Figure 5
Schematic illustration indicating the microbial colonization and oxygen distribution in the pore space of sandy sediments for grains with different sphericity. Red indicates oxic volumes, blue indicates anoxic volumes and green indicates microbial colonization. The perimeter to surface area ratio is the same between the two cases, but porosity is decreased from 0.7 (left) to 0.6 (right). Based on our results, golf-ball like structures with higher sphericity are better ventilated and thus facilitate microbial colonization. Notice, under in situ conditions the porewater flow is highly dynamic and regions of oxia/anoxia might vary.
