THE AMERICAN BAMBOOS WITH EMPHASIS IN THE GENUS GUADUA

Ximena Londono

Bamboos are an American as maize, potato and tomato. There are a total of 41 genera and 535 currently recognized species in the New World. Of a total of 1200 species and 90 genera of bamboos known in the world, it represents 45 % of the genera and species diversity.

In America there are two currently recognized tribes: the Bambusodae or woody bamboos and the Olyrodae or herbaceous bamboos. These herbaceous bamboos are perennial herbs of rain forest understories, often a great beauty and horticultural potential.

The tribe Bambusodae includs 21 genera and 429 species of woody bamboos and the Olyrodae 20 genera and 106 species of herbaceous bamboos.

Bamboos in America are distributed from aproximately 22* North latitude with Arundinaria gigantea in the eastern USA, to 47* South latitude with Chusquea culeo in Chile; they are found in almost all kind of habitats with the exception of desert regions, and are distributed from the humid lowland forest at sea level to the highlands in the Andes up to 4,300 m in the natural formation known as "paramo".

Among the American countries, Brazil has the greatest bamboo diversity, follow by Colombia, Venezuela, Ecuador, Costa Rica, Mexico and Peru. Brazil, including the Amazon basin and the Atlantic forest has the greatest diversity of genera and species and endemism in the New World, followed by the central and northern part of the Andes (Venezuela to Bolivia) and Mexico.

Since Pre-columbian times bamboo has been used in America, especially in Latin America where occur all the bamboo species except one. Latin America is defined as the area from Mexico through Central America and South America, including the Caribbean and West Indies. In Latin America there are reports of use of bamboo in every country. However, despite reports, bamboo in general should be considered asforest resource with little significance in the local economy in the majority of these countries. Generally the explotation of native bamboos in America is limited to the local use of species found close-by. It is only in Colombia, Ecuador, Brazil and more recently Costa Rica, where bamboo play a more conspicuous role in the local economy.

Recently, it has been calculated that there is a minimum of II millons hectares covered by bamboo in Latin America. Only in southwestern amazonian there is a bamboo-dominated area close to 180.000 square kilometers, equivalent to 18 millons hectares. It is probably the biggest natural bamboo forest of the world.

By the other hand, the annual deforestation rate of 1.3% has been increasing over the last 10 years as a result of the ever more critical socio-economic situation in the region, and the montane forest of the Andean region, where more of the woody bamboo species are found, is decreasing at a high rate as a result of both natural an antropogenic disturbance.

In America there are 4 currently recognized subtribes: the Arundinariinae, with a single species in the southeastern United States; the Chusqueinae, with 2 genera and 155 species, of which one genus (Chusquea) is by far the most speciose and widely distributed on New World bamboos; the Arthrostylidiinae with 12 genera and 157 species, and Guaduinae with 6 genera and 33 species.

The genus Chusquea is extremely diverse and because of that the specialist in this group, Dr. Lynn Clark of Iowa State University, has been subdivided it into three major subgenera and 5 sections. This group of bamboo can be recognized by its solid, rarely hollow culms, multiple and dimorphic buds at each node and the spikelet consisting of 4 glumes and one bisexual fertile floret. Chusquea has the widest altitudinal (0 to 4,300 m) and latitudinal ranges (24 N to 47 S) of any bamboo genus in the world. It is a primarily montane bamboo, occurring from northwestern Mexico to Uruguay and south-central Andean Argentina and Chile, with single disjunct species in the West Indies, Juan Fernandez Islands and the Guyana Highlands. Species are characterist of montane forests and high-altitude grassland vegetation, including cloud and elfin forest but few also grow in lowland tropical forests. The generic nameis derived from the world chusque, used by indigenous people in Colombia and Ecuador for this bamboo.

The culms of several bamboos are used in America for goods as diverse as housing, basketry, blowguns, and the distinctive wind instruments that produce the haunting folk music of the Andes. However, from a utilitarian human perspective, Guadua is the most important American bamboo. It is used widely for house construction in a bamboo culture that flourished along the inter-Andean rivers of Colombia and in a coastal Ecuador.

The subtribe Guaduinae consist of six genera (Apoclada, Criciuma, Eremocaulum, Guadua, Olmeca and Otatea) and 33 described species distributed from northwestern Mexico (27* N) throughout Central and South America to Argentina and Uruguay; it is not represent in the West Indies or Chile.

The genus Guadua include generally low-elevation bamboos but some memebers have been found at elevations up to 2,500 meters. Species of Guadua range from San Luis de Potosi in Mexico (23* N) to Uruguay and Argentina (35 S) but are not native to Chile or the west Indies, although G. angustifolia has been cultivated in Cuba, Puerto Rico, and Trinidad. Guadua is primarily an Amazonian genus with 45% of the species diversity found in the Amazon and Orinoco basins. Species range form elevations of o to 2,200 m but are much abundant and diverse at elevation below 1,500 meters. Guadua occurs in diverse habitats including lowland tropical and lower-montane forest, savannas, cerrados, gallery forest, and disturbed inter-Andean valley vegetation. The generic name derives from the vernacular names used by indigenous communities in Colombia and Ecuador. Guadua angustifolia is the physically largest native bamboos in the Neotropics; its culms may reach 30 meters in height and 15 to 22 centimeters in diameter. Guadua angustifolia also is the most economically important tropical bamboo in America duo to its large size, exceptional timber qualities, versatility, and natural durability. Colombia and Ecuador have strong tradition of using this material, and Costa Rica has in recent years developed the housing technology. This species plays a significant role in the daily lives of the local inhabitants. Its close relative, G. chacoensis from Brazil seems to have similar economic potential.

The most widespread Amazonian species is G. weberbaueri characterized by culm internode up to I meter long, the lumens often filled with water and elongate rhizome necks reaching 8 meters in length. Guadua sarcocarpa is the only species of Guadua known to have fleshy fruit and represents the first report of an edible fleshy bamboo fruit in the New World. These two species occupied extensive areas of the southwestern Amazon Basin centered just northwest of the junction of Brazil, Peru and Bolivia, known as pacales in Peru and tabocais in Brazil.

Guadua glomerata is another Amazonian species characterized by its thin, scandent and solid culms; G. paniculata is the most widely distributed species (Mexico to Brazil) within the genus; G. tagoara is especially abundant in the Atlantic forest of eastern Brazil, and it is characterized by its waxy culms containing water in the young internodes.

The use of bamboo by people in the New World date back by early in human history, however, with a future vision, it is necessary to continue ongoing work to improve the well-being of bamboo producers and user within the context of INBAR mission: enhancing the production, processing and utility of American bamboos on a systematic sustainable management; protection of the environment, conservation of biodiversity and promoting policies aimed at using the commodities as substitutes for timber.