Horizontal structure and floristic composition of the shrubby-arboreal strata in forests planted to rehabilitate a degraded area of the Brazilian Atlantic Forest, Rio do Janeiro
Farias dos Santos,Joana
Holanda de Oliveira,Schweyka Stanley
The study was taken in a reclamation area where soil was removed up to 13 meters deep in 1979, near Itaguaí county, Brazil (23º 55' 07'' S, 43º 49' 73'' O). In 2007 the composition and horizontal structure of the shrubby-arboreal strata was evaluated in five 13 years old forest plantations with similar environment conditions. For rehabilitation, rustic pioneer species were used to guarantee a sustainable successional process, which depends on species selection and their functional complementarities. Treatments were: T0 (control); T1 (100 % of exotic species); T2 (52% of exotic species); T3 (50% exotic and 50% native); T4 (39% exotic and 61% native); and T5 (15% exotic and 85% native). Variables measured were height, DBH (≥ 3.0 cm), basal area, canopy cover, horizontal structure (density, dominance, frequency and importance value) Diversity Index (Shannon-Weaver) and Similarity Index (Jaccard), on four permanent plots of 5 x 15 m (75m²) per treatment. Fourteen species were planted in 1994 and 13 years later, 23 species of 21 genus and 11 botanical families were found. Treatment T5 had the greatest individual numbers and variability of canopy and density cover, T2 had the greatest species diversity and T4 the greatest height and individual basal area; on the other hand, T1 had the lowest individual number, density and mixture coefficient. All species combinations used were more efficient on rehabilitation than in the control area which didn't show any arboreal species in 28 years.