Diversity and structure of the woody component of a restinga in Alcântara, Maranhão State, Brazil

Abstract

Although Maranhão State has the second longest coastline of Brazil, phytosociological studies are necessary to expand the knowledge of the restinga vegetation therein. Thus, the present study characterizes structural parameters of the woody component of a restinga in Alcântara city, west coast of Maranhão State. The phytosociological sampling included thirteen 100 m parallel transects, totaling 50 points. The inclusion criterion established for the species was perimeter at ground level ≥ 10 cm. We sampled 34 species, 26 genera, and 17 families, totaling 200 individuals. The species with the highest importance value (IV) were Guettarda angelica Mart. ex Müll.Arg., Anacardium occidentale L., Myrcia splendens (Sw.) DC., Cenostigma bracteosum (Tul.) E. Gagnon & G.P. Lewis, Fridericia sp., Eugenia stictopetala Mart. ex DC., and Mouriri guianensis Aubl. The average height of the specimens was 4.44 m, and the average diameter was 12.6 cm. The Shannon diversity index found in the restinga was 2.92 nat. ind-1, and Pielou’s evenness was 0.83. It is worth mentioning the presence of Sapium glandulosum (L.) Morong and Manilkara bidentata (A.DC.) A.Chev, which are common species of the Cerrado and the Amazonian forest, respectively. Our findings contribute to the knowledge of diversity, generating data for the development of conservation studies, besides reinforcing the influence of the flora of neighboring ecosystems in the colonization of the restingas of Maranhão State.