Grasses post-fire seed bank in grassland of Northwestern Patagonia (Argentina)

GONZALEZ S.; GHERMANDI L.; BECKER G.

Workshop; Restoring Natural Capital; 2003

The accumulation of highly inflamable thin fuel in the semi-arid grasslands and the environment conditions, that favour the ignition, make these environments very propense to fire (Bond 2001).Fire promotes species recruitment from the seed banks through litter removal, resource liberation, competition elimination and allelopatic substances and pathogens destruction (Whelan 1986). There are few works, that evaluate seed banks changes in the early postfire succession (Ferrandis et al. 1999).During the last century the grassland of northwestern Patagonia had been utilized for livestock grazing. These systems are codominated by two grasses with different forage value: Stipa speciosa (less palatable) and Festuca pallescens (very desirable). Both species compete for resources.The aim of this work was study the grasses seed bank composition and density in a post-fire grassland. This knowledge will contribute to formulate management rules for a sustainable use of these grasslands.