Carbon sinks

Trees are nearly 50% carbon. During the growth processes, trees remove or sequester carbon dioxide from the atmosphere, convert it to carbon-based tissues during photosynthesis, release oxygen as a by-product and the carbon then remains tied up in the tree tissue until they die or are harvested. Hence trees are long-term storehouses of carbon - or carbon sinks.

When harvested and converted into long-lasting wood products, they continue to store that locked-up carbon.

Trees create and sustain local climates and play a crucial role in sequestering atmospheric carbon dioxide that fuels global warming.

A healthy semi-mature Douglas fir forest can fix 4 metric tonnes of carbon per hectare per year; for beech the figure is around 2.5 tonnes.

High emission companies are interested in woodland creation as a green flagship offsetting activity. Current embryonic trading regimes suggest that the carbon store associated with new native woodland could have a value in the order of £500-1000 / ha.

Woodland stores much more carbon than other types of vegetation. And faster growing, managed woodlands accumulate more carbon than derelict ones.

Air pollution may interact with other stresses to cause damage to trees and carbon dioxide levels are increasing. Trees use carbon in their metabolism and structure. Some species may benefit from increased carbon dioxide levels but the consequential warming of the planet may change their distribution patterns and those of the creatures that depend on them.

More: FC Info. Note 48. Forests, Carbon & Climate Change : the UK Contribution. By Mark Broadmeadow (2003).