Estudo do perfil e estruturas florísticas de populações de Bactris Gasipaes (Pupunheira)

Abstract

The palm diversity knowledge in the Brazilian Amazon has been growing recently. Understanding the behavior of palm populations, especially B. gasipaes (“pupunha”) in the context of native forests degradation, is a challenge since these species can adapt to different environmental conditions and may be negatively affected by spatial occupation, productivity or even their morphological characteristics. Anthropic action or even natural phenomena can have transformative effect on the behavior of these plant populations. Thus, the aim of this research is to describe the vertical and horizontal structure of B. gasipaes populations as a contribution to understanding the behavior of this species, considering the environment where it is inserted. The research was carried out at São José farm, community Murituba, located in Vila Amazônia, Municipality of Parintins-AM. The data were collected in a plantation of pupunha, delimited in 4 permanent 10 x 10 m plots zigzag distributed in an plantation area of 50x100m2 . Individuals with DBH ≥ 10 were considered. The height of the palms was estimated by the measurements of a dendrometric drawing board. 75 individuals distributed among the plots were measured. The results showed the mean values to DAP varying 11.6m for plot 1, 11,8 m for plot 2, 11,8m for plot 3 and 10.7m for plot 4 showing a small variation between the plots. The mean palms height varied of 9.73 for plot 1, 7.63 for plot 2 , 6,8 for plot 3 and 11,9m for plot 4. The height of the individuals varied from 1,5m (minimum) to 23m (maximum) height. The smaller palms (1.5m to 6.0m) are the tillering (“perfilhamento”), which compete for nutrient with the mother plant and with other shoots and possibly, this is the factor contribuiting for the smaller sizes. Considering the five size classes, were frequently noticed adult individuals with no reproductive stage as well as adults at reproductive stage. Considering the vertical profile in the plots, the Palm trees (“Pupunheiras”) presented discontinuous individuals sizes, with floristic canopy ranging from 2m to 23m in height. The horizontal profile shows the superposition of the crowns among the majority of individuals. This fact may lead individuals to a homeostasis state, that is, to make development static.