Structure of a tropical rainforest 10 years after selective logging in Moju-Pará

ABSTRACT Studies of the floristic and structural dynamics in forest exploitation areas allow to assess the impacts and provide basic information for the rational forest management. In this context, the floristic and structural dynamics were evaluated in a rainforest, ten years after its logging. The experiment was performed in 200 ha of the Experimental Field of Embrapa Eastern Amazon, in Moju - PA, where logging was done. Around the nine gaps selected, 10 m x 50 m tracks were installed, divided into square plots of 10 m side (1-5), where the plants with DBH ≥ 5 cm were inventoried. In plots 1, 3 and 5 and in the gap center subplots of 2 m x 2 m were installed where individuals with height ≥ 10 cm and DBH < 5 cm were measured. The forest monitoring covered a period of 9.5 years, between March 1998 and October 2007. The structural analysis was based on the parameters of abundance, frequency, dominance, natural regeneration, sociological position and extended importance value index (EIVI) and compared the forest structures in 2007 and 1998. Ten years after logging, the high heterogeneity was maintained and increased in the younger population, due to the entry of species with strong demand for light. However, the floristic composition and structure of the managed forest still show great importance of species that, in undisturbed forests, would not have great expression in terms of EIVI.