0 – 10 M fallen
Emergent Layer
The tallest trees break through the canopy into open sun and wind. Hawks and eagles nest up here, catching thermals that few other living things ever reach.
10 – 22 M fallen
Canopy Layer
A dense ceiling of leaves catches most of the forest's sunlight and carries out most of its photosynthesis. Squirrels can cross long stretches of it without ever touching the ground, leaping branch to branch through the cover.
22 – 35 M fallen
Understory
Only two or three percent of daylight makes it down this far. A sapling can hold still here for decades, waiting in the dim light for a gap to open in the canopy above.
35 – 45 M fallen
Forest Floor
A single handful of soil holds more living organisms than there are people on Earth. Fungi and insects break down what falls here, and everything the leaf was becomes part of what the roots reach for next.
Somewhere above you, the tree it fell from is still standing.