Treefall damage forms a three-part structure called a chablis, not a clean hole.

Evidence

Falling trees do not always create clearly delimited holes in the forest. The complex configurations resulting from a treefall can be seen in the idealized dumb­ bell-shaped “chablis” (Oldeman, 1978). Chablis is a medieval French word, with­ out an English equivalent, denoting the fall of a tree, the resulting damage, and the fallen tree itself. In the ideal chablis, the fallen trunk forms the axis of the damaged area, outlined as a dumbbell on the ground. At one end, above the former base of the tree, is a gap in the upper canopy, while lower forest layers remain intact. Along the axis, the trunk may have sliced down among its neighbors, disturbing the subcanopy but otherwise causing little change in forest structure. At the other end, the tree crown obliterates the understory, while the upper canopy layers may be completely or partly damaged. — S. T. A. Pickett and P. S. White, eds., The Ecology of Natural Disturbance and…, 383

Categorization

• DEFINE: Defines ‘chablis’ — the core structural vocabulary for reading gaps in the landscape course.
• XREF: This dumbbell/chablis shape connects directly to the Soundscape book’s own breakpoint logic — disturbance creates gradients, not clean breaks.