The role of soil seed bank in the early stages of plant recovery after fire in a Pinus pinaster forest in SE Spain.

The implication of the viable soil seed bank in the early stages of the plant recovery after fire was studied in a recently burnt Mediterranean pine forest of Pinus pinaster. Seed number contained in soil samples taken inmediately after fire and emergent seedling number recorded in the field during the subsequent year were compared. Although the fire effect was important, available seed density in the soil after fire was relatively high (around 2,200 seeds/m(2)). A small group of species containing the main shrub species in the unburnt community predominated both in the viable seed bank and field germination after fire. However, these species showed low germination rates in the field, as opposed to species with the lowest presence in the seed bark. The predominance of woody obligate seeders in the seed bark after fire and the high specific correspondence between seed bank and germination in the field, emphasize the important role of the seed bank contained in the soil before fire in the postfire species establishment.