Potential for estimating carbon fluxes in forest soils using "C techniques. Yew Zealand Joiirizal of Forestry Science

Three studies explored the potential of the conventional radiocarbon dating procedure combined with the analysis of the degree of incorporation of 14C derived from nuclear weapons testing (14C-bomb) during the early 1960s, for determining carbon turnover in forest soils. The first study examined the gross annual turnover rate of soil carbon within the tree rooting zone of a mixed deciduous oak/ash/birch woodland (Meathop Wood) situated on an acid brown earth soil overlying carboniferous limestone. The turnover was estimated by dividing the soil carbon content of several soil layers (O + Of 0-5,5-10,10-15,15-25, 25-35, and 35-50 cm depths) by their respective mean carbon age (carbon mean residence time) derived from the 14C analyses. The total turnover of carbon, estimated as 3860 kg C/ha/yr, very closely agreed with the estimated total carbon inputs to soil as litter components (leaf litter, twigs, flowers and fruits, herb layer throughfall, and stem flow plus root decay) of 3895 kg C/ha/yr. The latter data were derived from intensive site studies carried out during the International Biological Programme. Close agreemen