Avaliação de áreas de caatinga em diferentes estágios sucessionais.

Abstract

The objective of this study was to evaluate the behavior of plant caatinga in different successional stages, and the relation of soil fertility with the quality of herbaceous forage. The experiment was conducted at the Ant Farm, Municipality of Santa Terezinha - PB. 9 plots were demarcated in different successional stages, and they are 3 young, 3 intermediate and 3 adults, which was held collect phonological information, collect of soil below the edge and outside the canopy and collect herbs, below and outside the canopy. For the phenology was performed descriptive statistics. The vegetation of the caatinga behaves differently from other regions, loss of leaves for three consecutive months is answer to water stress characteristic of the region. However, in this same period is the flowering and fruiting, varying only the adult stage what fruits both in the rainy season and during dry period can be explained by showing a higher diversity of species, with 11 different species, while the intermediate stage showed 8 species and young stage only 3 species. The collect of soil was held at the end of the rainy period. The analyzed variables did not differ significantly, except magnesium, which showed a higher concentration in the young successional stage. In the rainy period can be found herbaceous species in the plots assessed, and recorded only the presence of Aristida setifolia H. B. K. and Sida cordifolia L. In the young stage was observed a much of dry matter / ha than other successional stages, was observed also that the collect of material outside the canopy stood, presenting 220kg/ha, for this because these are species that need the presence of light to grow. The herbaceous extract present in the young successional stage collected outside the canopy showed higher amount of dry matter / ha, but its protein content is lower than the other treatments. The analysis of the herb was found in Mg, a correlation with the FDN and HEM, interfering positively, or the presence of Mg caused an increase on in percentage FDN and HEM.