Supply Of Dead Wood Research Articles

Effects of forest gap formation and deadwood enrichment on oribatid mites (Acari: Oribatida) vary between regions

Most forests in Central Europe are subject to human management, especially timber harvesting, which alters soil conditions by creating gaps in the forest canopy and reduces the availability of deadwood. However, consequences of these management practices, in particular the combined effect of gap formation and deadwood removal, have been largely neglected. Here, we investigated the abundance, diversity and community composition of oribatid mites (Acari: Oribatida) in forests where deadwood availability and gap formation were manipulated in a full factorial design (Control, Gap, Deadwood, Gap + Deadwood). Forest gaps of about 30 m in diameter were established by felling trees, which were subsequently removed (Gap) or left on site as deadwood (Gap + Deadwood). Nearby forest sites without gaps were enriched with the equal amount of felled trees (Deadwood) or left untreated (Control). Experimental treatments were established at 29 forest sites including deciduous and coniferous stands in three regions of Germany, i.e. the Swabian Alb, Hanich-Dün and Schorfheide-Chorin in the south, center and north, respectively. One year after establishment of the treatments, we sampled 10,777 individuals and 104 species of oribatid mites. Deadwood addition significantly increased the density of oribatid mites in the Hainich-Dün from 24,036 to 46,658 ind. m-². Specifically, species of Oppiidae with relatively short life cycles and high reproductive output benefited from the additional deadwood supply, resulting in shifts in community compositions between treatments with and without deadwood. By contrast, mean oribatid mite density decreased from an average of 64,083 in controls to 36,621 ind. m-² in forest gaps of the Schorfheide-Chorin and the Swabian Alb. Presumably, adverse abiotic conditions, mainly amplified drought, induced higher mortality rates in these regions. Overall, deadwood addition and forest gap formation had strong effects on oribatid mite communities, although the magnitude of each effect was similar between forest types and largely determined by regional context. This emphasizes that the effects of forest management practices on oribatid mite communities cannot be generalized across regional scales, suggesting that management plans should carefully consider regional differences.

Forest dieback in a protected area triggers the return of the primeval forest specialist Peltis grossa (Coleoptera, Trogossitidae)

AbstractForest set‐aside is a commonly employed conservation strategy, but large‐scale disturbances regularly evoke discussions on its utility for biodiversity conservation in former production forests. In this study, we reconstructed the return of a primeval forest specialist, the beetle Peltis grossa (Linnaeus, 1758) of the family Trogossitidae, to two national parks after more than a century of absence. To illuminate historical processes and the role of potential refuges and species' size, we compared the beetle's current distribution collected in a large‐scale citizen science approach, with historical data and the current distribution of two closely related, smaller species. We quantified deadwood preferences and investigated the effect of benign neglect versus salvage‐logging management practices on P. grossa abundances. Our findings support the view that P. grossa survived in the southern Bohemian Forest, which enabled its recolonization of the landscapes. However, a build‐up of the population was dependent upon a massive supply of deadwood by bark beetles within the refuge area. In a large area in the north of the study region that >20 years ago contained ample amounts of deadwood, forest succession outpaced colonization by P. grossa. The current probability of the species' presence decreased with distance to the presumed refuge area from 70% to 5% at 40 km. In the present core distribution area of P. grossa, salvage logging reduced its abundance by the factor 20. These results provide three important lessons on the potential of natural disturbances as a biodiversity restoration tool in forest set‐asides: First, large supply of deadwood by disturbance can trigger the return of locally extinct primeval forest specialists. Second, the species must survive within a critical distance (for P. grossa < 10–40 km). Third, salvage logging significantly reduces the population densities of forest specialists by reducing habitat amount.

Living, dead, and absent trees-How do moth outbreaks shape small-scale patterns of soil organic matter stocks and dynamics at the Subarctic mountain birch treeline?

Mountain birch forests (Betula pubescens Ehrh. ssp. czerepanovii) at the subarctic treeline not only benefit from global warming, but are also increasingly affected by caterpillar outbreaks from foliage-feeding geometrid moths. Both of these factors have unknown consequences on soil organic carbon (SOC) stocks and biogeochemical cycles. We measured SOC stocks down to the bedrock under living trees and under two stages of dead trees (12 and 55years since moth outbreak) and treeless tundra in northern Finland. We also measured in-situ soil respiration, potential SOC decomposability, biological (enzyme activities and microbial biomass), and chemical (N, mineral N, and pH) soil properties. SOC stocks were significantly higher under living trees (4.1±2.1kg m²) than in the treeless tundra (2.4±0.6kg m²), and remained at an elevated level even 12 (3.7±1.7kg m²) and 55years (4.9±3.0kg m²) after tree death. Effects of tree status on SOC stocks decreased with increasing distance from the tree and with increasing depth, that is, a significant effect of tree status was found in the organic layer, but not in mineral soil. Soil under living trees was characterized by higher mineral N contents, microbial biomass, microbial activity, and soil respiration compared with the treeless tundra; soils under dead trees were intermediate between these two. The results suggest accelerated organic matter turnover under living trees but a positive net effect on SOC stocks. Slowed organic matter turnover and continuous supply of deadwood may explain why SOC stocks remained elevated under dead trees, despite the heavy decrease in aboveground C stocks. We conclude that the increased occurrence of moth damage with climate change would have minor effects on SOC stocks, but ultimately decrease ecosystem C stocks (49% within 55years in this area), if the mountain birch forests will not be able to recover from the outbreaks.

An indicator species highlights continuous deadwood supply is a key ecological attribute of boreal old‐growth forests

AbstractOld‐growth forests are optimal habitats for many woodpeckers, which are often themselves excellent indicators of deadwood‐associated biodiversity. Old‐growth forests are, however, heterogeneous ecosystems in terms of structure, composition, and deadwood characteristics, thus implying a varied use of these forests by woodpeckers. In boreal landscapes, old‐growth stands are threatened by forest harvesting; however, there is little information in regard to the consequences for biodiversity with the loss of specific types of old‐growth forests. This study aimed to assess how the black‐backed woodpecker (Picoides arcticus), a biodiversity indicator species associated with old‐growth forest attributes, uses different types of old‐growth forests for its foraging needs. We identified woodpecker foraging marks in 24 boreal old‐growth forest stands in eastern Canada that were dominated by black spruce (Picea mariana), located within the home range of eight black‐backed woodpeckers. We identified the various old‐growth forest types using a typology based on the structural attributes of old‐growth stands. We classified the sampled stands into four old‐growth forest types, corresponding to different successional stages (recent or old, relative to the onset of the old‐growth stage), composition (pure black spruce or mixed black spruce–balsam fir [Abies balsamea]), and productivity (ongoing paludification or not). The black‐backed woodpecker foraged in all types of old‐growth forests, but favored dense old‐growth forests that were not paludified and that showed a high temporal continuity (i.e., old‐growth dynamics probably started more than a century ago). The temporal continuity of the old‐growth state allows for the continuous supply of large, slightly decayed snags, the preferred foraging substrates of the black‐backed woodpecker. The old‐growth forest type most favored by this woodpecker is, however, also the forest type most often targeted first by logging operations. Protecting the biodiversity associated with recent deadwood in managed areas thus requires maintaining a sufficient area and density of dense, old‐growth black spruce‐dominated forests in managed areas.

Testing the Effect of Snag and Cavity Supply on Deadwood-Associated Species in a Managed Boreal Forest

Standing deadwood is an important attribute of old-growth boreal forests and it provides essential microhabitats for deadwood-associated species. In managed boreal forests, short rotations tend to limit the amount and diversity of standing deadwood. This study evaluates if the anthropogenic supply of deadwood attributes through tree girdling or by providing nest boxes may favor deadwood-associated species. We studied the short-term response of saproxylic beetles, foraging woodpeckers, and secondary cavity users to snag and cavity supply in 50 to 70-year-old black spruce stands. In spring 2015, we girdled 8000 black spruce according to two spatial distributions (uniform and clustered), and we also installed 450 nest boxes of six different sizes at three distances from the forest edge. Using trunk window traps, we captured significantly more beetles in sites with girdled trees than in control sites in both 2015 and 2016. We also recorded a trend of a greater abundance of beetles in clusters of girdled trees than within uniformly distributed girdled trees. Trypodendron lineatum (Oliver) dominated beetle assemblages, representing 88.5% of all species in 2015 and 74.6% in 2016. The number of beetles captured was 7× higher in 2015 than in 2016. In contrast, we observed greater amounts of woodpecker foraging marks in fall 2016 than in either fall 2015 or spring 2016. Woodpeckers foraged significantly more in clusters of girdled trees than within uniformly distributed girdled trees. Woodpeckers’ foraging mark presence was positively associated with the proportion of recent cuts at 1 km around the study sites. Five Boreal Chickadee (Poecile hudsonicus Forster) pairs used nest boxes and occupied smaller box sizes that were located away from the forest edge. Our study showed that structural enrichment can be effective in rapidly attracting deadwood-associated species within managed forest stands.

Predictors of habitat use and nesting success for two sympatric species of boreal woodpeckers in an unburned, managed forest landscape

Forest harvesting reduces mean stand age and dead wood amount. Among species dependent upon older forests and dead wood, primary excavators such as woodpeckers play an important ecological role by providing cavities for many other species. Conservation of these species thus requires striking a balance between timber harvesting and dead wood supply, especially under moderate natural disturbance regimes. In this study, we quantified habitat use in two closely-related, sympatric species: Black-backed (Picoides arcticus) and American Three-toed (P. dorsalis) Woodpecker, in the highlands of northern New Brunswick, Canada. Natural fires are rare in this ecoregion and forest harvesting is the main agent of landscape change, along with infrequent outbreaks of spruce budworm (Choristoneura fumiferana). Based on its habitat use patterns in other ecoregions, we hypothesized that Black-backed Woodpecker would select nest sites in mature coniferous forest stands and we expected that it would achieve a higher nest survival rate in forest stands than within, or at the edge of, cutblocks. Owing to sample size limitations for American Three-toed Woodpecker, statistical analyses were restricted to its occurrence patterns. Both species co-occurred, and there was no difference in detectability following conspecific and heterospecific playbacks. Contrary to our prediction, Black-backed Woodpecker selected nest sites with higher proportions of recently cut areas within 50 m than at randomly selected sites. Black-backed Woodpecker selected cutblocks for nesting when suitable snags were available and mature forest stands were present nearby as foraging habitat. For the species to persist in this landscape, the supply of snags must be continuous and forest stands must be sufficiently mature to host saproxylic insects.

Evaluating multifunctionality and adaptive capacity of mountain forest management alternatives under climate change in the Eastern Alps

Future provisioning of ecosystem services (ES) from mountain forests is uncertain due to potential impacts of climate change. For a case study catchment in the Eastern Alps in Austria we analysed how management and climate change may affect the provisioning of four ES (timber production, carbon sequestration, biodiversity and bird habitat quality, and protection against gravitational hazards). We used the PICUS forest ecosystem model to project seven management alternatives that differed with regard to cutting pattern size (SLIT, PATCH, STRIP) and two harvesting intensity levels (in terms of return interval) under historic climate and five transient climate change scenarios over 100 years. In addition no management and sanitary management were simulated. In total twelve indicators were linked to model output to quantify ES provisioning. Results under historic climate showed increased volume and carbon stocks in low-intensity management, while high-intensity management decreased stocks. Bird habitat quality was maintained only by low-intensity management using SLIT and PATCH cuts. In particular rockfall protection decreased strongly under the STRIP cut scenario. Improved tree growth in warming scenarios was counterbalanced by increasing damage from bark beetle disturbances. Canopy openings and increased deadwood supply from disturbances partly fostered bird habitat quality in no-management alternatives. Overall none of the management alternatives performed best for all ES. PATCH and SLIT regimes at (currently practiced) low intensity appeared as compromise to achieve multifunctionality at small scale. As involved trade-offs among ES can be substantial, partial segregation with priority on specific services in designated zones is recommended.

Communities of fungi in decomposed wood of oak and pine

Abstract The abundance and diversity of wood decomposing fungi were investigated by isolating and cultivating filamentous fungi from wood and by detection of fruit bodies of ascomycetous and basidiomycetous fungi. The objective was to study the impact of forest management on fungi in 100-year-old oak and 87-year-old Scots pine forests in Northern Poland. Fungi were found on coarse woody debris of decayed stumps and fallen logs, boughs and branches in each of the three (managed and unmanaged) examined stands. In total, 226 species of Oomycota and fungi were recorded. Oak wood was colonized by one species of Oomycota and 141 species of fungi including Zygomycota (19 species), Ascomycota (103 species) and Basidiomycota (19 species). Scots pine wood was also colonized by one species of Oomycota and 138 species of fungi including Zygomycota (19 species), Ascomycota (90 species) and Basidiomycota (29 species). In the first, second and third stages of decomposition, the oak wood was colonized by 101, 89 and 56 species of fungi respectively and pine wood was colonized by 82, 103 and 47 species respectively. Eighty three of the observed species (37%) occurred on both types of wood, while the other species displayed nutritional preferences. A decrease in the number of species with advancing decay indicates the necessity for a continuous supply of dead wood to the forest ecosystem. This supply would secure the continuity of fauna and flora and guarantee a stable forest development. The nutritional and ecological preferences of many fungal species furthermore indicate the necessity of supplying the forests with wood of different species. In commercially managed forests the results obtained here will aid in: (i) the development of strategies for effective dead wood management in the context of forest productivity and future wood stock growth, as well as (ii) finding a compromise between forest management requirements and environmental protection.

Slash harvesting does not undermine beetle diversity on small clear-cuts containing sufficient legacies

Logging residues (slash) constitute an increasingly important source of renewable energy in forested countries, but their intensive extraction can reduce biodiversity. Important research issues include the mitigation potential of reduced logging and slash extraction levels, and their feasibility in production forestry. We performed a comparative study on beetle assemblages in relation to slash extraction practices in Estonia, where silviculture retains higher deadwood amounts than in intensive forestry systems, slash extraction level is ca. 50 %, and final fellings retain at least 5 % of the standing stock. We sampled beetles using flight-interception traps on six pairs of retention cut sites (one conventional and one slash-harvested; average size ca. 2 ha; in three forest site-types). The material comprised 11,948 beetle specimens identified to species level (500 species). Species of conservation concern occurred regularly in all sites, while a total of 18 putative pest species comprised only ca. 3 % of individuals in both treatments. There were no clear influences of slash extraction on species richness, abundance or assemblage composition. The main gradients in the assemblage composition were trapping season and site type; the latter co-varying with tree-species composition and deadwood volumes. We conclude that slash harvesting that retains (depending on forest type) 5–25 m3 ha−1 of coarse deadwood and 10–35 m3 ha−1 of fine deadwood neither reduces beetle diversity (at least of highly mobile species in the short term) nor affects pest outbreaks in our study system. To sustain beetle diversity, sufficient deadwood legacies should be supplemented with live-tree retention for a continuous deadwood supply during post-harvest succession.

Dutch elm Disease and the Habitat of Endangered Rosalia LongicornRosalia alpina(L.): A Conservation Paradox?

ABSTRACT In central Europe, the endangered Rosalia longicorn Rosalia alpina (L.) has rarely been observed to develop in the wood of elms Ulmus sp.; however, this beetle has recently expanded into habitats formed by elms. The factors driving these changes are unknown in detail, but a potential one is the increasing amount of breeding material, namely, dead elm wood. Dutch elm disease, caused by the fungi Ophiostoma ulmi and O. novo-ulmi, by killing off elm trees, has created a supply of dead wood. The aim of this work was to assess the potential role of Dutch elm disease in the formation of habitats suitable for the endangered Rosalia longicorn. The health of four elm stands (Carpathians, SE Poland) was analysed and the pathogen responsible for elm death were determined by DNA sequence comparison. O. novo-ulmi — the causative agent of Dutch elm disease — was isolated from weakened and dying trees at all studied localities. In total, 30% of the elm trees were dead, 34% showed signs of dieback or were moribu...

The importance of coarse woody debris for vascular plants in temperate mixed deciduous forests

Deadwood in various stages of decomposition and diverse spatial arrangements provides habitat for numerous organisms. However, knowledge on the colonization of deadwood by vascular plants in mixed deciduous forests is insufficient. We carried out our study in an oak–lime–hornbeam forest in northeastern Poland. Downed logs were colonized by 49 vascular plant species, a number higher than reported from any other type of forest. Species richness and abundance of plants increased with log diameter and decomposition. The former was higher on broadleaf deadwood than on coniferous deadwood (46 vs. 38 species). The frequency and abundance on logs were higher for small-seeded plants (<1 mg) than for bigger, heavier seeded plants. Deadwood surface served as an ecological filter, keeping small seeds in cracks, but allowing bigger seeds to roll down. Tree seedling density increased with wood decomposition. However, for eight of nine species, it was higher on the ground than on deadwood. Only spruce seedlings were recorded almost exclusively on deadwood, constituting a crucial substrate for spruce regeneration in meso-eutrophic forests. Therefore, we stress the importance of constant deadwood supply, on the scale of decades, to ensure the diversity of this substrate and to allow the natural dynamics of deadwood-dependent species populations.

Modelling deadwood supply for biodiversity conservation: Considerations, challenges and recommendations

There are concerns that deadwood supply (both snags and downed wood) may become a limiting resource for biodiversity conservation as the bio-economy develops. Despite this concern, it remains difficult to monitor all elements of biodiversity to ensure that forest management activities are not reducing deadwood below minimum thresholds. As a dynamic resource, deadwood quantity and quality does change throughout forest succession. Simulation modelling represents one approach to integrating this variability and supporting the refinement of forest management guidelines. In this paper, we review important considerations for developing deadwood models that address biodiversity concerns. These include defining initial conditions, estimating deadwood inputs over time, identifying parameters necessary to represent biodiversity, identifying data available to parameterize, calibrate and validate models, and identifying requirements for model validation and documentation. In addition, we consider how deadwood characteristics such as form, size, state of decay, tree species, cause of mortality and position can be treated in models to represent the full range of biodiversity requirements. Lastly, we review examples of stand-alone and study-specific deadwood modelling approaches to provide a road map for development of a robust, temporally dynamic deadwood model that addresses biodiversity and sustainability issues related to biomass harvest for bioenergy.

Welche Faktoren bestimmen den Erfolg der Moderholzverjüngung im Fichtenurwald Scatlè?

Which factors determine regeneration on nurse logs in the Scatlè virgin forest? Harsh environmental conditions in subalpine forests render Norway spruce regeneration difficult, limiting germination and establishment to a few microsites such as decaying logs. In 2002, spruce regeneration was studied on coarse woody debris (CWD) in the Swiss virgin forest Scatlè. In 2012, regeneration status and the factors characterizing environmental conditions were re-assessed. The statistical model that had been parameterized with the 2002 data also performed well with the explanatory variables measured in 2012, indicating that regeneration on CWD is a non-random, complex process resulting from the interaction of several ecological factors. A 5.5-fold increase of regeneration density was observed over the past ten years, which is most likely attributable to a higher abundance of suitable microsites on CWD: 1) an increase of moderately and strongly decayed wood, 2) average sunshine duration in June of 50 to 120 minutes per day, 3) a decrease of the plot-to-ground distance with little competition by the surrounding ground vegetation, 4) an increase of the thickness of moss cover. The mast years of 2009 and 2011 certainly were influential for the increase of regeneration density. Establishment of regeneration may start as early as six years after tree death, but logs older than 23 years were most suitable. Natural regeneration on rotten wood thus is a slow and long-lasting process, and the sustainability of regeneration requires a continuous supply of dead wood of different decay stages. Besides the important role of dead and dying trees for spruce regeneration, we also found an important role of CWD for biodiversity, as fifteen species of decay fungi were detected, two of them having the status of endangered species.

Wood resource and not fungi attract early‐successional saproxylic species of Heteroptera – an experimental approach

Abstract The availability of dead wood and ability to colonise these ephemeral structures are crucial for sustaining vital populations of saproxylic insects. These insects locate suitable resources mostly visually and via olfactory cues emitted by dead wood and/or wood‐decaying fungi. For the conservation of saproxylic species of Heteroptera, a poorly studied group with a high proportion of threatened species, it is crucial to know which dead‐wood structures are needed and how they are detected and colonised. In a field experiment, we exposed different amounts of dead‐wood logs and branches of the main tree species of montane beech forests (Abies alba, Fagus sylvatica) on sunny and shady forest plots. We sampled saproxylic heteropterans and sporocarps of wood‐decaying fungi in two consecutive years to test the hypothesis that early‐successional saproxylic heteropterans are more attracted to wood‐decaying fungi than to wood itself. The activity densities of saproxylic heteropterans measured with flight‐interception traps increased with increasing surface of coarse woody debris and was higher under sunny conditions. Tree species, fine woody debris and abundance of sporocarps had no significant effect. Our results suggest that during the early‐successional forest stage, dead wood provides more important cues than fungi in the search of saproxylic heteropterans for suitable hosts despite assumed close associations of the insects and certain fungal species. To improve habitats for saproxylic heteropterans, we recommend increasing the supply of dead wood of large diameter (>30 cm) in montane beech forests, particularly in sunny gaps. This can easily be realised during logging operations by gap felling.

Temporal variation of polypore diversity based on modelled dead wood dynamics in managed and natural Norway spruce forests

Decline of dead wood in managed boreal forests has variously affected polypore species that use it as their substrate, some now being listed as threatened while some are still thriving. Management of polypore diversity requires species-specific information about their occurrence probabilities, which partially depend on stand dead wood availability and other properties.We implemented an ensemble of polypore habitat models to simulations of stand and dead wood availability estimated with a decomposition model we fitted to data. We asked how management of a boreal Norway spruce stand influences the dead wood availability and polypore occurrence probabilities and their diversity.Simulations of multiple polypore species with stand management scenarios provided insight to dead wood dynamics and polypore species management. In a managed stand, diversity thrived after final harvesting, but declined to low level by mid-rotation. Harvest residues and stumps, although low quality substrate for many species, were important for diversity in young managed stand due to their high quantities. High mixtures of naturalness in stand management were required to elevate diversity of managed spruce stands from the mid-rotation lows to levels in natural-like stands.Our study suggests that dead-wood supply of managed stands could be optimised to lift lowest species expectations towards levels in natural-like forests, but it seems that reaching these levels requires dead-wood quantities much higher than provided by conventional management. Management of stand diversity can presumably be facilitated with wise landscape planning but more research is needed in order to incorporate polypores to spatio-temporal management simulation context.

Long-Term Impacts of Forest Ditching on Non-Aquatic Biodiversity: Conservation Perspectives for a Novel Ecosystem

Artificial drainage (ditching) is widely used to increase timber yield in northern forests. When the drainage systems are maintained, their environmental impacts are likely to accumulate over time and along accompanying management, notably after logging when new forest develops on decayed peat. Our study provides the first comprehensive documentation of long-term ditching impacts on terrestrial and arboreal biodiversity by comparing natural alder swamps and second-generation drained forests that have evolved from such swamps in Estonia. We explored species composition of four potentially drainage-sensitive taxonomic groups (vascular plants, bryophytes, lichens, and snails), abundance of species of conservation concern, and their relationships with stand structure in two-ha plots representing four management types (ranging from old growth to clearcut). We found that drainage affected plot-scale species richness only weakly but it profoundly changed assemblage composition. Bryophytes and lichens were the taxonomic groups that were most sensitive both to drainage and timber-harvesting; in closed stands they responded to changed microhabitat structure, notably impoverished tree diversity and dead-wood supply. As a result, natural old-growth plots were the most species-rich and hosted several specific species of conservation concern. Because the most influential structural changes are slow, drainage impacts may be long hidden. The results also indicated that even very old drained stands do not provide quality habitats for old-growth species of drier forest types. However, drained forests hosted many threatened species that were less site type specific, including early-successional vascular plants and snails on clearcuts and retention cuts, and bryophytes and lichens of successional and old forests. We conclude that three types of specific science-based management tools are needed to mitigate ditching effects on forest biodiversity: (i) silvicultural techniques to maintain stand structural complexity; (ii) context-dependent spatial analysis and planning of drained landscapes; and (iii) lists of focal species to monitor and guide ditching practices.

Dead wood and polypore diversity in natural post-fire succession forests and managed stands – Lessons for biodiversity management in boreal forests

We tested the extent to which forestry mimics natural stand-replacing fire dynamics, and what factors best explain species richness and assemblages of polyporous fungi in natural northern boreal Picea abies-dominated forests and managed forests which were either clear-cut and planted with pine, or selectively logged. The amount of coarse woody debris (CWD) and diversity of polypores in old-growth forests and in forests at three natural post-fire successional stages (young, middle-aged, old) were compared with managed forests at comparable successional stages. Fire created a high amount of CWD, providing a supply of dead wood for saproxylic species for at least 50–70y. Dead wood volumes remained high throughout the natural forest succession, exceeding at all stages 18m3ha−1, the threshold value established in the study for the occurrence of red-listed species. The richness of polypore species was highest on young post-fire sites, and their species composition, including red-listed species, was comparable to that of old-growth forests (>300y) used as references. The amount of CWD in natural post-fire forests was over two to twenty times higher than that on clear-cut sites, and species diversity on clear-cut sites was considerably lower than on sites undergoing natural succession, with no occurrences of red-listed species. A relatively diverse polypore flora was found in selectively logged forests, likely due to rather a high volume and continuity of spruce CWD. The results indicate a strong but non-linear relationship between total volume of CWD and species richness of polypores, but successional stage and naturalness also explained part of the variation. The species assemblages were influenced most by the decay stage of CWD, tree species composition and naturalness of the site. The results demonstrate the importance of old-growth and young post-fire forests as landscape-level habitats and species pools, especially for red-listed species. We recommend that old-growth spruce forests be preserved whenever possible and that high CWD volumes be generated locally for red-listed species, for example, by prescribed burning. Regeneration forests for spruce, extended rotation periods and the use of logging techniques other than clear-cutting would help in maintaining species diversity in spruce-associated species in boreal forests.

Ecological requirements of a rare saproxylic beetle Cucujus haematodes- the beetles’ stronghold on the edge of its distribution area

Abstract. 1. Cucujus haematodes is a rare obligate saproxylic beetle with Eurasian distribution range. 2. The species has suffered a sharp decline in the European part of its distribution range, which can be attributed to the loss of forest habitats with a continuous supply of dead wood. 3. We found that this species is largely distributed in the Primorskiy Region (far eastern Russia), where it can reach strong populations in late stages of pioneer forest succession. 4. Contrary to the observations in Europe, C. haematodes occurred predominantly in lower altitudes and it preferred broadleaved trees. 5. Our guild analysis showed springtails (Collembola), mites (Acarina), ants (Formicidae) and subcortical histerids (Histeridae) and carabids (Carabidae) to be the most associated species at the microhabitat level. 6. Cucujus haematodes can be considered as a species of high conservation value because it shares the habitat with some other threatened saproxylic beetles, such as Boros schneideri (Boridae), Pytho kolwensis (Pythidae), Cardiophorus nigerrimus (Elateridae) and Dendrophagus crenatus (Silvanidae).

Legacies from natural forest dynamics: Different effects of forest management on wood-inhabiting fungi in pine and spruce forests

The species composition of wood-inhabiting fungi (polypores and corticoids) was investigated on 1138 spruce logs and 992 pine logs in 90 managed and 34 natural or near-natural spruce and pine forests in SE Norway. Altogether, the study included 290 species of wood-inhabiting fungi. Comparisons of logs with similar properties (standardized tree species, decay class, dimension class) in natural and managed forests showed a significant reduction in species number per log in managed spruce forests, but not in managed pine forests. The species number per log in managed spruce forests was 10–55% lower than on logs from natural spruce forests. The reduction was strongest on logs of large dimensions. A comparison of 200–400 spruce logs from natural and managed forests showed a 25% reduction in species richness corresponding to a conservative loss of ca. 40 species on a regional scale. A closer inspection revealed that species confined to medium and very decayed spruce logs were disfavored in managed forests, whereas species on early decay classes and decay generalists were unaffected. Similarly, species preferring large spruce logs were disfavored in managed forests. Forest management had strongest impact on low-frequent species in the spruce forests (more than 50% reduction), whereas common species were modestly affected. Corticoid fungi were more adversely affected than polypore fungi. These results indicate that wood-decaying fungi in pine forests are more adapted to forest disturbances than spruce-associated species. Management measures securing a continuous supply of dead wood are more important in spruce forests than in pine forests.

Ecological requirements of a rare saproxylic beetle Cucujus haematodes- the beetles’ stronghold on the edge of its distribution area

Abstract. 1. Cucujus haematodes is a rare obligate saproxylic beetle with Eurasian distribution range. 2. The species has suffered a sharp decline in the European part of its distribution range, which can be attributed to the loss of forest habitats with a continuous supply of dead wood. 3. We found that this species is largely distributed in the Primorskiy Region (far eastern Russia), where it can reach strong populations in late stages of pioneer forest succession. 4. Contrary to the observations in Europe, C. haematodes occurred predominantly in lower altitudes and it preferred broadleaved trees. 5. Our guild analysis showed springtails (Collembola), mites (Acarina), ants (Formicidae) and subcortical histerids (Histeridae) and carabids (Carabidae) to be the most associated species at the microhabitat level. 6. Cucujus haematodes can be considered as a species of high conservation value because it shares the habitat with some other threatened saproxylic beetles, such as Boros schneideri (Boridae), Pytho kolwensis (Pythidae), Cardiophorus nigerrimus (Elateridae) and Dendrophagus crenatus (Silvanidae).