Carbon in Dutch forest ecosystems

Abstract

The forest area in the Netherlands equals c330 000 ha. It mainly consists of young plantations of conifers on poor, dry sandy soils. Average age is approximately 50 yrs. The present average standing volume is 170 m3 ha-1 and average volume increment was 9.0 m3ha-1yr-1 over 1984-89. At present, c63.7 Mt C is stored in the entire forest, including dead organic matter in the forest soil. Almost 60% of this is stored in the stable humus in the soil compartment. The average carbon stock in the stable humus is 113 Mg C ha-1, whereas only 59 Mg C ha-1 is contained in the living biomass and 19 Mg C ha-1 is contained in the litter layer. The average stock in the living biomass is largest for beech Fagus sylvatica stands with 124 Mg C ha-1. Annual c0.66 Mt C of atmospheric carbon is stored by means of stem volume increment when harvesting is not considered. On average, for the entire forested area, at present about half of the annual storage is harvested each year, which means that the forest at present acts as a net carbon sink to the amount of c 0.33 Mt C yr-1. The largest net accumulation is attained in beech stands, and amounts to 1.8 Mg C ha-1yr-1. Long rotations with species like oak, Quercus spp., beech and Douglas-fir Pseudotsuga menziesii which may build-up a large standing biomass and which produce durable wood products, are most suitable for a long-term storage of carbon. -from Authors