Blowing in the Wind: Storm-Resisting Features of the Design of Trees
Abstract: Many of the features of trees represent arrangements that minimize the chance that they will uproot when exposed to high winds. At least four schemes, singly or in combination, keep the bases of trees from rotating in the face of the turning moment imposed by the drag of their leaves. Trunks and petioles are relatively more resistant to bending than to twisting, giving good support but permitting drag-reducing reconfiguration in high winds. Leaves curl and cluster in a variety of ways, all of which greatly reduce the drag they incur relative to the values for ordinary thin and flexible objects such as flags. However, information derived from measurement and experimentation about such mechanical matters is still quite limited.