Composição e diversidade florística de sementes em área de caatinga - PB.

Abstract

The present study evaluated qualitatively and quantitatively the seed bank of an area of Caatinga, located in Patos - PB. 35 parcels were systematically arranged 10x10m and from these, samples were randomly collected at 5 cm depth with wood template of 40 x 40cm. Each sample was individually homogenized and placed to germinate in two environments: full sun and shade to 50% reduction of light. The sampling was taken in June 2012, remaining evaluated on the assessment Nursery of UFCG / CSTR for six months. It was recorded 237 individuals belonging to 13 families and 26 species were identified, including trees, shrubs / sub shrubs and herbaceous. The trees represented 19 individuals belonging to 3 species of one family, shrubs and sub shrubs represented 49 individuals belonging to 10 species of 5 families and herbaceous represented 169 individuals of 13 species of 9 families. The total density of the seed bank was approximately 43 seeds/m2 (423,000 without / ha), being superior to other caatinga areas studied. The treatment showed a shadow density of 33.2 seed/m2 with greater diversity of subjects. The treatment in full sun got density of 9.28 seed/m2 with lower diversity of individuals, although a higher number of families were identified. Herbaceous individuals excelled in number of germinated seeds, followed by shrubs and trees. Among the 10 species common in both treatments, we emphasize the herbaceous species Aristida pallens Cav. and Amaranthus viridis (L.) with a larger number of individuals.