Biomass of South Brazilian highland grassland under management with burning and mowing: Characterization of vegetation and feedstock for energy

Abstract

This study aimed to evaluate the effects of different management practices on the phytosociological composition and biomass production for energy generation in high-altitude grasslands in southern Brazil. In the first study area, mowing was performed 8 months (R8) and 15 months (R15) after a burning event. In the second study area, mowing was conducted for 24 months (RQ24) following burning. Before mowing, the vegetation was characterized through phytosociological surveys, and biomass was quantified by weighing and determining its moisture content. Regarding floristic composition, both intermediate mowing between burning and the exclusive use of fire, at 24-month intervals, were able to alter the vegetation composition of the high-altitude grasslands. The exclusive use of fire had a greater detrimental effect on the forage quality of the vegetation. The potential for biomass production varies among the species composing the vegetation and the different management practices of the high-altitude grasslands. The most suitable recommendation for managing high-altitude grassland is the implementation of intermittent prescribed burning, interspersed with two mowing events over a 24-month period. This practice will yield high-quality forage biomass for livestock and provide opportunities for the utilization of energy biomass by agricultural communities in the region.