Bamboo Fiber

Bamboos are arborescent grasses that range from 10 cm to 20 m tall (Scurlock 2000, Lise 1987). The common name bamboo refers to 1250 species comprising the subfamily Bambusoideae within the grass family Poaceae. Approximately 1000 species occur in Asia within 180,000 square kilometers (Scurlock 2000). Although bamboos are most concentrated in the tropics, they exist in subtropical and temperate regions in five continents (Scurlock 2000). They grow at elevations from sea level to 4000 meters (Scurlock 2000). China, with 300 species, is the world's largest producer of bamboo, but India, Bangladesh, Indonesia, and Thailand are major producers as well (Scurlock 2000).

Although bamboo species vary in appearance, much of their physiology is consistent (Scurlock 2000). All bamboos are perennial (Lin et al. 2001). The upright stems, called culms or canes, consist of nodes (rings where branches originate) and internodes (the spaces between the nodes). Each culm is made up of 50% parenchyma and 50% vascular bundles (Kleinhenz and Midmore 2001). Bamboo can grow at an unparalleled rate of 1 meter per day, reaching its mature height within a few months (Lin et al. 2001, Liese 1989). This is because nearly all of its growth at first is internode elongation, after which the stems thicken and increase in density for the next few years (Scurlock 2000). The stems begin as compact buds originating from a long, horizontal rhizome (a root-like underground stem). Each rhizome can branch to spread over tens of meters (Scurlock 2000). In the spring, the buds, which have compact nodes and internodes, elongate and become sharply-pointed to penetrate the soil. Culms can grow either clumped (sympodial) or spreading (monopodial). Unlike other tall grasses, bamboo lacks the C4 photosynthetic pathway, which is thought to cause greater efficiency in water and nutrient use in high light conditions (Scurlock 2000). The environmental conditions most favorable for bamboo growth are high temperatures, soil moisture, and humidity (Kleinhenz and Midmore 2001).

Bamboo is an extremely versatile material. Its culms are used to make paper, agricultural tools, musical instruments, fishing equipment, paper, textiles, and handicrafts. They are also used in construction. Bamboo shoots are commonly used in Asian cooking and are exported heavily from Taiwan and Thailand (Scurlock 2000). In Japan, charcoal made from bamboo is used as a deodorizer (Nishimura 2004). The leaves and bark are used medicinally for their antifungal, anti-tumor, and antibacterial properties (Nishina et al. 1991, Volker and Midmore 2001). According to Wang and Ng (2003), bamboo produces an antifungal protein called Dendrocin, which can be isolated from the shoots. In addition, bamboo produces an antibacterial substance called bamboo kun, which has been isolated in Phyllostachys heterocycla (Nishina et al. 1991).

Due to its antibacterial and antimicrobial properties, as well as its water-absorbing capacity, bamboo is an ideal textile material. The culms for making fabric are harvested at 1 year, when the fiber quality is highest (Kleinhenz and Midmore 2001). After the culms are alkali pulped, they are spun into yarn by the same method as with cotton linter processing (Shen et al. 2004). Bamboo fabric has the same surface properties and wicking capacity as cotton, probably because bamboo fibers are porous (Shen et al. 2004, Parameswaran and Liese 1976). The fabric also retains its antibacterial and antifungal qualities because the bamboo kun binds to the cellulose during pulping. According to China Bambro Textile Co., Ltd., a leader in bamboo textiles, bamboo fabric maintains its antibacterial function after fifty washes, according to the Japan Textile Inspection Association.

Bamboo is an environmentally-friendly crop. It typically grows well in poor soil that is unusable for other crops, and it is often planted to rehabilitate degraded areas. The long, branching rhizomes stabilize soil and minimize erosion in areas with heavy rain or earthquakes (Nishimura 2004). Despite the great height of many species, their root systems are shallow and thick, rarely reaching below 40 cm under the ground (Kleinhenz and Midmore 2001). Due to its shallow roots, along with its ability to absorb and sequester ions and carbon efficiently, bamboo rarely leaches the soil of nutrients (Kleinhenz and Midmore 2001). Despite its rapid growth rate and its tolerance for poor soil, however, bamboo must be harvested carefully in order to maintain its supply. Over-harvesting causes an overall decrease in timber production, and inadequate harvesting causes the culms to become overcrowded (Kleinhenz and Midmore 2001). In India, irregular harvesting has been shown to cause localized overcrowding and a higher percentage of dead, broken, and malformed culms unsuitable for industrial use. Unfortunately, bamboo has recently been overexploited as a resource due to improper management and increasing demand (Kleinhenz and Midmore 2001). With improved harvesting, however, bamboo will continue to be a valuable renewable resource.

Sources:

China Bambro Textile Co., Ltd. Bamboo Yarns and Fibers. 2003.

Kleinhenz, V., Midmore, D. 2001. Aspects of Bamboo Agronomy. Advances in Agronomy 74: 99-145.

Liese, W. 1987. Research on Bamboo. Wood Science and Technology 21:189-209.

Lin, J., He, X., Hu, Y., Kuang, T., and Ceulemans, R. 2001. Lignification and lignin heterogeneity for various age classes of bamboo (Phyllostachys pubescens) stems. Physiologia Plantarum 114:296-302.

Nishimura, O. 2004. The Role of Bamboo in the Sustainable Economic Development: From a Viewpoint of Social Common Capital. Japan Society of Mechanical Engineering International Journal 47(4): 527-532.

Nishina, A., Hasegawa, K., Uchibori, T., Seine, H., and Osawa, T. 1991. 2,6-Dimethoxy-p-benzouinone as an Antibacterial Substance in the Bark of Phyllostachys heterocycla var. Pubescens, a Species of Thick-Stemmed Bamboo. Journal of Agricultural Food Chemistry 39:266-269.

Parameswaran, N., and Liese, W. 1976. On the Fine Structure of Bamboo Fibres. Wood Science and Technology 10:231-246.

Scurlock, J.M.O. 2000. Bamboo: An Overlooked Biomass Resource? Oak Ridge National Laboratory, Environmental Sciences Division, Publication No. 4963. Available electronically at www.doe.gov/bridge.

Shen, Q., Liu, D., Gao, Y., and Chen, Y. 2004. Surface properties of bamboo fiber and a comparison with cotton linter fibers. Colloids and Surfaces 35:193-195.

Wang, H.X. and Ng, T.B. 2003. Dendrocin, a distinctive antifungal protein from bamboo shoots. Biochemical and Biophysical Research Communications 307:750-755.

April Dobbs, who wrote this article, is a recent graduate of the University of California, Berkeley, where she studied genetics and plant biology. In her spare time, she enjoys playing the cello, reading, raising chickens, hiking, and studying local floras. April will be a WOOFER in Nova Scotia until she begins serving in the Peace Corps in Ukraine in February 2008.