Three decades of Eucalyptus expansion in the Amazon: trends, research gaps and sustainability challenges

Eucalyptus plantation expansion has intensified across Amazonian frontier regions, driven by increasing demand for biomass, energy and wood products. Understanding how scientific research has addressed this process is essential for supporting evidence-based environmental management. This study presents a bibliometric analysis of the scientific literature on Eucalyptus cultivation in the Amazon, aiming to identify research trends, thematic priorities and knowledge gaps relevant to land-use planning and environmental governance. Publications were retrieved from the Scopus database and analysed using the bibliometrix package in R. The results show that research on eucalyptus in the Amazon remains relatively limited and geographically uneven, with Brazil accounting for most publications but with modest participation from institutions located within the Amazon region itself. Thematic analysis indicates a strong concentration of studies on pest dynamics and plantation management, whereas key ecosystem processes, such as biodiversity responses, hydrological interactions and ecosystem carbon dynamics, remain comparatively underexplored. The literature highlights the role of eucalyptus plantations in supplying biomass for agro-industrial and bioenergy systems in frontier states. Funding analyses further reveal structural asymmetries in the distribution of scientific resources directed to the Amazon. Overall, advancing the sustainability of eucalyptus expansion in the Amazon requires strengthening locally grounded research capacity and expanding interdisciplinary studies integrating ecological processes, carbon dynamics and spatial planning. Such efforts are essential to support environmental management strategies capable of reconciling regional development with biodiversity conservation and long-term ecosystem resilience.