Bamboos are a wonderful gift of nature. Their versatility has given rise to a multitude of uses of traditional and cultural value in countries where they are abundant. Many people of Asia, Africa and South America are dependent on bamboo for their livelihood. Bamboo harvested from forests or grown in homesteads is used extensively in housing and cottage industries. Bamboo, referred to as “poor man’s timber” is now being rediscovered as nature’s “green gold”.
Giant bamboos yield more cubic metres of semi finished material per ha than all plantation-grown hard woods and most soft woods and are only matched in annual yield by the fastest growing soft woods such as Eucalyptus and radiata pine. Therefore bamboos are competitive or better than wood alternatives in terms of annual yield, showing their potential for the future.
|Bamboo plantlets growing in trays in net house
The growing human population and consequent increase in per capita consumption have put great pressure on global resources. It is wise to look for renewable resources with least adverse effects on the environment. In this context, bamboo is the most versatile renewable and eco friendly resource.
The greatest advantage of bamboo is undoubtedly its enormous growth rate. Bamboo shoots in tropical countries grow up to 30 metres within six months. A plantation of tropical giant bamboo will take less than 10 years to mature while the equivalent for a plantation of timber may range from 15 years in Eucalyptus to 70 years in Teak.
The underground rhizome of a bamboo clump produces new above ground culms annually so that there is a continuous production of new culms that enable harvesting of older mature culms. Thus, unlike a timber tree which requires replanting after harvesting, bamboo can be harvested sustainably.
Bamboo is relatively cheap compared to timber, easy to transport and has long-fibre which, makes it an important raw material for making paper pulp, the oldest industrial use of bamboo. Since bamboo and wood have a similar chemical composition, pulp yields from both resources are similar but the yield per hectare, superior in bamboo, determines the cost of raw material. India, China, Indonesia, Malaysia are among the countries that use bamboo in paper pulp production.
Since the 1990s, a wealth of new bamboo materials has become available through industrial processing of raw culms. Many innovations in production technology led to the development of bamboo materials with different properties and possibilities. Bamboo Mat Board (BMB), Strand Woven Bamboo (SWB), Bamboo Particle Board (BPB), Ply Bamboo, and Bamboo Composites are some of these products with various applications in high end markets in the West. BMB is made from thin bamboo strips woven into mats. Mats treated with resin are hot pressed to make extremely hard boards.
These can even be processed into corrugated boards and used as low cost roofing. SWB is a product made from thin rough bamboo strips glued together and pressurized in moulds to form beams. SWB has very high density (approximately 1080 kg/ m3) and hardness, which makes it suitable for use in heavy duty structures. Recently, higher resin content versions of SWB were developed suitable as alternatives for quality tropical hardwoods such as teak. Ply Bamboo is produced by laminating bamboo strips into boards and used in flooring, furniture board and veneer.
Giant bamboos are used in making these products because they yield more.
When these bamboos are used in producing paper pulp, the yield can be higher, even double, as culms are harvested at an early age of 1 to 2 years compared to an age of 4 to 5 years required for production of wood alternatives.
Due to their high densities and annual yields, giant bamboos also have enormous potential for production of bio fuels. The energy value of bamboo reported in the range of 16 to 20 MJ per kg by several researchers is similar to the energy content of woody biomass at 17MJ per kg.
A mature plantation of giant bamboo (Yodha una), Dendrocalamus giganteus, can give a yield estimated at 250 MT per ha of culms. In the paper pulp production, 50 MT of culms may be converted to 20 MT of paper pulp. At a price of US $ 500 per MT of paper pulp, a gross annual income of US $ 10,000 per ha may be possible.
River banks, degraded tea lands and other areas prone to erosion are suitable for growing bamboo. Bamboo will be the most promising for reforesting degraded land where trees may not survive.
We must make an effort to be benefited by the vast potentials that bamboo can offer for economical and environmental sustenance. Since bamboo is fast growing and plantations are established relatively fast, the output will be apparent within a few years.The constraint for establishing bamboo plantations was lack of good quality propagules.
It is heartening to note that the Riverine Bamboo Project of the Mahaweli Authority is producing bamboo propagules by tissue culture. This project, launched by the then President, was a brainchild of late Professor Aries Kovoor, Science Advisor to the President (1996 – 2005). It is a unique undertaking where a tissue culture technology developed by original research in the country i.e. in the Plant Biotechnology Project of the Institute of Fundamental Studies, was used for the first time in downstream application successfully.
After infrastructure development and training in bamboo propagation by tissue culture in 2004, distribution of propagules for planting commenced in 2007. Presently over 200,000 plants have been distributed free of charge, through Community Based Organisations, for planting in the Mahaweli Systems, especially in the Upper Mahaweli catchment area.
The next hurdle is field planting and management of stands. If we make the field planting successful, there is hope that in less than 10 years, the country will be enriched with a substantial wealth of bamboo.