Where water collects, so does the wind. That means, that elm seeds can collect in the dry season where water will collect later, without using water to do so. 

Footprints are also excellent for this.

But it works without footprints too. Here the cracks of a temporary pond catch windblown seeds, while seeds that fell in the water are virtually glued to the surface.

The wind can pack the seeds in as tightly as carpenter ants filling a cavity in a lodgepole pine in preparation for winter!

It’s a way of digging your way into the earth without having a shovel. Energy efficient, for sure!

Such soft soils, even the rain makes an impact like meteors on the Sea of Tranquility!

Forget the Eagle Lunar Landing Module. For efficiency, the elm has our technology beat.