Forests are a unique study ecosystem that can reveal global insights into the patterns and processes associated with biological invasions via their natural diversity, as well as their diversity of anthropogenic interactions. In this chapter we focus on emblematic species groups in different forest ecosystems, giving temperate and tropical examples of plant, pathogen and arthropod invasions. Impacts of biological invasions on biodiversity are often complex and context-dependent, as in the case of the non-native tree Robinia pseudoacacia. Experiences of the invasiveness, invisibility and risk mitigation of forest pathogens, non-native bark and ambrosia beetles in Europe represent important insight that has the potential to help control non-native species worldwide. Indeed, actively managing forest ecosystems is critical to deal with non-native invasive species via direct control as well as building inherent resilience to invasion. However, there are important differences between regions that are further explored here for both tropical and temperate forests. In addition, by using a novel code of conduct, specific aspects for mitigating invasion risk from plantations are presented. Benefits for the management of biological invasions will flow from knowledge on the effects of context-specific management actions and via their integrated application in preventing and stopping forest invasions.