Abstract
In the Amazon estuary, the açaí palm (Euterpe oleracea) grows on the tidal floodplain. The fruit of this plant is a regional staple food. Owing to the selective removal of other tree species, intensive açaí-growing regions are rapidly expanding. At present, the effects of water level fluctuations, topography, and intensive cultivation on açaí growth are poorly understood. In the present study, we investigated the effects of water level fluctuations with different topography and plant species mixtures on açaí growth, by surveying trees in six study plots on Cação Island, five plots on Murutizal Island, and two plots each on Juruateua and Juba islands, Pará State, Brazil. Elevation and above- and underground water levels were measured to assess submergence conditions in the plots on Cação Island. Açaí exhibited better growth on higher ground at 5 m, non-reducing surface soil, shorter durations of submergence (110-120 h month －1), more consecutive days of non-submergence (6 d month －1), and in the presence of mututi (Pterocarpus sp.), miriti (Mauritia flexuosa), and ucuúba (Virola surinamensis). The results for most of the study sites suggest that >6 consecutive days of non-submergence per month resulted in land characteristics that were suitable for sustainable açaí production and simultaneous ecosystem conservation. The results also suggested a combination of other tree species (>20% of total), and density of approximately 1,000 açaí ha－1 was appropriate for efficient açaí production.
