The sensitivity of organic-rich archaeological layers at Bryggen in Bergen, Norway, to changes in soil temperatures, water contents and oxygen concentrations is investigated. This is done by linking measurements of oxic decay at varying temperatures and water contents with on-site monitoring data using a one-pool decomposition model. The results show that the model can be used to elucidate the current in situ decay and to evaluate where and when the decay takes place. Future investigations need to include long-term incubation experiments and decay studies at zero or very low oxygen contents in order to improve the robustness of predictions.