Spatial variation of seedling distribution in an east Mediterranean pine woodland at the beginning of post-fire succession

Most of the area in pine woodlands is occupied by perennial seeders that re generate from seeds in the first winter after the fire and by annuals. Cont rol of the germination in the regenerating vegetation after wildfire is the refore a primary ecological component of the post-fire succession in this e cosystem. The aim of the study presented here was to determine the distribu tion of Pinus, Cistus and other plants seeds around burned Pinus halepensis trees, and to measure the conditions related to seed germination in the up per soil layers in the same locations. The study was carried out in a 50-ye ar old planted Pinus halepensis woodland that was burned down by a wildfire in July 1995. The variation of seedbank density was determined by collecti ng samples under the canopies of burned trees and in a nearby open area. Pi ne seedbank density decreased and that of Cistus and annuals increased with increasing distance from the burned trunks. Most pine seeds were present i n the ash layer while those of the other plants were in the soil. In situ g ermination experiments showed that seedling density decreased with distance from the burned trunks while the proportion of pines in the seedling popul ation increased. This was a result of seedbank variation and germination in hibition by the high pH conditions caused by the ash. The establishment of sparse pine seedling under the dead tree canopies insured their rapid devel opment without interference by other plants and played a key role in the re generation and stability of the pine woodland community. The concomitant ma ss germination of the perennial seeders in the rest of the area prevented i nvasion by annuals.