Lowland floristic assessment of Pico da Neblina National Park, Brazil

Abstract

Pico da Neblina National Park, located in north-western Amazonia,Brazil, is characterized by considerable habitat diversity resulting from anorographic zonation of vegetation (from 100 to 3,014 m above sealevel) and a mosaic pattern of soil types with lowland primary tropicalrainforest being the predominant ecosystem. A tree inventory of the lowlandareas of the Park was conducted as part of an ecological study of primates. Twohectares of forest were inventoried within the limits of a 500 hectare studysite. There were 1569 trees with diameter at breast height ≥10 cm in the sample (minimum of 229 species in 45 families). Thetree species Eperua leucantha and Hevea cf.brasiliensis dominated the forest accounting for 29% of thesampled trees. Three forest types were represented: chavascal, terra firme andcaatinga. Caatinga was the least diverse forest (H′ = 0.9), andterrafirme the most diverse (H′ = 1.5). Low diversity in caatinga wasassociated with high species dominance by Eperua leucantha, Micrandrasprucei and Hevea cf. brasiliensis whichtogether accounted for 66% of all sampled trees in one caatinga plot.Compared to Amazonian forests elsewhere, the ranking order of plant families inPico da Neblina was peculiar in that Leguminosae sensulatuand Euphorbiaceae dominated the sample accounting for 52% of all markedtrees. Such families were represented by few tree species, all of which werecharacterized by dry, large-seeded sclerocarpic fruits. The consequentlow availability of fleshy fruits in the forest is suggested as a possiblecontributing factor to the observed low abundance and diversity of primates inthe lowlands of Pico da Neblina.