Does fire affects reproductive phenology of natives vs. an introduced species? A case study in open woodlands of northwestern Pagatonia

CAVALLERO, LAURA; RAFFAELE, ESTELA

San Luis

Congreso; XXIII Reunión Argentina de Ecología; 2008

Asociación Argentina de Ecología

Reproductive phenology of plants can influence many ecosystem processes like pollination, seed dispersal, etc. Fire can influence reproductive phenology of plants, enhancing the reproductive rate of many species because of increased temperature, solar radiation and nutrient flow. Disturbances as fire can promote proliferation of exotic species in native plant communities. In this study we analyze the fire effect on reproductive phenology in three native species belonging to two guilds (a shrub: Berberis buxifolia and two small trees: Maytenus boaria and Schinus patagonicus) and in an exotic shrub (Rosa rubiginosa). Flowering and fruiting phenology of the four species was monitored in a burned and its neighbouring unburned area. The following variables were registered: Flowering and fruiting onset, flowering and fruiting duration and fruit set. The shrubs flowered and fruited in the burned site, but the small trees only did in the unburned site. Therefore, fire effects on reproductive phenology are different between shrubs and small trees. B. buxifolia and R. rubiginosa behaved as post-fire pioneer sprouters because they flowered and fruited two years after fire had occurred. In contrast, M. boaria and S. patagonicus have proved that can flourish and bear ripe fruits at least four years after fire, suggesting that they need to store more resources to invest in sexual reproduction. There is no overlapping in the flowering and fruiting phenophases between the natives and the exotic species. Therefore, they do not compete in resource offering to pollinators and seed dispersers.