Estrutura populacional e aspectos reprodutivos de uma população de Ameroglossum sp. (Scrophulariaceae) em um inselberg no tropico semiarido paraibano

Abstract

The vegetation of inselbergs is currently used as a model for studies by presenting a plant diversity of great interest to scientists in several areas, such as botany, genetics, especially in the area of ecology. The vegetation structure of an inselberg was characterized, and the reproductive systems of an endemic species of this ecosystem (Ameroglossum sp. nv.) was analyzed in an inselberg (35 ° 52'50 .3''W 7 ° 10.8 S'') located in Timbaúba Farm, Lagoa de Pedra District, Esperança City - PB. The method used was 5 x 5m plots, and phytosociological parameters were analyzed and pollination tests was applied, which were marked 30 flowers for each test, natural pollination, self-pollination, and geitonogamy. We recorded 21 species belonging to 16 families by the phytosociological methods, and the most representative families were: Orchidaceae (three species), Apocynaceae (two) Euphorbiaceae (two) and Cactaceae (two). Among the species found, Enchorilium spectabile was the species that showed the highest value of importance because it covered extensive areas on the inselberg, other species that stood out were: Euphorbia brasiliensis (41), Anthurium petrofilium (27), Borreria verticillata (22), C. polyphyllum (15), M. carunceroides (10), that was found in all plots with Ameroglossum sp. nv. Demonstrating that these species have a beneficial association, because they form large clusters that difficult the passage of animals, while forming a more wet and shaded place on the rock. The natural pollination tests had a fruit set of 100%, while the tests of cross-pollination between individuals of different plants showed that the fruit was 82% but for the geitonogamy test was 80%, but the self-pollination tests were not obtained any results. Thus, it is concluded that this species has pollination mechanisms that increase genetic variability between individuals in the population that facilitates the adaptation of this species to the inselberg environment.