The study was made in Atlantic forest fragments in the lowland region of the protected area of São João river basin, Rio de Janeiro state, Brazil. The aim of the study was to test the hypothesis that fragment size alters macro-nutrients concentrations in leaves of the main tree species (Guarea guidonea e Cupania oblongifolia) in the area. Adult leaves of Guarea e Cupania were sampled in three small (23- 33 ha), three medium (130 - 155 ha) and three large (500 - 2300 ha) fragments. Carbon, N, Ca, Mg and K were determined. The results showed that, in general, the reduction of the fragment size did not affect the nutritional status of the species studied. Nevertheless, the higher Mg concentrations in Cupania oblongifolia leaves in the small fragments (5.0±0.8 mg/g) compared with the medium (4.0±0.3 mg/g) and large (3.5±0.7 mg/g) ones indicated an effect of the reduction of the fragment area over this element.
Cupania oblongifolia; forest fragmentation; Guarea guidonea; leaf nutrients