RESUMO No intuito de avaliar a fisionomia, estrutura e o efeito de borda de um sub-bosque lenhoso, foram estudados dois remanescentes de Floresta Atlântica em Igarassu, Pernambuco (Mata do Pezinho - MPZ, 27 ha e Mata da BR - MBR, 99 ha). Para tanto, instalaram-se 10 parcelas de 5 × 5 m nas bordas (até 50 m da margem), interior I (50 - 100 m) e interior II (> 300 m) em cada fragmento. Em MPZ, registraram-se 1152 indivíduos e 65 espécies (H' = 3,186 nats/ind.): 36 na borda, 42 e 39, no interior I e II. Entre ambientes, ocorreram diferenças estruturais que individualizaram a borda e poucas diferenças fisionômicas. Em MBR, registraram-se 1405 indivíduos e 67 espécies (H' = 3,068 nats/ind.): 37 na borda, 36 e 48 no interior I e II. Diferenças fisionômicas e estruturais distinguiram, principalmente, as parcelas referentes ao interior II. Floristicamente, os fragmentos tiveram similaridade de 45,5%, sendo estruturalmente distintos: em MPZ, há mais indivíduos típicos de sub-bosque e menos espécies raras; MBR conserva maior riqueza, mais espécies raras e mais indivíduos regenerantes do dossel. Em ambos, há uma diferenciação do ambiente de borda, mais evidente no menor fragmento, e do interior II, principalmente no maior remanescente.

ABSTRACT The woody understorey of two Atlantic Rainforest remnants in Igarassu, Pernambuco, were studied (Pezinho Forest - MPZ, 27ha and BR Forest - MBR, 99ha), aiming at assessing physiognomy, structure and edge influence over the vegetation. Ten 5 × 5m plots were set up at the edge (0-50m from forest margin), interior I (50- 100m) and interior II (>300m) of each fragment. In MPZ, 1152 individuals and 65 species were recorded (H'=3.186 nats/ ind.): 36, 42 and 39 on the edge, interior I and II, respectively. Structural differences were found between habitats, individualizing the edge, although little physiognomic differences were encountered. In MBR, 1405 individuals and 67 species were registered (H'=3,068 nats/ind.): 37 species in the edge, 36 and 48 in Interior I and II. Physiognomic and structural differences mainly distinguished the Interior II. Floristically, a similarity of 45.5% was found between fragments, which were structurally different: in MPZ, there were more understorey-typical individuals and less rare species; MBR retained greater species richness, more rare species and higher regeneration of canopy species. In both, there was an understorey differentiation at the edges, more evident in the smaller fragment, and, in the larger remnant, differentiation of interior II.