The physiognomy and structure of the tree component of a montane forest fragment located in an area at 900 m altitude (8º11'144" -8º12'27" S and 36º23'730" -36º24'638" W), with 948 mm of annual rainfall, and deep soil were studied. All alive or dead standing plants with diameter at breast height > 5 cm, within 50 contiguous plots, 10 x 20 m each, had their trunk diameter, total plant height and canopy projection area measured. The species were classified in relation to their leaf size, deciduousness, and lamina composition. A total of 61 species were sampled plus one unidentified taxon. Plant density, basal area and average and maximum height and diameters were 1,553 plant ha-1, 39 m² ha-1, 10.3 and 30 m, 14.2 and 105 cm, respectively. About 75% of all alive plants had between 1.4 and 3 m high. The distribution of basal and canopy areas according to height class indicated two ranges of plant concentrations: 7-13 and 19-22 m. The forest fragment represents a transition between humid and dry montane forests. Most of the species are evergreen with simple microphyllous leaves (Casearia sylvestris Sw., Guapira nitida (Schmidt) Lundell, Marlierea clausseniana (O. Berg) Kiaersk., Ocotea aff. elegans Mez, Plinia sp.), they occurred in the canopy of the forest, together with notophyllous species (Amaioua cf. guianensis Aubl. and Roupala paulensis Sleumer) and mesophyllous (Fabaceae sp. and Inga marginata Willd.). The emergent trees are mostly deciduous and compound leaf species, such as Copaifera trapezifolia Hayne and Eriotheca crenulaticalyx A. Robyns.
Brazilian Northeast; phytosociology; semi-arid; vertical structure
