The influence of aspect and forest edge effects on the ecology of the wood ant, Formica rufa L. (Hymenoptera: Formicidae)

Habitat fragmentation is widely recognised as a major threat to global biodiversity and by decreasing the size of habitat patches and disrupting important ecological processes through exposure to edge effects, is detrimental to many taxonomic groups, including insects. This research aimed to determine the influence of edge effects on the ecology of the wood ant, Formica rufa L. through an intensive study of a single site in Northamptonshire. The study focused upon the impact of both aspect and distance-related edge effects, measured along three edge to interior transects, a total of 82 sample nests and five control points within four study aspects located around the wood. Nest location and characteristics, density, colony structure, and the phenology of activities were also recorded. Overall, southern transects received more light but lower wind speeds than the other aspects and also supported a greater diversity of tree species. Southern nests also received significantly more light in the early and late parts of the year than nests in other aspects. At the random sampling points, nests received significantly more light and lower wind speeds than the controls. Compared with the controls, nests supported a higher plant species richness, but in terms of abundance, only sycamore (Acer pseudoplatanus) and elder (Sambucus nigra) were found in greater numbers at nest sites than controls. The south also supported significantly higher nest densities and had a higher percentage of polydomous colonies than the other aspects. The results showed that aspect mediated edge effects caused differences in wood ant phenology. Colonies in the south left hibernation earlier, began reproduction earlier, and had completed the reproductive cycle before colonies in the other aspects had begun theirs. Overall, these results are the first to show the impacts of aspect and distance related forest edge effects on F. rufa