dripline

The circle on the ground directly beneath the outermost edge of a tree’s canopy — where rain collects on the leaves and drips to the earth below. The dripline is a boundary: inside it, the ground is sheltered, shaded, and fed by nutrients washing off the leaves; outside it, the exposure changes. Roots extend well beyond the dripline, but the dripline is where the tree’s influence is most visible on the surface. Also true of rock shelter overhangs.