Current issue: 53(4)
The colonisation of a burned clear-cut by ants in southern Finland was monitored using pitfall traps, artificial nest sites, and direct nest sampling from the ground and stumps. Clearcutting and fire seemed to have destroyed wood-ant colonies (Formica rufa group), and also other mature-forest species suffered from fire. Myrmica ruginodis Nylander was able to survive only in less severely burned moist sites, whereas it benefitted from the enhanced light conditions in a non-burned clear-cut. The fire resulted in an essentially ant-free terrain into which pioneering species immigrated. The mortality of nest-founding queens appeared to be high. The results supported the hypothesis that the pioneering species tend to be those that are capable of independent colony founding, followed by species founding nests through temporary nest parasitism. The succession of the burned clear-cut differed from that of the non-burned one, suggesting that habitat selection in immigration and priority effects, i.e. competition, introduce deterministic components in the successional pathways of boreal ant communities.
The paper describes the systematics, distribution, abundance and nest sites of Formica rufa -group in different Finnish forest types. In addition, it has been estimated the availability of Finnish ants in the biological competition.
F. polyctena, F. aquilonia and F. lugubris are distributed over whole Finland. F. rufa and F. nigricans to Southern Finland only. The relative abundace of ant nests diminish to Northern Finland. F. rufa -group prefer most forest on moist land (Myrtillus and Oxalis-Myrtillus types), mixed forests of Norway spruce (Picea abies (L.) H. Karsts), Scots pine (Pinus sylvestris L.) and birch (Betula sp.), and the silvicultural density 0.6–0.7 (good or satisfactory density), but they avoid broadleaved and pure one-tree species forests. For the biological competition the most competitive ant species seem to be F. polyctena and F. aquilonia.
The PDF includes a summary in English.