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Oil palm plantations across the tropics are intended to promote sustainable production by incorporating degraded lands while sparing old-growth forests. Here, we examine the trajectory of an Amazonian-forest focal landscape as it experiences the expansion of oil palm and its interactions with multiple land-uses. Land-use composition, landscape spatial configuration and structure in a 765.65-km2 watershed were examined over a 16-yr period (2002–2018) via Landsat imagery. Briefly, (1) old-growth forest coverage dropped from 37.3 % to 18.3 % across the whole landscape, (2) secondary forest and arable fields expanded until 2014, and (3) oil palm plantations emerged in 2010 with a positive trend thereafter, resulting in an 11.9 % expansion until 2018. In 2018, only 140.7 km2 of old-growth forest persisted, while oil palm plantations covered 91.8 km2. Oil palm expansion resulted from 14 land-use trajectories, with changes involving old-growth forests accounting for half the area (48.1 %) covered by plantations in 2018. However, only 0.4 % of the plantation area resulted from a direct conversion of old-growth forests. Landscape structure became increasingly degraded, which included the elimination of gallery forests, the proliferation of edge-affected habitats and the collapse of forest structural connectivity. Our results suggest that the eastern Amazon is still experiencing forest loss and exhibit highly dynamic land-use changes. Furthermore, landscapes continue to suffer degradation of key attributes related to biodiversity persistence and the provision of ecosystem services. Oil palm plantations have a catalytic effect on land-use dynamics, speeding up forest shrinking and landscape degradation. The oil palm sector requires a better governance based on guidelines able to guarantee either the persistence or the emergence of biodiversity-friendly landscapes. [ABSTRACT FROM AUTHOR]

The exploitation of non-timber forest products has been encouraged in order to reconcile economic uses, biodiversity conservation and the provision of ecosystem services. In this paper we investigate how increments on the açaí palm density (Euterpe oleracea) via forest management change tree assemblages across 47 plots in the Amazon estuarine forest (Brazil). Assemblage attributes were confronted to açai clump density, soil fertility, canopy openness and elevation. Both tree species density and richness were negatively affected by acai, but species richness was also affected by tree abundance. Species-accumulation curves also indicated higher alpha and beta diversity across low-intensity forest patches with high-intensity patches lacking half of the tree species. A small set of species dominated forest patches, but açaí density did not correlate with the abundance of valuable species. Explanatory variables, including açai density, explained a small fraction of the variation on the functional profile of tree assemblages, but functional richness was reduced by a half across forest stands exceeding 600 açaí clumps per ha. Our results suggest that açaí intensification alters the structure of woody plant assemblages in estuarine forest. Tree abundance and species richness consistently declines as açaí clump density increases, with some forest stands being dominated by açaí and almost lacking any tree species. Accordingly, landscapes dominated by high-intensity forest stands are largely impoverished in terms of understory, canopy and emergent tree species. These findings question the current legal regulations and thresholds adopted for açai management, while alert for potential disasters caused by poorly-regulated extractions of NTFPs. • Açaí intensification for enhancing fruit yield represents a complete reorganization of the estuarine forest. • Landscapes dominated by high-intensity forest stands are largely impoverished in terms of understory, canopy and emergent tree species. • Current legal regulations on açaí intensification fail to protect forest integrity and biodiversity. • Açaí represents a key economic opportunity for locals but a real threat for the estuarine forest. [ABSTRACT FROM AUTHOR]