Production of Açaí (<i>Euterpe oleracea</i> Mart.) under different management inten-sities in Amazonian floodplain (Varzea) forests

The Amazon region encompasses a wide range of vegetation formations due to variations in its conditions, from the Andeanfoothills to the mouth of the Amazon River. Among these are floodplain forests along the vast river network, which, despitetheir extent, remain poorly studied. Amazonian floodplain (várzea) forests sustain high biomass and socioecological value, yettheir ecological functioning and response to management remain unclear, particularly for native açaí (Euterpe oleracea Mart.),a key species in regional agroextractive economies. This study assessed whether management intensity through canopyopenness affects production in açaí stands within a riverine community on Ilha das Cinzas, Pará, shaped by seasonal floodingand long-term traditional use. Four sites were selected with two areas under high management (HM) and two areas with lowmanagement (LM) intensities were surveyed. Structural and floristic contrasts were evident: high intensity areas exhibitedgreater canopy openness (HM = 24.62%; LM = 11.83%) and reduced species richness (HM = 19; LM = 32), indicating simplifiedforest structure. Fruit yield mirrored clump architecture, with HM averaging 4 kg and 3 kg in LM per raceme, and fruit densityper centimeter of rachis followed the same trend (HM = 41.7 g·cm-1; LM = 33,1 g·cm-1). Linear mixed-effects models revealedthat this difference is linked to structural palm’s traits, rather than canopy openness. At the stem level, diameter of breast height (DBH) and rachis length positively influenced fruit weight, while total leaf area, stem height and radiance availability were not significant predictors. In floodplain açaí systems, productivity is governed primarily by intrinsic palm’s structural traits rather than selective thinning or canopy modification. Practices that maintain productive stems and ensure continuous recruitment are likely to sustain fruit yields. This approach fosters resilient agroextractive systems, stabilizes seasonal production, and safeguards the livelihoods of riverine communities that depend on these forests.