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1. Suppression of wildfires in boreal landscapes has become widespread and has seriously affected many fire favoured species. However, little is known about the response of organism assemblages to large wildfires in regions with a long history of effective fire suppression, such as Scandinavia. 2. We studied the short-term effects of a >1600 ha wildfire on beetle assemblages in northern Sweden. The first summer after fire, beetles were sampled in 12 sites using 36 large window traps, half in old pine forest stands in the burned area and half in similar, but unburned control stands. The entire beetle assemblage and eight subgroups were analysed: saproxylics, non-saproxylics, moderately fire favoured, strongly fire favoured, fungivores, predators, cambium consumers and red-listed species. 3. Species composition differed markedly between burned and unburned forests in all nine groups. Furthermore, beetle abundance was higher in the burned area for the entire assemblage and for saproxylics, both groups of fire favoured species, predators and cambium consumers. Species number was higher only for non-saproxylics, strongly fire favoured species and cambium consumers. 4. Our results show that wildfire has rapid and strong effects on a wide range of beetles. However, we only trapped two individuals of fire-dependent beetles, which may suggest a lack of such species in the region, possibly due to >100 years of fire suppression. At the regional scale, the studied wildfire may potentially increase the abundance of these beetles after a longer period of reproduction in the burned area. [ABSTRACT FROM AUTHOR]

Abstract: Predatory beetles are important natural enemies of early successional cambium feeding beetles and knowledge about their ecology is of paramount importance for biological control and sustainable forest management. We used a large-scale experiment including 3 stand types (clear-cut, mature managed and old-growth stand) and 6 dead wood substrates (burned, shaded, white rot inoculated, brown rot inoculated, untreated control logs and created snags) to test substrate preferences of 10 common predatory beetle species. We collected insects in eclector traps and measured dead wood availability within 100m from the experimental logs at each site. We also tested the relationships between predators and prey at the trap level. Stand type was important for all predators; Nudobius lentus and Ampedus tristis were more abundant on clear-cuts while Phloeonomus sjoebergi, Quedius plagiatus, Epuraea boreella, Epuraea pygmaea, Epuraea angustula, Rhizophagus dispar and Epuraea laeviscula were more abundant in mature managed and old-growth stands. Snags differed most from the control logs supporting significantly more E. boreella and E. angustula and significantly less P. sjoebergi, E. pygmaea, A. tristis and R. dispar. Prey abundance proved to be more important than dead wood availability at the stand level for most species, although the response varied among species. At the trap level, the abundances of P. sjoebergi, E. laeviscula and Q. plagiatus were correlated with the abundances of their known prey species. P. sjoebergi, E. boreella, E. pygmaea, R. dispar and N. lentus were correlated with total bark beetle abundance suggesting that many predators might be less specific in their choice of prey than previously thought. The variable response of the 10 examined predatory beetles at different levels of scale suggests complex relationships with their prey and environment. The conservation of this group of beetles is important both to achieve environmental goals but also for biological control of potential pest species. Thus, conservation oriented measures needs to be performed aiming at improving both substrate and stand qualities. [Copyright &y& Elsevier]

Abstract: Different functional groups of beetles are likely to exhibit different responses to forest management and it is essential that we gain knowledge on these responses to understand and minimize the negative impacts of forestry in boreal ecosystems. In a large-scale manipulative experiment in nine sites (including 27 stands) in northern Sweden, we tested how saproxylic beetles, fire-favoured beetles and functional groups of beetles were affected by log treatment (shaded, burnt and fungi inoculated logs) and stand type (clear-cuts, mature managed and old-growth stands). All sites included one clear-cut, one mature managed stand and one old-growth stand, which give in total 27 stands. Fresh logs were placed out in the stands and exposed to different treatments. Insects were caught in eclector traps attached to the experimental logs. Log treatment, stand type and their interactions affected abundance, species richness and assemblages of saproxylic beetles, fire-favoured beetles and functional groups of beetles. Cambium consumers were less abundant on burnt logs compared with control logs. Furthermore, the assemblage composition differed between burnt logs and control logs for fire-favoured species and cambium consumers. On the clear-cuts burnt logs hosted lower abundance of all saproxylic beetles and fire-favoured species. For predators, the assemblage composition differed between burnt logs and control logs on clear-cuts. Shaded logs hosted lower abundance of wood borers compared to control logs. Shaded logs also supported different assemblages of saproxylic beetles and predators compared with the control logs on clear cuts. The effect of stand type was stronger than the effect of log treatment and for most of the examined groups; the clear-cuts differed from the mature managed and old-growth stands, while few differences was detected between mature managed and old-growth stands. The results indicate that in an area with intense forestry, both old-growth forest reserves and the creation of suitable substrates in managed forests are needed to conserve functionally intact beetle assemblages. [Copyright &y& Elsevier]

Abstract: Modern forestry practices have decreased the abundance of coarse woody debris (CWD), and as a result many species that depend on dead wood are now threatened. This implies a need to develop forestry practices that maintain biodiversity. We examined the conservation value of experimental spruce logs (control logs, logs placed in natural shade, and cut tree tops) for wood-inhabiting fungi in two forest stands, one nature reserve and one mature managed forest, in each of seven forest areas in northern Sweden. Here we report the initial findings of the experiment that was established in winter 2001–2002 and data were collected in 2002, 2003 and 2006. A pre-inventory of the local species composition in 2002 revealed a higher per area species richness, including red-listed species, in reserves than in managed forests. Ordination analyses of the experimental logs showed a significant effect of area, while not of stand type in 2003. ANOVA analysis showed no significant effect of stand type on species richness and abundance. In 2006, the species assemblage started to differentiate between the two stand types and forest age, forest site type (moisture), and distance to forest reserves, all explained part of the variation, whereas the amount of CWD, and species composition at the start of the experiment only showed a marginal effect. The early successional fungal community was dominated by two functional groups, humus-decayers and white-rot species, both characterized by a rapid, early colonization and fruit-body formation on the competition-free new substrate. A similar positive response to the new substrate was also observed for the mycorrhizal species in 2006. The high frequency and early appearance of humus-decayers and mycorrhizal species that do not primarily depend upon CWD for their nutrition suggest that their formation of fruiting bodies is limited by substrate availability. Thus some mycorrhizal fungi are apparently rare due to lack of suitable substrate for fruit-body formation. Evidence of dispersal-limitation was observed in 2006. Fomitopsis pinicola, an early colonizer in boreal forests, playing a key role for other wood-inhabiting organisms, colonized significantly more logs in the reserve stands compared with the managed stands. Our data demonstrate that lack of CWD strongly affects both species that depend upon wood for nutrition and species that depend upon wood for fruit-body formation. Thus some species may show an apparent rarity due to lack of suitable substrate. We conclude that creation of CWD appears to be a useful method to maintain or restore fungal diversity in boreal coniferous forests. [Copyright &y& Elsevier]