O papel de plantios homogêneos de espécies florestais nativas em promover a regeneração natural na Amazônia central

Abstract

Forest plantations cover a large area in many countries and it is increasing the concern about the role of plantations in the biodiversity conservation. In this study we evaluated the seedling species richness in five 35 years old pure plantations (Simarouba amara, Dinizia excelsa, Dipteryx odorata, Bagassa guianensis and Jacaranda copaia), composed by native species and the surround primary forests, in the region of Manaus, Amazonas, Brazil (2°35 51.28 S; 60°02 10.57 W). The plantations forests presented values of species richness close to recorded in primary forests, with exception of Jacaranda copaia plantation. The relationship between species composition and the several environmental variables sampled was carried out by canonical correspondence analyses (CCA). The CCA resulted in correlations between species composition, validated by Monte Carlo test, with the percentage of canopy openness, concentration of nitrogen, pH, base saturation and concentration of aluminum in soil. Our results showed that homogeneous forest plantations can contain biodiversity levels nearly to primary forests, and reinforce the value of human modified landscapes in the biodiversity conservation scenario.