Dinâmica de população e distribuição espacial da palmeira babaçu (Attalea speciosa Mart. ex Spreng.) no projeto de assentamento Benfica, Itupiranga, Pará.

Abstract

The objective of this study was to provide information to support public policies to establish sustainable management of babassu (Attalea speciosa Mart. ex Spreng) from results on population dynamics and spatial distribution of the species in the Benfica Settlement Project, state of Pará, Brazil. The specific objectives were: to analyze the population structure of babassu in different habitats; to analyze the dynamics of babassu according to the level of exploitation; and to analyze the automatic detection of palms in very high spatial resolution satellite images (GeoEye, 0.50 m). A total of 6,747 individuals from six life stages (seedling to adult) in forest areas (n = 4), pastures of different ages (n = 17) and babaçuais (babassu lands, n = 4) were studied. The yearly structural data obtained (2013-2016) were: petiole length, number of leaves, total height, stipe height, crown circumference, and diameter at 30cm aboveground and at breast height. Studies have indicated that the population structure of babassu is different among habitats, mainly between the secondary environments (pasture and babaçual) and primary forests. In order to simulate the dynamics of the species as a function of different levels of exploitation (0%, 10%, 25%, 50%, 75% and 100% of fruit collection) a Bayesian hierarchical model was used. The simulation results revealed that the collection rates of 50% or 75% are consistent with a viable population for 15 years. For automatic detection, the "Compt-palm" algorithm was used in a GeoEye image (0.50 m) from 2013 validated through field methods (i.e. structural census and georeferencing). The detection algorithm recognized individuals of two stages of life (stages 5 and 6) and the results of detection (75.45% of quality) of palms in natural areas not planted were considered promising. This information can help public policies in the establishment of a species sustainable management meetsing social demands on the availability of such resource. It also foresees the tendencies of the babassu populations according to the level of exploitation.