Analysis of the Establishment of Seedlings of Açai (Euterpe Oleracea Mart.) in the Understory of a Forest of Amazon Floodplain

Abstract

The effects of diffuse solar radiation (DSR), precipitation, and air temperature on survival and mortality of seedlings of açai (Euterpe oleracea Mart.) were evaluated in an estuarine floodplain forest located in the environmental protection area of Combu Island, Belém, Pará, Brazil, in the period from April 2010 to January 2011. An automatic weather station was installed in the understory of Combu Island to collect from the elements, whose location was defined by taking into account the sheer number of seedlings of açai and the incidence of diffuse radiation through canopy sunflecks on the solar panel. Six plots of 2 m × 20 m were demarcated and divided into 10 subplots of 2 m × 2 m in the directions of north, south, east, and west and two others at random around the station. The seedlings with a height between 10 cm and 2 m were quantified and monitored biweekly for survival and mortality. Data were statistically analyzed by a Pearson correlation. Initially, 1072 individuals were recorded, with a significant survival rate of 764 (71.3%) and a mortality rate of 308 (28.7%); therefore, a positive correlation between precipitation and survival was seen, while DSR directly influenced the mortality in the months of May–July 2010, mainly in continuous days of radiation above 34.56 MJ m−2 day−1.