Are there saproxylic beetle species characteristic of high dead wood connectivity?

Saproxylic beetles have been shown to be vulnerable to within-forest fragmentation expressed as large distances between single dead wood pieces (low spatial connectivity of dead wood). From samples of a two-year study of saproxylic beetles, species that were characteristic of sites with high dead wood connectivity were identified by Canonical Correspondence Analysis, the method of Dufrêne and Legendre (IndVal) and by considering the species occurring exclusively in sites with high dead wood connectivity. These species differed mainly from the other species by their high habitat specificity. Hence, there arc species-specific responses of saproxylic beetles to the spatial arrangement of dead wood. High dead wood connectivity must be achieved in managed forests to sustain species which are particularly vulnerable to fragmentation.     

Mark recapture estimates of dispersal ability and observations on the territorial behaviour of the rare hoverfly,Hammerschmidtia ferruginea (Diptera,Syrphidae)

In order to effectively manage habitat for fragmented populations, we need to know details of resource utilisation, and the capacity of species to colonise unoccupied habitat patches. Dispersal is vital in maintaining viable populations in increasingly fragmented environments by allowing re-colonisation of areas in which populations have gone extinct. In the UK, the endangered aspen hoverfly Hammerschmidtia ferruginea (Fallén 1817) (Diptera, Syrphidae) depends on a limited and transient breeding habitat: decaying aspen wood Populus tremula L. (Salicaceae). Conservation management for H. ferruginea involves encouraging aspen expansion across Scotland, and ensuring retention, maintenance and continuity of dead wood where H. ferruginea has been recorded and in areas that may link populations. In order to do this effectively we need to know how far H. ferruginea can disperse. By taking advantage of the tendency of adults to group on decaying aspen logs, we estimated dispersal ability through mark recapture techniques. In the first year, 1,066 flies were marked as they emerged from aspen logs and 78 were re-sighted at artificially-placed decaying aspen logs up to 4 km from the release site. In the second year, of 1,157 individually marked flies, 112 were re-sighted and one was observed 5 km from the release site. Territorial behaviour was recorded at all (19) decaying aspen log locations. In total, 72 males were recorded defending territories, which overlapped with 68 % of recorded female oviposition sites. Among males only, wing length was positively associated with dispersal. While these results show H. ferruginea is capable of locating decaying logs up to 5 km away, most dispersing individuals (68 %) were recorded at 1 km, which should be taken into account in developing management protocols. If enough dead wood is available it should be distributed within a radius of 1–2 km, and where possible, as stepping-stones linking up aspen woodlands. We discuss the implications of our findings for the natural history of this species, and make recommendations for its conservation management.     

Increasing temperature may compensate for lower amounts of dead wood in driving richness of saproxylic beetles

Global warming and land‐use change are expected to be additive threats to global diversity, to which insects contribute the highest proportion. Insects are strongly influenced by temperature but also require specific habitat resources, and thus interaction between the two factors is likely. We selected saproxylic beetles as a model group because their life cycle depends on dead wood, which is highly threatened by land use. We tested the extent to which higher temperatures compensate for the negative effects of low amounts of dead wood on saproxylic beetle species richness (Temperature–Dead wood compensation hypothesis) on both a macroclimate and a topoclimate scale (north‐ and south‐facing slopes). We analyzed 1404 flight‐interception trap catches across Europe to test for interaction effects of temperature and dead‐wood amount on species richness. To experimentally test our findings from the activity trap data, we additionally reared beetles from 80 bundles of dead wood initially exposed at high and low elevations. At the topoclimate scale, we analyzed trap catches and reared beetles from dead wood exposed in 20 forest stands on south‐facing and north‐facing slopes in one region. On the macroscale, both temperature and dead‐wood amount positively affected total and threatened species richness independently, but their interaction was significantly negative, indicating compensation. On both scales and irrespective of the method, species richness decreased with temperature decline. Our observation that increasing temperature compensates for lower amounts of dead wood has two important implications. First, managers of production forests should adapt their dead‐wood enrichment strategy to site‐specific temperature conditions. Second, an increase in temperature will compensate at least partially for poor habitat conditions in production forests. Such a perspective contrasts the general assumption of reinforcing impacts of global warming and habitat loss on biodiversity, but it is corroborated by recent range expansions of threatened beetle species.     

Using forest history and spatial patterns to identify potential high conservation value forests in Romania

Naturally dynamic forests have a high proportion of biotopes with old large trees, diverse vertical and horizontal structure at multiple scales, and much dead wood. As such, they provide habitat to species and ecosystem processes that forests managed for wood production cannot provide to the same degree. Whether termed old-growth, ancient, virgin, intact, primeval or continuity forests, a major challenge and need is to map such potential high conservation value forest for subsequent inclusion in functional habitat networks for biodiversity conservation in forest landscapes. Given that the delivery time of natural forest properties is much longer than of industry wood, we explore the usefulness of using historical maps to identify forests that have been continuously present for 220 years (potential old-growth) versus 140 years (potential aging forest) in a case study in the Romanian Carpathian Mountains (see Online Resource 1). While the total forest cover increased by 35 % over the past two centuries, the area of potential aging and potential old-growth forest declined by 56 and 34 %, respectively. Spatial modelling of edge effects and patch size for virtual species with different requirements indicated an even greater decrease in the area of functional habitat networks of old-growth and ageing forest. Our analyses show that compared to simple mapping of potential high conservation forests, the area of functional habitat patches is severely overestimated, and caution is needed when estimating the area of potential high conservation value forests that form functional habitat networks, i.e. a green infrastructure. In addition, the landscape and regional scale connectivity of patches needs to be considered. We argue that the use of historical maps combined with assessment of spatial patterns is an effective tool for identifying and analyzing potential high conservation value forests in a landscape context.     

Importance of habitat patch size for occupancy and density of aspen-associated saproxylic beetles

In Fennoscandian boreal forests, aspen (Populus tremula) is one of the most important tree species for biodiversity. In this study we explore how occupancy and density of beetles associated with dead aspen are related to habitat patch size and connectedness in a 45,000 ha boreal managed forest landscape in central Sweden. Patch size was estimated as amount of breeding substrate and connectedness as crown cover of living aspen in the surrounding landscape. The beetles were sampled by sieving of bark or by inspection of species-characteristic galleries in 56 patches with dead aspen. Six of nine aspen-associated species (Xylotrechus rusticus, Ptilinus fuscus, Mycetophagus fulvicollis, Cyphaea curtula, Homalota plana and Endomychus coccineus) showed a positive significant relationship between habitat patch size and occupancy. For all these species, except C. curtula, there was also a significant positive relationship between patch size and density. Connectedness was not retained as a significant variable in the analyses. Species not defined as aspen-associated constituted a significantly larger proportion of the total density of individuals of saproxylic beetles in smaller habitat patches than in larger patches. Richness of aspen-associated species was positively related to habitat patch size. Efforts in the managed forest should be directed towards preserving and creating larger patches of living and dead aspen trees and increasing the amount of aspen at the landscape level.     

The saproxylic beetle assemblage associated with different host trees in Southwest China

Dead wood is a habitat for many insects and other small animals, some of which may be rare or endangered and in need of effective protection. In this paper, saproxylic beetle assemblages associated with different host trees in the subtropical forests in southwestern China were investigated. A total of 277 species (1 439 specimens) in 36 beetle families were collected from 117 dead wood samples, of which 101 samples were identified and respectively belonged to 12 tree genera. The number of saproxylic beetle species varied greatly among logs of different tree genera, with the highest diversity on logs of Juglans. Generally, broad‐leaved trees had a higher richness and abundance of saproxylic species than coniferous trees. Cluster analysis revealed that assemblages from broad‐leaved tree genera were generally similar (except for Betula) and assemblages from coniferous trees formed another distinct cluster. The subsequent indicator analysis proposed that there are different characteristic species for different cluster groups of host tree genera. In our study, log diameter has no positive influence on beetle species density. Conversely, comparisons of individual‐based rarefaction curves suggested that beetle species richness was highest in the small diameter class both in coniferous and broad‐leaved tree genera. With increased wood decay, proportion of habitat specialists (saproxylic beetles living on one tree genus) decreased, whereas proportion of habitat generalists (living on more than three tree genera) increased. The beetle species density was found to be higher in early stages, and decreased in later stages as well. A negative influence of altitude on saproxylic beetle species richness and abundance was detected. It was indicated that different tree genera and altitudes possibly display cross effects in modulating the altitudinal distribution and host preference of the beetles.     

Large proportion of wood dependent lichens in boreal pine forest are confined to old hard wood

Intensive forest management has led to a population decline in many species, including those dependent on dead wood. Many lichens are known to depend on dead wood, but their habitat requirements have been little studied. In this study we investigated the habitat requirements of wood dependent lichens on coarse dead wood (diameter >10 cm) of Scots pine Pinus sylvestris in managed boreal forests in central Sweden. Twenty-one wood dependent lichen species were recorded, of which eleven were confined to old (estimated to be >120 years old) and hard dead wood. Almost all of this wood has emanated from kelo trees, i.e. decorticated and resin-impregnated standing pine trees that died long time ago. We found four red-listed species, of which two were exclusive and two highly associated with old and hard wood. Lichen species composition differed significantly among dead wood types (low stumps, snags, logs), wood hardness, wood age and occurrence of fire scars. Snags had higher number of species per dead wood area than logs and low stumps, and old snags had higher number of species per dead wood area than young ones. Since wood from kelo trees harbours a specialized lichen flora, conservation of wood dependent lichens requires management strategies ensuring the future presence of this wood type. Besides preserving available kelo wood, the formation of this substratum should be supported by setting aside P. sylvestris forests and subject these to prescribed burnings as well as to allow wild fires in some of these forests.     

Structures determining bryophyte species richness in a managed forest landscape in boreo-nemoral Europe

Forest patches with high biological value are protected as woodland key habitats (WKH), which are identified by the presence of forest structures and indicator species. However, management for conservation needs to consider also managed forests as habitats for species. In this respect, there is a need to set quantitative targets for species and structures at different landscape scales. Due to non-intensive methods of forest management used prior to 1940 in Latvia, it might be expected that large areas of forest have developed structures that can support many species characteristic of natural forests. The aim of the study was to create a model that best described the richness of bryophyte species that are characteristic of natural forests, using forest structures as explanatory factors. The structures and bryophyte communities on living trees and coarse woody debris (CWD) were described in plots along transects blindly placed in areas dominated by State forests under commercial management. Explanatory variables related to tree species composition and tree size explained 54% of the variation in WKH indicator species richness on living trees. The best explanatory factors were maximum diameter of deciduous tree species and CWD. Low richness of total bryophyte and indicator species was found on dead wood, and the amount of variation in bryophyte species richness on CWD explained by explanatory variables was low. The study indicates the importance of deciduous tree substrate in managed forests in maintaining the spatial continuity of epiphytic species diversity. However, the forests in the managed forest landscape did not support high diversity of epixylic species, even in the WKHs, due to low diversity of suitable dead wood substrate.     

The importance of forest type,tree species and wood posture to saproxylic wasp (Hymenoptera) communities in the southeastern United States

Although the forests of the southeastern United States are among the most productive and diverse in North America, information needed to develop conservation guidelines for the saproxylic (i.e., dependent on dead wood) fauna endemic to the region is lacking. Particularly little is known about the habitat associations and requirements of saproxylic parasitoids even though these organisms may be even more vulnerable than their hosts. We sampled parasitoids emerging from dead wood taken from two forest types (an upland pine-dominated forest and a lowland hardwood-dominated forest), three tree species (Liquidambar styraciflua L., Pinus taeda L., and Quercus nigra L.) and two wood postures (standing dead trees (i.e., snags) and fallen logs) in South Carolina. Parasitoid abundance did not differ between forest types or among tree species, but did differ between wood postures, being higher in snags than logs. This difference may have been due to the logs being in contact with the ground or surrounding vegetation and therefore less accessible to parasitoids. Parasitoid abundance and density decreased with height on both snags and logs. Species richness did not differ between forest types, among tree species or between wood postures. According to analysis of similarities, parasitoid communities did not differ between forest types, but did differ among tree species. The wasp communities associated with the different tree species and posture combinations were distinct. In addition, communities associated with the upper boles and crowns of snags were distinct from those occurring lower on snags. These results emphasize the importance of maintaining tree diversity in managed forests as well as retaining or creating entire snags at the time of harvest.     

Decomposing logs increase oribatid mite assemblage diversity in mixedwood boreal forest

The removal of timber during harvesting substantially reduces important invertebrate habitat, most noticeably microhabitats associated with fallen trees. Oribatid mite diversity in downed woody material (DWM) using species-level data has not been well studied. We investigated the influence of decaying logs on the spatial distribution of oribatid mites on the forest floor at the sylviculture et aménagement forestiers écosystémique (SAFE) research station in the Abitibi region in NW Québec. In June 2006, six aspen logs were selected for study, and samples were taken at three distances for each log: directly on top of the log (ON), directly beside the log (ADJ) and at least one metre away from the log and any other fallen wood (AWAY). Samples ON logs consisted of a litter layer sample, an upper wood sample and an inner wood sample. Samples at the ADJ and AWAY distances consisted of litter samples and soil cores. The highest species richness was collected ON logs, and logs harboured a distinct oribatid species composition compared to nearby forest floor. There were species-specific changes in abundance with increasing distance away from DWM, which indicates an influence of DWM in structuring oribatid assemblages on the forest floor. Additionally, each layer (litter, wood and soil) exhibited a unique species composition and hosted a different diversity of oribatid mites. This study further highlights the importance of DWM to forest biodiversity by creating habitat for unique assemblages of oribatid mites.     

Availability of coarse woody debris in a boreal old‐growth Picea abies forest

Abstract. This study reports temporal (based on cross‐dated dead trees) and spatial patterns of availability of coarse woody debris (CWD) from Picea abies in a Swedish boreal landscape with discrete old‐growth forest patches in a wetland matrix. Data were collected from 29 patches ranging in size from 0.3 to 28 ha. A total of 897 dead trees with a minimum diameter of > 15 cm occurred on the 7.2 ha area analysed. The year of death was established for 50% of these trees. CWD volume ranged from 17 to 65 m³/ha for downed logs and from 0.5 to 13 m³/ha for standing snags. CWD of all decay stages and diameter classes occurred abundantly and the probability of finding logs of all decay stages and sizes was very high at the scale of single hectares. Tree mortality differed among 5 yr periods. However, during the last 50 yr no 5 yr period produced less than 3 logs/ha. Decay rates were highly variable among different logs. Logs with soft wood and some wood pieces lost (decay stage 5) died ca. 34 years ago. This suggests a fairly rapid decay in this northern forest. The data indicate a high and continuous availability of CWD of all types. It is likely, therefore, that selection pressures for efficient dispersal among CWD dependent species may not be very high. Consequently, species with narrow habitat demands and/or low dispersal ability may have evolved and this may contribute to the decrease of certain species in the managed landscape.     

Wood-decay type and fungal guild dominance across a North American log transplant experiment

We incubated 196 large-diameter aspen (Populus tremuloides), birch (Betula papyrifera), and pine (Pinus taeda) logs on the FACE Wood Decomposition Experiment encompassing eight climatically-distinct forest sites in the United States. We sampled dead wood from these large-diameter logs after 2 to 6 y of decomposition and determined wood rot type as a continuous variable using the lignin loss/density loss ratio (L/D) and assessed wood-rotting fungal guilds using high-throughput amplicon sequencing (HTAS) of the ITS-2 marker. We found L/D values in line with a white rot dominance in all three tree species, with pine having lower L/D values than aspen and birch. Based on HTAS data, white rot fungi were the most abundant and diverse wood-rotting fungal guild, and soft rot fungi were more abundant and diverse than brown rot fungi in logs with low L/D values. For aspen and birch logs, decay type was related to the wood density at sampling. For the pine logs, decay type was associated with the balance between white and brown/soft rot fungi abundance and OTU richness. Our results demonstrate that decay type is governed by biotic and abiotic factors, which vary by tree species.     

Consequences of forest fragmentation for polyporous fungi at two spatial scales

Greatly reduced area of old-growth forests and the very low amount of dead wood in managed forests in northern Europe have caused a marked decline in the populations of saproxylic species. It is less clear at which spatial and temporal scales these adverse changes are taking place, and more information is needed to reliably predict which species are especially sensitive to loss and fragmentation of habitat. Here we compare species richness, incidence of occurrence in forest fragments, and abundance of polyporous fungal species and species groups between two regions in Finland with contrasting histories of forestry and a marked difference in the amount and spatial configuration of old-growth forests. We also analyse the consequences of increasing loss of connectivity on the presence and abundance of polypores in a study region with a documented short-term history of old-growth fragmentation. Our results show that the species number, incidence of occurrence, and abundance of especially the rare, threatened, and near-threatened species are much lower in the old-growth fragments in Häme in southern Finland in comparison with Kuhmo in eastern Finland, most probably because of the longer history of intensive forestry in Häme. Among the rare species, the species that show the greatest difference between the two regions (at the scale of 500 km) also tended to respond most strongly to the more recent forest fragmentation within the study region in Kuhmo (at the scale of 50 km). Polypores associated with spruce seem to be more strongly affected by forestry than species associated with pine, possibly reflecting the differences in the natural dynamics of spruce-dominated and pine-dominated forests.     

Linking woodland key habitat inventory and forest inventory data to prioritize districts needing conservation efforts

Woodland key habitat (WKH) inventories have been conducted in northern European countries, with the aim to create networks of minimally disturbed forest stands for protection. The goal of national forest inventory is to provide information relevant to forest management, such as on forest types, trees species composition, age structure and wood volume. The aim of this study was to link these two inventory databases to identify districts of Latvia most deficient in connectivity and habitat quality, in order to prioritize districts needing conservation effort. As an example, the area of deciduous forest with nemoral tree species (oak, ash, lime, maple and elm) and aspen was chosen. These forests provide habitat for a specific community of epiphytes. Using information in the WKH database, habitat quality in different districts of Latvia was estimated by the frequencies of occurrence of structural elements and selected indicator epiphyte species in nemoral tree species and aspen WKHs. Using digital data in the national forest inventory database, fragmentation metrics were determined for forests that, according to age and tree species composition, could potentially be nemoral tree and aspen WKHs. On a regional level, the lowest habitat quality in WKH occurred in districts that had the least fragmentation of potential WKH forest. In the less fragmented areas, the habitat quality of the existing WKH will likely increase in the future, and could be promoted by management to create structural elements typical of natural forests. The districts with the most fragmented nemoral and aspen forests, contained WKHs with the best habitat quality. A focus on protection should be given to these stands as they are the most likely to support source populations, and there is a need to improve spatial continuity of suitable tree substrate in these areas.     

Relationships between spatial configuration of tropical forest patches and woody plant diversity in northeastern Puerto Rico

The destruction and fragmentation of tropical forests are major sources of global biodiversity loss. A better understanding of anthropogenically altered landscapes and their relationships with species diversity and composition is needed in order to protect biodiversity in these environments. The spatial patterns of a landscape may control the ecological processes that shape species diversity and composition. However, there is little information about how plant diversity varies with the spatial configuration of forest patches especially in fragmented tropical habitats. The northeastern part of Puerto Rico provides the opportunity to study the relationships between species richness and composition of woody plants (shrubs and trees) and spatial variables [i.e., patch area and shape, patch isolation, connectivity, and distance to the Luquillo Experimental Forest (LEF)] in tropical forest patches that have regenerated from pasturelands. The spatial data were obtained from aerial color photographs from year 2000. Each photo interpretation was digitized into a GIS package, and 12 forest patches (24–34 years old) were selected within a study area of 28 km². The woody plant species composition of the patches was determined by a systematic floristic survey. The species diversity (Shannon index) and species richness of woody plants correlated positively with the area and the shape of the forest patch. Larger patches, and patches with more habitat edge or convolution, provided conditions for a higher diversity of woody plants. Moreover, the distance of the forest patches to the LEF, which is a source of propagules, correlated negatively with species richness. Plant species composition was also related to patch size and shape and distance to the LEF. These results indicate that there is a link between landscape structure and species diversity and composition and that patches that have similar area, shape, and distance to the LEF provide similar conditions for the existence of a particular plant community. In addition, forest patches that were closer together had more similarity in woody plant species composition than patches that were farther apart, suggesting that seed dispersal for some species is limited at the scale of 10 km.     

Habitat associations of <Emphasis Type="Italic">Agathidium pulchellum</Emphasis>, an endangered old-growth forest beetle species living on slime moulds

The beetle genus Agathidium is the largest insect group documented that principally feeds on slime moulds. Agathidium pulchellum, one of the rarest Agathidium species in Europe, is listed in the EU’s Habitats Directive. We studied the habitat associations of A. pulchellum in 44 sites located in old-growth and managed forests in eastern Finland. Agathidium pulchellum occurred exclusively on the slime-mould species Trichia decipiens. The host was associated with mid-decayed aspen, spruce and birch logs, and its incidence grew with both increasing log diameter and stand-level log density of spruce and aspen. We also observed that even if its host was present, the beetle was absent from sites with less than 80 aspen and spruce logs per hectare. All sites with A. pulchellum were natural forests of high conservation value. Our results show that it is possible to systematically survey the occurrence of A. pulchellum.     

Preferences of dead wood inhabiting bryophytes for decay stage,log size and habitat types in Hungarian beech forests

Abstract

This study describes the quantitative preferences of epixylic bryophytes for decay stages, log size and habitat type. The two habitats investigated were zonal (situated on plateaux without extreme microclimatic conditions) and ravine-like near-natural beech stands. Preferences of 30 bryophyte species are described using logistic regression modelling. The species pool differed between habitat types. In the ravine-like forests more species are found. Regionally rare epixylic species (mainly liverworts) were limited to these forests. The species richness of individual logs was also higher in the ravine-like than in the zonal forests and the proportion of logs of all sizes colonized by bryophytes was higher in the former. The species were classified into four categories on the basis of their preference for decay stages: strict epixylics, indifferent species, preferential epixylics and epiphytes. The epixylics and preferential epixylics prefer advanced decay stages while the latter extend further into earlier decay stages than strict epixylics. Common epixylic species have a wider tolerance to decay stage than rare ones. Probabilities of species occurrence increase with log size, more strongly in zonal stands than in ravines. A simple successional scheme for bryophyte succession on dead wood is proposed on the basis of the observed species responses.     

Species richness of tropical wood-inhabiting macrofungi provides support for species-energy theory

A study was undertaken at the El Verde Field Station in Puerto Rico to determine the effect of energy available from newly dead trees on the species richness of macrofungal communities that inhabit them. It is hypothesized that there is a positive relationship between available energy and species richness. Energy was measured using the volume of the dead trees and the wood density of living trees of the same species. One hundred ninety-four logs of known tree species were surveyed 1 y for fruiting bodies of macrofungi at monthly intervals. For individual logs, log volume had a significant positive effect on macrofungal species richness. Younger logs had significantly higher species richness than older logs, and those with less apparent decay had more species than those with more decay. When logs were grouped by tree species, total wood volume and density of live wood had a significant positive effect and average log diameter had a negative effect on total species richness and abundance of the wood-inhabiting macrofungi. Macrofungal richness and abundance constantly increased with initial wood density; there was no evidence for a unimodal relationship. These results support the proposed relationship between species richness and energy.     

Beetles provide directed dispersal of viable spores of a keystone wood decay fungus

Wood decay fungi are considered to be dispersed by wind, but dispersal by animals may also be important, and more so in managed forests where dead wood is scarce. We investigated whether beetles could disperse spores of the keystone species Fomitopsis pinicola. Beetles were collected on sporocarps and newly felled spruce logs, a favourable habitat for spore deposition. Viable spores (and successful germination) of F. pinicola were detected by dikaryotization of monokaryotic bait mycelium from beetle samples. Viable spores were on the exoskeleton and in the faeces of all beetles collected from sporulating sporocarps. On fresh spruce logs, nine beetle species transported viable spores, of which several bore into the bark. Our results demonstrate that beetles can provide directed dispersal of wood decay fungi. Potentially, it could contribute to a higher persistence of some species in fragmented forests where spore deposition by wind on dead wood is less likely.     

Linking substrate and habitat requirements of wood‐inhabiting fungi to their regional extinction vulnerability

Loss of old‐growth forests and greatly reduced volumes of coarse dead wood in managed forests are the main reasons for the decline of many wood‐inhabiting species in Europe and elsewhere. To assess the habitat requirements and extinction vulnerability of 13 polypore species associated mainly with spruce, their occurrences were recorded on 96 521 dead‐wood objects in 331 stands along a regional gradient of forest utilization history across southern‐middle boreal Finland. The substrates studied included a variety of tree species and dead‐wood qualities investigated in both unmanaged and managed stands at different successional stages. Hierarchical logistic regression models were constructed to analyze the relationships between the occurrence probability of individual species and variables at the substrate, stand and regional scales. The substrate preferences of the polypore species studied overlapped, since most of them favored large‐diameter spruce logs in mid‐decay stages. However, only a few species were restricted to this substrate. Other species were able to use a wider range of host tree species and qualities of dead wood, including man‐made substrates that are abundant in managed forests (logging residues and stumps). Species confined to logs had a significantly lower occurrence probability in regions with the longest and most intensive forest use history. Species less specialized in their resource use showed no decline or the opposite trend. Loss of threatened species is likely if the preservation of old‐growth forests is not combined with conservation measures in managed forests. Increasing extraction of logging residues and stumps for biofuel may cause non‐threatened species to decline by reducing substrate qualities utilized by them. The hierarchical models predicted a considerable part of the variation in Species' occurrence probabilities, and therefore provide powerful tools for setting quantitative targets for management.