REGENERAÇÃO NATURAL DA JUREMA PRETA EM ÁREAS SOB PASTEJO DE BOVINOS

Abstract

Natural regeneration depends on a series of environmental factors, which determine seed and seedling bank composition, and plant community structure of a site. Jurema preta (Mimosa tenuiflora (Willd) Poiret) is a pioneer legume tree that colonizes degraded sites of the Caatinga and produces a great number of seeds in several months of the year. In despite of its abundance, there is little information on the dynamics of jurema preta natural regeneration. Thus, a study was carried out to find out if seed germination and plantule survivorship under jurema preta canopy are affected by the annual April or July pruning of fine branches of a few jurema preta plants in a native Caatinga thicket submitted to continuous cattle browsing. Data analyses show that seed germination occurs in the beginning of the rainy season, and that in this period of moisture availability, plantule bank is composed by 17 to 58 thousand seedlings/ha. This number decreases during the rainy season, until it reaches a minimum of 3.7 to 7.5 thousand seedlings/ha, at the end of the dry season, in an ecological strategy of recurrent annual colonization. April or July pruning shows no consistent effect on jurema preta natural regeneration in areas submitted to bovine browsing, although plantule number was temporary and positively affected by pruning in one of the experimental site at the peak of the rainy season