Stages Of Decay Research Articles

Mechanical, physical and compositional effects of Meruliporia incrassata on Southern Yellow Pine

Abstract With the growing risk of fungal degradation in timber-framed structures from significant moisture intrusion events due to climate change, it is increasingly critical to develop mechanistic relationships between fungal degradation mechanisms and the strength of untreated wood components. While extensive work has been performed characterizing wood decay, no study has yet addressed the effects of Meruliporia incrassata on untreated Southern Yellow Pine. This seeks to address this knowledge gap by evaluating the effects of the common brown rot fungus on an ubiquitous building material in the southeast United States – Southern Yellow Pine. Properties of Southern Yellow Pine were evaluated at seven decay stages over the course of 12 weeks of exposure to M. incrassata. Changes in physical properties – mass, density, and moisture content – were measured at each stage. Changes in stiffness were characterized via ultrasonic pulse velocity testing, and thermogravimetric analysis was utilized to assess compositional changes. The study found rapid and significant losses in stiffness at decay stages as early as four-weeks. Hemicellulose and cellulose degradation occurred steadily throughout the decay period. These results can be utilized to develop a stronger understanding of the mechanical behavior of timber-framed structures in the United States degraded by brown rot.

Fungal Community Succession of Populus grandidentata (Bigtooth Aspen) during Wood Decomposition

Fungal communities are primary decomposers of detritus, including coarse woody debris (CWD). We investigated the succession of fungal decomposer communities in CWD through different stages of decay in the wide-ranging and early successional tree species Populus grandidentata (bigtooth aspen). We compared shifts in fungal communities over time with concurrent changes in substrate chemistry and in bacterial community composition, the latter deriving from an earlier study of the same system. We found that fungal communities were highly dynamic during the stages of CWD decay, rapidly colonizing standing dead trees and gradually changing in composition until the late stages of decomposed wood were integrated into soil organic matter. Fungal communities were most similar to neighboring stages of decay, with fungal diversity, abundance, and enzyme activity positively related to percent nitrogen, irrespective of decay class. In contrast to other studies, we found that species diversity remained unchanged across decay classes. Differences in enzyme profiles across CWD decay stages mirrored changes in carbon recalcitrance, as B-D-xylosidase, peroxidase, and Leucyl aminopeptidase activity increased as decomposition progressed. Finally, fungal and bacterial gene abundances were stable and increased, respectively, with the extent of CWD decay, suggesting that fungal-driven decomposition was associated with shifting community composition and associated enzyme functions rather than fungal quantities.

Mechanical characteristics and microstructure of saturated sand under monotonic and cyclic loading conditions

To gain a deeper understanding regarding the intrinsic properties and correlations of macro mechanical responses, including critical states and large flow deformations under monotonic and cyclic loading conditions, with a view to revealing the fundamental characteristics of internal forces and deformations in granular materials. A series of undrained triaxial compression, triaxial extension and cyclic triaxial numerical tests are performed using discrete element method (DEM) software PFC3D. Under both monotonic and cyclic loading conditions, a comparable deformation mechanism of strain softening and strain hardening is observed, and the effective stress skeleton curves are in good agreement. As the progression from high stress ratio to the critical stress ratio, flow deformation and strain hardening are observed in saturated sand, where the mechanical coordination number gradually increases and the sliding ratio, suspended particle ratio decrease. The fabric anisotropy tends to increase in the flow deformation stage, decreases slightly in the strain hardening stage but remains highly anisotropic, and decreases rapidly in the stress decay (unloading) stage. As the cycle number increases after liquefaction of the sample, the percentage of deviatoric strain in the flow deformation stage to the total unidirectional shear strain increases, while the percentage in stress decay (unloading)/hardening stages decreases, which means that the strain development of samples is more fully developed in the flow deformation stage. The results serve as a reference for studying soil dilatancy and modifying constitutive models.

Evaluation of dowel bearing strength of fungal-decayed cross-laminated timber

ABSTRACT Dowel bearing strength of three cross-laminated timber (CLT) species (Douglas-fir, Norway spruce, spruce pine fir) were periodically assessed through 40 weeks of exposure to two brown rot fungi species (Gloeophyllum trabeum and Rhodonia placenta). Time-dependent regression models were developed to describe the relationship between level of fungal exposure and dowel bearing strength of CLT. Obtained dowel bearing strength values were used to predict the capacity of floor-to-wall CLT connection systems. Predicted strength values were compared with capacity of actual connection systems which were subjected to similar biodeterioration treatments. Significant reductions in the dowel bearing strength of CLT were observed 30 weeks after fungal inoculation. Similar patterns of degradation were observed for both fungi in all three CLT species, but R. placenta was slightly more aggressive than G. trabeum, causing a 16.2 MPa reduction in dowel bearing strength of Douglas-fir after 40 weeks of exposure. Connection capacities estimated using National Design Specification yield models for dowel type fasteners and the dowel bearing strength of fungal-damaged CLT were consistent with observed properties and were within 85% of actual capacity of connections tested, especially in early stages of decay.

Decomposition and dipteran succession on buried rabbits carcasses

The rabbit carcasses used in this study were buried at depths of 20 and 40 cm, were examined to construct a fly succession database on buried carrion in Riyadh, Saudi Arabia. Twenty-four rabbits were buried, 12 at 20 cm and 12 at 40 cm. One carcass at each depth was exhumed at 10-day intervals up to 120 days. The degradation rate varied among the carcasses. Differences in species and their colonization were also found in the superficial and exhumed carcasses. Eleven species of flies were recorded on carcasses interred at a depth of 20 cm and seven species at 40 cm, while 13 species were recorded on the carcasses over the top of the soil. Species Rhyncomya sp (Diptera: Calliphoridae), Sarcophaga dux Thomson, and Dolichotachina marginella (Wiedemann) (Diptera: Sarcophagidae) were dominant at both depths, while Chrysomya albiceps (Wiedeman), Chrysomya rufifaces (Macquart) (Diptera: Calliphoridae), Musca domestica Linnaeus, and Musca sorbens Wiedemann (Diptera: Muscidae) were dominant in surface carcasses. Megaselia scalaris (Loew) ((Diptera: Phoridae) is a common and typical forensic indicator that was found in the decay/advanced decay and dry stages at a depth of 20 cm. These findings are possibly useful in forensic investigations involving buried bodies in Riyadh, Saudi Arabia.

A cryptically diverse microbial community drives organic matter decomposition in forests

Despite the critical role of microorganisms in plant and fungal residue decomposition, our understanding of their full diversity remains limited. This is due largely to the rapid microbial succession during decomposition, a scarcity of studies including multiple sampling times, and the omission of a species richness index encompassing all decay stages. To address these gaps, we conducted a meta-analysis of 12 studies, each examining bacterial and fungal communities at multiple time points during decomposition. We aimed to determine the overall microbial diversity involved in decomposition processes by aggregating microbial richness at different time points. By comparing cumulative microbial OTU (operational taxonomic unit) richness with single time point microbial richness, we show that the cumulative richness was 2–5 times greater, indicating that a high yet frequently overlooked diversity of microorganisms is involved in the decomposition process. This pattern was consistent across different organic matter types (plant and fungal residues) for both major microbial domains (bacteria and fungi). Moreover, the appearance rate of novel OTUs generally decreased over time for most organic matter types, except for dead wood, which accumulated new fungal OTUs at a notable pace. Our results collectively emphasize the importance of considering various microbial domains, organic matter types, and time points to successfully characterize the diversity of microorganisms involved in decomposition. Further, given the hidden cumulative number of bacterial and fungal species held within plant and fungal residues across decay stages, we propose that these substrates are crucial microbial reservoirs to include to accurately assess global terrestrial microbial diversity.

Degradation by brown rot fungi increases the hygroscopicity of heat-treated wood

Heat treatment increases the decay resistance of wood by decreasing its hygroscopicity, but the wood material remains degradable by fungi. This study investigated the degradation of heat-treated wood by brown rot fungi, with the aim of identifying fungal-induced hygroscopicity changes that facilitate degradation. Scots pine sapwood samples were modified under superheated steam at 200 and 230 °C and then exposed to Coniophora puteana and Rhodonia placenta in a stacked-sample decay test to produce samples in different stages of decay. Sorption isotherms were measured starting in desorption from the undried, decaying state to investigate their hygroscopic properties. Although there were substantial differences in degradative ability between the two fungi, the results revealed that decay by both species increased the hygroscopicity of wood in the decaying state, particularly at high relative humidity. The effect was stronger in the heat-treated samples, which showed a steep increase in moisture content at low decay mass losses. The reference samples showed decreased hygroscopicity in absorption from the dry state, while the heat-treated samples still showed an increase at low mass losses. Near infrared spectroscopy showed that the early stages of decay were characterised by the degradation of hemicellulose and chemical changes to cellulose and lignin, which may explain the increase in hygroscopicity. The results provide a new perspective on brown rot decay and offer insight into the degradation of heat-treated wood.

Accelerating Quantum Decay by Multiple Tunneling Barriers.

A quantum particle constrained between two high potential barriers provides a paradigmatic example of a system sustaining quasi-bound (or resonance) states. When the system is prepared in one of such quasi-bound states, the wave function approximately maintains its shape but decays in time in a nearly exponential manner radiating into the surrounding space, the lifetime being of the order of the reciprocal of the width of the resonance peak in the transmission spectrum. Naively, one could think that adding more lateral barriers would preferentially slow down or prevent the quantum decay since tunneling is expected to become less probable and due to quantum backflow induced by multiple scattering processes. However, this is not always the case and in the early stage of the dynamics quantum decay can be accelerated (rather than decelerated) by additional lateral barriers, even when the barrier heights are arbitrarily large. The decay acceleration originates from resonant tunneling effects and is associated to large deviations from an exponential decay law. We discuss such a counterintuitive phenomenon by considering the hopping dynamics of a quantum particle on a tight-binding lattice with on-site potential barriers.

Tree Species Affect Beetle Diversity on the Common Deciduous Dead Wood in Lithuanian Unmanaged Forests

Beetles living in dead wood are species-specific, suggesting that beetle diversity may vary between different deciduous tree species. However, the patterns of diversity variation among deciduous trees are still poorly understood. In this study, we investigated the diversity of beetles associated with dead wood in the second decay stage in four protected areas of Lithuania, using trunk-emergence traps on Alnus glutinosa L., Gaertn. (black alder), Betula sp. L. (birch), Fraxinus excelsior L. (European ash), Populus tremula L. (European aspen), Quercus robur L. (common oak), and Tilia cordata Mill. (small-leaved linden). The findings of our study indicated variation in beetle diversity among the six tree species examined. We identified the greatest diversity of beetles in the decaying trunks of Quercus robur, followed by T. cordata, and F. excelsior. Our cluster analysis suggested a higher similarity in beetle diversity among tree species sharing the same type of bark; however, our db-RDA analysis showed that tree species explained more variance in the data than bark type. Our results support previous research highlighting the importance of dead wood species diversity in maintaining the diversity of beetles in forests. Within the context of current biodiversity decline, understanding the similarities or differences in beetle communities between tree species is key to tackling the loss of insect species.

Successional pattern of necrophagous diptera on a dead Asiatic jackal’s (Canis aureus Linnaeus, 1758) body in Veerangana durgawati Wildlife Sanctuary, Madhya Pradesh, India

The field of forensic entomology emphasizes the close relationship between insects and cadavers, as well as the utilization of insects in medicolegal investigations, and helps understand the reasons for death. In forensic science, the presence of necrophagous dipteran flies on a dead body is particularly important as well as they play a significant role in the decomposition of the carcass. In recent times, necrophagous fly data has been used to investigate the causes of mortality. The evidence is useful in the estimation of post-mortem interval (PMI) which is important insolvingmedico-legal cases in human beings, and also helpful in wildlife forensics. The present paper reports day-wise observations of the dipteran visitors on the decaying corpse of the Asiatic Jackal in the Veerangana Durgawati Wildlife Sanctuary, Damoh district, Madhya Pradesh. Adult dipteran flies consisting of five species fewer than four families namely Calliphoridae, Sarcophagidae, Muscidae, and Sepsidae were collected from the site. Chrysomya megacephala was the first visitor of the carcass and both Chrysomya megacephala and Chrysomya rufifacies were the most common species during the various stages of decay of the cadaver. The other necrophagous flies which visited the cadaver were: Musca planiceps, Sarcophaga (Seniorwhitea) princeps, and Themira bifida. This study is the first of its kind conducted in Central India. The findings might be used to supplement the information in forensic investigations for criminal cases and wildlife hunting from India

Responses of necrophilous beetles to animal mass mortality in the Australian Alps

A diversity of insects can be found at the remains of dead animals (carrion) and they play a vital role in its decomposition and recycling. An emerging global problem with carrion is animal mass mortality events – the sudden, rapid die-off of many animals resulting in a large increase to the localised carrion resource pool. Yet, little is known about how insects respond to sudden and large inputs of carrion. We conducted an experiment in a mountainous alpine region of south-eastern Australia and compared beetle assemblages found at single carcass and mass mortality sites. We also examined the effects of vertebrate exclusion, and decomposition stage on beetles. We found 4,774 beetles representing 146 different species/morphospecies from 17 families. The most abundant species was Saprinus cyaneus cyaneus (Histeridae), and species of Staphylinidae and Silphidae also dominated the fauna, which is typical for necrophilous beetles in Australia. We also found a clear temporal change in beetle assemblages, with abundance and richness peaking during the active decay stage. We found that beetle abundance was greater at single carcasses than mass mortality sites, possibly as an artifact of sampling, and that species richness was similar among these two carcass treatment types. We found no significant effect of vertebrate exclusion on beetles, suggesting that large scavengers in the study system may not influence necrophilous insect communities around carrion.Implications for insect conservation: Our study highlights the diversity of beetles that can be found at carrion and their similar composition to the fauna found in other areas in the south-east of the Australian continent. Beetles may have reduced abundance at mass mortality sites which could affect their ability to contribute to carrion removal relative to smaller carrion quantities. Further research is required to quantify the role of other insects in carrion removal under a range of natural and mass mortality scenarios.

Assessment of Fungal Succession in Decomposing Swine Carcasses (Sus scrofa L.) Using DNA Metabarcoding.

The decomposition of animal bodies is a process defined by specific stages, described by the state of the body and participation of certain guilds of invertebrates and microorganisms. While the participation of invertebrates in decomposing is well-studied and actively used in crime scene investigations, information on bacteria and fungi from the scene is rarely collected or used in the identification of important factors such as estimated time of death. Modern molecular techniques such as DNA metabarcoding allow the identification and quantification of the composition of microbial communities. In this study, we used DNA metabarcoding to monitor fungal succession during the decomposition of juvenile pigs in grasslands of New Jersey, USA. Our findings show that decomposition stages differ in a diversity of fungal communities. In particular, we noted increased fungal species richness in the more advanced stages of decomposition (e.g., bloat and decay stages), with unique fungal taxa becoming active with the progression of decay. Overall, our findings improve knowledge of how fungi contribute to forensically relevant decomposition and could help with the assessment of crime scenes.

Time series DNA barcoding provides insight into factors influencing wood-boring and bark-feeding insect communities in Scots pine, Sitka spruce, and Noble fir stands.

Bark-feeding and wood-boring insect pests can have significant negative impacts on conifers and wood production. The damage they cause is expected to increase in the future due to climate change and the growth of international trade. This study employed DNA barcoding of beetle juveniles (Coleoptera) sampled from standing trap trees and cut log piles at regular intervals over a 2-yr period to monitor the beetle community dynamics and associated environmental factors. Tree species was found to have a major influence on beetle communities, most strikingly at the start of early decay stages. Lower species diversity was reported from standing trap tree samples compared to log pile samples, likely due to higher residual defences in dying and recently dead trees. While the species identified from standing trap trees are more likely to be a threat to the forestry sector, the species found in the log piles are more likely to be beneficial due to their high abundance and their ability to compete with pests for breeding substrate. The analysis of beetles collected inside trees revealed additional information on ontogenetic niches and host preferences beyond that acquired solely from flight interception trap data. Our results offer insights on community composition and dynamics of bark-feeding and wood-boring insect species in Welsh conifer forests and provide resources for monitoring and management of potential pest species.

Identification of characteristic aroma compounds for spicy in Iris lactea var. chinensis.

Iris lactea var. chinensis (Fisch.) Koidz has a unique floral fragrance that differs from that of other Iris spp.; however, its characteristic aroma composition remains unknown. This study aimed to identify the floral fragrance components of I. lactea var. chinensis during different flowering stages using headspace solid-phase microextraction in conjunction with gas chromatography mass spectrometry, electronic nose, and sensory evaluation. During the three flowering phases (bud stage, bloom stage, and decay stage), 70 volatile organic compounds (VOCs), including 13 aldehydes, 13 esters, 11 alcohols, 10 alkanes, 8 ketones, 7 terpenes, 7 benzenoids, and 1 nitrogenous compound, were identified. According to principal component analysis, the primary VOCs were (-)-pinene, β-irone, methyl heptenone, phenylethanol, hexanol, and 2-pinene. A comparison of the differential VOCs across the different flowering stages using orthogonal partial least squares discriminant analysis and hierarchical clustering analysis revealed that 3-carene appeared only in the bud stage, whereas hexanol, ethyl caprate, ethyl caproate, linalool, (-)-pinene, and 2-pinene appeared or were present at significantly increased levels during the bloom stage. The phenylethanol, methyl heptenone, 3-methylheptane, and β-irone reached a peak in the decay stage. The odor activity value and sensory evaluation suggested that "spicy" is the most typical odor of I. lactea var. chinensis, mainly due to 2-methoxy-3-sec-butylpyrazine, which is rare in floral fragrances.

Running and Reading Remnant Danwei Walls in China's Postsocialist City

Built on visual and running/walking ethnography, this article analyzes visual traces left on remnant danwei walls in postsocialist China. The article considers danwei walls as yiji (remnant traces) that serve as loci of political memory and as a medium to host other visual traces by a variety of different actors. Drawing on a range of concepts from cultural studies and visual ethnography, the article provides a close reading of these traces, treating them as important historical documents and examples of how human actors interact with the built environment during China's postsocialist transformation. The article is built around three case studies, each of which captures different stages of the physical decay of the danwei as represented in the materiality of the walls in varying states of (dis)repair and the different nature of the visual traces local actors have left on them. The analysis of traces—understood as signs on the walls as well as the walls themselves—reveals a story of the ways in which humans interact with a very specific part of China's built environment at a moment of transition and of how relationships between these human actors change in the process. The article provides a reading of visual social phenomena, contributing to the understanding of signifying practices in postsocialist urban China.

SENPR disinformation spreading model to discuss the control of the spread of disinformation in emergencies

The spread of disinformation in online social networks (OSNs) poses a significant threat to maintaining normal social order. It is important to understand when and how intervention measures can control the spread of disinformation. We propose a novel information spreading model called susceptible, exposed, negative-infected, positive-infected, recovered population (SENPR) to describe the disinformation dynamics in OSNs under the intervention strategy. The model in this study considers that the susceptible population in the network is transformed into an exposed population through the influence of two information-dissemination methods that affect other susceptible people in the network. Subsequently, the stability of the model was analyzed to verify the validity of the obtained theoretical results. Finally, the influence of different parameters on the spread of disinformation is described, and corresponding management strategies to suppress the spread of false information in emergency situations are discussed. The results show that word-of-mouth is the main mode of communication in the “development” and “burst” stages of information spreading. The earlier the intervention is implemented, the sooner the number of people affected by word-of-mouth begins to decline and the sooner the spreading of disinformation reaches the saturation and decay stages.

Intraguild scavenging on carnivore carcasses is delayed enough to allow successful dispersal of maggots for pupation

AbstractVertebrate carcasses are a valuable resource for a wide range of organisms, although their consumption rates can vary greatly by the type of carcasses. Studies have indicated that mammalian carnivores rarely consume carnivore carcasses, particularly in the early stages of decay, and thus these carcasses may potentially serve as a reproductive resource for necrophagous arthropods such as blowflies. However, it is unknown whether delays in consumption by carnivores are sufficient for necrophagous arthropods to complete their life cycle in the carcasses. This study addressed this question by monitoring 69 raccoon carcasses using camera traps in Yakumo, southern Hokkaido, Japan, during the summer seasons of 2016–2019. The decay stages of the carcasses were categorized by carefully observing the videos captured by the camera traps, and the timing of maggot dispersion was estimated. The first visitation and first consumption of vertebrate scavengers were also modelled, and the proportion of carcasses visited or consumed by vertebrate scavengers prior to maggot dispersion was determined each year. The proportion of carcasses visited by vertebrate scavengers before maggot dispersal ranged between c. 50% in 2017 and c. 30% in other years. However, only c. 20% of carcasses in each year were consumed before maggot dispersal, and consumption was only partial. The first species to scavenge at carcasses were red foxes and raccoon dogs, with the exception of two carcasses that were first scavenged by large‐billed crows. These results suggest that while delayed visitation of carcasses may partly explain delayed consumption, active avoidance of phylogenetically related species may increase the chances of successful maggot dispersal. Our approach of using careful video observations and statistical modelling may apply to a wide range of habitats and could improve our understanding of the ecological consequences of the taboo against cannibalism.

New Finds and Ecology of the Rare Liverworts Scapania apiculata, Scapania carinthiaca, and Scapania scapanioides in Austria.

Scapania apiculata, Scapania carinthiaca, and Scapania scapanioides are rare deadwood-dwelling liverworts threatened across Europe. Scapania carinthiaca is thus listed in the Habitats Directive. However, their distribution data are scattered, and their ecologic demands are insufficiently studied. Here, we present new locations and data on the ecology of the species, which resulted from a targeted search in selected regions of Austria. We found ten new sites each for Scapania apiculata and Scapania scapanioides and twenty for Scapania carinthiaca. Reproduction was exclusively asexual. The macroclimates of all known locations in Austria did not differ significantly between the three species. It was consistently wet, with a mean annual precipitation of 1615.3 mm, a high evenness of rainfall, and a low desiccation risk. The mean temperature averaged 7.4 °C. The habitat was shaded dead wood of Picea abies, Abies alba, and Fagus sylvatica of all decay stages at a median distance of 2.5 m from streams or springy areas in semi-natural forests of montane and submontane regions. Thus, high deadwood volumes under a suitable climate are a prerequisite for the occurrences of the species. The number of locations of new finds has more than doubled in Austria and thus in Europe.

A composite approach to produce reference datasets for extratropical cyclone tracks: application to Mediterranean cyclones

Abstract. Many cyclone detection and tracking methods (CDTMs) have been developed in the past to study the climatology of extratropical cyclones. However, all CDTMs have different approaches in defining and tracking cyclone centers. This naturally leads to cyclone track climatologies with inconsistent physical characteristics. More than that, it is typical for CDTMs to produce a non-negligible number of tracks of weak atmospheric features, which do not correspond to large-scale or mesoscale vortices and can differ significantly between CDTMs. Lack of consensus in CDTM outputs and the inclusion of significant numbers of uncertain tracks therein have long prohibited the production of a commonly accepted reference dataset of extratropical cyclone tracks. Such a dataset could allow comparable results on the analysis of storm track climatologies and could also contribute to the evaluation and improvement of CDTMs. To cover this gap, we present a new methodological approach that combines overlapping tracks from different CDTMs and produces composite tracks that concentrate the agreement of more than one CDTM. In this study we apply this methodology to the outputs of 10 well-established CDTMs which were originally applied to ERA5 reanalysis in the 42-year period of 1979–2020. We tested the sensitivity of our results to the spatiotemporal criteria that identify overlapping cyclone tracks, and for benchmarking reasons, we produced five reference datasets of subjectively tracked cyclones. Results show that climatological numbers of composite tracks are substantially lower than the ones of individual CDTMs, while benchmarking scores remain high (i.e., counting the number of subjectively tracked cyclones captured by the composite tracks). Our results show that composite tracks tend to describe more intense and longer-lasting cyclones with more distinguished early, mature and decay stages than the cyclone tracks produced by individual CDTMs. Ranking the composite tracks according to their confidence level (defined by the number of contributing CDTMs), it is shown that the higher the confidence level, the more intense and long-lasting cyclones are produced. Given the advantage of our methodology in producing cyclone tracks with physically meaningful and distinctive life stages, we propose composite tracks as reference datasets for climatological research in the Mediterranean. The Supplement provides the composite Mediterranean tracks for all confidence levels, and in the conclusion we discuss their adequate use for scientific research and applications.

Wood decomposition, carbon, nitrogen, and pH values in logs of 8 tree species 14 and 15 years after a catastrophic windthrow in a mesic broad-leaved forest in the East European plain

There are limited studies of decomposition of coarse woody debris (CWD) in natural conditions of multi-species mesic broad-leaved forests. We investigated 49 lying logs of 7 angiosperm and 1 gymnosperm species 14 and 15 years after a mass windthrow in an old-growth broad-leaved forest. We observed high heterogeneity of logs in terms of decomposition stages: up to 4 stages in one transverse disk and up to 5 stages in longitudinal fragments of one log. Due to the high heterogeneity of logs, we investigated traits of wood samples rather than individual logs. Bulk density, carbon and nitrogen concentrations, and pH values were examined for 188 CWD samples of 8 species at 5 decomposition stages (from stage 1 least to stage 5 most decayed wood) and 24 control samples of live trees (3 replicates for each species; zero stage of decay). Changes of deadwood volume, carbon and nitrogen stocks over 14 and 15 years after the windthrow were estimated by re-surveying transects established in 2010. From the first to the fifth decay stage, the mean CWD density decreased for all species and averaged 54 ± 16 kg m−3 (SD) at the 5th stage of decay. Regarding decomposition rates, the tree species were arranged in descending rate from diffuse-porous (Populus tremula, Betula pendula, Tilia cordata, and Acer platanoides) to ring-porous (Ulmus glabra, Fraxinus excelsior, and Quercus robur) angiosperms and the coniferous Picea abies was after the diffuse-porous species series and before the ring-porous species. Carbon concentration ranged from 39 to 54 %, but did not change significantly during decomposition (mean value for all species in all decay stages was 45.8 ± 2.5 %). Nitrogen concentration (percentage of dry mass) increased with increasing decay stage and the mean value was 0.2 ± 0.1 % at the zero stage and 0.9 ± 0.5 % at the last decay stage. Despite the increase in N concentration, the mass N per volume decreased during decomposition for all samples considered together due to a significant decrease in wood density. The change in C/N values during deadwood decay reflected the transition of organic matter from the CWD to the SOM (soil organic matter) in forest ecosystems: the ratio C/N varied from 829 (Picea, zero stage) to 16 (Ulmus, last stage) with the mean values 286 ± 149 and 75 ± 45 at the zero and the last stages, respectively. We observed a quadratic trend in the variation of wood pH values by stages: pH mainly decreased from the initial values to the minimum in the middle stages of decay, and then increased in the advanced stages. The mean deadwood volume in the surveyed plots decreased 1.4-fold in the 14–15 years after the windthrow, but the mean stocks of carbon and nitrogen decreased 3 and 2-fold, respectively. Over time, the different decomposition rate of fallen logs leads to a decrease in the proportion of C and N stored in diffuse-porous species at the expense of an increase in this proportion in ring-porous species. This result is worth considering in a carbon management strategy: planting, maintaining stands, and retaining deadwood of ring-porous species, such as Quercus, Ulmus and Fraxinus, promote relatively long-term carbon storage.