Friday, August 10, 2007

PS 72-97: Fire does not increase alien species recruitment in the coastal matorral of Chile

Susana Gómez-González, Cristian Torres, Graciela Valencia, and Lohengrin Cavieres. Universidad de Concepción

 

The aim of this study was to evaluate the effect of fire on the emergence from soil seedbank of alien and native species in the coastal matorral of central Chile. We selected three sites in the coastal matorral of the Region of Valparaíso, where wildfires had occurred in January and February 2006. Two sites were classified as high-severity fires and one site was classified as low-severity fire. Immediately after fire, 20 soil samples were taken in the burnt area of each site. Beside the burnt area, 20 soil samples were taken in the unburnt area (used as control). In a greenhouse, all samples were watered and the seedlings emerging were registered daily. High-severity fires significantly reduced the species richness and seedling density of alien species emerged from soil seedbank. However, low-severity fire did not affect the emergence of alien species. In contrast, there was no effect of fire on the emergence of native species, independently of fire severity. Despite there were negative effects of fire only on alien species, the percentage of alien species was above 50% in all treatments and sites. Native species are more resistant to fire than it has been traditionally thought. Fire severity could be an important factor determining alien versus native species recruitment after fire in the coastal matorral of central Chile. Funded by MECESUP UCO-0214 and P02-051-F ICM.