Study of the soil seed bank in a caatinga area invaded by Parkinsonia aculeata L.

Abstract

This study aims to evaluate the impacts of biological invasion  by Parkinsonia aculeata L. in the soil seed bank of a caatinga. The studied area was stratified in three environments: I) Invasive population nucleus; II) Invaded nucleus surrounding and III) Caatinga remaining without the presence of adult individuals of the invasive species. Were randomly collected 50 soil samples in each environment, with the aid of iron gauge. The experiment was carried out in a greenhouse, being the monitoring of seedling emergence, the technique used to the evaluation. The floristic composition, diversity, similarity and the structure were evaluated with the Softwares Bioestat 5.0 and Mata native 2.0. Were registered about 51,000 individuals, distributed in 28 families, 91 genus and 130 species. The environment III has shown the highest species richness, followed by environments II and I. The average density of the seed bank was 8,620 seeds/m2. About the similarity, the environments have not shown differences among themselves. The results showed that the process of biological invasion by P. aculeata significantly reduces the density and simplifies the specific composition of the soil seed bank.