbergieae) in Brazil , In: Brittonia , Volume 49, Issue 1, 1997, pp. 87-109. ISSN 0007-196X : doi : 10.2307 / 2807701 .
Web links
- Data sheet - Dalbergia nigra Fr. All. (Rio Palisander, Brazilian rosewood) at Handelshölzer by HG Richter and MJ Dallwitz .
- Data sheet with distribution map at The Forest Legality Alliance .
- Datasheet - Brazilian Rosewood Dalbergia nigra at Global Trees Campaign .
Individual evidence
- ↑ a b c d e f g h i j k l m n o p q r s Klaus-Günther Dahms: The wood portrait: Rosewood . Dalbergia latifolia Roxb .; Dalbergia nigra (Vell.) Fr .; Family Leguminosae / Fabaceae. In wood as a raw material. 47 (8), 1989, pp. 337-342, doi : 10.1007 / BF02610554 .
- ↑ a b c d e f g RA Ribeiro, JP Lemos-Filho, ACS Ramos & MB Lovato: Phylogeography of the endangered rosewood Dalbergia nigra (Fabaceae): insights into the evolutionary history and conservation of the Brazilian Atlantic Forest. In: Heredity. Volume 106, Issue 1, 2011, pp. 46–57: doi : 10.1038 / hdy.2010.64 PMC 3183853 (free full text).
- ↑ a b c Gerald Koch: Wood species database “macroHOLZdata”, developed in 2008 at the Thünen Institute for Wood Research in Hamburg, available on CD from the Thünen Institute, contact details: Gerald Koch, Thünen Institute .
- ↑ NMM Donadio, MESP Dematte: Morfologia de frutos, sementes e plântulas de canafístula (Peltophorum dubium (Spreng.) Taub.) E jacarandá-da-bahia (Dalbergia nigra (Vell.) Fr.All. Ex Benth.) - Fabaceae - Fruits, seeds and seedlings morphology of Peltophorum dubium (Spreng.) Taub. and Dalbergia nigra (Vell.) Fr.All. ex Benth. - Fabaceae. In: Revista Brasileira de Sementes. Volume 22, No. 1, 2000, pp. 64-73. Full text PDF. ( Memento of the original from February 1, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Federal Agency for Nature Conservation - List of the wood species protected in CITES and VO (EG) 338/97 , as of August 10, 2013 (PDF; 176 kB).
- ↑ Dalbergia nigra in the endangered Red List species the IUCN 2014 Posted by: N. Varty, 1998. Accessed January 14, 2015.
- ↑ First publication scanned at biodiversitylibrary.org .
- ↑ Dalbergia nigra at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed January 18, 2014.
- ↑ Dalbergia nigra in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved January 18, 2014.
- ↑ The Thünen Center of Competence for Wood Origin : Legal Background .
- ↑ Peter Gasson et al .: Wood identification of Dalbergia nigra (CITES Appendix I) using quantitative wood anatomy, principal components analysis and naïve Bayes classification. In: Annals of Botany. Volume 105, 2010, pp. 45-56.
- ↑ a b c d e f g h i j Rudi Wagenführ: Wooden atlas. 6th edition, Carl Hanser Verlag, 2006, pp. 599-601.
- ↑ Handbook of Hardwoods. Building Research Establishment from Her Majesty's Stationary Office, 1972.
- ↑ BM Hausen: Types of wood with harmful ingredients. DRW-Verlags-GmbH, Stuttgart, 1973.
