The carbon accumulated in the wood of the world's forests accounts for 32% of the 1,200 Gt, which includes carbon absorbed by forest ecosystems. In the strategy of terrestrial carbon management, the following main issues are distinguished sequestration, conservation and substitution. Comparative studies show environmental advantages of wood products over the industries producing wood substitutes. To produce 1 tonne of construction wood, approximately 580 kWh of energy is required, while competing materials need much higher energy inputs e.g. bricks – 4 times more than wood; cement – 5 times more, plastic – 6 times more, steel – 24 times more and aluminium – 126 times more energy than wood. Wood also becomes an increasingly more attractive biofuel. The U.S. President announced in 2007 ‘the initiative on modern energy', including the replacement by 2025 of over 75% of U.S. oil imports from the Middle East by biofuels. 80−375 litres of ethanol can be produced from 1 tonne of absolutely dry wood. It is expected that 905 million tonnes of agricultural waste and 334 million tonnes of wood biomass will be available annually by 2030. The cultivation of agro−fuel products can be extended to woodlands generating conflicts in land use and increasing deforestation with the implications for biodiversity, climate change and water. The area previously designed for food production may be allocated for the production of biofuels, which can cause a rise in agricultural product prices and threaten food security.

Sylwan 155 (3): 195-201