Population dynamics of attalea excelsa (arecaceae) in floodplain forest of the amazonian estuary

Abstract

Attalea excelsa (urucurizeiro) is a dominant palm of the estuarine floodplains, with great potential for non-timber management. This study evaluated the population dynamics of urucurizeiro and the factors that contribute to colonising of this species in a flooded environment. Individuals with base height circumference ≥ 30 cm in 2011 and 2014 were measured in 55.95 ha of floodplain forest in southern Amapá, Brazil. The parameters of population dynamics (mortality, recruitment and growth) in high and low floodplain environments were determined. Ripley's K function was used to analyse the spatial distribution. Population density in 2011 was 3.99 individual ha-1, and in 2014 the density increased to 4.09 individual ha-1. Mortality rate was zero and the recruitment rate was 1.05% year-1. Basal area in 2011 was 0.49 m2 ha-1 and in 2014, it reached 0.72 m2 ha-1. Diameter growth rate was 5.32 cm year-1. The population presented an aggregate distribution pattern. Structural differences in diameter (F = 9.15, p = 0.003) and basal area (F = 10.7, p = 0.001) were evident between high and low floodplain forests. The increase in diameter was higher in low floodplain (3.98 cm year-1) compared with high floodplain (1.35 cm year-1). The patterns shown by A. excelsa are reflections of its high adaptation to the daily flooded environment.