Later Stages Of Decay Research Articles

Development of Piophila megastigmata (Diptera: Piophilida) at seven constant temperatures

In forensic entomology, the time-related growth and development of carrion insects allows for the estimation of the minimum postmortem interval (PMImin). Piophila megastigmata (Diptera: Piophilidae) is of great significance in estimating PMImin in the late stage of corpse decay. In this paper, the development of P. megastigmata was investigated under the seven constant temperatures of 16–34 °C. The total development time at each temperature was 970.38, 824.50, 593.13, 498.25, 392.00, 385.63 and 405.87 h, respectively. The isomorphen diagram shows the trend of development during different developmental stages at different temperatures. By using a revised linear regression model, the estimated lower lethal developmental thresholds (TL) and thermal summation constant (K) were found to be 10.57 °C and 6936.78 degree hours, respectively. According to a nonlinear model, the TL, upper lethal developmental thresholds (TH), and intrinsic optimum temperature (TΦ) were determined to be 7.53, 34.68, and20.43 °C, respectively. Also, logistic function and an isomegalen diagram were constructed according to the continuous changes in larval body length, and illustrates the time required to develop to a certain length at different temperatures. The obtained results offer crucial fundamental developmental information regarding P. megastigmata, which can be applied in PMImin estimation.

Fungal trait‐environment relationships in wood‐inhabiting communities of boreal forest patches

Abstract Fungal traits can provide a mechanistic understanding of how wood‐inhabiting fungi interact with their environment and how that influences community assembly in deadwood. However, fungal trait exploration is relatively new and almost no studies measure fungal traits in their environment. In this study we tested species‐ and trait‐environment relationships in reproducing fungal communities inhabiting 571 Norway spruce (Picea abies) logs in 55 isolated forest patches (0.1–9.9 ha) of different naturalness types, located in Northern boreal Sweden. The studied patches were (1) semi‐natural set‐aside patches within highly managed landscapes, or (2) old‐growth natural patches located in an unmanaged landscape. We tested species and trait relationships to deadwood substrate and forest patch variables. We measured mean fruit body size and density for each of the 19 species within communities. Traits assembled in relation to log decay stage and forest patch naturalness, illustrating the important role of deterministic environmental filtering in shaping reproducing wood‐inhabiting fungal communities. Early decay stage communities had larger, less dense, annual fruiting bodies of half‐resupinate type and were more often white‐rot fungi. Species rich mid‐decay stage communities had mixed trait assemblages with more long lived perennial fruit bodies of intermediate size, and both brown‐ and white‐rot fungi equally represented. Finally, late decay stage communities had smaller, denser and perennial fruit bodies, more often of the brown‐rot type. The relationships between the studied traits and decay stages were similar in both set‐aside and natural patches. However, set‐aside semi‐natural patches in highly managed landscapes more frequently supported species with smaller, perennial and resupinate fruit bodies compared to natural patches in an unmanaged landscape. Synthesis. We found that log decay stage was the primary driver of fungal community assembly of species and traits in isolated forest patches. Our results suggest that decay stage filters four reproduction traits (fruit body density, size, lifespan and type) and one resource‐use trait (white or brown rot). Our results highlights, for the first time, that communities with diverse fungal reproductive traits are maintained foremost across all deadwood decay stages under different forest naturalness conditions. Read the free Plain Language Summary for this article on the Journal blog.

Microhabitat diversity – A crucial factor shaping macrofungal communities and morphological trait expression in dead wood

The majority of studies exploring the ecology of saprotrophic fungi have worked with individual logs as homogenous sampling units, neglecting the presence of microhabitats and inner complexity. Based on close to 7000 sporocarp records of more than 450 fungal taxa from 134 decaying beech logs we investigated microhabitat preferences in macrofungi and linked these to sporocarp traits. The respective microhabitats were defined by the local wood decay stage, vertical position on the fallen log and special habitat features (hollows, fracture surfaces, woody material fallen from the log). We found microhabitat associations to be non-random in relation to fungal community composition and sporocarp morphology, indicating an evolutionary link between dead wood niche and sporocarp morphology. While log-level fungal species richness peaked at intermediate decay stages, taxa with significant indicator values were skewed towards early and late decay stages, when defined at microhabitat decay level. This suggests that the commonly found peak in fungal species richness on dead logs in intermediate decay stages expresses a peak in niche diversity rather than a peak in taxa decay stage preferences.

Elevated CO2 enhances decomposition and modifies litter‐associated fungal assemblages in a natural Eucalyptus woodland

Abstract Litter decomposition is a key process governing carbon and nutrient cycles in forest ecosystems that is expected to be impacted by increasing atmospheric carbon dioxide (CO2) concentrations. We conducted two complementary field studies to assess the effects of elevated CO2 on Eucalyptus tereticornis litter decomposition processes. First, we used bags of two different mesh sizes to assess the effect of macrofauna and elevated CO2 over 24 months on mass loss of litter grown under ambient CO2. We then assessed the effect of elevated CO2 during the decomposition of litter grown under each combination of (i) ambient CO2 or elevated CO2 and (ii) during a psyllid outbreak that triggered significant canopy loss or later in canopy developing when psyllid densities were low. Both macrofauna and elevated CO2 enhanced mass loss at late decay stages in the first study, with no interactive effect. Again, mass loss was greater at elevated CO2 at late decay stages in the second study, particularly for non‐psyllid‐impacted litter grown at elevated CO2. In both studies, CO2 concentration during decomposition influenced fungal assemblages and these effects were observed before any effects on decomposition were observed, with some fungi linked to saprotrophic guilds being found with higher frequency under elevated CO2. CO2 concentrations under which leaves developed and whether leaves were psyllid‐impacted was also important in shaping fungal assemblages. Synthesis. The positive effect on mass loss at late decay stages is contrary to previous findings where elevated CO2 generally reduced decomposition rates. Our results show that elevated CO2 effects on decay rates are context‐specific. Further research is required to establish the mechanisms through which this occurs to better model elevated CO2 effects on global carbon dynamics. Read the free Plain Language Summary for this article on the Journal blog.

A decadal study reveals that restoration guided by an umbrella species does not reach target levels

Abstract 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.

Metagenomic insights into the dynamic degradation of brown algal polysaccharides by kelp-associated microbiota.

Marine bacteria play important roles in the degradation and cycling of algal polysaccharides. However, the dynamics of epiphytic bacterial communities and their roles in algal polysaccharide degradation during kelp decay are still unclear. Here, we performed metagenomic analyses to investigate the identities and predicted metabolic abilities of epiphytic bacterial communities during the early and late decay stages of the kelp Saccharina japonica. During kelp decay, the dominant epiphytic bacterial communities shifted from Gammaproteobacteria to Verrucomicrobia and Bacteroidetes. In the early decay stage of S. japonica, epiphytic bacteria primarily targeted kelp-derived labile alginate for degradation, among which the gammaproteobacterial Vibrionaceae (particularly Vibrio) and Psychromonadaceae (particularly Psychromonas), abundant in alginate lyases belonging to the polysaccharide lyase (PL) families PL6, PL7, and PL17, were key alginate degraders. More complex fucoidan was preferred to be degraded in the late decay stage of S. japonica by epiphytic bacteria, predominantly from Verrucomicrobia (particularly Lentimonas), Pirellulaceae of Planctomycetes (particularly Rhodopirellula), Pontiellaceae of Kiritimatiellota, and Flavobacteriaceae of Bacteroidetes, which depended on using glycoside hydrolases (GHs) from the GH29, GH95, and GH141 families and sulfatases from the S1_15, S1_16, S1_17, and S1_25 families to depolymerize fucoidan. The pathways for algal polysaccharide degradation in dominant epiphytic bacterial groups were reconstructed based on analyses of metagenome-assembled genomes. This study sheds light on the roles of different epiphytic bacteria in the degradation of brown algal polysaccharides.IMPORTANCEKelps are important primary producers in coastal marine ecosystems. Polysaccharides, as major components of brown algal biomass, constitute a large fraction of organic carbon in the ocean. However, knowledge of the identities and pathways of epiphytic bacteria involved in the degradation process of brown algal polysaccharides during kelp decay is still elusive. Here, based on metagenomic analyses, the succession of epiphytic bacterial communities and their metabolic potential were investigated during the early and late decay stages of Saccharina japonica. Our study revealed a transition in algal polysaccharide-degrading bacteria during kelp decay, shifting from alginate-degrading Gammaproteobacteria to fucoidan-degrading Verrucomicrobia, Planctomycetes, Kiritimatiellota, and Bacteroidetes. A model for the dynamic degradation of algal cell wall polysaccharides, a complex organic carbon, by epiphytic microbiota during kelp decay was proposed. This study deepens our understanding of the role of epiphytic bacteria in marine algal carbon cycling as well as pathogen control in algal culture.

Seasonal roost characteristics and fall behavior of coastal populations of Northern Myotis (Myotis septentrionalis)

Abstract Temperate bats exhibit seasonal and sex differences in resource selection and activity patterns that are influenced by ambient conditions. During fall, individuals face energetic trade-offs as they make choices relating to migration, mating, and hibernation that may diverge for populations throughout their range. However, research has largely focused on the summer maternity and winter hibernation seasons, whereas the prehibernation period remains comparatively understudied. Northern Myotis (Myotis septentrionalis) have experienced precipitous population declines from white-nose syndrome (WNS), leading to their protected status in the United States and Canada. Therefore, understanding their ecology throughout the year is paramount to inform conservation. We compared seasonal roosts and documented fall behaviors between study sites and sexes on 3 islands: Long Island (New York), Martha’s Vineyard, and Nantucket Island (Massachusetts). Between 2017 and 2020, we radio-tracked 54 individuals to analyze activity patterns and characterize fall roosts to compare with previously known summer roosts. Summer tree roosts were of smaller diameter, later stages of decay, and lower canopy closure than those used in fall. Both sexes selected trees of similar diameter and decay stage during fall. Anthropogenic roost use was documented in both seasons but use of anthropogenic structures was greater during fall and increased as the season progressed. Bats made short inter-roost movements with males traveling greater distances than females on average. Activity occurred until late November, with males exhibiting a longer active period than females. We tracked 23% of tagged bats to local hibernacula in subterranean anthropogenic structures, the majority of which were crawlspaces underneath houses. Use of anthropogenic structures for roosts and hibernacula may facilitate survival of this species in coastal regions despite the presence of WNS infections. Timing of restrictions on forest management activities for bat conservation may be mismatched based on prehibernation activity observed in these coastal populations, and the conservation of habitat surrounding anthropogenic roosts or hibernacula may be warranted if the structures themselves cannot be protected.

Metabolic activities and ultrastructure imaging at late-stage of wood decomposition in interactive brown rot - white rot fungal combinations

Basidiomycota brown rot fungus ( Fomitopsis pinicola ) and two white rot fungi ( Phlebia radiata , Trichaptum abietinum ) were cultivated on thin slices of spruce wood individually and in interspecies combinations. Within 12 months, F. pinicola substantially decomposed spruce wood observed as mass loss, also in three-species combinations. However, white rot fungi through hyphal interactions negatively affected the brown-rot indicative iron reduction capacity of F. pinicola . Decay-signature gene expression in mycelial interaction zones indicated suppression of brown rot mechanism but stimulation of enzymatic white-rot lignin attack by P. radiata . Wood ultrastructure imaging showed white-rot dominance in the fungal combinations, whereas destructive brown-rot was evident with F. pinicola alone. Our results confirm the dynamic pattern of enzyme production in fungal combinations, and transition from brown to white rot decomposition metabolism during the late stage of wood decay after one year of interspecific interactions.

Successional development of wood-inhabiting fungi associated with dominant tree species in a natural temperate floodplain forest

Fungi play a crucial role in dead wood decay, being the major decomposers of wood and affecting microbiota associated with dead wood. We sampled dead wood from five deciduous tree species over more than forty years of decay in a natural European floodplain forest with high tree species diversity. While the assembly of dead wood fungal communities shows a high level of stochasticity, it also indicates clear successional patterns, with fungal taxa either specific for early or late stages of wood decay. No clear patterns of fungal biomass content over time were observed. Out of 220 major fungal operational taxonomic units, less than 8% were associated with a single tree species, most of them with Quercus robur . Tree species and wood chemistry, particularly pH, were the most important drivers of fungal community composition. This study highlights the importance of dead wood and tree species diversity for preserving the biodiversity of fungi. • Tree species-rich floodplain forest shows high diversity of wood fungi on dead wood. • Most fungi show low specificity and inhabit wood of multiple hardwood tree species. • Tree species-specific fungi are more abundant in early and late decomposition stages. • Fungal communities of deadwood are most affected by tree species and wood chemistry. • Fungal community assembly is largely stochastic but shows tractable succession.

Fertilizer Reduction Combined with Organic Liquid Fertilizer Improved Canopy Structure and Function and Increased Cotton Yield

The application of organic liquid fertilizer combined with chemical fertilizer is one of the key technologies used to simultaneously improve cotton yield and efficiently utilize resources. However, organic fertilizer is usually applied once as a base fertilizer during production, and few studies have been conducted on topdressing with water during the growth period. Therefore, in this study, Xinluzao 74 was used as the experimental material, and a single fertilizer application (CF) was used as a control in 2019–2020 under the conditions of integrated control of water and fertilizer with mulch drip irrigation. Five combinations of reduction in chemical fertilizer combined with organic fertilizer (OF1, OF2, OF3, OF4, and OF5) were used to investigate the influences of chemical fertilizer combined with organic liquid fertilizer on the leaf area index (LAI), canopy openness (DIFN), mean foliage tilt angle (MTA), photosynthetically active radiation (PAR), canopy apparent photosynthesis (CAP), and yield and quality of cotton. The results show that among the different fertilization treatments, the OF2 treatment had the best results, not only ensuring a suitable LAI (4.8) and maintaining a large DIFN (0.1) but also increasing the light transmittance of the middle and lower canopies (0.02–0.03). At the same time, CAP increased significantly compared with that in the CF treatment, with an average increase of 12.8%. The high value lasted for a long time, and the late decay stage remained at 8.9 μmol m−2 s−1. The ratio of the population respiration rate to total photosynthesis (CR/TCAP) decreased significantly, with an average decrease of 13.5%. Compared with that in CF, the lint yield increased by 27.0% in the other treatments. The correlation analysis showed that lint yield was positively correlated with the relative chlorophyll content (SPAD value), PAR transmittance (PARU) and CAP in the upper canopy (p < 0.05) and significantly negatively correlated with PAR transmittance (PARM) in the middle canopy and PAR transmittance (PARD) and CR/TCAP in the lower canopy (p < 0.05). Therefore, under mulch drip irrigation, the OF2 treatment (OF + 80% CF) improved the canopy structure of cotton at the late growth stage, increased the population photosynthetic rate, and increased lint yield significantly; thus, this approach can be used as an effective fertilization method to achieve the goal of decreasing costs and increasing efficiency in cotton production.

The importance of termites and fire to dead wood consumption in the longleaf pine ecosystem

Microbes, insects, and fire are the primary drivers of wood loss from most ecosystems, but interactions among these factors remain poorly understood. In this study, we tested the hypothesis that termites and fire have a synergistic effect on wood loss from the fire-adapted longleaf pine (Pinus palustris Mill.) ecosystem in the southeastern United States. We predicted that the extensive galleries created by termites would promote the ignition and consumption of logs by fire. We exposed logs from which termites had or had not been excluded to prescribed fire after 2.5 years in the field. We found little support for our hypothesis as there was no significant interactive effect of termites and fire on wood mass loss. Moreover, there was no significant difference in mass loss between burned and unburned logs. Termites were responsible for about 13.3% of observed mass loss in unprotected logs, a significant effect, while microbial activity accounted for most of the remaining mass loss. We conclude that fire has little effect on wood loss from the longleaf pine ecosystem and that termite activity does not strongly promote wood combustion. However, longer term research involving multiple burn cycles, later stages of decay, and differing fire intensities will be needed to fully address this question.

A phylogenetic assessment of Pholiota and the new genus Pyrrhulomyces

ABSTRACT Multigene data sets were assembled to evaluate the phylogeny of species attributed to the genus Pholiota sensu A.H. Sm. & Hesler. This effort included generation of just more than 200 new sequences from 19 type collections of Pholiota and recent samples from East Asia. Phylogenetic analyses reinforced the autonomous phylogenetic positions of pholiotoid taxa in the genera Flammula (Hymenogastraceae) and Kuehneromyces (Strophariaceae). Samples of Pholiota astragalina from diverse geographic regions split into two species-level lineages but occupied an isolated phylogenetic position apart from Pholiota sensu stricto. The new genus Pyrrhulomyces is described to accommodate P. astragalina and a new cryptic species from the Southern Appalachians, Pyrrhulomyces amariceps. Pyrrhulomyces is distinguished from other genera of Strophariaceae by the blackening basidiomata with a bitter taste, smooth basidiospores without a germ pore under light microscopy, presence of pleurochrysocystidia, an ixocutis, rugulose spore ornamentation under scanning electron microscope (SEM), and association with late stages of conifer wood decay. Pholiota subochracea was found to be sister to a clade containing samples of Hypholoma and Bogbodia, but this portion of the Strophariaceae will require further taxon and gene sampling to resolve relationships between these three taxa. Pholiota sensu stricto comprised at least two major groups, but several residual poorly placed lineages were also noted depending on the data set analyzed. New combinations are made in the genera Flammula, Kuehneromyces, and Stropharia for three species of Pholiota—P. abieticola, P. obscura, and P. scabella, respectively, based on molecular annotation of type collections. Overall, 20 new synonymies are proposed, mostly in Pholiota. Illustrations of Pyrrhulomyces are provided along with a key to genera of Strophariaceae and Hymenogastraceae.

Assessment of volatile metabolites for in situ detection of fungal decay in wooden structures

Although incipient fungal decay of wood may be difficult to detect in early stages, it causes a significant decrease in wood strength. Developing a reliable non-destructive identification method of decay to overcome wood replacement costs is necessary. This study examined mass losses and compression strength decrease of a softwood, spruce pine (Pinus glabra), and a hardwood, quaking aspen (Populus tremuloides), exposed to two brown rot (Gloeophyllum trabeum and Postia placenta) and two white rot (Trametes versicolor and Irpex lacteus) fungi, and identified fungal volatile organic compounds (VOCs) collected over 12 weeks of decay. Principal component analysis (PCA) of VOCs spectra differentiated volatiles emitted from sound wood and wood exposed to fungi. Volatile compounds from two fungal species revealed distinctive patterns of early and late decay stages in each wood species. The overall distinct volatile patterns of fungal decay showed promising results for development of non-destructive identification of incipient decay in wooden building structures.

Development of Necrobia rufipes (De Geer, 1775) (Coleoptera: Cleridae) under constant temperatures and its implication in forensic entomology

After the death of humans or animals, the odors released at different stages of decay attract various insects, and other arthropods, to the corpses. Therefore, the development of insects, and other arthropods present on corpses, can be assessed to estimate the minimum postmortem interval since death. In general, necrophagous blow flies are the insects that first colonize corpses. With progressing decay, other necrophagous and predatory insects arrive at the corpses, which will develop on or around these either by feeding directly on the corpses or by prey on other immature insects. Beetles (Coleoptera) mainly arrive at the corpses during the later stages of decay, and play important roles in cases with longer postmortem intervals. Necrobia rufipes (De Geer, 1755) (Coleoptera: Cleridae) is an important stored-product species with world-wide distribution. Moreover, it is also a forensically important insect species. At temperatures of 22, 25, 28, 31, 34, and 36°C (±0.5°C), the developmental periods from egg to adult were 113.20±2.96, 66.16±3.22, 50.61±1.95, 38.26±2.48, 37.97±2.40, and 31.20±2.11 days, respectively. In vivo measurements obtained the morphological indexes of larvae. The growth curve and the equation of the relationship between development time, body lengths, and mesonotum widths were simulated. The isomorphen diagram model, the isomegalen diagram model, and the thermal summation model were established. In addition, the widths of head capsules and pronota of larvae at different instars were determined by cluster analysis. Classifiers were created and validated by linear discriminant analysis.

Diagnostic of the spectral properties of Aquila X-1 by Insight-HXMT snapshots during the early propeller phase

We study the 2018 outburst of Aql X-1 via the monitor of all sky X-ray image (MAXI) data. We show that the outburst starting in February 2018 is a member of short-low class in the frame of outburst duration and the peak count rate although the outburst morphology is slightly different from the other fast-rise-exponential-decay (FRED) type outbursts with a milder rising stage. We study the partial accretion in the weak propeller stage of Aql X-1 via the MAXI data of the 2018 outburst. We report on the spectral analysis of 3 observations of Aquila X-1 obtained by Insight – hard X-ray modulation telescope (Insight-HXMT) during the late decay stage of the 2018 outburst. We discuss that the data taken by Insight-HXMT is just after the transition to the weak propeller stage. Our analysis shows the necessity of a comptonization component to take into account the existence of an electron cloud resulting photons partly up-scattered.

Fungal Adaptation to the Advanced Stages of Wood Decomposition: Insights from the Steccherinum ochraceum.

Steccherinum ochraceum is a white rot basidiomycete with wide ecological amplitude. It occurs in different regions of Russia and throughout the world, occupying different climatic zones. S. ochraceum colonizes stumps, trunks, and branches of various deciduous (seldom coniferous) trees. As a secondary colonizing fungus, S. ochraceum is mainly observed at the late decay stages. Here, we present the de novo assembly and annotation of the genome of S. ochraceum, LE-BIN 3174. This is the 8th published genome of fungus from the residual polyporoid clade and the first from the Steccherinaceae family. The obtained genome provides a first glimpse into the genetic and enzymatic mechanisms governing adaptation of S. ochraceum to an ecological niche of pre-degraded wood. It is proposed that increased number of carbohydrate-active enzymes (CAZymes) belonging to the AA superfamily and decreased number of CAZymes belonging to the GH superfamily reflects substrate preferences of S. ochraceum. This proposition is further substantiated by the results of the biochemical plate tests and exoproteomic study, which demonstrates that S. ochraceum assumes the intermediate position between typical primary colonizing fungi and litter decomposers or humus saprotrophs. Phylogenetic analysis of S. ochraceum laccase and class II peroxidase genes revealed the distinct evolutional origin of these genes in the Steccherinaceae family.

An evolutionary signal to fungal succession during plant litter decay.

ABSTRACTEcologists have frequently observed a pattern of fungal succession during litter decomposition, wherein different fungal taxa dominate different stages of decay in individual ecosystems. However, it is unclear which biological features of fungi give rise to this pattern. We tested a longstanding hypothesis that fungal succession depends on the evolutionary history of species, such that different fungal phyla prefer different decay stages. To test this hypothesis, we performed a meta-analysis across studies in 22 different ecosystem types to synthesize fungal decomposer abundances at early, middle and late stages of plant litter decay. Fungal phyla varied in relative abundance throughout decay, with fungi in the Ascomycota reaching highest relative abundance during early stages of decay (P < 0.001) and fungi in the Zygomycota reaching highest relative abundance during late stages of decay (P < 0.001). The best multiple regression model to explain variation in abundance of these fungal phyla during decay included decay stage, as well as plant litter type and climate factors. Most variation in decay-stage preference of fungal taxa was observed at basal taxonomic levels (phylum and class) rather than finer taxonomic levels (e.g. genus). For many finer-scale taxonomic groups and functional groups of fungi, plant litter type and climate factors were better correlates with relative abundance than decay stage per se, suggesting that the patchiness of fungal community composition in space is related to both resource and climate niches of different fungal taxa. Our study indicates that decomposer fungal succession is partially rooted in fungal decomposers’ deep evolutionary history, traceable to the divergence among phyla.

Micarea fennica, a new lignicolous lichen species from Finland

A new species Micarea fennica is described based on phenotypic and molecular features. The species is characterized by a pale olive green, bright green or greyish green minutely granular thallus composed of goniocysts, and stalked pycnidia that are dark grey to dark brown with Sedifolia-grey pigment in the wall structures (K+ violet, C+ violet), 0.2–0.5(–1) mm tall and covered by a thin white tomentum. The species produces micareic acid. Micarea fennica is similar to M. hedlundii and M. botryoides, but differs by having a paler granular thallus, stalked dark grey to dark brown pycnidia covered by a thin white tomentum and the production of micareic acid. The new species occupies soft lignum of late decay stages and is probably rare.

Experimentally induced community assembly of polypores reveals the importance of both environmental filtering and assembly history

Abstract The community assembly of wood-inhabiting fungi follows a successional pathway, with newly emerging resource patches being colonised by pioneer species, followed by those specialised on later stages of decay. The primary coloniser species have been suggested to strongly influence the assembly of the later-arriving community. We created an artificial resource pulse and studied the assembly of polypores over an 11 yr period to ask how the identities of the colonising species depend on the environmental characteristics and the assembly history of the dead wood unit. Our results support the view that community assembly in fungi is a highly stochastic process, as even detailed description of the characteristics of dead wood (host tree species, size, decay class of the resource unit, its bark cover and how sunken it is to the ground) and the prior community structure provided only limited predictive power on the newly colonising species. Yet, we identified distinct links between primary and secondary colonising species and showed how the spatial aggregation of dead wood had a great impact on the community assembly.

Electric resistance tomography and stress wave tomography for decay detection in trees-a comparison study.

BackgroundTo ensure the safety of trees, two NDT (nondestructive testing) techniques, electric resistance tomography and stress wave tomography, were employed to quantitatively detect and characterize the internal decay of standing trees. Comparisons between those two techniques were done to make full use of the individual capability for decay detection.MethodsEighty trees (40 Manchurian ash and 40 Populus simonii) were detected, then wood increment cores were obtained from each cross disc trial. The Dt, which was defined as the value determined by the mass loss ratio of each wood core, was regarded as the true severity of decay. Using ordinary least-squares regression to analyze the relationship between Dt and De (De was defined as the severity of decay determined by electric resistance tomography) and between Dt and Ds (Ds was defined as the severity of decay determined by stress wave tomography).ResultsThe results showed that both methods could estimate the severity of decay in trees. In terms of different stages of decay, when Dt < 30%, De had a strong positive correlation with Dt (R2 = 0.677, P < 0.01), while, when Dt ≥ 30%, Ds had a significant positive correlation relationship with Dt (R2 = 0.645, P < 0.01).ConclusionElectric resistance tomography was better than stress wave tomography for testing in the early stages of decay, while stress wave tomography can be used effectively in the late stage of decay. It is suggested that each technique can be used in the practice of internal decay testing of standing trees based on decay stages and operating conditions.