Skogsmyror (Formica rufa-gruppen) i monokulturell granskog och i nyckelbiotoper med hög andel gran i södra Sverige

Sammanfattning: Ants belonging to the Formica rufa group (wood ants) and their mounds have a large impact on forest ecosystems. This makes them considered keystone species. Several species of wood ants are threatened globally according to the IUCN red list. In this degree project mound densities and mound volumes were evaluated and compared between Norway spruce monocultures and high part Norway spruce woodland key habitats (WKHs) in southern Sweden. There were no significant differences in neihter mound densities nor mound volumes between the two stand types. However, mounds were distributed differently within the stand types and tree density correlated negatively to mound density in both stand types. Wood ant mounds were absent in the interior of monoculture stands, except in light gaps, while several mounds where located in the interior of WKHs. My results suggest that there is not enough light in the interior of monocultures in southern Sweden for wood ants to be able to colonize. Large monoculture areas may lack wood ants if gaps are missing. Therefore, gaps inside monocultures should be made more common in Swedish forests in order to benefit wood ants in production forests. Small clearcuts seem to benefit wood ant dispersal in monocultural stands. Therefore, smaller clearcuts should be preferred over the large areas presently clearcutted due to the negative effects of large clearcuts on wood ants.