What is the matrix ? A sea or a habitat for saproxylic Coleoptera in deciduous forest fragments in boreal forest
(English)Manuscript (Other academic)
We compared two regions that differed in the level of habitat fragmentation regarding deciduous trees. Brassberget, a less fragmented region, and Gåsberget, a more fragmented region that had a 2 % lower proportion of deciduous forest than Brassberget. We investigated the assemblage of saproxylic Coleoptera in birch in remnant patches of deciduous forest as well as in two matrix forest-types: mature coniferous forest and clear-cuts. We exposed 240 standardized birch bolts (tree bole, 1m in length) to natural colonization in a total of 30 forest sites and then collected Coleoptera emerging from those bolts. The saproxylic Coleoptera assemblages reflected the underlying regional difference in level of fragmentation. In the less fragmented region the Coleoptera assemblages in deciduous remnants and mature coniferous forest were largely similar in species composition, guild proportions, species richness, evenness, and dominance. The clear-cuts in this region differed from the other two forest types in all these community measures. In the more fragmented region there was a different pattern. In that region, the deciduous remnants were different from the matrix forest types, both mature coniferous sites and clear-cuts, in species composition, guild proportions, and evenness whereas the two matrix forest types had largely converged regarding all these community measures. Regional comparisons of forest types, showed that there was forest-type convergence in guild proportions in both deciduous remnants and in clear-cuts but regional divergence in mature coniferous sites. Thus, the effects of increasing habitat fragmentation was primarily found in mature coniferous forest. We conclude that in the less fragmented region, mature matrix forest retain habitat characteristics similar enough to natural deciduous forest to allow a saproxylic Coleoptera fauna similar to the one in deciduous forest-fire remnants to develop.
Research subject Animal Ecology
IdentifiersURN: urn:nbn:se:uu:diva-88762OAI: oai:DiVA.org:uu-88762DiVA: diva2:159028