Arthropods play crucial roles for ecosystem functioning and biodiversity conservation in forests, but their diversity and functioning can be strongly affected by forest management strategies. These strategies often involve the planting of tree species outside of their natural range (e.g. Norway spruce and Douglas fir in Central Europe). However, when it comes to non-native tree species, such as Douglas fir in temperate forest of Europe, we only have limited knowledge of how the planting of these species in monoculture or mixture with native tree species (e.g. European beech) affects arthropod communities. Our project aims at a comprehensive analysis of how the diversity, community composition, and functioning of arthropods respond to differences in forest stand type (monocultures and mixtures of native and non-native tree species) under different environmental conditions. We will focus on species-rich groups of the arthropod macrofauna of the forest floor and tree canopy to assess stand type-specific differences in microhabitat conditions, species turnover and diversity partitioning, and ecosystem functions (insect herbivory and biocontrol potential). Our results can help to better evaluate the ecological consequences of planting non-native tree species, and to develop approaches that help to optimize the ecological benefits obtainable from mixtures of native and non-native tree species.