Variation in aboveground biomass of Allagoptera arenaria (Gomes) O. Kuntze (Arecaceae) on the Marambaia beach ridge, Rio de Janeiro, Brazil

Variation of aboveground biomass of Allagoptera arenaria (Gomes) O. Kuntze (Arecaceae) along five topographic profiles perpendicular to the ocean was examined in a palm scrub community on Marambaia beach ridge, Rio de Janeiro State, Brazil. Aerial biomass was positively correlated with distance from the sea (F = 39.57; R2 = 0.69; P < 0.01) as was detritus cover (F = 525.92; R2 = 0.92; P < 0.01). A. arenaria growth is closely related to the topography of the beach area. Dense populations of this palm enrich the soil by increasing organic matter under the plants through dead leaf material. This promotes the accumulation of nutrients and the creation of microclimates that favor the establishment of other species.