Açaí management intensification impoverishes Amazonian avian assemblages in estuarine forests

Abstract

Non-timber forest product (NTFP) exploitation has emerged as an alternative to deforestation in human-modified landscapes, but their overexploitation can also reduce biodiversity if it leads to chronic habitat degradation. This study investigates the effects of management intensification on the taxonomic and functional diversity of bird assemblages in Amazonian floodplain forests. The management is directed at enhancing açaí palm (Euterpe oleracea Mart.) density for fruit production in the estuarine floodplains of Pará, Brazil. We explored community change across a gradient of açaí palm density ranging from 11 to 1430 clumps.ha−1 and we used multimodel inference to assess its effects on the richness, abundance, and functional attributes of bird guilds. We found that increasing açaí density was negatively correlated with species richness at local and landscape scales, leading to shifts in richness and composition especially negatively impacting insectivores and ‘forest dependent species’, whilst only a few species benefitted from intensification, such as Pitangus sulphuratus. These changes in avian community structure associated with açaí management intensification indicate that demand for this NTFP is driving ecological degradation of Amazon estuarine forests at local and landscape scales. Our findings underscore the need to regulate açaí management intensity to safeguard estuarine forest biodiversity.