We store firewood leaning against the house walls on the northern side, on a concrete pavement. There isn't space elsewhere.
We consider laying the new supply of firewood on (treated) planks (parallel to walls), so the wood is not directly on ground (so it wouldn't rot/mould). We could also connect a vertical beam to the plank (loaded with the wood) and the overhang roof to make the side support (so there's no need to cross-stack the wood on the edges).
We could also lift it a bit more and put the planks on short beams, that would be perpendicular to them (and the wall). This would allow for airflow at the bottom. Many firewood sheds on the internet have this feature. But does it make any difference in this case (narrow tall stack of wood?)
There is already airflow from the top and from the front. In case of a 2 m tall stack of 0.5 m long pieces, adding the bottom spacing would besides the front and top add only 20% of the 'aired' area. Unless it would enable some super-potent mode of airflow, this looks like a small number.
Even smaller, when you consider also doing this: not leaning the firewood against the wall, but moving it ~10 cm off the wall. Then, raising it above ground would add only 11% aired area.
I'm asking because moving it above the ground (using also the perpendicular beams, not just the simple parallel planks) requires more work and material.