EVOLUTION OF HERBACEOUS SAVANNA IN CAATINGA AREA UNDER GRAZING

Abstract

The objective of this research was to evaluate the effect of goat grazing on the structure of six species of herbaceous: Cyperus uncinulatus Schrad ex. Nees, Paspalum scutatum Nees ex. Trin, Diodia sp., Aristida adscensionis L., Chamaecrista desvauxii (Collad) Killip and Evolvulus filipes Mart. and total coverage on the ground in the Caatinga, northeastern of Brazil. The experiment was conducted at the Experimental Farm School/UFPB in São João do Cariri-PB in three contiguous areas during the year 2008. The treatments consisted of three stocking rates divided into three paddocks: 3.1 an/ha; 1.5 an/ha and 0 an/ha (control). To analyze the structure of herbaceous species it was monitored the coverage of species in 30 plots of 1 m2 per treatment, totaling 90 plots sampled. The total soil coverage was monitored in these plots, in a total of 23 readings. The ground cover decrease due to the consumption of herbaceous species in the rainy season, reducing the frequency of species except Aristida adscensionis L. and Evolvulus filipes Mart. that were more persistent at grazing. The species monitored were sensitive to pulses of precipitation, sufficient to trigger a physiological response in terms of plant growth and development.