Fig. 4. A general conceptual model depicting oak barren dynamics for a 0.25-ha patch across a 150-yr period. A vertical belt running from east to west across the center of each quadrat is presented for comparison of vertical structure. Presettlement conditions (A) represent a state of tree-grass coexistence with scattered oak grubs and a graminoid matrix. The cessation of fire, however, led to the recruitment of large even-aged oaks, an understory shrub layer that was not previously present, and the loss of the original ground layer (B). Initial results are shown for the process-only (C) and structural manipulation (D) restoration models.