Dinâmica da regeneração natural de florestas secundárias (capoeiras) do Nordeste Paraense

Abstract

The vegetation cover in northeastern Pará is formed, in its great majority, by secondary vegetation in different stages of development, which can offer a high potential for products, if properly managed. However, there are still few studies on the subject. Research on the dynamics of natural regeneration is essential for the preparation and correct application of management plans and silvicultural treatments. With the objective of contributing to the knowledge of the dynamics of natural regeneration in secondary forests, this work was developed in the municipality of Capitão Poço, in northeastern Pará, in two successional forests that are approximately 13 and 18 years old. Subplots of 5m x 5m were allocated for sampling sticks (No > DBH? 2.5 in) and sticks (DBH < 2.5 cm and height?1.5 m) and sub-plots of 1m x 5m for sampling seedlings (30 in? height?1.5 m). The behavior of the species dynamics was evaluated by the Natural Regeneration Rate (TR%). The results show that the youngest vegetation presented a total regeneration rate of 79.7%. The class called sticky showed a TR% of 90.6%, the variegated ones of -18.2%, and the small ones of 7.3%. Species such as Vismiaguianensis, iacistema aggregatum and Talisia guianensis remained stable and with individuals in all size classes. The oldest secondary forest showed during observations a positive rate of 20%, and the classes of poles, sticks and saplings obtained the following regeneration rates 25.9%, 12.5% and -18.4%, respectively. Licania beteromorpba, Hymatanthus sucuuba and Psychotria racemosa were some of the species that remained stable. Floristic diversity increased in the forests studied as succession progressed.