Dinâmica populacional de Vouacapoua americana Aubl. (Acapu) em áreas de floresta tropical úmida de terra firme, influenciada por clareiras no município de Moju, (PA.), Brasil.

Abstract

Studies about forest populational dynamics from gaps are very important to a best comprehension about to happen in a forest, supplying subsidy to elaboration and application of forest management. This thesis had as aim to evaluate the populous dynamics of Vouacapoua americana Aubl. in two phases: in the natural regeneration (height > 10cm and DBH < 5cm) and in the adult individuals with DBH≥ 5cm. The analysis comprehended the period from March 1998 to March 2007, in an exploit selectively area in 1997, located in the Experimental Field of Embrapa Western Amazon in the Moju town in the State of Pará. This exploration to originate several gaps, which nine were used in this study, the size varying between 231 m² and 748m². Each gap had its centre determined and from side it was marked four lanes of 10m x 50m in the direction North, South, East and West. In the study to determine in the natural regeneration, it was implanted three parcels of 2m x 2m in each lane, in the distances border of the clearing, 20m and 40m respectively. Afterwards, they were used the mathematics models Natural Regeneration Tax (RT%), Ingress (I%) and Mortality (M%). In the evaluation of populational dynamics of individuals with DBH ≥ 5cm, they were introduced in five parcels of 10m X 10m in each lane, which were evaluated the variables: Abundance, Ingress (I%), Mortality (M%) and the Annual Current Improvement (ACI) in diameter. The data were evaluated by Bioestat 5.0 software, through variance analysis of three factors (direction, distances and in a period of ten years). There was no difference significant statistically in the 5% of factors TR% as in reason of directions, of distances and in the ten years of monitoring, the TR% presents negative in this study. For the individuals with DBH ≥ 5cm, it was registered the entry of the three ingress from first till fourth year of monitoring and only the register of a death, that happens in the third year. The species shows the biggest values of diametric growth to the directions of North and West. The diametric distribution presents discontinue and decreasing. The Vouacapoua americana Aubl. in general, presented a behavior of a species belonging to the ecological group of intermediaries.