Sediment size distribution (%) in the different depth layers, expressed as an average (SD) value between the different cores used in the experiment.

Cores 13 and 14 (1120 μatm treatment) as well as the layer deeper than 4 cm of core 20 (3000 μatm treatment) have not been considered in this analysis and in the subsequent ones as they have been showed to greatly differ from the other samples (See text for details).