Bamboo furniture. Phyllostachys aurea. Virginia Carmiol Umaña
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Our Continent, since it is the youngest, lacks a timetable specifying the flowering season of the different species.
In Costa Rica there have been instances of sporadic flowering of Guadua, Dendrocalamus, Bambusa vulgaris, and Chusquea.
Growth
There are various phases in the growth of bamboo; the first is slow, followed by a phase of such great growth that there is no other plant in nature that equals it.
According to research carried out in Japan, daily growth is positively related to temperature and negatively to humidity.
Apparently, some species such as Phyllostachys, grow more during the day, while others such as Leleba multiplex or Dendrocalamus strictus grow more during the night.
The rate of growth various greatly according to species; the record in 24 hours is 1.21 m [almost 4 feet]. For the Americas there are practically no studies of this type.
In species of the pachymorphous group, the stalk reaches it maximum height in approximately 80 to 110 days; in the leptomorphous group in 30 to 80 days.
Once the stalk has reached its maximum height it is important to allow it to mature on the plant in order to increase its hardness and resistance.
Generally this period of seasoning reaches its limit after three years.
It is important to realize that the stalk emerges from the ground with the diameter that it will have throughout its life, so that it must not be expected that in maturity there will be an increase in its transverse section.
When the stock is young, or recently planted, it will produce slender stalks and these will grow to maturity independently.
In time the stock will develop and produce thicker stalks.
Cutting in a plantation is beneficial, and it is customary to thin it by cutting the more slender stalks to stimulate growth.
The internode ceases to grow when the bract or cover that protects the stalk pulls slightly away from the node immediately below.
Physical and Mechanical Properties
In relation to the bambooʼs physical and mechanical properties, the forces of tension and compression are much greater along the length of the fiber than those perpendicular to it; for this reason it is used as a vertical reinforcement in concrete structures.
The shell or outer layer of the stalk is without doubt the most resistant part; in addition, the mechanical properties vary from the base, to the middle, to the upper sections of the stalk.
The mechanical properties are reduced by intense heat and by an increase in the moisture content: the latter should not exceed 15%, otherwise the plant will be subject to rot or to fungal infestation.
Heat, on the other hand, produces loss in resistance of the stalk, a factor that is taken advantage of by man in the process of bending in the manufacture of furniture.
The application of heat should be moderate; bamboo burns easily.
Principal Species
With the exception of Europe, native bamboo species are found in every one of the Earth’s continents.
Experts in the matter differ widely as to the number of genera and species; it is still not known exactly how many there are.
There are botanists who mention 30 genera and 550 species, while others maintain that there exist 47 genera and 1 250 species; of these there are 13 and 662, respectively, in Japan alone.
For the Americas, F.A. McClure has carried out an excellent job of classification; this researcher reclassified the genus Guadua as a subgenus of the genus Bambusa, so that Guadua angustifolia is now classified as Bambusa guadua. McClure’s classification which includes in 17 genera native to the Americas, and which includes four new genera and four new species, can be found in his book Genera of Bamboo Native to the World (Gramineae: Bambusoideae), edited by Thomas R. Soderstrom, and printed by the Smithsonian Institution Press in 1973.
In pre-Columbian times, the Indigenous population of the Americas, made considerable use of bamboo.
Today, the areas in which bamboo is cultivated are limited: they range form 39°24’ North to 47° South (Argentina).
In Colombia, Peru, Ecuador, Brazil and Chile greater use is made of this plant than in the rest of the Continent.
In Costa Rica, as in the Americas in general, the distribution of bamboo has undergone considerable changes: the banana companies encouraged the cultivation of bamboo and imported species appropriate for the banana struts. Bambusa vulgaris is the species most widely used for this purpose. Dendrocolamus giganteus and Gigantochloa apus were also brought in.
The first imports of Guadua were the work of Mr. Carlos Manuel Rojas, owner the “Finca Bremen”.
The plants were brought from Brazil and were used to create a windbreak of some 5 km in Guapiles.
Eventually, bamboo ceased to be used for struts, and was replaced by piola (plastic cord).
At present attempts are being made to return to the traditional method which does not contaminate the environment.
The natural habitat of bamboo is the tropics, and our country presents optimal conditions for its growth.
The quality of the soil, the relative humidity and the rainfall make Costa Rica a fertile and appropriate area to assure a promising future for the cultivation of bamboo. There are various genera of the subfamily Bambusoideae in Costa Rica, among the most common being the Chusquea and Swallenochloa prized for the thickness of their culms.
These varieties are endemic and have not have so far not been used in craftwork; they are purely ornamental.
Studies show that in Costa Rica there are close to 16 genera and some 30 species.
There are four very valuable imported species in the country in terms of their yield and their industrialization in the short and medium term.
Each one of these species possesses its own characteristics for different purposes:
1. Phyllostachys aurea
2. Bambusa vulgaris
3. Guadua angustifolia
4. Dendrocalamus giganteus
Other varieties have only recently been introduced into the country or are present only in small quantities. Nonetheless, it has been established that some, such as Bambusa tulda, Dendrocalamus latiflorus, and Phyllostachys makino can be used in the production of paper pulp.
Phyllostachys aurea
Native to Asia. Member of the monopodial or leptomorphous group. In height it may reach up to 12 m [some 39 feet]; its diameter depends on the altitude in which it grows (the higher the plant, the greater the diameter: 3 to 5 cm [1 to 2 inches].)
Phyllostachus aurea grows above 800 m above sea level [over 2600 feet], but its major development is found at an altitude above 2000 m above sea level [6600 feet], in a colder climate with greater precipitation.
It is the variety traditionally employed in the manufacture of furniture. In the United States it is sold for fishing rods.
In Costa Rica it is found spread out through various regions: in Los Santos, Ciudad Neilly, San Isidro del General, San Carlos, Poas de Alajuela, La Garita de Alajuela, San Rafael de Heredia, Cartago, Paraíso; in the Central Plateau, it is found scattered througout several counties such as Alajuelita, Asseri, Escazú, Sabanilla, Moravia, Tres Ríos, and others. Depending on where it is found, it goes by different names: caña negra [black cane], caña china [Chinese cane], caña huesillo [little bone cane] and caña india [Indian cane]; however, it is preferable to use its scientific name to avoid confusion.
Bambusa