Decomposition of oak leaf litter is related to initial litter Mn concentrations

The factors determining the quantity of litter being incorporated into stable organic matter were examined as part of a broader study investigating carbon (C) sequestration in forest ecosystems. Litter was collected from 20 common oak (Quercus robur L.) stands in Wales (UK) and placed in litter-decomposition bags. These bags were installed in an oak stand for 3, 6, 12, 21, and 31 months to study the effect of litter quality on decomposition (mass loss) rates and the limit value for a broad-leaf species. Results indicate that the initial decomposition rate is highly correlated with the manganese content of the litter (P = 0.007, R2 = 0.34). In the final stages of decomposition, limit values ranged between 57% and 95% of initial litter mass. These estimated limit values were not significantly correlated with initial concentrations of other nutrients. However, Ca concentrations gave a significance level of P = 0.067. Estimated rates of C sequestration in soil ranged from 0.93 to 80.22 g C·m–2·year–1.