The environmental and anthropogenic impacts of nanoparticles on forest trees

Nanoparticles (NPs) are increasingly integrated into industrial and agricultural applications, yet their environmental impacts on forest ecosystems remain poorly characterized. Forest trees, as key components of global ecosystems, are both recipients and potential emitters of NPs, making forests critical but overlooked in the broader discussion of nanomaterial impacts. This review synthesizes current knowledge on NP interactions with forest ecosystems, focusing on their sources, pathways, transformations, and ecological consequences. NPs influence forest trees at molecular and physiological levels, with effects varying by type, size, concentration, and environmental context. While some NPs promote nutrient uptake, growth, and stress tolerance, others trigger oxidative stress and disrupt soil microbial communities and nutrient cycling. We highlight major knowledge gaps, including the lack of long-term field data and the limited understanding of NP impacts on soil fauna, microbial networks, and ecosystem processes. Furthermore, emerging applications of biodegradable and functionalized NPs for nutrient delivery, pest control, and genetic improvement are critically examined. This review underscores the urgent need for interdisciplinary research and regulatory frameworks to balance the benefits and risks of NPs in forestry. By integrating recent advances in nanotechnology and forest ecology, we propose strategies for harnessing sustainable NPs while safeguarding forest health and resilience amid escalating environmental pressures.