ABSTRACT
This chapter describes how fires affect vegetation structure in the mountain grasslands of northwest Argentina that are used for grazing. It investigates the effect that the time since the last fire event may have on plant species richness, vegetation structure, and biomass dynamics. Grazing and fire influence species composition and richness, determine dominant life-forms and therefore the general structure of the community. Fire promotes resprouting and is believed to encourage the development of more palatable life-forms. The study area consists of a mosaic of mountain grasslands and Alnus acuminata forest patches at an altitude of about 1700 masl. Time since the last fire event affected the total aerial biomass, the proportion of live biomass, standing dead, and litter, and the contribution of the different life-forms, both in terms of biomass and life-form frequency. In addition to the changes in life-form contribution, there was a change in the distribution of aerial biomass.
