Forest-type dependent response to spatial factors in birch-living saproxylic Coleoptera assemblages
(English)Manuscript (Other academic)
We studied spatial factors affecting the species composition of birch-living saproxylic (breeding in dead trees) Coleoptera. We sampled 30 forest sites in two regions by rearing Coleoptera from eight standardized birch-bolts (tree bole, 1m in length) from each site. A large part of variance in species composition could be explained by habitat variables (22.9 %), such as forest type, or spatial variables (15.8 %), such as distance apart. We compared three forest types – birch-dominated deciduous forest, mature coniferous forest, and clear-cuts – and found forest-type differences in response to spatial variables. The assemblages in deciduous sites responded to distance apart and showed some positive spatial autocorrelation up to a distance of 80 km. Assemblages in coniferous sites were different in the two regions whereas assemblages in clear-cuts did not respond to any spatial variables. Thus, the variation in species composition explained by spatial factors could mainly be attributed to spatial effects in two of the forest types: deciduous forest and mature coniferous forest. A conclusion from these results is that a metacommunity approach could be useful for understanding the community dynamics in the deciduous sites. Species in clear-cuts could conform more to the concept of patchy populations since the assemblages in those sites showed no spatial structure over the maximum inter-site distance of 105 km in this study.
Research subject Animal Ecology
IdentifiersURN: urn:nbn:se:uu:diva-88763OAI: oai:DiVA.org:uu-88763DiVA: diva2:159031