Wood has been used by man from time immemorial for construction purpose. Forest was the main source of wood. As the population increased the demand for wood also increased. With the industrial revolution the demand went further up. The indiscriminate deforestation is showing signs of global warming, melting of polar ice, rising of sea water level, draught and consequent destruction.
As Science and Technology developed, several alternate materials like metals, plastics and composites with improved strength and working properties were developed. But none of them had the feel of wood and it was concluded that there is no true substitute for wood. The continued search for wood led to the utilisation of secondary species of wood like rubber wood, a plantation timber.
Hevea Brasiliensis, the natural rubber tree, native of Brazil, is the most important commercial source of natural rubber and it is grown in about 9 million hectares in the tropical regions of Asia, Africa and America. With over 5,30,000 ha under rubber, India is now the third largest producer of natural rubber in the world.
At the age of 22 to 29 years, latex production becomes uneconomic and the trees are then cut and replanted. Thus the rubber plantation is a sustainable source of rubber as well as timber, contributing positively to the environment.
In India rubber is predominantly a small holders’ crop and over 87% of the rubber is from this sector. A rubber tree from small holdings will have about 0.57 m3 (20 CFT) of timber and the per ha yield is about 150 m3 (5295 CFT). The stem wood has timber value of only 60%. Present total availability of rubber wood is estimated as 0.94 million m3/yr. and it is estimated to be 1.5 m3/yr times by the end of the decade.
