Densidade e composição florística do banco de sementes de um trecho de floresta estacional semidecidual no campus da Universidade Federal de Viçosa, Viçosa, MG

Abstract

The objective of this paper was to characterize the seeds bank of a stretch at the Secondary Semideciduous Seasonal Forest, through the analysis of floristic aspects as well as seed density. This fragment is located on the UFV campus, in Viçosa, MG and is known as Mata da Praça de Esportes (Sports Court Forest), comprising an area of 10.65 ha under regeneration for 75 years. The sample area was subdivided into 40 plots of 3 x 5 m, distributed in 4 parallel transects. Composite samples were taken from 20 of those plots and then distributed within 40 wooden boxes, set up as seedling nurseries. Then, that amount was divided, allocating each half to shading levels of 11.5% and 60%. The total germination, as well as the one of the arbustive-arboreous species, was compared for the two conditions of shade by the test t for independent samples. The seed bank has been comprised mainly of invading herbs, mostly belonging to the Asteraceae, Solanaceae and Poaceae (15, 4 and 3 species, respectively) families. A total of 5,194 seedlings have been recorded, mostly being arbustive-arboreous pioneer species of the Melastomataceae and Cecropiaceae families. The seed germination carried out under shade was significantly higher than under the environment with 11.5% of shade (light). Zoochoric species were more abundant, indicating the importance of the Forest fragments as a source of resources and shelter for the local fauna. The high densities of pioneer arboreous and bush species such as Cecropia hololeuca, the species of the Melastomataceae, Asteraceae and Piperaceae, which are important for forest regeneration, indicate a resilience capacity of the studied area to restoration after disturbances.