Applying MERLIN for modelling nitrate leaching in a nitrogen saturated Douglas fir forest in the Netherlands after decreased atmospheric nitrogen input

The MERLIN model was applied on the results of a field-scale manipulation e xperiment with decreased nitrogen (N) deposition in an N saturated forest e cosystem in The Netherlands. The aim was to investigate the mechanisms that could explain the observed rapid response of nitrate leaching as a result of the decreased N input. Calibrating the model to pre-treatment data revea led that, despite the high atmospheric N input, the trees relied on N miner alised from refractory organic matter (ROM) for their growth. MERLIN could simulate only the fast response of nitrate leaching after decreased input i f this ROM mineralisation rate was decreased strongly at the time of the ma nipulation experiment.