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Methane is a powerful greenhouse gas, more potent than carbon dioxide, and emitted from a variety of natural sources including wetlands, permafrost, mammalian guts and termites. As increases in global temperatures continue to break records, quantifying the magnitudes of key methane sources has never been more pertinent. Over the last 40 years, the contribution of termites to the global methane budget has been subject to much debate. The most recent estimates of termite emissions range between 9 and 15 Tg CH4 year-1, approximately 4% of emissions from natural sources (excluding wetlands). However, we argue that the current approach for estimating termite contributions to the global methane budget is flawed. Key parameters, namely termite methane emissions from soil, deadwood, living tree stems, epigeal mounds and arboreal nests, are largely ignored in global estimates. This omission occurs because data are lacking and research objectives, crucially, neglect variation in termite ecology. Furthermore, inconsistencies in data collection methods prohibit the pooling of data required to compute global estimates. Here, we summarise the advances made over the last 40 years and illustrate how different aspects of termite ecology can influence the termite contribution to global methane emissions. Additionally, we highlight technological advances that may help researchers investigate termite methane emissions on a larger scale. Finally, we consider dynamic feedback mechanisms of climate warming and land-use change on termite methane emissions. We conclude that ultimately the global contribution of termites to atmospheric methane remains unknown and thus present an alternative framework for estimating their emissions. To significantly improve estimates, we outline outstanding questions to guide future research efforts.

Temperate forest soils are considered significant methane (CH4) sinks, but other methane sources and sinks within these forests, such as trees, litter, deadwood, and the production of volatile organic compounds are not well understood. Improved understanding of all CH4 fluxes in temperate forests could help mitigate CH4 emissions from other sources and improve the accuracy of global greenhouse gas budgets. This review highlights the characteristics of temperate forests that influence CH4 flux and assesses the current understanding of the CH4 cycle in temperate forests, with a focus on those managed for specific purposes. Methane fluxes from trees, litter, deadwood, and soil, as well as the interaction of canopy-released volatile organic compounds on atmospheric methane chemistry are quantified, the processes involved and factors (biological, climatic, management) affecting the magnitude and variance of these fluxes are discussed. Temperate forests are unique in that they are extremely variable due to strong seasonality and significant human intervention. These features control CH4 flux and need to be considered in CH4 budgets. The literature confirmed that temperate planted forest soils are a significant CH4 sink, but tree stems are a small CH4 source. CH4 fluxes from foliage and deadwood vary, and litter fluxes are negligible. The production of volatile organic compounds could increase CH4's lifetime in the atmosphere, but current in-forest measurements are insufficient to determine the magnitude of any effect. For all sources and sinks more research is required into the mechanisms and microbial community driving CH4 fluxes. The variability in CH4 fluxes within each component of the forest, is also not well understood and has led to overestimation of CH4 fluxes when scaling up measurements to a forest or global scale. A roadmap for sampling and scaling is required to ensure that all CH4 sinks and sources within temperate forests are accurately accounted for and able to be included in CH4 budgets and models to ensure accurate estimates of the contribution of temperate planted forests to the global CH4 cycle. [ABSTRACT FROM AUTHOR]

Nanopore raw read accuracy has improved to over 99%, making it a potential tool for metabarcoding. For broad adoption, guidelines on quality filtering are needed to ensure reliable taxonomic unit recovery. This study aims to provide those guidelines for a fungal metabarcoding context and to apply them to a case study of ectomycorrhizae in the decaying bark of Fagus sylvatica. We introduce the eNano pipeline to test two standard metabarcoding approaches: (1) Reference-based mapping leveraging UNITE's species hypothesis system (SH approach); (2) Constructing 98% OTUs (OTU approach). Our results demonstrate that both approaches are effective with Nanopore data. When using a reference database, we recommend strict mapping criteria rather than Phred-based filtering. Leveraging the SH-system further enhances reproducibility and facilitates cross-study communication. For the 98% OTUs, filtering reads at ≥Q25 is recommended. Our case study reveals that the decay gradient is a primary determinant of community composition and that specific mycorrhizal fungi colonize decaying bark. Complementing our metabarcoding results with root tip morphotypification, we identify Laccaria amethystina and Tomentella sublilacina as key ectomycorrhizae of saplings on decaying logs. These findings demonstrate that Nanopore sequencing can provide valuable ecological insights and support its broader use in fungal metabarcoding as read quality continues to improve. [ABSTRACT FROM AUTHOR]

We studied how management intensity and climate severity affect volume growth, timber yield, carbon stocks, and the amount of deadwood in Scots pine (Pinus sylvestris (L.)), Norway spruce (Picea abies (L.) Karst.), and silver birch (Betula pendula Roth.) dominated stands in the Republic of Karelia and Arkhangelsk region of northwest Russia. Using the forest ecosystem model (SIMA) under different climates (current and representative concentration pathway scenarios, RCP4.5 and RCP8.5), no-thinning, low, medium, and high intensity thinning rotational forestry regimes were simulated. Under RCPs, the volume growth and timber yield (5%–53%), carbon stocks (1%–22%), and deadwood amounts (11%–75%) increased for all Scots pine and silver birch stands. The use of low intensity management increased volume growth and carbon stocks (3%–16%) and deadwood amount (up to 60%) under RCPs, but not timber yield (±3%) in these stands. For Norway spruce stands, the volume growth (5%–26%), timber yield (23%–75%), and carbon stocks (5%–15%) decreased under RCP8.5, but deadwood amount increased (up to 142%). Intensive management increased volume growth (4%–19%), timber yield (4%–63%), carbon stocks (up to 14%), and deadwood amounts (up to 49%). Our results highlight that effects of climate severity and management intensity are site and species-specific for Eurasian's boreal forests. [ABSTRACT FROM AUTHOR]

Effective forest management is essential for mitigating climate change effects. This is why understanding forest growth dynamics is critical for its sustainable management. Thus, characterizing forest plot deadwood levels is vital for understanding forest dynamics, and for assessments of biomass, carbon stock, and biodiversity. For the first time, this study used the leaf area index (LAI) and L-moments to characterize and model forest plot deadwood levels in the Bavarian Forest National Park from airborne laser scanning (ALS) data. This study proposes methods that can be tested for forests, especially those in temperate climates with frequent cloud coverage and limited access. The proposed method is practically significant for effective planning and management of forest resources. First, plot decay levels were characterized based on their canopy leaf area density (LAD). Then, the deadwood levels were modeled to assess the relationships between the vegetation area index (VAI), gap fraction (GF), and the third L-moment ratio (T3). Finally, we tested the rule-based methods for classifying plot decay levels based on their biophysical structures. Our results per the LAD vertical profiles clearly showed the declining levels of decay from Level 1 to 5. Our findings from the models indicate that at a 95% confidence interval, 96% of the variation in GF was explained by the VAI with a significant negative association (VAIslope = −0.047; R2 = 0.96; (p < 0.001)), while the VAI explained 92% of the variation in T3 with a significant negative association (VAIslope = −0.50; R2 = 0.92; (p < 0.001)). Testing the rule-based methods, we found that the first rule (Lcv = 0.5) classified Levels 1 and 2 at (Lcv < 0.5) against Levels 3 to 5 at (Lcv > 0.5). However, the second rule (Lskew = 0) classified Level 1 (healthy plots) as closed canopy areas (Lskew < 0) against Levels 2 to 5 (deadwood) as open canopy areas (Lskew > 0). This approach is simple and more convenient for forest managers to exploit for mapping large forest gap areas for planning and managing forest resources for improved and effective forest management. [ABSTRACT FROM AUTHOR]

Forest deadwood is an important carbon reserve, estimated to contain 8% of the total forest carbon. This type of woody debris is recognized as a source of carbon dioxide (CO2), as the carbon is released back into the atmosphere by microbial decomposition. Production of methane (CH4) and nitrous oxide (N2O) has also been reported. In managed forests, logging residues form a major source of fine deadwood, but its role in the greenhouse gas exchange of forest ecosystems is poorly understood. We studied the greenhouse gas production of spruce and birch left-over fine woody debris and estimated the residence time of these residues at 18 spruce-dominated boreal forest sites in Central Finland. The study areas consisted of clear-cut forest stands, totally covering approximately 47 hectares, with logging residue ages varying between 0 and 10 years. The research was carried out over eight months from May to December 2019. We observed that CO2 dominated the greenhouse gas production of the logging residues, with the production being regulated by air temperature, tree species, residue age, and wood moisture. Emission of CO2 continued throughout the research period with a clear seasonal pattern. Production of CH4 and N2O was also observed, but not in climatically-relevant amounts. Deadwood half-life was estimated at 18 years for spruce and 9 years for birch. Our study demonstrates that logging residues form a mid-term carbon reserve and suggests that global warming could reduce the lifetime of the residues as a result of elevated and temperature-dependent CO2 release in the studied Myrtillus type forest stands. [ABSTRACT FROM AUTHOR]

Background and objectives: Forests are one of the most significant sources of species diversity in the biosphere, playing a crucial role in protecting endangered species. With a total of 115 indigenous plant species, Hyrcanian forests are considered one of the most valuable ecosystems in Iran and the world. Deadwood is one of the significant structural characteristics of these natural forests. Deadwood, as habitat trees, plays an essential role in maintaining biodiversity. Saproxylic species are invertebrates that depend on rotting wood, deadwood (standing or fallen), fungi, and other living organisms during part of their life cycle. Therefore, this study investigates and analyzes the need to replace the proposed word خشک دارزی instead of "saproxylic." Methodology: The method in this study involved a review of previous studies and the authors' research related to the comprehensive plan of saproxylic species diversity in northern Iran. Based on this, the study investigates and evaluates the most important reasons for using the Persian word خشک دارزی instead of "saproxylic" in seven different cases. These include a specialized review of the word "saproxylic," examining the distinction between obligatory and optional users of deadwood, estimating species related to deadwood, analyzing the variables affecting the abundance of saproxylic individuals, the relationship between the loss of biodiversity of Saproxylic species and the absence of deadwood, forest plantations and saproxylic individuals, and comparing the word "خشک دارزی with other similar words. Results: The specialized examination of the word "saproxylic" showed that this term forms the basis of biodiversity assessment in deadwood and describes insects living in decaying wood. Saproxylic organisms (hereafter: خشک دارزی ) directly and indirectly use deadwood as a source of energy or habitat. Twenty to twenty-five percent of the insects living in the forest are species related to deadwood. The results of examining the variables affecting the abundance of Saproxylic individuals showed that deadwood volume, the degree of deadwood decay, and the volume of living trees had significant effects on the frequency of Saproxylic individuals. Various studies also showed the relationship between the loss of biodiversity of Saproxylic individuals and the absence of deadwood, with traps (window and pit) always installed where deadwood is present. On the other hand, although plantations for wood production are one of the most important sources of wood on a wide scale, there is no sign of deadwood and, consequently, no presence of saproxylic individuals in these areas compared to natural forests. While the meaning of deadwood is a dried tree, in nature, deadwood is not always a completely dead tree. In many cases, only part of the trunk or crown of the tree is dead, while other parts are healthy. This term is known to all experts in forest ecology as referring to any part of a completely dead tree, aligning with the term deadwood. Conclusion: Therefore, the word "خشک دارزی instead of "Saproxylic" can effectively describe this category of species in the Persian language. Finally, the necessity of replacing non-Persian words with suitable Persian words and equating these words in scientific research writings, while preserving their expressive meaning in Persian, can be a positive step towards specialized vocabulary. [ABSTRACT FROM AUTHOR]

This study investigated the diversity and ecology of deadwood-inhabiting mushrooms in Yankari Game Reserve. Stratified random sampling was used for the data collection. A total of 23 different mushroom species belonging to 12 different families were found growing on deadwood in the study area, with Polyporaceae and Hymenochaetaceae as the most dominant mushroom families. The distribution, composition, and diversity of the different mushroom species differed according to their local habitats, growth substrate and tree species. The habitats with the highest mushroom species diversity were the Lowland Combretaceous Woodland, Pteleopsis habeensis Woodland. Their Shannon Index (H′) values were 2.31 and 1.96 respectively, and Simpson Index (D) values were 6.81 and 4.74, respectively. Their mushroom abundance was significantly (α = 0.05, p = 0.00) higher than that of Afzelia africana Woodland and Upland Combretaceous Woodland. The Main Trunk was the growth substrate with the highest H′ and D, which were 2.11 and 6.32, respectively; while the Branch had a significantly (α = 0.05, p = 0.00) higher abundance of mushrooms than the soil. Pteleopsis habeensis was the tree species that had the highest mushroom species richness and abundance with H′ (2.06) and D (5.07). The P. habeensis had significantly (α = 0.05, p = 0.00) higher mushroom abundance than all the rest of the thirteen different tree species. Trametes pubescens was the most abundant mushroom species, which was significantly (α = 0.05, p = 0.00) higher than the abundance of 10 species other mushroom species found in the study area. The result of this study can help forest managers conserve the diversity of deadwood-inhabiting mushrooms.

Abstract Background Carbon (C) sink and stock are among the most important ecosystem services provided by forests in climate change mitigation policies. In this context, old-growth forests constitute an essential reference point for the development of close-to-nature silviculture, including C management techniques. Despite their small extent in Europe, temperate old-growth forests are assumed to be among the most prominent in terms of biomass and C stored. However, monitoring and reporting of C stocks is still poorly understood. To better understand the C stock amount and distribution in temperate old-growth forests, we estimated the C stock of two old-growth stands in the Dinaric Alps applying different assessment methods, including direct and indirect approaches (e.g., field measurements and allometric equations vs. IPCC standard methods). This paper presents the quantification and the distribution of C across the five main forest C pools (i.e., aboveground, belowground, deadwood, litter and soil) in the study areas and the differences between the applied methods. Results We report a very prominent C stock in both study areas (507 Mg C ha− 1), concentrated in a few large trees (36% of C in 5% of trees). Moreover, we found significant differences in C stock estimation between direct and indirect methods. Indeed, the latter tended to underestimate or overestimate depending on the pool considered. Conclusions Comparison of our results with previous studies and data collected in European forests highlights the prominence of temperate forests, among which the Dinaric Alps old-growth forests are the largest. These findings provide an important benchmark for the development of future approaches to the management of the European temperate forests. However, further and deeper research on C stock and fluxes in old-growth stands is of prime importance to understand the potential and limits of the climate mitigation role of forests.

AbstractDeadwood, a vital component of forest ecosystems, constitutes a quintessential carbon reservoir that must be disclosed under the United Nations Framework Convention on Climate Change. This reservoir, comprising fallen logs, snags, and stumps, markedly affects carbon dynamics over decades. In this study, deadwood carbon stocks were quantified using data from 2674 sites in Japan surveyed between 2011 and 2015 via the National Forest Soil Carbon Inventory, and the deadwood carbon attributes in the country were explored. Deadwood were surveyed using the line intersect method for fallen logs and the belt transect method for stumps and snags. In Japan, the deadwood carbon stock (measured in t-C/ha) was quantified at 7.5 ± 9.74 (mean ± SD), with fallen logs at 3.26 ± 4.43, stumps at 2.45 ± 5.69, and snags at 1.80 ± 5.27, with significant differences detected among these stocks (p

Data acquisition for sustainable forest management has focused on obtaining high quality information to estimate biomass. Improving the quality of non-timber sustainability indicators, like deadwood volume, has been a minor interest. To explore how inventory approaches could be improved, we applied a Global Uncertainty and Sensitivity Analysis (GUSA) to evaluate which factors propagate more errors in deadwood modelling and how better data collection can minimize them. The impact of uncertainty on deadwood characteristics (diameter, collapse ratio, decay class, tree species, and position) was explored under stakeholders´ preferences, management actions, and climate change scenarios. GUSA showed that removing the prediction error in deadwood tree species and diameter would alter the most the total uncertainty in deadwood volume. We found that assessment of high deadwood volume was less uncertain for the scenarios where small deadwood items were left decaying on the forest floor (BAU) and for high-end climate change scenario (RCP8.5) which resulted in lower deadwood accumulation in forest stands and therefore also in lower likelihood of erroneous estimates. Reduced uncertainty in tree species and diameter class will elevate the certainty of deadwood volume to a similar level achieved in living biomass estimation. Our uncertainty and sensitivity analysis was successful in ranking factors propagating errors in estimate of deadwood and identified a strategy to minimize uncertainty in predicting deadwood characteristics. The estimation of uncertainty in deadwood levels under the scenarios developed in our study can help decision makers to evaluate risk of decreasing deadwood value for biodiversity conservation and climate change mitigation. [ABSTRACT FROM AUTHOR]

There is increasing concern into the decline of insect populations, with corresponding calls for conservation action aimed towards threatened species in particular. However, there is a distinct paucity of knowledge surrounding habitat requirements, microhabitat selection and conservation actions that may be undertaken for the vast majority of invertebrate species.Carabus intricatus (Coleoptera: Carabidae) Linnaeus, 1761 is a threatened ancient woodland specialist in the United Kingdom with a highly restricted distribution and is listed as a section 41 species of principal importance in England. Despite this, no empirical systematic evidence exists for even basic habitat requirements.Here, we used a patch‐occupancy modelling framework to determine occupancy and detection parameters for C. intricatus and a sympatric generalist species, C. problematicus, which is a potential competitor.Our models showed that decayed deadwood availability and leaf litter covering (an indicator of the availability of mature broadleaved trees) leads to higher occupancy of C. intricatus, whereas decayed dead wood availability and slug abundance are primary determinants of overall abundance. Additionally, detection models showed that higher humidity substantially increased activity of C. intricatus.For C. problematicus, ground moss coverage and overall deadwood volume most strongly influenced occupancy and abundance, whereas there were no humidity related influences on activity.The results support our general predictions about the specialist–generalist nature of the two species in the United Kingdom and indicate that key characteristics of old‐growth temperate rain forests, particularly the availability of deadwood and high humidity, are central to the conservation of these charismatic carabids. [ABSTRACT FROM AUTHOR]

Forest decline and dieback are growing phenomena worldwide, resulting in severe, large‐scale degradation of the canopy. This can profoundly alter the provision of trophic resources and microhabitats for canopy‐dwelling arthropods.In 2019, we assessed the effect of oak decline on the community of canopy‐dwelling Hymenoptera. We selected 21 oak stands and 42 plots, located in three forests in France, presenting contrasting levels of decline. Insects were sampled at the canopy level with green multi‐funnel and flight‐interception traps.We collected a particularly diverse community of 19,289 insect individuals belonging to 918 taxa, 10 larval trophic guilds and 7 nesting guilds.Oak decline had no effect on the abundance or richness of the overall community but significantly reshaped the community assemblages. Decline had contrasting effects depending on the taxa and guilds considered. Specialist parasitoids were more abundant at intermediate levels of decline severity while generalists were negatively affected. Taxa depending on ground‐related resources and microhabitats were promoted. Saproxylic taxa were more abundant while xylophagous insects were negatively impacted.Reduced leaf area index promoted several guilds and the diversity of the overall community. While an increasing tree mortality rate enhanced the abundance and diversity of deadwood resources, it had negative impacts on several Hymenoptera guilds. Our results suggest that micro‐environmental changes at the ground level due to canopy decline have major cascading effects on the communities of canopy‐dwelling Hymenoptera.Our study highlights the relevance of studying Hymenoptera communities to investigate the outcomes of disturbances on forest biodiversity. [ABSTRACT FROM AUTHOR]

The creation of artificial snags, so-called high stumps, within forest management operations is a recently established tool to enrich standing deadwood as a habitat for saproxylic species. In this study, we analysed the impact of active high stump management on saproxylic beetle species. We selected 63 high stumps in six Bavarian forest districts (Germany), which were felled and subjected to close examination, focusing on beetle (Coleoptera) colonization. We identified 63 emerged coleopteran species belonging to 29 families; a further 10 taxa were identified only at the genus or family level, respectively. Moreover, 17% of the obtained taxa are listed in the German Red List of Coleoptera. Furthermore, 32% of the examined high stump trunks, predominantly broad-leaved tree species, harboured Red List beetle taxa. In particular, trembling aspen (Populus tremula) showed a disproportionately high number of Red List beetle species. The total species richness of beetles was independent of the height, diameter and decay stage of the snags. High stumps (snags) containing Red List beetle species tended to have higher amounts of deadwood in their surroundings, but the difference was not significant. According to the results of our study, actively creating high stumps proved to be a suitable method for creating habitats and serve as stepping-stones for endangered saproxylic species. Proactive high stump management during harvest can be a valuable component of deadwood management and biodiversity protection in forests. [ABSTRACT FROM AUTHOR]

The deadwood contributes to an increase in soil heterogeneity due to the changing the microrelief (by the formation of windthrow-soil complexes), as well as changes in physical and chemical characteristics of decaying wood directly during xylolysis. We hypothesized that fallen logs as an element of microrelief influence the species composition and cover structure of vascular plants. We studied the influence of Picea abies (L.) Karst fallen logs of moderate and advanced decay stages on the horizontal distribution and heterogeneity of vascular plant cover in different microsite types (small boreal grass type, blueberry type, small boreal grass-blueberry type, herbs, and blueberry type) in old-growth middle taiga spruce forest in the Kivach State Nature Reserve (Republic of Karelia, Russia). The fallen deadwood acts as a factor of heterogeneity, causing reversible changes in the homogeneity of the original plant cover. The decaying logs influence the horizontal distribution of small herbs by changing the occurrence and density of shoots of Oxalis acetosella L., Maianthemum bifolium (L.) F.W. Schmidt, Vaccinium myrtillus L., and Vaccinium vitis-idaea L., as well as the occurrence of Luzula pilosa (L.) Willd. and Calamagrostis arundinacea (L.) Roth. Its impact on the heterogeneity parameters can be traced up to 20 cm from the log. The differences in vascular plant cover between fallen logs and the surrounding forest floor depend on the soil conditions of the microsite. The heterogeneity of conditions created by the logs smoothed out with increasing decay class, resulting in decreasing differences in the heterogeneity parameters of vascular plant cover between deadwood and forest floor. The changes in the homogeneity of the initial vascular plant cover by deadwood and the gradual smoothing of heterogeneity between the logs and the forest floor in rich and poor conditions have different, mainly opposite, trends. Finally, the structure of the vegetation cover reaches a state that is typical of particular growth conditions beyond deadwood. [ABSTRACT FROM AUTHOR]

The preservation of national parks has emerged as a significant component of Indonesia's climate mitigation efforts, primarily due to its substantial carbon stocks. However, little is known about the potential carbon stored in deadwoods within these areas. This study aims to estimate fallen deadwood carbon stocks in four national parks in Indonesia. The results show that the density of deadwood in study areas ranges from 0.26 - 0.79 g cm-3. Deadwood volume varies between 247.37 - 388.50 cm³. Bukit Tigapuluh National Park has the highest fallen deadwood biomass and carbon stock, accounting for 261.35 and 122.83 tons ha-1, respectively, followed by Sebangau National Park (187.41 and 88.08 tons ha-1), Kutai National Park (139.91 and 65.76 tons ha-1) and Lore Lindu National Park (87.90 and 41.32 tons ha-1). This study also found that large deadwood with diameters of >7.5 cm contributes to more than 80% of the total deadwood carbon stock. Understanding the carbon stock stored in deadwood within national park areas is crucial for refining estimates of potential avoided greenhouse gas emissions resulting from the conservation of national park forests. [ABSTRACT FROM AUTHOR]

Hazardous weather events, which are increasing in frequency with global climate change, pose a threat to forest ecosystems over large areas. Heavy and destructive ice rain occurred in the south of Primorye on November 19, 2020. As a result of the breaking of branches and trunks on the territory of Russky Island, which is part of the Vladivostok urban district, 9.4 ± 1.7 m3/ha of dead fallen wood, which amounted to 4.8% of the total stock of stem wood, was produced. More than a third of all trees lost 50% of their crown. Specific losses of crown phytomass, calculated using regional allometric equations, were estimated at 12.2 ± 2.1 t/ha. The species that were most vulnerable to ice rain (Tilia amurensis and Betula dahurica) were represented by the largest trees, with a wide crown and a large proportion of branches in the total biomass. Lower canopy species (Carpinus cordata and Acer mono) were less affected. The share of the fallen stock of the forest stand (in relation to the total stock) was positively related to the height above sea level (R2 = 0.54, p = 0.039), and the average diameter of the stand significantly correlated with the phytomass of the fallen part of the crowns (R2 = 0.51, p = 0.047). NDVI vegetation index values obtained from MODIS images for the 2020 and 2021 seasons (before and after the disturbance, respectively) differed significantly. [ABSTRACT FROM AUTHOR]

In recent years, the social acceptance of biodiversity conservation in forests is taking on increasing importance at an international level, both in the scientific community and among policy makers. In literature, many studies have investigated people’s preferences for biodiversity conservation in protected areas, while there is a knowledge gap on the social acceptance of biodiversity conservation in production forests. The aim of this study is to investigate visitors’ attitudes and perception towards biodiversity conservation through the creation of a Saproxylic Habitat Sites (SHSs) network in a case study in Germany (University Forest Sailershausen). To this end, a questionnaire survey was administered to a sample of 119 visitors from June to September 2023. The results show that the target of visitors is mainly composed by young people (under 30 years old) characterized by no or low income (66.1% of total respondents), mainly coming from Würzburg or other cities in Bavaria (86.4%). These visitors consider fauna and flora conservation and climate change mitigation as the most important ecosystem services provided by the University Forest Sailershausen. They perceive deadwood in the forest positively and assign higher aesthetic values to images of the University Forest Sailershausen with a high amount of deadwood (as within the SHSs) compared to images without deadwood. The preliminary results provided by this study can be considered a starting point for future research focused on the social acceptance of biodiversity conservation in production forests. [ABSTRACT FROM AUTHOR]

Restoration of degraded habitat is frequently used in ecological compensation. However, ecological restoration suffers from innate problems of long delivery times of features shown to be good proxies for biodiversity, e.g., large dead trees. We tested a possible way to circumvent this problem; the translocation of hard-to-come deadwood substrates from an impact area to a compensation area. Following translocation, deadwood density in the compensation area was locally equivalent to the impact area, around 20 m3 ha−1, a threshold for supporting high biodiversity of rare and red-listed species. However, deadwood composition differed between the impact and compensation area, showing a need to include more deadwood types, e.g., late decomposition deadwood, in the translocation scheme. To guide future compensation efforts, the cost for translocation at different spatial scales was calculated. We conclude that translocation of deadwood could provide a cost-efficient new tool for ecological compensation/restoration but that the method needs refinement. [ABSTRACT FROM AUTHOR]

Maintaining structural and functional elements of ecosystems are essential in order to preserve biodiversity and ecosystem function. As a means of guiding conservation work, the umbrella species concept was developed. In Sweden, one putative umbrella species, the white‐backed woodpecker, has guided conservation and restoration of deciduous forests for two decades.Here, we evaluate the decadal effects of restoration aimed at the white‐backed woodpecker on biodiversity of saproxylic beetles. We compare stands that were restored 12 to 21 years ago to non‐restored stands and historical white‐backed woodpecker habitats acting as restoration target stands.Restored stands contained higher deciduous deadwood volumes than non‐restored stands but lower volumes than restoration target stands. The deadwood in restored stands was concentrated in later decay stages, whereas target stand deadwood was more evenly distributed across decay stages.Restored stands had similar species richness and abundance of most groups of saproxylic beetles compared with non‐restored stands while not reaching the levels of restoration target stands. Species assemblages differed among all stand types with restored stands supporting late decay stage and generalist species while target stands supported more deciduous associated and threatened species.Synthesis and applications: We conclude that after one to two decades, restoration improve stand structure and benefit beetle diversity but that target levels are not yet reached. Thus, only partial restoration is achieved. Our results stress that for restoration to be successful both continuous and repeated restoration efforts are needed and that it is important to identify target levels of important habitat characteristics when assessing restoration outcome. We conclude that after one to two decades, restoration improve stand structure and benefit beetle diversity but that target levels are not yet reached. Thus, only partial restoration is achieved. Our results stress that for restoration to be successful both continuous and repeated restoration efforts are needed and that it is important to identify target levels of important habitat characteristics when assessing restoration outcome. [ABSTRACT FROM AUTHOR]

Biodiversity loss due to intensive timber production is a ubiquitous conservation issue across temperate and boreal forest ecosystems. Retention forestry, the retention of deadwood and old-growth features within production forest, is one management strategy that has been implemented in various countries around the world to conserve a wide range of taxa within managed forests. The success and ecological implications of retention forestry are currently subject to intensive investigation and while some taxa like birds and insects have already been studied frequently, larger mammals have received less attention. Pine martens are one of the few larger mammals in central Europe preferring older forest and potentially profiting directly from deadwood retention as a consequence of implemented retention forestry. The goal of our study was to assess the response of European marten species to deadwood retention in montane mixed forests. Using marten detection rates from camera traps on 135 research plots we assessed the response of martens to deadwood at three different spatial scales using generalized linear mixed models. We found no effect of lying deadwood on marten detections at the plot scale (1 ha) or in a 10 m radius around the camera traps. However, we found a significant increase of marten detections if logs (> 10 cm in diameter) were directly in front and in view of the camera trap. Our results show that deadwood retention as a measure of retention forestry does affect microhabitat use of martens, but not stand selection during the growing season. Logs directly in view of the camera trap increase marten detection rates as martens choose to move and forage along fallen trees when they are available. When using camera trapping to collect data on martens, trap positioning in front of logs can heavily bias trapping results when unaccounted for. [ABSTRACT FROM AUTHOR]

Nanopore raw read accuracy has improved to over 99%, making it a potential tool for metabarcoding. For broad adoption, guidelines on quality filtering are needed to ensure reliable taxonomic unit recovery. This study aims to provide those guidelines for a fungal metabarcoding context and to apply them to a case study of ectomycorrhizae in the decaying bark of Fagus sylvatica. We introduce the eNano pipeline to test two standard metabarcoding approaches: (1) Reference-based mapping leveraging UNITE’s species hypothesis system (SH approach); (2) Constructing 98% OTUs (OTU approach). Our results demonstrate that both approaches are effective with Nanopore data. When using a reference database, we recommend strict mapping criteria rather than Phred-based filtering. Leveraging the SH-system further enhances reproducibility and facilitates cross-study communication. For the 98% OTUs, filtering reads at ≥Q25 is recommended. Our case study reveals that the decay gradient is a primary determinant of community composition and that specific mycorrhizal fungi colonize decaying bark. Complementing our metabarcoding results with root tip morphotypification, we identify Laccaria amethystina and Tomentella sublilacina as key ectomycorrhizae of saplings on decaying logs. These findings demonstrate that Nanopore sequencing can provide valuable ecological insights and support its broader use in fungal metabarcoding as read quality continues to improve.

Assessing forest biodiversity, naturalness and old-growth status (B-N-OG) is crucial for supporting sustainable forest planning, yet comprehensive monitoring networks specifically designed for such purposes are lacking in many countries. National Forest Inventories (NFIs) are the official source of statistics on status and trends of forests. While initially designed for wood production assessment, NFI data may be pivotal for ecological forest monitoring, thanks to their robust sampling protocols—enabling statistical inference—and regular field campaigns that ensure continuous information updates. As a consequence, in this study we explore the potential of NFIs for estimating B-N-OG indexes, aiming to establish compatible, scientifically relevant, and cost-effective indicators using existing NFI data at a European level. Based on data from the 2005 Italian NFI collected from 6563 plots, 18 indicators were selected following previous experiences and then used to estimate B-N-OG aggregated indexes. Relationships between the 18 indicators and the three indexes were investigated, along with comparisons of their relationships relative to forest type categories, management types and protected versus non-protected areas. Results confirm that NFI data offer valuable insights into specific B-N-OG indexes, especially concerning forest structure and deadwood. Moreover, the indexes contribute to developing meaningful relationships across geographic regions, forest categories and types of management. However, limitations in NFI field protocols are evident, as they are not explicitly designed for certain indicators. The study suggests the potential for NFIs to evolve into accessible, harmonized European reference networks for B-N-OG assessment for better supporting sustainable forest management, planning and conservation decisions related to forest ecosystems. [ABSTRACT FROM AUTHOR]

The impact of deadwood in ecosystems is dependent on its longevity, as determined by decay rates controlled by decay agents. Despite the importance of macroclimate, significant variation of decay rates within a given macroclimatic envelope has been reported. Such variation may be driven by local‐scale microenvironmental conditions as regulated by the plant community structure as well as the presence of specific biotic and abiotic decay agents, decoupling the relation between macroclimate conditions and deadwood decay rates. In this study, we evaluated the relation between local‐scale variation in plant community structure with the decay rates of deadwood and the relative importance of biotic and abiotic decay agents in deadwood decay in Neotropical Cerrado. For this, we performed a wood mass loss experiment using Pinus taeda wood which was installed at three sites in three vegetation types differing in canopy cover—grasslands, savannas and woodlands; wood was divided into treatments according to deadwood exposure to decay agents—microorganism, termite and solar radiation. Across sites, we found termites and microbes decomposed wood twice as fast as microbes alone, while solar radiation was not a strong driver of deadwood decay in our sites. Additionally, local‐scale variation in plant community structure affected deadwood decay, as decay rates and frequency of wood blocks discovered by termites were lower in woodlands than in grasslands and savannas. Our study highlights the interactive effects of local‐scale variation in plant community structure and termites on deadwood turnover, mainly due to differences in termite foraging behaviour among vegetation types and highlights the key role of termites in deadwood decay throughout Neotropical savannas. [ABSTRACT FROM AUTHOR]

Assessments of synergies and trade-offs between climate change mitigation and forest biodiversity conservation have focused on set-aside areas. We evaluated a more comprehensive portfolio of silvicultural management adaptations to climate change and conservation measures exemplary for managed European beech forests. Based on the available literature, we assessed a range of common silvicultural management and conservation measures for their effects on carbon sequestration in forest and wood products and for substituting more carbon-intensive products. We complemented this review with carbon sequestration simulations for a typical mountainous beech forest region in Austria. We propose three priority actions to enhance the synergies between climate change mitigation and biodiversity. First, actively increase the proportion of European beech in secondary Norway spruce forests, even though beech will not be unaffected by expected water supply limitations. Secondly, optimize the benefits of shelterwood systems and promote uneven-aged forestry, and thirdly, enhance mixed tree species. Targeted conservation measures (deadwood, habitat trees, and old forest patches) increase the total C storage but decrease the annual C sequestration in forests, particularly in wood products. The establishment of a beech wood market with an extended product portfolio to reduce the use of fuelwood is essential for sustainable climate change mitigation. Since there are limitations in the production of saw timber quality beech wood on low fertility sites, C accumulation, and biodiversity can be emphasized in these areas. [ABSTRACT FROM AUTHOR]

Biodiversity loss is a significant problem at a global scale and may be amplified by climate change. In recent years, coniferous forests have had substantial dieback across Europe due to drought and subsequent bark-beetle outbreaks. As many studies on the consequences of disturbance and subsequent management have focused on natural stands, management implications for managed spruce stands are not well understood, even though such stands are widespread throughout Europe. In this study, beetle taxonomy, conservation value, and community composition are compared among spruce plantations and four post-disturbance management approaches: standing deadwood, lying deadwood, clear cuts, and long-term succession. Diversity and community composition differed significantly among management categories, while different beetle families responded similarly. Intact spruce stands harbored the lowest beetle diversity while the highest taxonomic diversity and conservation value was on clear cuts and stands with lying or standing deadwood. The proportion of forest specialists was highest in successional forests. In summary, different forest management categories harbored distinct beetle communities at the family-, species-, and ecological guild levels. Therefore, post-disturbance management should consider the landscape scale and include different management types. This enhances landscape heterogeneity and thus overall biodiversity but could also mitigate negative impacts of natural disturbances on ecosystem services. [ABSTRACT FROM AUTHOR]

Forest degradation induced by intensive forest management and temperature increase by climate change are resulting in biodiversity decline in boreal forests. Intensive forest management and high-end climate emission scenarios can further reduce the amount and diversity of deadwood, the limiting factor for habitats for saproxylic species in European boreal forests. The magnitude of their combined effects and how changes in forest management can affect deadwood diversity under a range of climate change scenarios are poorly understood. We used forest growth simulations to evaluate how forest management and climate change will individually and jointly affect habitats of red-listed saproxylic species in Finland. We simulated seven forest management regimes and three climate scenarios (reference, RCP4.5 and RCP8.5) over 100 years. Management regimes included set aside, continuous cover forestry, business-as-usual (BAU) and four modifications of BAU. Habitat suitability was assessed using a species-specific habitat suitability index, including 21 fungal and invertebrate species groups. “Winner” and “loser” species were identified based on the modelled impacts of forest management and climate change on their habitat suitability. We found that forest management had a major impact on habitat suitability of saproxylic species compared to climate change. Habitat suitability index varied by over 250% among management regimes, while overall change in habitat suitability index caused by climate change was on average only 2%. More species groups were identified as winners than losers from impacts of climate change (52%–95% were winners, depending on the climate change scenario and management regime). The largest increase in habitat suitability index was achieved under set aside (254%) and the climate scenario RCP8.5 (> 2%), while continuous cover forestry was the most suitable regime to increase habitat suitability of saproxylic species (up to + 11%) across all climate change scenarios. Our results show that close-to-nature management regimes (e.g., continuous cover forestry and set aside) can increase the habitat suitability of many saproxylic boreal species more than the basic business-as-usual regime. This suggests that biodiversity loss of many saproxylic species in boreal forests can be mitigated through improved forest management practices, even as climate change progresses. [ABSTRACT FROM AUTHOR]

Saproxylic insect species have deadwood‐specific requirements to survive, such as advanced decay stages. However, in some parts of the world, deadwood is currently considered an endangered resource. The Poqui's stag beetle Sclerostomulus nitidus (Coleoptera: Lucanidae)—a critically endangered saproxylic species—was rediscovered during the 2010s, but non‐academic collection currently threatens it with extinction in a projected 10‐year span.Our main aim was to identify key macro‐ and microhabitat tools to restore this species' population by associating the abundance of S. nitidus with deadwood micro‐ and macrohabitat variables such as vegetation type (pure Nothofagus stands vs. hygrophilous forest stands) and elevation.We measured decay stage (low, medium and high), volume and length of dead logs and the vegetation type and elevation of where they were available inside the restricted habitat of S. nitidus and assessed these variables as predictors of S. nitidus abundance using GLM analysis.We found that abundance (current and projected) is strongly associated (90%) with high stages of wood decay and lower elevations.Microhabitat restoration by (i) replacement of low‐quality highly decayed deadwood but keeping equal volumes and (ii) injection of highly suitable habitat as a novel fieldwork experiment could be the best short‐term to mid‐term alternative for saving S. nitidus. [ABSTRACT FROM AUTHOR]

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The mountain forests of the Northwestern Caucasus represent unique refugia for the native biodiversity of flora and fauna. Endemic species are also preserved among soil invertebrates, including the group of earthworms, which are important ecosystem engineers. This study assesses the spatial distribution of the endemic anecic species of earthworms Dendrobaena nassonovi nassonovi Kulagin, 1889 in deciduous, coniferous–deciduous, small-leaved, and conifer forests of the Northwestern Caucasus (a total of 1028 geographical points were surveyed, of which the species was found in 185 points) based on our own field data by modeling the current potential areas using the Maxent software. The D. n. nassonovi potential area maps show a high probability of the species inhabiting mid- and high-mountain forests of the Northwestern Caucasus and being confined to mixed coniferous–deciduous and beech forests. The optimum soil and climatic parameters, as well as a lack of large-scale business operations in the mid- and high-mountain forests, make it possible for these ecosystems to remain suitable refugia, in particular for the endemic anecic species of Caucasus earthworms D. n. nassonovi. [ABSTRACT FROM AUTHOR]

Deadwood in forests plays a critical role in maintaining the ecological functions. Small mammals use deadwood, and thus deadwood can mitigate the negative impacts of plantation on small mammals. This study focused on fallen dead trees in planted forests, and aimed to verify whether fallen dead trees affect behavioral patterns of Japanese squirrels. To clarify the use of fallen dead trees by Japanese squirrels in a Japanese cedar plantation, we observed squirrel behavior by camera trap surveys at 61 survey sites. Our findings showed that fallen dead trees play a crucial role in the behavior of Japanese squirrels, serving as landmarks for movement, vigilance, resting, and hoarding sites. These functions are critical for the survival of Japanese squirrels, suggesting that fallen dead trees in planted forests have positive impacts on their microenvironment use. The increase of deadwood due to disturbances such as heavy rainfall and snowfall resulting from climate change may provide benefits to arboreal small mammals in poorly managed planted forests. Additionally, leaving some of the deadwood generated during the harvesting process in properly managed forests can improve the quality of habitat for arboreal small mammals.

In the managed beech forests of Central Italy (Molise), the diversity of saproxylic species is potentially under threat by intensive management. To evaluate the impact of forestry on the biodiversity of these ecosystems, we analyzed the relationship between abundance of saproxylic beetles and (i) forest stand exposure and elevation, (ii) deadwood availability (coarse woody debris - CWD - and stumps), (iii) abundance of microhabitats. Four sampling sectors with different altitudes and exposure were identified in a 400-ha study area in the Appenine mountains. Fifteen circular plots (13 m radius) were established in each sector where deadwood and microhabitats were surveyed and saproxylic beetles sampled. We fitted joint species distribution models to quantify the relationship between forest attributes and saproxylic species’ abundance, including the interactions with their family and trophic category. Overall, 2334 specimens belonging to 64 species of saproxylic beetles were collected. Both abundance and species richness were higher in the sectors with high elevation (respectively, 55% and 44%) and South exposure (respectively, 28% and 44%). Average deadwood volumes were low (stumps: 7.6 m3 ha-1; CWD: 0.3 m3 ha-1; snags: 0.4 m3 ha-1), and insect galleries were the most abundant microhabitat (380 records over a total of 434). The most important variables affecting abundance were stump characteristics (model deviance = 81.2), elevation (deviance = 64.7), and CWD characteristics (deviance = 58.0). Our results show that topographical variables and forest structure jointly affect the abundance patterns of saproxylic beetle communities in managed beech forests. These ecological interactions imply that management has different impacts on the saproxylic communities in different topographic conditions. To acknowledge this complexity we advocate for a landscape-level forest management supporting the local beetle diversity maintaining a mosaic of semi-natural forest characteristics in different topographic contexts. The ecological value of the forest landscape will be further enhanced by the application of closer-to-nature management interventions based on deadwood retention, microhabitat creation and tree retention, in line with the guidelines of the new EU Forest Strategy for 2030.

In the last century, eucalypt plantations are increasing all over the world. Concretely, in the Basque Country (northern Iberian Peninsula), 7% of pine plantations have been recently substituted by eucalypt plantations, where little is known about their ecological impact on soil and plant diversity. However, the most relevant impact is due to forest management, as Eucalyptus globulus Labill. plantations have a short harvesting cycle, 12–15 years rotations. In fact, the species is able to regenerate from stumps; therefore, those plantations are replanted after 3–4 rotations. This type of invasive and frequent management could lead to further adverse effects on the ecosystem. The aim of this study was to characterise and compare the eucalypt plantations newly established (New: never been harvested) with older ones (Old: several times harvested and grown from stumps), having been established for at least 35 years, and to identify the primary factors that could influence the richness and diversity of vascular plant species in those plantations. The results indicated that both plantations exhibited comparable characteristics with respect to deadwood (volume and decay stage) and tree size and density. However, the Old plantations exhibited higher forest heterogeneity, pH, and higher shrub and herb richness and diversity. Overall, generalist and invasive species were found in the New plantations, while in the Old plantations, typical species of the native forests were also observed. The factor that influenced plant diversity was the volume of deadwood. Regarding life forms, higher altitude and proximity to watercourses favoured tree diversity; and lower canopy cover, shrub diversity. In conclusion, the longer the plantation has been established, the greater the number of species that are able to survive and adapt. This is probably due to the fact that management disturbance is specific and not sufficient to remove the already established plants and the soil seed bank.

In an attempt to reconcile wood extraction and forest biodiversity in managed boreal forests, ecosystem-based forest management (EBM) has become the de facto management approach. Retention forestry represents one prominent way that EBM is implemented in many parts of the world. Retention patches commonly left after harvesting serve as analogues of fire island remnants, which are patches of unburned forests in the burned forest matrix. Although the persistence of retention patches has been questioned, few studies have attempted to quantitatively compare forest attributes in both burned and harvested forests. As part of a larger program examining multiple aspects of ecosystem function in fire and harvest island remnants, we investigated the impact of disturbance type (fire/harvest) and forest edges on C stock in snags and coarse woody debris (CWD) found in island remnants in mixedwood boreal forests of Alberta, Canada. Total C stock (in snags and CWD) was similar between the two disturbance types and edge plots had similar total deadwood C stocks to interiors. The edges of island remnants had about two-fold more snag C stock than their interiors in both disturbance types, but C stock in CWD was unaffected by edge effects and disturbance type. Our results suggest that deadwood C dynamics in island remnants in fire and harvest disturbed boreal forests were similar, thus lending support for the continued implementation of retention forestry in Alberta.

Much remains unknown regarding the linkages between forest structure and microclimate as they regulate detrital decomposition. In this study, we use a factorial field experiment that included canopy gap creation and downed woody material (DW) additions conducted in a mature northern hardwood forest. Our objectives were to (1) test the individual and combined effects of canopy gaps and DW additions on detrital mass loss; (2) determine whether the factors regulating mass loss are similar among leaf litter, experimental wood stakes, and coarse DW; and (3) assess the microclimatic variables that most strongly influence mass loss of these detrital types. After three years, leaf litter mass loss within gaps, without or with DW additions, was significantly greater than that of any non-gap treatments. Mass loss of stakes was significantly greater in gaps, intermediate in gaps with DW additions, and lowest in non-gap treatments. Mass loss of wood stakes after 8 years varied by species, with aspen (Populus tremuloides) losing up to 93% and sugar maple (Acer saccharum) up to 82% of its original mass. Fourteen years following treatment, the experimental logs lost 55–70% of their original mass, with ash (Fraxinus spp.) decaying faster than maple. Gap creation and DW additions individually, but not in combination, increased mass loss of coarse DW. For most substrates tested, gaps were consistently and positively related to mass loss, with approximately 10% greater mass loss in gaps compared to non-gaps. The presence of deadwood strongly moderated litter decomposition, had minimal effect on small woody substrates in the short-term after gap creation, but was influential on longer-term decay patterns of larger DW. Predictive models for each substrate varied, though shared some similar drivers. Litter mass loss was positively correlated to increasing gap size, canopy openness, and soil moisture. Stake mass loss was positively correlated to increasing gap size and canopy openness for maple, but soil temperature for aspen. Mass loss for logs was driven by increasing DW volume and gap size for ash, but soil temperature for maple. Smaller-sized materials may be more sensitive to environmental conditions as opposed to logs for which microclimatic influence may lag or remain a minor driver for at least the initial decade of decomposition. Regardless of substrate type, the findings of this work highlight the potential for greater rates of detrital mass loss from forest systems under predicted increases in canopy disturbance rates with climate change and invasive insects and diseases. [ABSTRACT FROM AUTHOR]

Functional trait approaches are common in ecology, but a lack of clear hypotheses on how traits relate to environmental gradients (i.e., trait–niche relationships) often makes uncovering mechanisms difficult. Furthermore, measures of community functional structure differ in their implications, yet inferences are seldom compared among metrics. Community‐weighted mean trait values (CWMs), a common measure, are largely driven by the most common species and thus do not reflect community‐wide trait–niche relationships per se. Alternatively, trait–niche relationships can be estimated across a larger group of species using hierarchical joint species distribution models (JSDMs), quantified by a parameter Γ. We investigated how inferences about trait–niche relationships are affected by the choice of metric. Using deadwood‐dependent (saproxylic) beetles in fragmented Finnish forests, we followed a protocol for investigating trait–niche relationships by (1) identifying environmental filters (climate, forest age, and deadwood volume), (2) relating these to an ecological function (dispersal ability), and (3) identifying traits related to this function (wing morphology). We tested 18 hypothesized dispersal relationships using both CWM and Γ estimates across these environmental gradients. CWMs were more likely than Γ to show support for trait–niche relationships. Up to 13% of species' realized niches were explained by dispersal traits, but the directions of effects were consistent with fewer than 11%–39% of our 18 trait–niche hypotheses (depending on the metric used). This highlights the difficulty in connecting morphological traits and ecological functions in insects, despite the clear conceptual link between landscape connectivity and flight‐related traits. Caution is thus warranted in hypothesis development, particularly where apparent trait–function links are less clear. Inferences differ when CWMs versus Γ estimates are used, necessitating the choice of a metric that reflects study questions. CWMs help explain the effects of environmental gradients on community trait composition, whereas the effects of traits on species' niches are better estimated using hierarchical JSDMs. [ABSTRACT FROM AUTHOR]

Deadwood in forests plays a critical role in maintaining the ecological functions. Small mammals use deadwood, and thus deadwood can mitigate the negative impacts of plantation on small mammals. This study focused on fallen dead trees in planted forests, and aimed to verify whether fallen dead trees affect behavioral patterns of Japanese squirrels. To clarify the use of fallen dead trees by Japanese squirrels in a Japanese cedar plantation, we observed squirrel behavior by camera trap surveys at 61 survey sites. Our findings showed that fallen dead trees play a crucial role in the behavior of Japanese squirrels, serving as landmarks for movement, vigilance, resting, and hoarding sites. These functions are critical for the survival of Japanese squirrels, suggesting that fallen dead trees in planted forests have positive impacts on their microenvironment use. The increase of deadwood due to disturbances such as heavy rainfall and snowfall resulting from climate change may provide benefits to arboreal small mammals in poorly managed planted forests. Additionally, leaving some of the deadwood generated during the harvesting process in properly managed forests can improve the quality of habitat for arboreal small mammals. [ABSTRACT FROM AUTHOR]

This study examines microhabitat abundance and composition on retention trees in 20 young stands in Latvia that were clear-cut between 2002 and 2004. Retention trees play a vital role in sustaining biological diversity after clear-cutting, but their mortality rate is often high due to post-harvest environmental changes. This study compares tree-related microhabitat (TreM) abundance and composition on retention trees of different dimensions, species, and vitality. The tree height and diameter were measured, and the living status and position of each tree were determined. The research questions of the study were to assess the relationships between TreMs, tree dimensions, and species, as well as to compare the occurrence of TreMs on living and dead wood. The comprehensive analysis revealed that larger tree diameters and specific tree species (Populus tremula, Fraxinus excelsior, and Salix caprea) lead to a higher abundance of TreMs. The results also highlighted the importance of preserving deadwood within forest stands as it enhances the observed abundance of TreMs. This study provides the missing information on TreMs in Latvia, thus providing data for comparison in a wider region. [ABSTRACT FROM AUTHOR]

After large and severe wildfires, the establishment of tree regeneration, particularly for species without specific fire-adaptive traits, can be challenging. Within harsh environments, the presence of favorable microsites, as those provided by deadwood, enhancing microclimatic conditions, is crucial to the re-establishment of forest cover and thus to foster recovery dynamics. Active restoration strategies can have an impact on these dynamics, altering or hindering them. The main hypothesis of this study is that manipulating deadwood in terms of quantity and spatial arrangement can result in differences in natural regeneration density and composition. Post-disturbance regeneration dynamics and the role played by deadwood over time in the creation of safe sites for seedling establishment were investigated in an area affected by a high-severity wildfire that underwent different post-fire restoration treatments along a gradient of increasing deadwood manipulation, spanning from salvage logging to non-intervention. Two inventories were performed 5 and 11 years after the fire. Ground cover proportion was significantly different among treatments, with lower values of lying deadwood in salvaged sites. A higher probability of regeneration establishment close to deadwood was found in both surveys, confirming the facilitating role of deadwood on post-fire forest regeneration. Microsite dynamics resulting from deadwood facilitation were highlighted, with establishment probability and anisotropic relationships between deadwood elements and seedlings changing over time, as recovery processes slowly improved environmental conditions. In dry mountain areas affected by stand-replacing wildfires, by removing deadwood, salvage logging reduces the number of safe sites for regeneration, further impairing the ecosystem recovery. Passive management should be the ecologically preferred management strategy in these conditions, although intermediate interventions (e.g., felling without delimbing, leaving deadwood on the ground) could be effective alternatives, accelerating snag fall dynamics and immediately increasing favorable microsite availability. [ABSTRACT FROM AUTHOR]

The study aimed to quantify annual mortality and recruitment rates on permanent research plots in the Badínsky prales old-growth forest. The data measured in four stands originate from six censuses, which together cover a 48-year period. The mean annual mortality rate reached 4.2% (DBH > 2 cm) or 2.3% (DBH > 8 cm). The mortality peaked in the first part of the observation period, probably indicating an intermediate disturbance activity, and the subsequent declining trend led to minimum annual mortality during the last 20 years. We found substantially higher fir mortality in comparison with beech, primarily during the first decades of the measurement period. Among three size categories, the stems with DBH 2-8 cm showed the highest mortality rate. We detected the minimum fir recruitment rate throughout the observation period; on the other hand, the beech recruitment rate was relatively high responding to the open canopy. Standing and lying deadwood volumes indicated similar trends like mortality did, and high values of fir standing deadwood observed during the first decades can signify that a relatively high proportion of mortality was related to the fir decline caused by air pollution.

The deadwood contributes to an increase in soil heterogeneity due to the changing the microrelief (by the formation of windthrow-soil complexes), as well as changes in physical and chemical characteristics of decaying wood directly during xylolysis. We hypothesized that fallen logs as an element of microrelief influence the species composition and cover structure of vascular plants. We studied the influence of Picea abies (L.) Karst fallen logs of moderate and advanced decay stages on the horizontal distribution and heterogeneity of vascular plant cover in different microsite types (small boreal grass type, blueberry type, small boreal grass-blueberry type, herbs, and blueberry type) in old-growth middle taiga spruce forest in the Kivach State Nature Reserve (Republic of Karelia, Russia). The fallen deadwood acts as a factor of heterogeneity, causing reversible changes in the homogeneity of the original plant cover. The decaying logs influence the horizontal distribution of small herbs by changing the occurrence and density of shoots of Oxalis acetosella L., Maianthemum bifolium (L.) F.W. Schmidt, Vaccinium myrtillus L., and Vaccinium vitis-idaea L., as well as the occurrence of Luzula pilosa (L.) Willd. and Calamagrostis arundinacea (L.) Roth. Its impact on the heterogeneity parameters can be traced up to 20 cm from the log. The differences in vascular plant cover between fallen logs and the surrounding forest floor depend on the soil conditions of the microsite. The heterogeneity of conditions created by the logs smoothed out with increasing decay class, resulting in decreasing differences in the heterogeneity parameters of vascular plant cover between deadwood and forest floor. The changes in the homogeneity of the initial vascular plant cover by deadwood and the gradual smoothing of heterogeneity between the logs and the forest floor in rich and poor conditions have different, mainly opposite, trends. Finally, the structure of the vegetation cover reaches a state that is typical of particular growth conditions beyond deadwood.

The creation of artificial snags, so-called high stumps, within forest management operations is a recently established tool to enrich standing deadwood as a habitat for saproxylic species. In this study, we analysed the impact of active high stump management on saproxylic beetle species. We selected 63 high stumps in six Bavarian forest districts (Germany), which were felled and subjected to close examination, focusing on beetle (Coleoptera) colonization. We identified 63 emerged coleopteran species belonging to 29 families; a further 10 taxa were identified only at the genus or family level, respectively. Moreover, 17% of the obtained taxa are listed in the German Red List of Coleoptera. Furthermore, 32% of the examined high stump trunks, predominantly broad-leaved tree species, harboured Red List beetle taxa. In particular, trembling aspen (Populus tremula) showed a disproportionately high number of Red List beetle species. The total species richness of beetles was independent of the height, diameter and decay stage of the snags. High stumps (snags) containing Red List beetle species tended to have higher amounts of deadwood in their surroundings, but the difference was not significant. According to the results of our study, actively creating high stumps proved to be a suitable method for creating habitats and serve as stepping-stones for endangered saproxylic species. Proactive high stump management during harvest can be a valuable component of deadwood management and biodiversity protection in forests.

Abstract Functional trait approaches are common in ecology, but a lack of clear hypotheses on how traits relate to environmental gradients (i.e., trait–niche relationships) often makes uncovering mechanisms difficult. Furthermore, measures of community functional structure differ in their implications, yet inferences are seldom compared among metrics. Community‐weighted mean trait values (CWMs), a common measure, are largely driven by the most common species and thus do not reflect community‐wide trait–niche relationships per se. Alternatively, trait–niche relationships can be estimated across a larger group of species using hierarchical joint species distribution models (JSDMs), quantified by a parameter Γ. We investigated how inferences about trait–niche relationships are affected by the choice of metric. Using deadwood‐dependent (saproxylic) beetles in fragmented Finnish forests, we followed a protocol for investigating trait–niche relationships by (1) identifying environmental filters (climate, forest age, and deadwood volume), (2) relating these to an ecological function (dispersal ability), and (3) identifying traits related to this function (wing morphology). We tested 18 hypothesized dispersal relationships using both CWM and Γ estimates across these environmental gradients. CWMs were more likely than Γ to show support for trait–niche relationships. Up to 13% of species' realized niches were explained by dispersal traits, but the directions of effects were consistent with fewer than 11%–39% of our 18 trait–niche hypotheses (depending on the metric used). This highlights the difficulty in connecting morphological traits and ecological functions in insects, despite the clear conceptual link between landscape connectivity and flight‐related traits. Caution is thus warranted in hypothesis development, particularly where apparent trait–function links are less clear. Inferences differ when CWMs versus Γ estimates are used, necessitating the choice of a metric that reflects study questions. CWMs help explain the effects of environmental gradients on community trait composition, whereas the effects of traits on species' niches are better estimated using hierarchical JSDMs.

Most European forests are used for timber production. Given the limited extent of unmanaged (and especially primary) forests, it is essential to include commercial forests in the conservation of forest biodiversity. In order to develop ecologically sustainable forest management practices, it is important to understand the management impacts on forest-dwelling organisms. Experiments allow testing the effects of alternative management strategies, and monitoring of multiple taxa informs us on the response range across forest-dwelling organisms. To provide a representative picture of the currently available information, metadata on 28 multi-taxa forest management experiments were collected from 14 European countries. We demonstrate the potential of compiling these experiments in a single network to upscale results from the local to continental level and indicate directions for future research. Among the different forest types, temperate deciduous beech and oak-dominated forests are the best represented in the multi-taxa management experiments. Of all the experimental treatments, innovative ways of traditional management techniques (e.g., gap cutting and thinning) and conservation-oriented interventions (e.g., microhabitat enrichment) provide the best opportunity for large-scale analyses. Regarding the organism groups, woody regeneration, herbs, fungi, beetles, bryophytes, birds and lichens offer the largest potential for addressing management–biodiversity relationships at the European level. We identified knowledge gaps regarding boreal, hemiboreal and broadleaved evergreen forests, the treatments of large herbivore exclusion, prescribed burning and forest floor or water manipulations, and the monitoring of soil-dwelling organisms and some vertebrate classes, e.g., amphibians, reptiles and mammals. To improve multi-site comparisons, design of future experiments should be fitted to the set-up of the ongoing projects and standardised biodiversity sampling is suggested. However, the network described here opens the way to learn lessons on the impact on forest biodiversity of different management techniques at the continental level, and thus, supports biodiversity conservation in managed forests.

Selective browsing by deer on young trees may impede the management goal of increasing forest resilience against climate change and other disturbances. Deer population density is often considered the main driver of browsing impacts on young trees, however, a range of other variables such as food availability also affect this relationship. In this study, we use browsing survey data from 135 research plots to explore patterns of roe deer (Capreolus capreolus) browsing pressure on woody plants in mountainous forests in central Europe. We fitted species‐specific generalised linear mixed models for eight woody taxa, assessing the potential effects of understory characteristics, roe deer abundance and lying deadwood on browsing intensity. Our study reveals conspecific and associational effects for woody taxa that are intermediately browsed by roe deer. Selective browsing pressure was mediated by preferences of plants, in that, browsing of strongly preferred woody taxa as for example mountain ash (Sorbus aucuparia) and of least preferred woody taxa, for example Norway spruce (Picea abies) was not affected by the surrounding understory vegetation, while browsing pressure on intermediately browsed species like for example silver fir (Abies alba) was affected by understory characteristics. Contrary to our expectations, roe deer abundance was only positively associated with browsing pressure on silver fir and bilberry (Vaccinium myrtillus), while all other plants were unaffected by deer abundance. Finally, we did not find an influence of lying deadwood volume on the browsing pressure on any woody‐plant species. Overall, our results indicate that patterns in browsing preference and intensity are species‐specific processes and are partly affected by the surrounding understory vegetation. Current management strategies that aim to reduce browsing pressure through culling may be inefficient as they do not address other drivers of browsing pressure. However, managers also need to consider the characteristics of the local understory vegetation in addition to deer abundance and design species‐specific plans to reduce browsing on woody plant taxa. [ABSTRACT FROM AUTHOR]

Habitat loss is considered a major threat for biodiversity. However, the scales on which its effects occur are still insufficiently understood, namely, is the amount of available habitat important for species richness on both local and landscape scales? We studied the effects of local and landscape‐scale habitat amount on local‐scale species density of deadwood‐dependent lichens in Swedish boreal forests. Creation and retention of deadwood are common practices to benefit forest biodiversity, and recognizing the relevant scale is critical for them to be successful.We surveyed deadwood‐dependent lichens in 90 unmanaged forest stands that differed in the local and landscape habitat amount. The local habitat amount was measured as the amount of deadwood in the sampled stands (m2 deadwood ha−1), while six alternative proxies were used to estimate the landscape habitat amount, that is, the amount of deadwood in the surrounding landscapes. Lichen species density (number of species per standardized deadwood area of 3.7 m2) was modelled as a function of local and landscape habitat amount at multiple scales (300 m–5 km from the stands).Lichen species density increased with the landscape habitat amount. The proportion of old forests (>100 years, including newly clear‐cut stands that until recently were old forests) within 5 km from the stands explained species density better than the other proxies of landscape habitat amount. Local deadwood amount did not affect species density, and there was no interaction between the local and landscape habitat amount.Synthesis and applications: To promote the conservation of deadwood‐dependent lichens, the amount of old forests in managed forest landscapes should be maintained or increased. A certain amount of deadwood hosted more lichen species when situated in a landscape with more old forest, while there was no effect of the local deadwood amount. This suggests that management aimed at increasing the local species density of deadwood‐dwelling lichens should focus on creating and maintaining habitat in the surrounding landscape rather than only adding deadwood to that local site. In other words, effective management for deadwood‐dependent lichen diversity requires landscape‐scale habitat protection. [ABSTRACT FROM AUTHOR]

Antrodiella species (Agaricomycotina, Polyporales) are often growing on or near to the living, dead, or dying fruitbodies of pioneer wood-inhabiting fungi. Antrodiella citrinella always occurs on wood that previously has been decayed by the polypore Fomitopsis pinicola. However, the underlying mechanism remained unclear. Based on field observations, it has been assumed that the succeeding species is not only a highly competitive wood decomposer but also a mycoparasite feeding on the preceding species. To investigate the interaction between A. citrinella and the putative host F. pinicola, the species were grown in dual cultures at different temperatures (5–25 °C). The interaction tests were complemented with qualitative enzymatic tests for both species and microscopic examination of the interaction zone. In the dual cultures, A. citrinella replaced F. pinicola only at low temperature (5 °C); at higher temperatures (25 °C), it was vice versa. Light microscopy revealed preferential growth of A. citrinella toward F. pinicola, hyphal contact, and finally death of F. pinicola hyphae. Enzymatic tests showed that A. citrinella is capable to degrade extracellular proteins, chitin, cellulose, and lignin. We interpret the interaction as mycoparasitism, as we suggest that A. citrinella is capable to recognize, kill, and feed from F. pinicola, beside its ability to degrade woody substrates. The results are discussed in an ecological context. [ABSTRACT FROM AUTHOR]