CARBON STORAGE AND SEQUESTRATION IN THE FORESTS OF NORTHERN-IRELAND

The rate of accumulation of carbon in forests and woodlands in Norther n Ireland was estimated using the record of forest planting since 1900 and a model that calculated the flow of carbon from the atmosphere to trees, litter, soil, wood products and back to the atmosphere. It was assumed that all conifer forests had the carbon accumulation characte ristics of Picea sitchensis, and upper and lower estimates of carbon s torage were calculated assuming Yield Class 16 m(3) ha(-1) a(-1) unthi nned and Yield Class 14 m(3) ha(-1) a(-1) thinned. Broadleaved woodlan ds were assumed to have the carbon accumulation characteristics of Fag us sylvatica, Yield Class 6 m(3) ha(-1) a(-1). Northern Ireland curren tly has about 78 300 ha of forest, 83 per cent of which is coniferous, 77 per cent state-owned, mostly planted since 1945, with peak plantin g in 1960-1975. In 1990, conifer forests contained 3-4 MtC (trees + li tter) and broadleaved woodlands contained about 0.8 MtC (trees + litte r + new forest soil). In 1990, conifer forests were sequestering 0.15- 0.20 MtC a(-1) and broadleaved woodlands about 0.025 MtC a(-1). To mai ntain these sink sizes, new conifer forests need to be planted at 1500 -2000 ha a(-1), and new broadleaved woodland at 100-150 ha a(-1) in ad dition to full restocking. Current carbon sequestration by Northern Ir eland forests represents around 6.5-8.2 per cent of the total for UK f orests and is greater per hectare than in Britain because the average forest age is younger in Northern Ireland.