Marsh & Silt

Silt shook her head, letting fresh mineral grains run through her fingers. "But your recycled nutrients need something to hold them — and that's me. I bring the new: fresh mineral silt the river grinds off the mountains and drops here, grain by grain, building brand-new land where there was only water. That's the body of the soil, the mineral part. Soil isn't only the recycled past. It's also the freshly-arrived new."

The frog looked between them. "So which one is soil — the broken-down old, or the brand-new?" And for the first time, Marsh and Silt looked at each other and understood they'd each been holding half an answer. "Neither, alone," Marsh said slowly. "My nutrients with no mineral grains to cling to just wash away." "And my fresh mineral silt with no nutrients in it," Silt said, "is barren — nothing grows in pure ground-up rock. It's clean and new and dead."

So they watched what happened where their two streams actually met. Silt's fresh mineral grains piled into new flats; Marsh's decomposed nutrients soaked into them — and suddenly the barren new silt was fertile, the recycled past woven into the freshly-arrived body. "Together," Silt breathed, "we make ground that can actually grow something." And right on cue, the first tough pioneer seeds caught in the new fertile soil and took root — succession beginning, exactly where the old and the new had met.