Mound-building Formica ants are keystone species. Their large and long-lived nests are habitat to a broad range of associated species specific to these ants. While there is increasing evidence of local declines and extinctions due to fragmentation of their forest habitats and climate change, an assessment of population trends and threat status of these ants across European countries is largely lacking. This is mainly due to the lack of a common monitoring strategy and differences in conservation status throughout the EU. In addition, it is unknown how the species depending on Formica nest mounds, are impacted by these threats. The project aims to deliver a harmonized cost-effective EU-wide partially citizen science-based strategy for monitoring long-term population trends of these ants and their associates. In this project Luke’s research is mainly concentrated on the effects of forest management and landscape structure on the performance of these ants. The project is co-funded by EU commission Biodiversa+ and the Academy of Finland.