Pieces Of Wood Research Articles

Inter‐basin comparison of wood flux using random forest modelling and repeated wood extractions in unmonitored catchments

AbstractPredicting wood flux (i.e., wood piece number per time interval) or discharge (metre cubes of wood per second) in rivers is crucial for adequate integrated river management that balances risk assessment and ecological improvement. To enhance our understanding of the transport mechanisms of wood and assess their effects in various geographical contexts, it is necessary to conduct inter‐basin comparative studies and preliminary modelling. The wood flux of two river basins was analysed using video monitoring and random forest predictions based on hydrological drivers. The wood flux dynamics of the Ain and Allier rivers were both compared and contrasted. Although there was shared wood transport hysteresis, hourly wood flux, relative critical flow discharges of wood transport and certain hydrological factors exhibited differences between the two river basins. As a next step, the two random forest models, which were trained previously, were applied to predict wood flux and then wood discharge in a third river (the Rhône), in order to estimate a wood volume export, which can be compared with the wood volumes extracted over a series of a few monthly periods in the Génissiat reservoir. By using the random forest modelling, it is possible to estimate the volume of wood on the Rhône river. Despite the absence of any training data, there is a noticeable correlation, however, the estimated volumes were significantly overestimated. To resolve this issue, a correction factor was applied, accounting for disparities in wood recruitment dynamics between the Rhône basin and the training river basins. It was found that high flow events are underestimated, emphasizing the importance of incorporating local annotations and additional parameters in training the random forest model. Accurately predicting wood flux is important for integrated watershed management, but field observations are still lacking for validation and process‐based understanding.

‘Mary Magdalene Rises from the Dust,’ Twice

Liturgy was the perfect and unparalleled medium for public relations in the Middle Ages, and when it came to relics, it could transform any stone, bone, or a piece of wood into an object worthy of devotion. This article revolves around the activating force of the relics of Mary Magdalene in medieval France. It examines two liturgies—from Vézelay and from Saint-Maximin in Provence—honouring the saint, representing two distinct responses whose character reflects the priorities of the communities that produced them and the agendas that set them in motion. Liturgy was accorded a special role in bolstering the claims of Provence over the corporeal presence of Mary Magdalene in its midst, with liturgists adopting a more audacious and unreserved vocabulary to validate these claims over those of Vézelay.

Influence of friction between wood and support elements in the design of timber structures for roofing

Throughout history, wood has played a crucial role in all phases of building construction. Despite existing prejudices in Brazil regarding its use in structural systems, primarily due to the lack of dissemination of technical information, wood is gradually gaining more space in the market as a viable and environmentally sustainable alternative. With exceptional mechanical properties, wood is compatible with other widely used construction materials in the Brazilian structural market, such as concrete and steel. In this context, this research aims to analyze the influence of considering the friction coefficient caused by the sliding of the support with free horizontal displacements in isostatic trusses, investigating its impact on the design of the components that make up the truss. Such sliding generates a lateral friction force that promotes a restraining effect on the structure, potentially relieving stresses on the lower chord members. For this purpose, the Finite Element Method (FEM) is used as an analytical tool, supported by the iTruss verification software to validate the obtained results. By considering the frictional force generated on the support links of the analyzed trusses, the numerical results revealed changes in the design of structural profiles for all existing wood strength classes (D20, D30, D40, D50, and D60) in situations of friction between wood and wood, and between wood and concrete. A reduction in the volume of wooden pieces was observed, ranging from 5.88% to 8.54%, suggesting that the inclusion of the friction coefficient during structural calculations can result in savings, not only from a financial standpoint but also promoting environmental benefits by encouraging a more responsible use of wood in civil construction.

Once upon a Time, There Was a Piece of Wood: Present Knowledge and Future Perspectives in Fungal Deterioration of Wooden Cultural Heritage in Terrestrial Ecosystems and Diagnostic Tools.

Wooden Cultural Heritage (WCH) represents a significant portion of the world's historical and artistic heritage, consisting of immovable and movable artefacts. Despite the expertise developed since ancient times to enhance its durability, wooden artefacts are inevitably prone to degradation. Fungi play a pivotal role in the deterioration of WCH in terrestrial ecosystems, accelerating its decay and leading to alterations in color and strength. Reviewing the literature of the last 25 years, we aimed to provide a comprehensive overview of fungal diversity affecting WCH, the biochemical processes involved in wood decay, and the diagnostic tools available for fungal identification and damage evaluation. Climatic conditions influence the occurrence of fungal species in threatened WCH, characterized by a prevalence of wood-rot fungi (e.g., Serpula lacrymans, Coniophora puteana) in architectural heritage in temperate and continental climates and Ascomycota in indoor and harsh environments. More efforts are needed to address the knowledge fragmentation concerning biodiversity, the biology of the fungi involved, and succession in the degradative process, which is frequently centered solely on the main actors. Multidisciplinary collaboration among engineers, restorers, and life sciences scientists is vital for tackling the challenges posed by climate change with increased awareness. Traditional microbiology and culture collections are fundamental in laying solid foundations for a more comprehensive interpretation of big data.

How quickly does wood fragment in rivers? Methodological challenges, preliminary findings, and perspectives

AbstractLarge wood plays a significant role in fluvial ecosystems, influencing river geomorphology and ecology. However, it poses both benefits to river systems and risks, making it essential to understand its dynamics for effective management. A better understanding the wood breakdown process is required to evaluate the flood risk of wood in rivers. This paper aims to evaluate early‐stage fragmentation of wood in rivers after being recruited through bank erosion, taking into account its mobility and residence time. Two methods for characterising and monitoring wood fragmentation are suggested and compared: 1) photo‐interpretation based on ground and drone photo and 2) terrestrial LiDAR. We used Quantitative Structure Modelling (QSM) of point clouds to accurately simulate the full branching structure of trees. Close relationships exist between photo‐interpreted and LiDAR‐derived complexity metrics, but a scaled parameter (i.e., diameter) is needed to correlate branching complexity with volume. The debranching process occurs quickly, with a median reduction in branching complexity of over 80% within the initial 2 years. Further research with a larger sample size is necessary to investigate the impact of context – including transportation, submersion, accumulation, and isolation of wood pieces – on the fragmentation process. Field observations indicate that immobile wood pieces can experience a rapid reduction in their branching complexity, similar to the ones that are transported. Partial fine branching structure can be maintained on transported pieces. Both photo‐interpretation and terrestrial LiDAR offer complimentary approaches to monitoring wood fragmentation. Photo‐interpretation is easily implementable and may be used as a proxy for mechanical fragmentation, while terrestrial LiDAR may be used to monitor 3D wood fragmentation, volume and length evolution, following QSM modelling.

Long‐term dynamics of large wood in old‐growth and second‐growth stream reaches in the Cascade Range of Oregon

AbstractWe quantified temporal dynamics of wood storage, input, and transport over a 24‐year period in adjacent old‐growth and second‐growth forested reaches in Mack Creek, a third‐order stream in the Cascade Range of Oregon. The standing stocks of large wood in the old‐growth reach exceeded those at the second‐growth reach by more than double the number of wood pieces and triple the wood volume. Annual inputs of large wood were highly variable. Wood numbers delivered into the old‐growth reach were 3× higher and wood volume 10× greater than in the second‐growth reach. The movement of number and volume of logs did not differ significantly between the two reaches over time. Less than 2% of the logs moved in most years, and the highest proportion moved in the year of the 1996 flood (9% in old growth and 22% in second growth). Most of the large wood aggregated as jams in both reaches. The second‐growth reach lacked major jams, but 29% of the logs in the old growth were in full‐channel spanning jams. Long‐term observations of annual storage, input, and movement reveal the temporal dynamics of wood rather than static representations of the characteristics of wood. Input events and transport of wood in Mack Creek were episodic and varied greatly over the 24‐year study, which illustrates one of the major challenges and opportunities for understanding the cumulative dynamics of wood in streams.

Bonding Wood via Cellulose Aqueous Solution as Cell Wall Adhesive

The size of the wood plays a crucial role in determining its ultimate application. In order to break through the dimensions of natural wood, multiple pieces of wood are often bonded together with adhesives to form larger sizes. The physical and chemical properties of adhesives are different from those of natural wood, and this difference often leads to failure of the adhesive bonding interface. Herein, an aqueous solution of dissolved cellulose has been used as an adhesive to bond wood. The regenerated cellulose produced by recrystallization combines the wood fibers that originally existed on the wood surface cell wall. The resulting bonding wood interface consists of densely packed regenerated cellulose and wood cellulose fibers, which possess strong hydrogen bonds and physical entanglements. The shear strength has surpassed those of typical bio‐based adhesives and commercial adhesives. The same composition as natural wood endows this bonding interface with physical and chemical properties similar to natural wood such as weatherability. Bonding wood with this cellulose aqueous solution as an adhesive reduces the dependence on petrochemical‐based adhesives, and this facile and pressureless bonding strategy offers a promising route to manufacture sustainable wood composites with robust bonding interfaces.

First reported case of <i>Phoma multirostrata</i> from central India

A 50-year-old male patient, resident of Gondia, Maharashtra, India, presented with chief complaints of swelling and raw areas over left foot for 3 months. Patient was apparently alright 3 months prior when he had a traumatic injury with a piece of wood which went across his whole foot, which was removed by patient himself, and then he visited a private hospital where he was given various medications, which gave him partial relief. After a few days, the patient developed a painful swelling over the left foot, up to the ankle, which was associated with difficulty in walking and local rise of temperature, and not with fever or other symptoms. Following this, after a month, the patient developed a single raised lesion, which progressed to involve the whole left foot over a period of 5 days. The lesions then burst spontaneously, which was associated with bloody discharge. For these complaints, the patient visited a nearby hospital, where he was admitted and given various medications, including tablet amoxycillinpotassium clavulanate 625 mg, tablet pantoprazole 40 mg, tablet paracetamol 500 mg and fusidic acid cream application, which gave him partial relief. After a few days, the patient developed a burning sensation over these lesions, for which he was then referred to GMC, Nagpur, Maharashtra, India, from same hospital.

Identifying environmental factors affecting the microbial community composition on outdoor structural timber

Timber wood is a building material with many positive properties. However, its susceptibility to microbial degradation is a major challenge for outdoor usage. Although many wood-degrading fungal species are known, knowledge on their prevalence and diversity causing damage to exterior structural timber is still limited. Here, we sampled 46 decaying pieces of wood from outdoor constructions in the area of Hamburg, Germany; extracted their DNA; and investigated their microbial community composition by PCR amplicon sequencing of the fungal ITS2 region and partial bacterial 16S rRNA genes. In order to establish a link between the microbial community structure and environmental factors, we analysed the influence of wood species, its C and N contents, the effect of wood-soil contact, and the importance of its immediate environment (city, forest, meadow, park, respectively). We found that fungal and bacterial community composition colonising exterior timber was similar to fungi commonly found in forest deadwood. Of all basidiomycetous sequences retrieved, some, indicative for Perenniporia meridionalis, Dacrymyces capitatus, and Dacrymyces stillatus, were more frequently associated with severe wood damage. Whilst the most important environmental factor shaping fungal and bacterial community composition was the wood species, the immediate environment was important for fungal species whilst, for the occurrence of bacterial taxa, soil contact had a high impact. No influence was tangible for variation of the C or N content. In conclusion, our study demonstrates that wood colonising fungal and bacterial communities are equally responsive in their composition to wood species, but respond differently to environmental factors.Key points• Perenniporia meridionalis and Dacrymyces are frequently associated with wood damage• Fungal community composition on timber is affected by its surrounding environment• Bacterial community composition on structural timber is affected by soil contact

Foraging Activity of Termites at Different Sites in Multan, Pakistan

Termite monitoring is an important part of designing the management strategy. In the current study, termite activity was observed at four sites in Multan (three structures and one agriculture area). For this purpose, monitoring traps consisted of plastic bin and wood pieces were buried in soil. The termite activity was observed on weekly basis for two months during March and April 2022. The results indicated that there were five species (Odontotermes spp., Microcerotermes spp., Amitermes spp., Microtermes spp. and Coptotermes spp.) infesting the buildings and agriculture area. The lowest termite contacts in traps were observed on the 1st week which were increased with the passage of time (maximum contacts recorded on 4th week of April). Similarly, the numbers of termites were also less at the 1st inspection at all sites (24-2059 numbers per station) and maximum numbers of termites per station were recorded on 4th week of April. The results will be helpful to manage termite infestation.

Carbonized balsa wood-based photothermal evaporator for treating inorganic chemical wastewater.

Solar desalination provides a sustainable and eco-friendly solution for purifying wastewater, addressing environmental challenges associated with wastewater treatment. This study focuses on the purification of inorganic contaminants from laboratory chemical wastewater (ICWW) using a spherical solar still (SSS). To enhance the evaporation rate and overcome the impact of heavy metals on absorption efficiency, a carbonized balsa wood (CBW) solar evaporator was employed. Balsa wood pieces, carbonized at 250 °C for 15 min, were arranged in a SSS configuration. The CBW-integrated SSS demonstrated a remarkable freshwater productivity of 2.33 L/m2 for ICWW, surpassing the conventional SSS, which produced only 1.5 L/m2. The presence of heavy metal ions (Na+, Ca+, K+, and Mg2+) in ICWW significantly affected the evaporation rate, and the CBW solar evaporator exhibited an impressive removal efficiency of approximately 99%. Water quality parameters, including pH and chemical oxygen demand (COD), were investigated before and after treatment. The CBW-integrated SSS achieved an outstanding COD removal efficiency of about 99.77%, reducing the COD level from 229.51 to 0.521 mg/L. These results underscore the efficacy of the proposed solar desalination system in purifying ICWW, offering a promising approach to address environmental concerns associated with wastewater treatment.

Large Wood Transport and Accumulation Near the Separation Zone of a Channel Confluence

AbstractFallen trees enter the adjacent stream and are carried away downstream by the current. As the stream joins another one, the complex hydrodynamics near their confluence make the movement of wood hard to predict. These woods may accumulate near the confluence resulting in backwater and subsequent potential flooding. A laboratory study was conducted to investigate the movement and accumulation behavior of individual pieces of wood near the confluence. The characteristics of wood (i.e., the length, diameter, and density) and the hydraulic conditions (i.e., the discharge ratio and the release distance) were varied in this investigation. It was found that the wooden pieces released from the tributary got occasionally trapped in the flow separation zone of the confluence, whereupon they were mainly trapped by a clockwise vortex and continued to stay driven by a reverse cluster of currents within this zone. The accumulation probability of wood was mainly related to its length, the discharge ratio and the release distance. The effect of wood diameter and density within the tested parameters was negligible. The probability increased with an increase in the discharge ratio as well as a decrease in the release distance. The longer pieces had a higher probability of being trapped, whereas for those exceeding some critical value, the probability was nearly the same, or dropped sharply. A generalized model for wood accumulation near the confluence was developed for practical application. These findings carry significant implications for river management, particularly in preventing the risk of flooding caused by wood blockage.

Large wood fluctuation and longitudinal connectivity conditions along a segment of the Blanco River (Chilean Patagonia)

Data collected between 2015 and 2022 was utilised to assess longitudinal connectivity and explain the temporal and spatial fluctuation of large wood (LW) along the Blanco River, which was severely affected by the 2008 eruption of the Chaitén Volcano in southern Chile. The study was performed along a ~ 10.6-km long segment, which was divided into two sub-segments (upper and lower). LW source areas were identified using information from previous research, complemented by the analysis of satellite images to cover the study period. LW fluctuation was studied for the period 2017–2022, using field data and images from an unmanned aerial vehicle along seven 80 m-long reaches located within the lower sub-segment of the river. Using the generated georeferenced orthomosaics and digital elevation models, LW and wood jams (WJs) locations, abundance, dimensions, volumes, and WJs stability were assessed, as well as wood deposition patterns. Streambank erosions and landslides were found to be the main LW sources. Considering wood sourcing, and the variations in the number of LW and WJs, in the dimensions of individual LW and WJs volume and deposition patterns as indicators, it was possible to infer the longitudinal connectivity conditions for the studied segment through time. The results showed that the upper and lower subsegments were poorly connected. However, changes in LW abundance over time, its dimensions and volumes, and the very low stability of WJs, and LW deposition patterns indicative of fluvial transport confirmed that the lower subsegment was longitudinally connected. The results also verified that the presence of LW did not affect water or sediment longitudinal connectivity along the fluvial system. The volume of individual LW and WJs showed a decreasing trend with time in all study reaches. As the bank erosions able to source LW to the channel are also reducing with time, pieces of wood deposited in the active channel may become the only way to sustain LW availability for the next few years. Things could change with the occurrence of an extreme and infrequent flood able to connect the upper and lower sub-segments and force the river to initiate a new phase of planform adjustments.

PEMBERDAYAAN IRT GAMPONG ALUE BEURAWE MELALUI BUDIDAYA TANAMAN HIDROPONIK SEBAGAI UPAYA PENINGKATAN EKONOMI KELUARGA

Hydroponic system technology is a method of farming using planting media other than soil, such as pumice, gravel, sand, coconut fiber, pieces of wood or foam. This is done because the function of soil as a support for plant roots and as an intermediary for nutrient solutions can be replaced by flowing or adding nutrients, water and oxygen through this medium. The aim of this community service activity was to provide science and technology to the housewives of Gampong Alue Beurawe regarding the hydroponic system as a solution to the limited agricultural land in Gampong Alue Beurawe. Then, the results of the cultivated vegetables using this hydroponic system can be marketed and become a source of income for partners. The implementation of this activity was carried out in several stages, namely: 1) observation and legalization, 2) implementation of training, 3) practice of cultivating plants using a hydroponic system, and 4) evaluation. From the results of implementing this activity, the target partner has a series of household scale hydroponic systems as a business. Apart from that, target partners also have knowledge and skills in farming using a hydroponic system. The resulting hydroponic plant harvest have been marketed and become income for partners. This activity is expected to be an opportunity for new entrepreneurial partners who will join the business group in the future to keep up with current developments, so that they are able to compete in this globalized world.

One-Step Surgical Approach for Treating Lens-Induced Glaucoma with Iridodialysis Following Blunt Trauma

Introduction : Traumatic glaucoma is one of secondary glaucoma that can be challenging to treat. Blunt trauma to the eye may result in iritis, hyphema, lens subluxation, or dislocation leading to increased intraocular pressure (IOP). Every complication needs to be addressed promptly. Here we present about one-step surgical approach to treat lens indued glaucoma with iridodialysis following blunt trauma.
 Case Illustration : A 65-year-old man presented with a chief complaint of blurred vision and pain in his right eye for a month following blunt ocular trauma where he was hit with piece of wood while operating a chainsaw. Ophthalmologic examination revealed RE VA of 2/60 with IOP 32 mmHg. Anterior examination revealed a shallow anterior chamber, iridodialysis 90 degrees, cloudy lens with phacodonesis (Fig 1). Patient was diagnosed with lens-induced glaucoma, lens subluxation, iridodialysis and traumatic cataract. Patient was treated with antiglaucoma agents prior to surgery. One-step surgical approach: trabeculectomy, phacoemulsification with capsular tension ring, and iridodialysis repair become the treatment of choice (Fig 2). After one month of surgery, IOP decreased to 16 mmHg without anti-glaucoma medication, final VA RE achieved 0.2 (Fig 3).DiscussionManagement of traumatic glaucoma depends on the underlying cause of increased IOP. Trabeculectomy combined with lens extraction should be considered with degree of subluxation that may cause pupillary block. Repair iridodialysis can be done using various techniques.
 Conclusion : Management of traumatic glaucoma can be done with trabeculectomy, lens extraction and repair iridodialysis in one-step surgery. Surgical technique should be considered depending on the patient’s eye condition.

Occurrence of Neofusicoccum parvum Causing Canker and Branch Dieback of European Hazelnut in Maule Region, Chile.

The European hazelnut (Corylus avellana) is an important fruit crop cultivated in Chile, with over 17,000 ha planted (46%) in the Maule region, central Chile. During a routine orchard survey in seasons 2020-2021 and 2021-2022, in the Maule region, canker and dieback symptoms were observed in two commercial orchards of European hazelnut cv. Tonda Di Giffoni in San Rafael (8-year-olds) and Linares (15-year-olds), with an incidence between 10% and 36%, respectively, based on external symptoms. Twenty symptomatic branches exhibiting cankers, reduced vigor, wilting, twig death, and dieback, were collected. A cross-section of diseased branches revealed mostly brown V or U-shaped cankers of hard consistency. Branches were cut, and pieces of cankers were surface sterilized in 96% ethanol for 3 s and briefly flamed. Small pieces of wood (5 mm2) from the edge of cankered tissues were placed on Potato Dextrose Agar (2% PDA) amended with 0.1% Igepal CO-630 and incubated at 25°C for five days in the dark (Díaz and Latorre 2014). Pure cultures were obtained by transferring a hyphal tip from growing colonies to fresh PDA media. Eight pure cultures (NP-Haz01 to NP-Haz08) developed dark to olive-brown fast-growing colonies with scarce aerial mycelium after seven days at 25°C on PDA under near-UV light. These isolates showed a dark-olive color on the reverse side of Petri dishes and developed abundant, aggregated, and dark-brown globose pycnidia after 21 days at 25°C. Conidia were hyaline, aseptate, ellipsoidal, densely granulate, externally smooth, and thin-walled dark, that measured (9.5-) 15.5 ±1.2 (-17.3) x (5.1-) 7.2 ± 0.6 (-9.1) µm (n = 30), with a length/width ratio of 2.15. These isolates were tentatively identified morphologically as Neofusicoccum sp. Molecular identification was performed using ITS1/ITS4, Bt2a/Bt2b and EF1-728F/EF1-986R primers of the internal transcribed spacer (ITS1-5.8S-ITS2) region, a portion of the beta-tubulin (BT) and part of the translation elongation factor (EF1-) genes, respectively (Dissanayake et al. 2015). A MegaBlast search in GenBank showed a 99% similarity to isolate CMW9081, the ex-type of Neofusicocum parvum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips. The sequences were added to GenBank (OR393855 to OR393857 for ITS; OR400688 to OR400690 for BT; OR400691 to OR400693 for EF1-). Pathogenicity of three isolates (NP-Haz02, NP-Haz04, NP-Haz09) was studied on freshly made pruning wounds on attached branches of 3-year-old and one-year-old of European hazelnut cv. Tonda Di Giffoni in the San Rafael field. Fifteen pruning wounds were inoculated with 40 µL conidial suspension (105 conidia/mL) of each isolate of N. parvum. Sterile distilled water was used as a control treatment (n=15 branches) for branches of 3-year-olds and one-year-olds. Both pathogenicity tests were repeated once. Attached branches of 3-year-olds (6 months of incubation) and one-year-olds (4 months of incubation), developed necrotic streaks and cankers with a mean length of 33 to 82 mm and 25 to 51 mm, respectively. No necrotic streaks were observed in the branches treated with water. Neofusicoccum parvum was reisolated only from symptomatic tissues of inoculated branches, and morphological and molecularly (EF1-) identified, thus fulfilling Koch's postulates. Previously, other Botryosphaeriaceae spp. as Diplodia coryli (Guerrero and Pérez 2012) and D. mutila (Moya-Elizondo et al. 2023) have been obtained from canker and dieback of hazelnut in Chile. Recently, N. parvum was reported causing nut rot in hazelnuts in Italy (Wagas et al. 2022). To our knowledge, this is the first report of N. parvum causing canker and branch dieback of hazelnut trees in Chile and worldwide.

Sediment Response after Wildfires in Mountain Streams and Their Effects on Cultural Heritage: The Case of the 2021 Navalacruz Wildfire (Avila, Spain)

The 2021 Navalacruz wildfire occurred in a mountainous area in the Sistema Central (Spain). Despite having an average low severity index (dNBR), the loss of vegetation cover associated with the fire was responsible for a high rate of sedimentation in the rivers and streams. Additionally, the burned area affected up to 60 cultural heritage sites, including archaeological and ethnological sites, and damage ranged from burnt pieces of wood to the burial of archaeological sites. In the present work, we document and analyze the post-fire evolution in several rivers and streams. This is based on a field survey of infiltration rates, hydrodynamic modeling, and the study of channel morphological changes. Our analysis revealed how the first post-fire rains caused the mobilization and transport of ashes. This created hydrophobicity in the soils, resulting in large amounts of materials being transported to rivers and streams by subsequent medium- and low-magnitude storms. A hydrological and hydraulic model of the study catchments under pre- and post-fire conditions suggests that these trends are a consequence of a post-fire increase in flow rates for similar rainfall scenarios. In this respect, our estimates point at a significant increase in sediment transport capacities associated with this post-fire increase in flow rates. The combination of locally steep slopes with high-severity fire patches, and a considerable regolith (derived from pre-fire weathering), resulted in a series of cascading responses, such as an exacerbated supply of sand to the drainage network and the triggering of debris flows, followed by erosion and entrenchment.

First report of Diplodia bulgarica causing black canker on apple in California.

California is the sixth largest apple-producing state in the United States with a production that reached 4,654 ha in 2021. During the late winter of 2023, black canker symptoms were observed on branches of 'Gravenstein' apple (Malus domestica) in two commercial orchards in Sonoma County, California. The prevalence of symptomatic trees ranged from 10 to 30%. External symptoms included charcoal looking-cankers with the bark peeling off from the primary and secondary branches. Internally, cankers were dark brown in color with a hard consistency. Pycnidia were observed on the surface of older cankers. Fungal isolations were performed from disinfected (70% ethanol, 30 s) symptomatic branch samples (n = 15). Small wood pieces (5 mm length) were taken from the margin of diseased and healthy tissues, and placed on potato dextrose agar acidified with 92% lactic acid at 0.5 mL per liter (APDA). Plates were incubated at room temperature (20-22 °C) for 7 days. Colonies of Botryosphaeriaceae species (Phillips et al. 2013) (n = 12) were consistently recovered and pure cultures were obtained by transferring a single hyphal tip onto fresh APDA. Colonies were light gray with irregular margins. To induce pycnidia formation, two isolates (UCD11350 and UCD11351) were grown on pistachio leaf agar for 21 days. Conidia (n = 50) were thick-walled and ovoid in shape, initially hyaline, then turned pale brown and dark brown at maturity, and some of them became 1-septate, ranging from 18.9 to 24.0 (21.9) × 11.5 to 14.7 (13.4) µm. Isolates were identified by sequencing a partial region of the beta-tubulin (tub2) gene using the primers Bt2a/Bt2b (Glass and Donaldson 1995). BLAST searches on NCBI GenBank revealed 99.5 % identity with the Diplodia bulgarica ex-type (CBS 1245254). To confirm the identity, the rRNA internal transcribed spacer (ITS) and the translation elongation factor 1-alpha (tef1) were also sequenced using ITS5/ITS4 (White et al. 1990), and EF1-688F/EF1-1251R (Alves et al. 2008), respectively. A maximum parsimony multi-locus phylogenetic analysis clustered Californian isolates with reference strains of D. bulgarica. Sequences were deposited in GenBank (nos. OR631209 to OR631210, OR637361 to OR637362, OR637363 to OR637364 for ITS, tub2, and tef1, respectively). Pathogenicity tests were conducted on 2 to 3-year-old branches (n = 5) of over 20-year-old trees by inserting a 5-mm segment of a toothpick, completely colonized with each of the two isolates mentioned above, into a 1-mm-diameter hole made with a sterile drill bit. The same number of branches where mock inoculated with a non-colonized toothpick as negative control. The experiment was performed twice. After ten weeks, inoculations resulted in dark brown necrotic lesions that ranged from 54.0 to 59.8 mm in length. Negative controls remained asymptomatic. Koch's postulates were fulfilled by successfully recovering the isolates from the lesion margins, which were confirmed by morphology. Diplodia bulgarica was first described affecting M. sylvestris in Bulgaria (Phillips et al. 2012), and then detected on M. domestica causing cankers in Iran (Abdollahzadeh 2015), India (Nabi et al. 2020), Germany (Hinrichs-Berger al. 2021) and Türkiye (Eken 2021). The pathogen was also identified causing postharvest fruit rot (Eken 2022). To our knowledge, this is the first report of D. bulgarica causing branch canker on apple in California, which provides important information for developing detection and control strategies.

Work Safety and Safety Devices in Brazilian Wood Sawmills for the Improvement of Working Conditions

Workplace safety is essential to ensure the health and integrity of the worker. Sawmills are known for high risk and severe accidents, especially involving circular saws, tenoners and jointers, which can, however, be prevented through the use of personal protective equipment (PPE), employee training, and safety measures on machines and equipment. The aim of this study was to present a compilation of the data presented in the literature about the main risks in sawmills, regulatory standards, the construction of a safety system, and the safety devices to be used. To choose the best safety methods, it is crucial to evaluate the types of risks present. Among the most common risks in sawmill machinery are mechanical, electrical, thermal, noise-induced, vibration-induced, caused by materials and substances, and disregarding of ergonomic principles. To reduce these risks, sawmills should have action plans that comply with regulatory standards, such as the use of PPE, machinery and equipment protection, demarcation of danger zones, workplace cleanliness, and operator training. Safety devices used in sawmills help reduce accidents and should be chosen based on machine’s use, the nature and frequency of access, types of risks, and the probability and severity of injury. For circular saws, risks can be minimized through the use of basic protections such as a splitter and guards, in addition to a push device for wood pieces. Tenoners and jointers present higher risks with sharp tools in contact with body parts, protective guarding in hazardous areas is recommended. In all cases, the use of personal protective equipment is essential.

A high‐resolution inter‐annual framework for exploring hydrological drivers of large wood dynamics

AbstractRivers with alluvial bars store more wood than those without, supplied through channel shifting. However, wood dynamics (arrival or new deposits, departure or entrainment, and stable or immobile pieces) can vary substantially over time in response to critical hydrological drivers that are largely unknown. To evaluate them, we studied the dynamics of large wood pieces and logjams along a 12‐km reach of the lower Allier River using six series of aerial images of variable resolution acquired between 2009 and 2020, during which maximum river discharge fluctuated around the dominant flood discharge (Q1.5) that is potentially the bankfull discharge along this well‐preserved not incised reach. Individual wood departure was best correlated with water levels exceeding dominant flood discharge. The duration of the highest magnitude flood was best correlated with wood depositions, with shorter floods resulting in a higher number of deposits. Finally, most of the wood remained stable when river discharge did not exceed 60% of Q1.5 over a long period of time. Changes in inter‐annual wood budget (reach‐scale) depend on the duration over which discharge exceeded 60% of Q1.5. Hydrological conditions driving jam build‐up and removal were similar to those controlling individual wood piece dynamics. The results suggest that specific hydrological conditions influence the dynamics of large wood and log jams in the Allier River. Understanding the dynamics of large wood and its impact on river morphology is fundamental for successful river management and habitat restoration initiatives.