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Intensive forestry practises in the Swedish landscape have led to the loss and fragmentation of stable old-growth habitats. We investigated relationships between landscape composition at multiple scales and the composition of saproxylic beetle assemblages in nine clear-cut, mature managed and old-growth spruce-dominated forest stands in the central boreal zone of Sweden. We set out fresh spruce and birch logs and created spruce snags in 2001–2002 to experimentally test the effects of coarse woody debris (CWD) type and forest management on the composition of early and late successional, and red-listed saproxylic beetle assemblages. We examined effects of CWD availability at 100 m, and landscape composition at 1 and 10 km on saproxylic beetle abundances. Additionally, we tested whether assemblage similarity decreased with increasing distance between sites. We collected beetles from the experimental logs using eclector and window traps in four periods during 2003. CWD was measured and landscape composition data was obtained from maps of remotely sensed data. The composition of saproxylic beetles differed among different CWD substrates and between clear-cuts and the older stand types, however differences between mature managed and old-growth forests were significant only for red-listed species. Assemblage similarities for red-listed species on clear-cuts were more different at greater distances apart, indicating that they have more localised distributions. CWD availability within 100 m of the study sites was rarely important in determining the abundance of species, suggesting that early successional saproxylic beetles can disperse further than this distance. At a larger scale, a large area of suitable stand types within both 1 and 10 km resulted in greater abundances in the study sites for several common and habitat-specific species. The availability of suitable habitat at scales of 1–10 km is thus likely to be important in the survival of many saproxylic species in forestry-fragmented areas. [ABSTRACT FROM AUTHOR]

The species‐energy hypothesis predicts increasing biodiversity with increasing energy in ecosystems. Proxies for energy availability are often grouped into ambient energy (i.e., solar radiation) and substrate energy (i.e., non‐structural carbohydrates or nutritional content). The relative importance of substrate energy is thought to decrease with increasing trophic level from primary consumers to predators, with reciprocal effects of ambient energy. Yet, empirical tests are lacking. We compiled data on 332,557 deadwood‐inhabiting beetles of 901 species reared from wood of 49 tree species across Europe. Using host‐phylogeny‐controlled models, we show that the relative importance of substrate energy versus ambient energy decreases with increasing trophic levels: the diversity of zoophagous and mycetophagous beetles was determined by ambient energy, while non‐structural carbohydrate content in woody tissues determined that of xylophagous beetles. Our study thus overall supports the species‐energy hypothesis and specifies that the relative importance of ambient temperature increases with increasing trophic level with opposite effects for substrate energy. [ABSTRACT FROM AUTHOR]

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]