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To evaluate the impact of forest plantations on soil microbial catabolic diversity, this study investigated the microbial response to the addition of various carbon-rich substrates in different ages of forest plantations and compared catabolic diversity between a nitrogen-fixing tree species (Alder, Alnus subcordata C. A. M.) and a non-nitrogen-fixing one (Oak, Quercus castaneifolia C. A. M.). The study also analyzed the effects of carbon substrates found in association with roots, such as carbohydrates, carboxylic acids, amino acids, and amine groups, on substrate-induced respiration. The diversity indices (Simpson and Shannon diversity indicies) and Shannon evenness index demonstrated higher values in the oldest plantations than the youngest ones (with an order of 25 > 20 > 15 years). In younger plantations (15 and 20 years old), oak stands exhibited higher microbial diversity compared to alder stands. However, at 25 years old, alder plantation displayed greater diversity than the oak plantation, as indicated by higher values for the Shannon diversity index (2.77), Simpson diversity index (0.93), and Shannon evenness index (0.89). Forest plantations with alder and oak species significantly enhanced catabolic evenness and diversity, thereby increasing the soil capacity to decompose organic matter and the resilience of the soil to disturbance. These findings suggest that both alder and oak plantations can promote soil microbial diversity, but the influence might differ depending on the specific age of the trees. In conclusion, this study highlights the influence of forest plantations on soil microbial catabolic diversity, demonstrating the potential of diverse tree species to promote soil health and resilience through enhanced functional complexity. [ABSTRACT FROM AUTHOR]

Alders are nitrogen (N)-fixing riparian trees that promote leaf litter decomposition in streams through their high-nutrient leaf litter inputs. While alders are widespread across Europe, their populations are at risk due to infection by the oomycete Phytophthora ×alni, which causes alder dieback. Moreover, alder death opens a space for the establishment of an aggressive N-fixing invasive species, the black locust (Robinia pseudoacacia). Shifts from riparian vegetation containing healthy to infected alder and, eventually, alder loss and replacement with black locust may alter the key process of leaf litter decomposition and associated microbial decomposer assemblages. We examined this question in a microcosm experiment comparing three types of leaf litter mixtures: one representing an original riparian forest composed of healthy alder (Alnus lusitanica), ash (Fraxinus angustifolia), and poplar (Populus nigra); one with the same species composition where alder had been infected by P. ×alni; and one where alder had been replaced with black locust. The experiment lasted six weeks, and every two weeks, microbially driven decomposition, fungal biomass, reproduction, and assemblage structure were measured. Decomposition was highest in mixtures with infected alder and lowest in mixtures with black locust, reflecting differences in leaf nutrient concentrations. Mixtures with alder showed distinct fungal assemblages and higher sporulation rates than mixtures with black locust. Our results indicate that alder loss and its replacement with black locust may alter key stream ecosystem processes and assemblages, with important changes already occurring during alder infection. This highlights the importance of maintaining heathy riparian forests to preserve proper stream ecosystem functioning. [ABSTRACT FROM AUTHOR]

This article highlights the evolution, birth and legacy of the world's first neonatal surgical unit established at Alder Hey Children's Hospital Liverpool in 1953. Peter Paul Rickham, a creative pioneering and innovative surgeon, is credited here as a major driving force that helped shape and progress the modern day development of neonatal surgery. Rickham's vision was realised by studying neonatal surgical disorders and the mortality rate of congenital anomalies in Mersey Region while working as a young senior registrar with Isabella Forshall. Rickham defined the extent of the problem(s) and set to work as a newly appointed consultant a vision for improving outcomes with the creation and establishment of a preeminent world leading neonatal surgical unit. Surgeons from all over the world travelled to work, learn and train with Rickham and the paediatric surgical staff team at Alder Hey in the subsequent years to follow. Neonatal anaesthesia greatly advanced by Jackson Rees a colleague working in Liverpool with Rickham allowed huge success to flourish—'the impossible became possible'. The neonatal surgical unit in Liverpool became the benchmark and prototype for units to develop around the world immediately resulting in improvement in the survival of newborn infants undergoing surgery from 22 to 74%. Rickham's contributions to neonatal and paediatric surgery are truly remarkable. Alder Hey hosts an international symposium and special dinner with Rickham family members as VIP guests in its calendar of events. A symposium highlight is the Rickham Lecture with the PPR Gold Medal awarded to an international renowned leader in the field of paediatric surgery and the surgical sciences. [ABSTRACT FROM AUTHOR]

The article discusses the findings from the Kosilovo mire in north-western Russia, focusing on the pollen data and sediment description. The mire is located in a temperate continental climate zone with mixed coniferous-broadleaved forests. The sediment core collected from the mire revealed changes in vegetation over the past 10,000 years, indicating shifts in tree species composition and climate conditions. The study also highlights the impact of human activity on the mire ecosystem. [Extracted from the article]

Between 2010 and 2015, an extensive survey of Phytophthora diversity was performed across Portugal. Baiting and direct isolation tests obtained 48 Phytophthora taxa in 62 of 70 forest stands (89%) from 148 of 302 rhizosphere soil samples (49%) and 25 of 29 tree species (86%), and from bark cankers of Alnus lusitanica and Fagus sylvatica; from 33 of 34 rivers and forest streams (97%); and in 12 of 13 forest nurseries (92%) from 54 of 87 root ball samples (61%) and 16 of 21 tree species (76%). The 799 Phytophthora isolates belonged to 28 known and three recently described species; one designated and two new non‐hybrid taxa; and five designated and nine new hybrid taxa. The majority, 34 Phytophthora taxa (71%), are introduced aliens in Europe while nine (19%) and five (10%) taxa are of cryptic and native origin, respectively. Phytophthora cinnamomi was the most common species in forests (56%) and forest nurseries (61%). Multiple first records for Portugal and partly Europe of both Phytophthora taxa and tree declines and new host–Phytophthora associations were found. Isolation rates from forest soil differed considerably between declining (65%) and healthy trees (10%), regardless of the tree species. The widespread infestations of nurseries with aggressive wide‐host range pathogens like P. cinnamomi, P. pseudocryptogea, P. ×cambivora, P. multivora and P. plurivora, and host‐specific pathogens like P. alticola, P. quercetorum and P. quercina, will inevitably cause their further spread to the wider environment, exacerbating pathogen threats to forest ecosystems and thus weakening their resilience to climatic extremes. [ABSTRACT FROM AUTHOR]

Studies on a cycloisomerization reaction of 2‐prenylated‐2H‐pyrans towards cis‐fused tetrahydro‐6H‐benzo[c]chromene systems (reduced cis‐THC analogues) are reported. The transformation is catalyzed by iron chloride and proceeds with the formation of two new bonds and two stereocenters diastereoselectively. The same catalyst also promotes the formation of these products via a one‐pot tandem Knoevenagel condensation of 1,3‐cyclohexanediones and citral or farnesal aldehydes, followed by cycloisomerization establishing a direct assembly of this important scaffold. [ABSTRACT FROM AUTHOR]

Understanding of the process of hydraulic redistribution in agricultural landscapes is important for informing agroforestry design and agricultural management. The measurement of hydraulic lift and redistribution in the field is still a challenge. Due to the robustness of stable isotope analysis, we hypothesized that the measurement and analysis of the natural abundance of stable isotopes δ2H and δ1⁸O, in the twigs of agroforestry trees, stems of wheat intercrop, rain, and soil water coupled to an isotopic mixing modeling by IsoSource supplemented with other physiological crop parameters, would estimate the extent of hydraulic redistribution in intercropping, and inform the design of an agroforestry system. There are still many plant species that have not been investigated for their potential hydraulic redistribution yet, and Alnus acuminata is among them, therefore this study aimed to contribute to filling that gap. The field experiment was conducted in an Andic soil of the northern Rwanda highlands to address the extent of water efflux redistribution from tree roots of Alnus acuminata to the wheat intercrop across bench terraces. The study involved the measurement of the natural abundance of stable isotopes δ2H, and δ1⁸O of the tree twigs, soil and wheat stems at distances of 1, 3, 5, and 7 m from the tree lines of Alnus acuminata, and of rainwater. The isotopic mixing modeling was supplemented by measuring both specific leaf area (SLA) and carbon discrimination (Δ13C) in the wheat leaf. We noted a significant (p < 0.01) gradient in the depletion of wheat xylem water δ2H and δ18O signatures moving further away from the tree lines. Based on the wheat value of δ2H, the isoSource indicated that the trees may have contributed the wheat water up to 64.3 ± 2.6% at 5 m from the trees, and the values of both the SLA (cm2 g–1) and ∆13C (‰) of wheat leaf indicated the water use efficiency of wheat significantly improved around the trees up to 3 m away from the trees with 140.10 ± 3.74 cm2 g–1, 149.56 ± 3.43 cm2 g–1 and 20.6 ± 0.1‰, 20.8 ± 0.1‰ at 1 m and 3 m for SLA and ∆13C respectively. We concluded that Alnus acuminata exhibits significant hydraulic redistribution in the field. [ABSTRACT FROM AUTHOR]

The N2-fixing trees Alnus spp. have been widely encroaching into boreal peatlands, but the nutrient responses of native vascular plants remain unclear. Here, we compared nutrient concentrations and isotope signal of six common plants (Betula fruticosa, Salix rosmarinifolia, Vaccinium uliginosum, Rhododendron tomentosum, Chamaedaphne calyculata, and Eriophorum vaginatum) between Alnus hirsuta island and open peatland and assessed plant nutrient responses to A. hirsuta encroachment in boreal peatlands. Alnus hirsuta encroachment increased nitrogen (N) concentration of leaf, branch, and stem. Despite no significant interspecific difference in branch and stem, the increment magnitude of leaf N concentration varied among species, with greatest magnitude for R. tomentosum (55.1% ± 40.7%) and lowest for E. vaginatum (9.80% ± 4.40%) and B. fruticosa (18.4% ± 10.7%). Except for E. vaginatum, the significant increase in δ15N occurred for all organs of shrubs, with interspecific differences in change of leaf δ15N. According to the mass balance equation involving leaf δ15N, R. tomentosum and E. vaginatum, respectively, obtained highest (40.5% ± 19.8%) and lowest proportions (–14.0% ± 30.5%) of N from A. hirsuta. Moreover, the increment magnitudes of leaf N concentration showed a positive linear relationship with the proportion of N from A. hirsuta. In addition, A. hirsuta encroachment reduced leaf phosphorus (P) concentration of deciduous shrubs (i.e., B. fruticosa, S. rosmarinifolia, and V. uliginosum), thus increasing N:P ratio. These findings indicate that Alnus encroachment improves native plant N status and selectively intensifies P limitation of native deciduous shrubs, and highlight that the N acquisition from the symbiotic N2-fixing system regulates plant N responses in boreal peatlands. [ABSTRACT FROM AUTHOR]

The dataset presents a 43 year-long reanalysis of pollen seasons for three major allergenic genera of trees in Europe: alder (Alnus), birch (Betula), and olive (Olea). Driven by the meteorological reanalysis ERA5, the atmospheric composition model SILAM predicted the flowering period and calculated the Europe-wide dispersion pattern of pollen for the years 1980–2022. The model applied an extended 4-dimensional variational data assimilation of in-situ observations of aerobiological networks in 34 European countries to reproduce the inter-annual variability and trends of pollen production and distribution. The control variable of the assimilation procedure was the total pollen release during each flowering season, implemented as an annual correction factor to the mean pollen production. The dataset was designed as an input to studies on climate-induced and anthropogenically driven changes in the European vegetation, biodiversity monitoring, bioaerosol modelling and assessment, as well as, in combination with intra-seasonal observations, for health-related applications. [ABSTRACT FROM AUTHOR]

The sudden leaks from the Nord Stream gas pipelines, which began on 26 September 2022, released a substantial amount of methane (CH4) into the atmosphere. From the Infrared Atmospheric Sounding Interferometer (IASI) instrument onboard EUMETSAT's MetOp-B, we document the first satellite-based retrievals of column-average CH4 (XCH4) that clearly show the large CH4 plume emitted from the pipelines. The data display elevations greater than 200 ppb (parts per billion, ∼ 11 %) above observed background values (1882 ± 21 ppb). Based on the IASI data, together with an integrated mass enhancement technique and formal model-based inversions applied for the first time to thermal infrared satellite methane plume data, we quantify the total mass of CH4 emitted into the atmosphere during the first 2 d of the leaks to be 219–427 GgCH4. Substantial temporal heterogeneity is displayed in our model-derived flux rate, with three or four distinct peaks in emission rate over the first 2 d. Our range overlaps with other previous estimates, which were 75–230 GgCH4 and were mostly based on inversions that assimilated in situ observations from nearby tower sites. However, our derived values are generally larger than those previous results, with the differences likely due to the fact that our results are the first to use satellite-based observations of XCH4 from the days following the leaks. We incorporate multiple satellite overpasses that monitored the CH4 plume as it was transported across Scandinavia and the North Sea up to the evening of 28 September 2022. We produced model simulations of the atmospheric transport of the plume using the Eulerian atmospheric transport model, TOMCAT, which show good representation of the plume location in the days following the leaks. The performance of simulated CH4 mixing ratios at four nearby in situ measurement sites compared to the observed in situ values is mixed, which highlights the challenges inherent in representing short-term plume movement over a specific location using a model such as TOMCAT with a relatively coarse Eulerian grid. Our results confirm the leak of the Nord Stream pipes to clearly be the largest individual fossil-fuel-related leak of CH4 on record, greatly surpassing the previous largest leak (95 GgCH4) at the Aliso Canyon gas facility in California in 2015–2016. [ABSTRACT FROM AUTHOR]

Trees established in linear formations can be utilised as windbreak structures on farms as a form of agroforestry system. We present an extensive data package collected from an active berry farm located near Stellenbosch, South Africa, considering hydrological, pedological, dendrological and meteorological measurements centred around an Italian alder (Alnus cordata (Loisel.) Duby) windbreak and a blackberry (Rubus fruticosus L. Var. "Waldo") crop. Data were collected between September 2019 and June 2021. The data are available from and include the following measurements (i) meteorological variables – solar radiation, precipitation characteristics, vapour pressure deficit, air temperature, humidity, atmospheric pressure, wind speed and direction, gust speed, and lightning strikes and distance recorded at 10 min intervals; (ii) hydrological measurements – soil moisture and matric potential in two profiles at 15 min intervals alongside soil samples at various depths describing soil texture, hydraulic conductivity, and water retention parameters; (iii) soil characteristics – a soil profile description accompanied by 60 topsoil samples describing carbon, nitrogen, and exchangeable base cation concentrations, as well as potential cation exchange capacity and descriptions of soil texture; and (iv) dendrological measurements – point cloud data for the studied windbreak trees and surrounding features, cylinder models of the windbreak trees with volume and biomass data, and foliage data as a product of an existing leaf creation algorithm. The described dataset provides a multidisciplinary approach to assess the impact and interaction of windbreaks and tree structures in agroforestry landscapes, aiding future work concerning water fluxes, nutrient distribution, microclimate and carbon sequestration. The dataset, including high-resolution time series and point cloud data, offers valuable insights for managing the windbreak's influence and serves as a unique training dataset for spatial analysis (https://doi.org/10.5880/fidgeo.2023.028 ,). [ABSTRACT FROM AUTHOR]

Tree rings in high mountain forests represent a valuable natural archive for climate reconstructions and understanding the impact of climate change on forest ecosystems. In this context, the dendroclimatic potential of Alnus acuminata (alder) was evaluated by selecting 25 trees from seven localities in the Mantaro Valley. Computational programs such as Image-Pro Plus, COFECHA, ARSTAN, Sigma Plot, and the IAWA Standard List were utilized. Densitometry, performed with the QTRS-01X equipment using X-ray technology, provided ring width and apparent density diagrams. Seven chronological periods were identified, covering a span of 37.5 years, with the years 1960-1966, 1972-1978, and 2004-2010 showing the greatest growth, and the years 1966-1970, 1980-1986, and 1999-2005 showing the least growth. Furthermore, the alder exhibited particular sensitivity to low winter temperatures in the higher altitude sampling areas. Samples from Colpar 12-A* and Paca 10-A* showed wall thicknesses of 4.39 and 4.60 µm, respectively, attributable to low temperatures. Additionally, a significant negative correlation was observed between minimum temperature and ring width index (r= -0.38, p<0.005) from 1972 to 2008. In terms of precipitation and ring width index, a positive correlation (r= 0.26, p<0.005) was evidenced from 1949 to 2009, positively influencing its development. These findings underscore the dendroclimatic potential of the species, contributing to the understanding of climatic history and the prediction of future conditions in development areas. [ABSTRACT FROM AUTHOR]

In the socio-ecological landscapes of tropical mountains, including the highly diverse Eastern Himalaya, fragments of natural forests have been traditionally managed as part of different agriculture systems. Recent studies have recognized their role as important biodiversity repositories outside protected areas. However, basic information on forest structure and composition of these forests outside protected areas is still limited in the Himalaya. In the current study, diversity, structure, composition, and regeneration status of non-protected forests were studied across 15 spatially different sites in the socio-ecological landscapes of Darjeeling-Sikkim, Eastern Himalaya, across an approximate elevation range of 500-2300 m above sea level. Quadrats (20 m × 5 m) were used to enumerate woody species in the study area. Enumeration of 156 quadrats (= 1.56 ha) resulted in a total of 249 woody species, of which species such as Schima wallichii, Alnus nepalensis, and Engelhardtia spicata were found to dominate the existing stand of trees. The vegetation structure of these forests was found to be almost comparable with that of protected forests, as assessed by prior studies in the same landscape. Species composition of woody plants in the study area were found to be primarily influenced by elevation. Assessment of regeneration patterns found the forests to have a high regeneration potential, however, the most dominant tree species of the area had relatively fewer saplings, indicating probable replacement of localized species of large trees by disturbance-adapted species. The current study adds to the literature on the structure and composition of non-protected forests in the tropical mountains. [ABSTRACT FROM AUTHOR]

Diels‐Alder between nitroalkenes derived from a sugar scaffold and cyclopentadiene were examined. Depending on chemical structure of nitroalkene and polarity of solvent used, the reaction proceeded via the formation of a nitronate intermediate. Cyclic nitronates highly functionalized were obtained as chemically stable and stereochemically pure compounds. [3,3] sigmatropic shift of these ones afforded the Diels Alder cycloadducts in quantitative yield. Mechanistic aspects of reaction between nitroalkenes and cyclopentadiene has been studied using DFT computational methods. Nitronate derivatives are attractive intermediates and open the way for the construction of valuable compounds with potential applications. [ABSTRACT FROM AUTHOR]

This document is a list of reviewers who have served in the past year for manuscripts submitted to various ecology journals. The authors, editors, staff, and members of the Ecological Society of America (ESA) express their gratitude to these individuals for their thoughtful and critical reviews. The list includes a diverse range of names from different cultural backgrounds, reflecting the inclusive nature of the field of ecology. [Extracted from the article]

The reported work presents the diastereo, regio-, and π-facial selective synthesis of hetero-Diels-Alder (H-DA) cycloadducts with diazene derivatives viz. di-isopropyldiazocarboxylate and diethylazodicarboxylate with cis-/trans-3-butadienyl-β-lactams having stereocentres at its α and β-position. The H-DA reactions resulted in the formation of β-lactam tethered—3,6-dihydro-pyridazines in good yields. [ABSTRACT FROM AUTHOR]

The ability of plants to colonize the fluvial environment and withstand uprooting by floods is largely controlled by the anchoring effect of roots. We characterized the root architecture and tensile strength of Alnus incana, a riparian tree species of the Betulaceae family for which there are no systematic observations of its vertical root structure. Four A. incana individuals and two nearby Populus nigra 3–10 years old growing on bars in gravel‐bed rivers were excavated. Their root structure was characterized in terms of root diameter, age, and depth and was related to sediment grain size and scour or deposition by floods. Root tensile strength was also measured as a function of root diameter using a load cell and displacement transducer attached to individual roots. The architecture of A. incana roots differed from that of nearby P. nigra, as all roots were in fine, sandy sediments, growing in one or more dense radial layers of which the most prominent was 0.2–0.3 m below the surface. The layers reflect deposition of fine sediments during floods. New fine sediment deposits promote the growth of a new root layer close to the aggraded ground surface. Root tensile strength was similar to Salicaceae species. These observations indicate that A. incana colonizes habitats that have already received fine sediment deposition, most likely induced by other young plants, especially Salicaceae species. A. incana then provides a high near‐surface root biomass, potentially further stabilizing surfaces and playing a complementary role as an ecosystem engineer. [ABSTRACT FROM AUTHOR]

Lead (Pb) is a common toxic heavy metal element that can be absorbed by plant roots and enter the food chain, damaging human health. Alnus cremastogyne has a wide native range, is fast growing, has a wide range of timber uses, and has rhizomatous roots that can improve planted soils. In this study, we evaluated whether Alnus cremastogyne has the potential to remediate Pb-contaminated soils through a 6-month pot experiment in soils with different Pb concentrations (0, 50, 100, 200, and 400 mg/kg). Our results indicate that Alnus cremastogyne plant height, basal diameter, and organ biomass decreased, H2O2 and MDA content increased, and the activities of antioxidant enzymes and osmotic regulators increased and then decreased with increasing lead concentrations. The Pb bioconcentration factor of Alnus cremastogyne was less than 1 at all Pb concentrations, and Pb accumulated mainly in the root system. This indicates that Alnus cremastogyne is not a Pb-enriched plant and does not have outstanding Pb transport capacity. The growth of Alnus cremastogyne was not significantly affected at low Pb concentrations, and its plant height, basal diameter, and biomass were significantly suppressed under high Pb stress. Therefore, Alnus cremastogyne is not a suitable species for the remediation of lead-contaminated soils but can be used as a silvicultural species in environments with low lead levels. [ABSTRACT FROM AUTHOR]

This work studies the multiple sources of impacts and disturbances in the Laja River (Central Chile) and evaluates the changes in water and sediment flows and planimetric geomorphic changes. The disturbances sources correspond to hydroelectric plants, water withdrawals for irrigation and the sustained decrease trend in rainfall in the basin. The changes in the plan‐view shape of the river reach were quantified using remote sensing techniques, through a supervised classification of Landsat 5 TM and 8 OLI satellite images, identified Water (W), Islands and Riverine Vegetation (IRV) and Bars and Banks Without Vegetation (BBWV), obtained a Kappa index>0,83 for a period of 15 years (2006–2021). Compared with historical records, the period of analysis shows a decrease in annual rainfall by 17.5%. In addition, water withdrawals for irrigation have contributed to a 64% decrease in monthly stream discharge during the dry season. As a consequence of the decrease in annual rainfall and water withdrawals for irrigation, the sediment transport capacity has also decreased by 10.5%. The changes in morphological driving variables (stream flows and sediment transport regimes) have manifested themselves in morphological changes, where it was possible to establish that a change in the channel form occurred in the last 15 years, going from a river with a single channel to a braided one. An important vegetation establishment has accompanied this morphological change on both riverbanks and the central bars. The colonizing vegetation corresponds to fast‐growing non‐native species (Salix spp., Populus spp. and Alnus spp). A stabilization of the channel form is expected, consolidating itself as a braided section with alternating vegetated bars. [ABSTRACT FROM AUTHOR]

A crude morpholine enamine of acetone treated with Lawesson's reagent unexpectedly yielded a six-membered thiaphosphinane-4-one. This compound is the first example of a new class of heterocycles. It has been proven that it is formed from 4-methyl-2-morpholino-1,3-pentadiene which is usually present in crude morpholine enamine batches. A mechanism of this regioselective reaction was postulated and a characteristic chair-like conformation of the product was examined in detail. Additionally, some unusual primary fragmentations of the product with the loss of H2S and isobutylene were observed for positive and negative ESI ionization mode, respectively. [ABSTRACT FROM AUTHOR]

A number of Phytophthora species have been identified as destructive plant pathogens and invasive species. They have the potential to affect a wide range of host plants and cause diseases in agricultural and forest ecosystems. Two Phytophthora species from rhizosphere soil samples collected from declining Alnus glutinosa in Bulgaria were isolated in the autumn of 2022. They were identified as Phytophthora polonica and Phytophthora hydropathica according to the DNA sequence analysis of the ITS region, as well as their morphological and physiological characteristics. The pathogenicity of both species to common and gray alder was evaluated by the inoculation of detached leaves and cuttings. Experimental data proved that P. polonica and P. hydropathica are able to cause leaf necrosis not only on A. glutinosa from which they were derived, but also on A. incana. No significant deference in the aggressiveness of the studied isolates from both Phytophthora species against the two tested plants was observed. Therefore, P. polonica and P. hydropathica were determined as potential threats for alder ecosystems in the country. This is the first report for the isolation of P. polonica in Bulgaria and represents the most southeastern point of the species distribution in Europe. [ABSTRACT FROM AUTHOR]

Background: The use of balloon microcatheters in interventional neuroradiology is well documented. However, their use is sometimes limited by the small diameter and excessive tortuosity of the vasculature. The Scepter Mini dual-lumen balloon microcatheter (SMBM) (Microvention, Aliso Viejo, CA) has been designed to address these challenges by decreasing the distal catheter profile, allowing distal access to the target vessel. Methods: This is a single-centre retrospective analysis of the initial cases performed using the Scepter Mini balloon microcatheter. The targeted conditions were vascular malformations. Patient clinical data, angiographic features of the vascular abnormalities and operation reports were reviewed and the procedural parameters, radiation doses, occlusion rates and complications were assessed. Results: A total of 15 SMBM were used in 11 cases. In all cases the procedure performed was balloon inflation and antegrade delivery of precipitating hydrophobic injectable liquid (PHIL) (Microvention, Aliso Viejo, CA) for embolisation of a targeted feeding vessel and cranial and spinal vascular malformations. Successful feeding vessel distal access and antegrade liquid embolisation was achieved in 100% of the cases. One of the 11 cases was an emergency procedure. One procedural target vessel rupture, likely due to overinflation, and three minor post-procedure complications were observed. Conclusion: The SMBM represents a significant advance in the treatment of cerebrospinal vascular malformations, allowing balloon catheter access into tortuous and small calibre vessels. [ABSTRACT FROM AUTHOR]

A taxonomically comprehensive perspective on the fungal associates of bark beetles (Coleoptera: Curculionidae: Scolytinae), and powerful molecular tools for detection of these fungi, are imperative to understanding bark beetle impacts on forest ecosystems. The most common filamentous fungi living alongside bark beetles in infested trees are ophiostomatoids (Ascomycota: Ophiostomatales and Microascales), yet an undescribed species of Neonectria (Neonectria sp. nov.; Ascomycota: Hypocreales) was recently identified cohabitating with the alder bark beetle, Alniphagus aspericollis, in red alder, Alnus rubra. The hardwood-infesting alder bark beetle is found throughout the range of its red alder host in the Pacific Coast region of North America and is associated with Neonectria sp. nov. in southwestern British Columbia, Canada. The aim of this study was to describe and name Neonectria sp. nov. and to develop a quantitative PCR (qPCR) assay to enable rapid detection of Neonectria sp. nov. from individual adult alder bark beetles and to define the distribution of the fungus. Neonectria sp. nov. was phylogenetically and morphologically determined to represent a distinct species closely related to N. ditissima and is described herein as Neonectria bordenii sp. nov. Neonectria bordenii was reliably detected from individual wholebeetle DNA extractions using a probe-based qPCR assay targeting multi-copy internal transcribed spacers (ITS) of nuclear ribosomal DNA. The qPCR assay amplified the fungus from 87.8 % (36/41) of individual alder bark beetle samples and was highly sensitive to N. bordenii, with a lower limit of detection of 1 × 10-6 ng/µL of culture DNA (or ~262 genome copies). Application of the qPCR assay developed in this study will expedite future research evaluating N. bordenii as a potential symbiote of the alder bark beetle. [ABSTRACT FROM AUTHOR]

Particleboard, engineered wood products as part of a large family of wood composite materials, developed in use mainly in the 1950s and 1960s to utilize inferior wood and wood waste when good-quality wood was in short supply; the annual production capacity worldwide is over 100 million m3. It is also necessary to have a lot of wood raw material for its production, although raw material resources are limited on our planet. In addition to the main wood species, it is therefore possible to think about the wider use of alternative, lesser-known European species of alder, larch, and birch in particleboard production. These three wood species represent an eco-friendly and sustainable wood alternative to the conventional wood raw materials used. This review confirms the diversity of the use of these three species in different fields and proves their suitability in relation to particleboard production. Fundamental research is ongoing in certain universities to determine the proportional shares of use of these tree species in particleboard (in a certain weight proportion in their core layers) for the purpose of formulating the correct technology shares and rules for their application in the wood-based panel industry. [ABSTRACT FROM AUTHOR]

Nitrogen oxides (NOx) play an important role for atmospheric chemistry and radiative forcing. However, NOx emissions from the vast northern circumpolar permafrost regions have not been studied in situ due to limitations of measurement techniques. Our goals were to validate the offline analytical technique, and based on this, to widely quantify in situ NOx emissions from peatlands in the southern Eurasian permafrost region. To this end, we conducted a comparison of online and offline flux measurements in 2018 and 2019 using the synthetic air flushing, steady‐state opaque chamber method. With differences in annual average and cumulative fluxes less than 0.1 μg N m−2 h−1 and 0.01 kg N ha−1 year−1, the online and offline fluxes were in good agreement, demonstrating the feasibility of conducting offline measurements in remote regions without power supply. The flux measurements over 2 years showed obvious NOx emissions of 0.05–0.14 and 0.13–0.30 kg N ha−1 year−1 in the hollow and hummock microtopography of permafrost peatlands, respectively. The rapid expansion of alder (Alnus sibirica) in the peatlands induced by permafrost degradation significantly increased soil mineral N contents and NOx emissions depending on the age of alder (0.64–1.74 and 1.44–2.20 kg N ha−1 year−1 from the alder forests with tree ages of 1–10 years and 11–20 years, respectively). Alder expansion also intensively altered the thermal state of permafrost including the sharp increases of soil temperatures during the non‐growing season from October to April and active layer thickness. This study provides the first in situ evidences of NOx emissions from the northern circumpolar permafrost regions and uncovers the well‐documented expansion of alders can substantially stimulate NOx emissions and thus, significantly affect air quality, radiative forcing, and ecosystem productivity in the pristine regions. [ABSTRACT FROM AUTHOR]

Alder yellows (ALY) phytoplasma (16SrV-C) is associated with ALY, a disease of several Alnus (alder) species in Europe and A. rubra in North America. In all affected species, the symptoms are similar. However, latent infections are common. ALY phytoplasma includes different strains which may be occasionally transmitted to grapevines leading to some grapevine yellows diseases. In the current study, visual symptom assessment and PCR-based methods using universal and group-specific phytoplasma primers were used to update and extend knowledge on the occurrence, impact, and genetic diversity of ALY phytoplasma in declining and non-symptomatic A. glutinosa and A. cordata trees in the Basilicata and Campania regions of southern Italy. ALY phytoplasma was detected in 80% of alder trees examined. In symptomatic trees, no other cause of disease was observed. More than half of alder trees that tested phytoplasma-positive proved to be latently infected. A considerable genetic variability was observed among the newly recorded ALY phytoplasma strains in southern Italy in almost of the genes examined. These included 16S rRNA, 16S/23S rDNA spacer region, ribosomal protein rpsV (rpl22) and rpsC (rps3), map, imp, and groEL genes. Eleven new genotypes were identified at map gene sequence level. However, the genetic differences observed were not related to plant host species, geographical origin, and symptoms shown by infected alder trees. Also, this study indicates that ALY phytoplasma is more widespread than previously thought. [ABSTRACT FROM AUTHOR]

We analyzed mineralogical characteristics, and major as well as rare earth element concentrations, from a cryptotephra layer in sediments of the infilled maar of Auel (Eifel, Germany). The results of detailed geochemical analyses of clinopyroxenes and their glassy rims from the Auel cryptotephra layer showed that they are similar to those from the thick Campanian Ignimbrite tephra occurrence in a loess section at Urluia (Romania). Both tephras show idiomorphic green clinopyroxenes and formation of distorted grains up to millimeter scale. The cryptotephra in the Auel core has a modelled age of around 39,940 yr b2k in the ELSA-20 chronology, almost identical to the latest 40Ar/39Ar dates for the Campanian Ignimbrite/Y-5 (CI/Y-5) eruption. These observations suggest that parts of the CI/Y-5 ash cloud were transported also northwestward into Central Europe, whereas the main branch of the CI/Y-5 ash plume was transported from southern Italy towards the NE, E, and SE. Based on pollen analyses, we conclude there was no direct effect on vegetation from the CI/Y-5 fallout in the Eifel area. Trees, shrubs, and grasses remained at pre-tephra-airfall levels for roughly 240 years, but changed around 39,700 yr b2k when thermophilic woody plants (e.g., Alnus and Carpinus) disappeared and Artemisia spread. This change in vegetation was well after the Laschamp geomagnetic excursion and also after the GI9 interstadial and quite probably represents the onset of the Heinrich Event 4 (H4) cold spell, when climatic conditions over the North Atlantic, and apparently also in Central Europe, deteriorated sharply. [ABSTRACT FROM AUTHOR]

Wood heat treatment has been held an effect way to adjust wood color. To obtain a better understanding of the in-service color stability of heat-treated wood, heat-treated and untreated red alder boards were exposed to outdoor space, indoor space lit by LED lights and transitional space of a bay window for one year. The evolution of CIELAB color parameters was recorded and the chemical changes of the irradiated boards were analyzed using Fourier transform infrared spectroscopy. It was found that the heat treatment significantly darkened the wood, and higher treatment temperature led to a darker appearance. The exposure tests lowered the color difference caused by the treatment. The color stability of heat-treated and untreated wood is space and time dependent. The indoor space exerted limited influence on wood color. The outdoor space eventually turned the board color to silver gray with the combined forces of photodegradation and leaching, which basically eliminated the visual difference between different types of boards. In the transitional space, all the boards experienced a yellowing process mainly induced by longer wavelength light, to which, the heat-treated boards were more sensitive and showed greater color change than the untreated ones. [ABSTRACT FROM AUTHOR]

The present research is framed within an interdisciplinary archeological project that aims to reconstruct the environmental conditions in which human occupations developed in the locality of Barrancas, Dry Puna Argentina, during the Holocene. The aims of this work were to: (1) study the regional vegetation and the modern pollen dispersal-sedimentation process; and (2) generate a reference database for interpretation of the fossil pollen records of the Holocene in the Dry Puna (3) provide information for the study of the relationship between human populations and vegetation in the area during the Late-Holocene. The results show that the main pollen types that characterize the regional vegetation were represented in the surface samples (herbaceous steppe, shrub steppe, mixed steppe, and vegas). Also the environments with evidence of anthropic impact were identified by specific plant species and the corresponding pollen grain. The representation of the vegetation was quantified according to the different pollen types. The study used indices of association to establish relationships between modern pollen and vegetation, and showed a weak association for Solanaceae and Verbenaceae; an over-representation of Ephedrae, Alnus acuminata, Malvaceae, Chenopodiaceae-Amaranthaceae; an association of Asteraceae; the absence of association of Cactaceae and Portulacaceae; and a strong association of Poaceae. These results allow us to specify the interpretation of fossil records and past environments in relation to anthropic modifications on the landscape. [ABSTRACT FROM AUTHOR]

Today, allergies have become a serious problem. PR-10 proteins are clinically relevant allergens that have the ability to bind hydrophobic ligands, which can significantly increase their allergenicity potential. It has been recently shown that not only the birch pollen allergen Bet v 1 but also the alder pollen allergen Aln g 1, might act as a true sensitizer of the immune system. The current investigation is aimed at the further study of the allergenic and structural features of Aln g 1. By using qPCR, we showed that Aln g 1 was able to upregulate alarmins in epithelial cells, playing an important role in sensitization. With the use of CD-spectroscopy and ELISA assays with the sera of allergic patients, we demonstrated that Aln g 1 did not completely restore its structure after thermal denaturation, which led to a decrease in its IgE-binding capacity. Using site-directed mutagenesis, we revealed that the replacement of two residues (Asp27 and Leu30) in the structure of Aln g 1 led to a decrease in its ability to bind to both IgE from sera of allergic patients and lipid ligands. The obtained data open a prospect for the development of hypoallergenic variants of the major alder allergen Aln g 1 for allergen-specific immunotherapy. [ABSTRACT FROM AUTHOR]

Atmospheric CO2 levels have been increasing, and likewise, increasing drought events have been following increasing temperatures. There is very little literature on the effects of climate change factors on early-successional deciduous species used for ecological restoration. Thus, morphological and allometric variation in four coppiced early-successional deciduous species was examined in response to a 2 × 2 factorial of ambient CO2 (aCO2, 400 ppm) and elevated CO2 (eCO2, 800 ppm), as well as well-watered and drought treatments with 15%–20% and 5%–10% volumetric moisture content, respectively, grown in sandy soil with low soil nitrogen (N) under greenhouse conditions. The four species examined were as follows: green alder (Alnus viridis subsp. crispa (Ait.) Turrill), speckled alder (A. incana subsp. rugosa (Du Roi) R.T. Clausen), gray birch (Betula populifolia (Marshall)), and white birch (B. papyrifera (Marshall)), and all are from the same phylogenetic family, Betulaceae. Genus differences in morphological and growth traits were large, especially in response to the environmental treatments used. Alders upregulated all growth traits under eCO2 because of the strong coppicing sink effect and the additional foliar N provided by the actinorhizal ability of the genus, whereas birches remained the same or slightly decreased under eCO2. As a result, alders have a significantly greater foliar N than birches, with 2.8 and 1.0%, respectively. All species reduced growth under drought, and green alder had the greatest stem dry mass growth, followed by speckled alder and then the birches. Under drought, eCO2 not only mitigated the alder drought dry mass but, in fact, doubled the stem dm, whereas eCO2 only just mitigated the birches drought response. When corrected for size using stem height, alders allocated more to stem and leaf and less to root dry mass than birches. Atmospheric CO2 and soil moisture treatments changed organ biomass allocation. The tallest stem height was the best predictor of total (above and below) dry mass. With increasing atmospheric CO2, particularly on low nutrient sites, the results show alders are capable of sequestering far more carbon than birches. In addition, with more atmospheric CO2, alders can mitigate against drought conditions better compared to birches. [ABSTRACT FROM AUTHOR]

The results of the study obtained for spores and pollen from the subfossil spectra of samples from the Bykovsky Peninsula (northern Yakutia) are presented in order to compare them with the current vegetation composition, to consider the major cryogenic disturbances of palynological remains, and to analyze their cryogenic destruction processes. The abundant alien pollen of Betula sect. Nanae and Alnus in the spectra is due to open landscapes, relatively low pollen productivity, and the transition of herbs and shrubs prevailing in the local phytocenoses to a vegetative propagation in severe climatic conditions. The selective role of cryogenesis in the spore–pollen spectra formation is related to repeated sediment thawing and freezing cycles, resulting in physical damage (ruptures and cracks) in palynological remains. The results of research contribute to the study of the methodological aspects of palynotaphonomy in cryolithic zone sediments. They can be used to reconstruct the Neopleistocene landscapes and vegetation and to study cryopreservation of fossil living organisms and their diversity in the permafrost areas. [ABSTRACT FROM AUTHOR]

Landmark-based geometric morphometrics (GM) was used to examine, for the first time, spontaneous hybridization between Alnus incana (L.) Moench and Alnus rohlenae Vít, Douda and Mandák, and to assess inter- and intrapopulation variability in leaf shape, leaf size and venation in natural populations in Serbia (Western Balkans). Two geographically distant (30 km) and two close (1.2 km) populations were selected to examine hybridization. The variability in leaf shapes was assessed by canonical variate analysis and linear discriminant analysis performed on the symmetric component of variation. Covariation between the symmetric component of shape variation and the number of pairs of secondary leaf veins was investigated with partial least squares analysis. Static allometry was examined for the first time in the genus Alnus Mill. A higher proportion of A. incana leaves was classified as A. rohlenae in geographically close populations, which is in accordance with the hypothesis about spontaneous hybridization. No single leaf of A. rohlenae was classified as A. incana, indicating that putative hybrids can only be found in grey alder populations. This study demonstrates that GM is a powerful tool for species delimitation and hybrid detection in the genus Alnus and it can be used for preliminary screening in hybrid zones. [ABSTRACT FROM AUTHOR]

Caucasian alder (Alnus subcordata) is among the major constituents of the Hyrcanian forests extending all along the southern coast of the Caspian Sea in northern Iran. An angular leaf spot with a yellowish chlorotic halo has attained a widespread occurrence throughout the forest and suburban areas of the northern provinces including Guilan, Mazandaran and Golestan. Strains of a Xanthomonas sp. were consistently isolated from the symptomatic leaves of A. subcordata. Colonies of the isolates were yellow circular, convex and mucoid on nutrient agar containing glucose or sucrose. In multilocus sequence analysis using the genes gyrB, rpoD, dnaK, gltA, fyuA and gapA, the representative isolates occupied a clade shared by the known pathovars of Xanthomonas arboricola. The isolates were relatively heterogeneous phenotypically, but more so in their rep‐PCR fingerprints. Pathogenicity of several isolates was confirmed on seedlings of A. subcordata and Alnus rhombifolia, whereas Alnus cordata, Alnus glutinosa and Alnus crispa appeared not to be susceptible. Based on these characteristics, the isolates causing angular leaf spots of Caucasian alder appear to represent a novel pathovar of X. arboricola. [ABSTRACT FROM AUTHOR]

Black alder Alnus glutinosa (L.) Gaertn. and grey alder Alnus incana (L.) Moench, cover up to 11% of the forest area in Latvia. As alder dieback caused mainly by Phytophthora has been reported in several countries, we aimed to assess the distribution of Phytophthora-like symptomatic alders in Latvia and surveyed 208 alder-dominated forest stands. Symptomatic alders were found in 28% of stands, and in 8% of stands, the infected tree proportion comprised more than 10% of trees. Pocket Diagnostics® tests confirmed Phytophthora or other oomycete infection in 13% of stands, mainly in Central and Eastern Latvia. Trees that tested positive were mainly grey alder (1.0% of the overall number of surveyed grey alders), and fewer black alders tested positive (0.2% of the overall number of surveyed black alders). Grey alder had a significantly higher probability of having symptoms at both the stand level (probability 0.429) and the individual tree level (probability 0.017) in comparison to black alder (probabilities 0.185 and 0.004, respectively). In conclusion, alders with Phytophthora-like symptoms were found throughout the territory of Latvia, however, infection risk for the economically important tree species black alder is low. [ABSTRACT FROM AUTHOR]

We study the long time behaviour of a Brownian particle evolving in a dynamic random environment. Recently, Cannizzaro et al. (Ann Probab 50(6):2475–2498, 2022) proved sharp log -super diffusive bounds for a Brownian particle in the curl of (a regularisation of) the 2-D Gaussian Free Field (GFF) ω ̲ . We consider a one parameter family of Markovian and Gaussian dynamic environments which are reversible with respect to the law of ω ̲ . Adapting their method, we show that if s ≥ 1 , with s = 1 corresponding to the standard stochastic heat equation, then the particle stays log -super diffusive, whereas if s < 1 , corresponding to a fractional heat equation, then the particle becomes diffusive. In fact, for s < 1 , we show that this is a particular case of Komorowski and Olla (J Funct Anal 197(1):179–211, 2003), which yields an invariance principle through a Sector Condition result. Our main results agree with the Alder–Wainwright scaling argument (see Alder and Wainwright in Phys Rev Lett 18:988–990, 1967; Alder and Wainwright in Phys Rev A 1:18–21, 1970; Alder et al. in Phys Rev A 4:233–237, 1971; Forster et al. in Phys Rev A 16:732–749, 1977) used originally in Tóth and Valkó (J Stat Phys 147(1):113–131, 2012) to predict the log -corrections to diffusivity. We also provide examples which display log a -super diffusive behaviour for a ∈ (0 , 1 / 2 ] . [ABSTRACT FROM AUTHOR]

Alnus glutinosa is an actinorhizal plant that fixes N via actinomycetes. Compared to other trees, A. glutinosa is more resistant to environmental stress and able to uptake soil nutrients more easily. Alnus glutinosa grows well not only in natural stands but also in degraded environment or soil in need of restoration. Changes in the contents of selected macro-, micro-, and non-nutrient elements in the leaves of A. glutinosa during the vegetation season were monitored in the Ore Mountains (Czech Republic), an area affected by extreme air pollution in the past. Decreased foliar content of N, P, K, and Cu, and increased content of Ca, Mn, Zn, and Al were observed; the content of other elements (S, Mg, Pb, and Cd) varied during the growing season or remained constant. From the viewpoint of nutrition, the content of N, S, Ca, and Mg macroelements was adequate; concentrations of P and K were low. Excessive amounts of Mn and Zn were measured, and the level of Cu was good. Non-nutrient elements Pb and Cd were present at the background level, and the level of Al was high. N/P, N/Ca, N/Mg, and Ca/Mg ratios were balanced, S/N value showed the lack of S, and N/K ratio indicated low content of K, which caused also suboptimal K/Ca and K/Mg values. The P/Al ratio varied from balanced to lower values. The content of individual elements and monitored changes were influenced by the amount of elements in the soil, moisture conditions, foliage phenology, and altitude. [ABSTRACT FROM AUTHOR]

Barren sites that lack soil are exposed to some of the harshest elements, which include high temperatures, solar radiation, wind, extreme temperature changes, and low soil moisture and nutrient conditions. An ecological restoration experiment was conducted using three site-preparation treatments, straw (S), Meri-Crusher (MC), and coarse woody debris (CWD), in a site-/no site-preparation 2 × 2 × 2 factorial on sites that had been barren for 25 years. In addition, four early successional deciduous species, white birch (WB, Betula papyrifera Marshall), gray birch (GB, Betula populifolia Marshall), green alder (GA, Alnus viridis Vill. subsp. crispa Ait), and speckled alder (SA, Alnus incana L. subsp. rugosa Du Roi), were examined. The two- and three-way interactions were almost all magnitude effects and not rank changes. Gray birch had the greatest overall first-year height growth, followed by GA, SA, and WB, with 12.1, 9.7, 9.6, and 5.6 cm, respectively. Straw doubled first-year growth, while CWD and MC increased first-year height growth by 43 and 31%, respectively. Straw's ability to retain moisture in the dry summer provided the greatest benefit. In the second year, GA had the greatest height growth, followed by SA, GB, and WB, with 42.5, 30.5, 13.4, and 13.0 cm, respectively. Alders form symbiotic relationships with N-fixing bacteria and, although this was observed in some first-year roots, they did not fully express this advantage at these severely degraded sites until the second year, which allowed them to surpass birches in growth. Site-preparation treatments furthered their height growth affect, with S, and CWD doubling second-year height growth and MC, with an increase of 25%. Alders and birches had, on average, three and one stems, respectively, and the mean stem number of alders increased under S and CWD. After two years, overall stem dry mass had very large genus and species differences with GA, SA, GB, and WB, with 58.4, 30.3, 5.4, and 4.0 g, respectively. The N-fixing ability of alders under these conditions resulted in a 13-fold stem dry mass production increase compared with birches. Straw tripled, CWD doubled, and MC increased stem dry mass by 40%. For WB, site-preparation combinations had an additive effect, whereas GB, GA, and SA had several combined site-preparation treatments showing synergistic results, which were greater than the additive effects of single treatments. Under the control (no site prep.), second-year stem dry masses for WB, GB, GA, and SA were 0.7, 1.4, 17.8, and 0.5 g, respectively. Under the three combined treatments, MC × S × CWD, WB, GB, GA, and SA had 6.6, 12.3, 115.7, and 70.6 g stem dry masses, respectively. SA is ecologically a lowland species, hence the low 0.5 g under the control; however, the result under the three combined treatments demonstrates their combined effectiveness on these barren sites. Green alder seems to be the best adapted to the sites, having the greatest stem dry mass under control, although that was considerably magnified under the site-preparation treatments. This study using combinations of treatments with these early successional species introduces a novel research concept, and similar studies in the literature are currently lacking, creating an opportunity for future exploration. [ABSTRACT FROM AUTHOR]

Alnus (Alnus acuminata Kunth) has been widely promoted under climate change mitigation and adaptation programs in the East African highlands. However, information is lacking on the impact of pruning management and green manure (GM) application on soil health and the productivity of associated crops. Using a large suit of soil quality indicators, crop growth and yield measurements, this study identified appropriate combinations of alnus pruning levels and GM application for sustainable intensification of potato (Solanum tuberosum) and wheat (Triticum aestivum) production in alley cropping with Alnus. This study compared six treatments, namely, (1) sole crops of potato or wheat (control), (2) sole crop + GM, (3) 75% pruning, (4) 75% pruning + GM, (5) 90% pruning and (6) 90% pruning + GM. In all treatments potato and wheat were grown in rotation. The best treatments were the 75% pruning + GM and 90% pruning + GM, which significantly differed from the control in soil pH, soil organic carbon (SOC), total nitrogen (TN), total phosphorus (P), exchangeable calcium (Ca) contents, the N:P and C:P stoichiometric ratios and the soil structural stability index (SSI). These treatments increased soil pH by 5–6%, SOC by 74–82%, TN by 58–68%, exchangeable Ca by 76–81%, total P by 17–21%, the N:P ratio by 40%, C:P ratio by 43–51%, SSI by 71–79%, potato tuber yields by 17–21% and wheat yields by 21–32% over the control. Therefore, it is concluded that pruning and application of alnus green manure can significantly improve soil health and crop productivity on degraded soils in the study area. [ABSTRACT FROM AUTHOR]

In this study, alder, spruce, and beech woods were used for homogeneous symmetric, inhomogeneous symmetric (combined) and inhomogeneous non-symmetric glued laminated timber (glulam) beams glued with resorcinol phenol formaldehyde (RPF) adhesive. The aim of this paper is to determine and compare the modulus of elasticity of glulam beams using three methods, i.e., analytical calculation, numerical model (FEM) and experimental testing. As an additional characteristic, the bending strength (MOR) of the beams was determined during experimental testing. Analytical calculation was used to calculate the modulus of elasticity (MOE) of glued laminated timber based on the knowledge of the modulus of elasticity of solid wood and to estimate the location of the neutral axis during bending. According to calculations, for symmetrical combinations, the deviation from the real neutral axis does not exceed 5%. In the case of the modulus of elasticity, the deviation is an average of 4.1% from that of the actual measured beams. The numerical model includes finite element modelling, where the deflection of the modelled beams can be calculated with a deviation of up to 10%. The last method was experimental testing of glued beams using four-point bending, in which, among homogeneous beams, beech glulam beams achieved the highest MOE and MOR, while alder glulam beams achieved the lowest. The combination of wood species resulted in an increase in both MOE and MOR compared to homogeneous spruce and alder beams. [ABSTRACT FROM AUTHOR]

Three central steps during the biosynthesis of cytochalasan precursors, including reductive release, Knoevenagel cyclisation and Diels Alder cyclisation are not yet understood at a detailed molecular level. In this work we investigated the reductive release step catalysed by a hybrid polyketide synthase non‐ribosomal peptide synthetase (PKS‐NRPS) from the pyrichalasin H pathway. Synthetic thiolesters were used as substrate mimics for in vitro studies with the isolated reduction (R) and holo‐thiolation (T) domains of the PKS‐NRPS hybrid PyiS. These assays demonstrate that the PyiS R‐domain mainly catalyses an NADPH‐dependent reductive release of an aldehyde intermediate that quickly undergoes spontaneous Knoevenagel cyclisation. The R‐domain can only process substrates that are covalently bound to the phosphopantetheine thiol of the upstream T‐domain, but it shows little selectivity for the polyketide. [ABSTRACT FROM AUTHOR]

This study delved into the combustion properties of combined glulam bonded using polyurethane (PUR) and resorcinol-phenol-formaldehyde (RPF) adhesives. The experiment involved three distinct wood species, namely, spruce, alder, and beech, which were combined in homogeneous, non-homogeneous symmetrical, and non-homogeneous asymmetrical arrangements. These species were selected to represent a spectrum, namely, softwood (spruce), low-density hardwood (alder), and high-density hardwood (beech). The varying combinations of wood species illustrate potential compositions within structural elements, aiming to optimize mechanical bending resistance. Various parameters were measured during combustion, namely, the heat release rate (HRR), peak heat release rate (pHRR), mass loss rate (MLR), average rate of heat emission (ARHE), peak average rate of heat emission (MARHE), time to ignition (TTI), and effective heat of combustion (EHC). The findings indicate that incorporating beech wood into the composite glulam resulted in an increase in heat release, significantly altering the burning characteristics, which was particularly evident at the second peak. Conversely, the use of spruce wood exhibited the lowest heat release rate. Alder wood, when subjected to heat flux at the glued joint, displayed the highest heat emission, aligning with the results for EHC and MARHE. This observation suggests that wood species prone to early thermal decomposition emit more heat within a shorter duration. The time to ignition (TTI) was consistent, occurring between the first and second minute across all tested wood species and combinations. Notably, when subjected to heat flux, the glulam samples bonded with PUR adhesive experienced complete delamination of the initial two glued joints, whereas those bonded with RPF adhesive exhibited only partial delamination. [ABSTRACT FROM AUTHOR]

Atmospheric CO2 levels have been increasing, and these changes may result in differential adaptive responses in both genera and species and highlight the need to increase carbon sequestration. Ecophysiological and morphological responses of four early-successional deciduous species were examined under ambient CO2 (aCO2, 400 ppm) and elevated CO2 (eCO2, 800 ppm) treatments. The four species, all of which are used in restoration, were Alnus viridis subsp. crispa (Ait.) Turrill (green alder), A. incana subsp. rugosa (Du Roi) R.T. Clausen (speckled alder), Betula populifolia (Marshall) (gray birch), and B. papyrifera (Marshall) (white birch); all are from the same phylogenetic family, Betulaceae. We examined biochemical efficiencies, gas exchange, chlorophyll fluorescence, chlorophyll concentrations, foliar nitrogen (N), and growth traits. A general linear model, analysis of variance, was used to analyze the functional carbon efficiency and growth differences, if any, among genera, species, and provenances (only for growth traits). The alders had greater biochemical efficiency traits than birches, and alders upregulated these traits, whereas birches mostly downregulated these traits in response to eCO2. In response to eCO2, assimilation either remained the same or was upregulated for alders but downregulated for birches. Stomatal conductance was downregulated for all four species in response to eCO2. Intrinsic water use efficiency was greater for alders than for birches. Alders exhibited a consistent upregulation of stem dry mass and height growth, whereas birches were somewhat lower in height and stem dry mass in response to eCO2. Foliar N played an important role in relation to ecophysiological traits and had significant effects relative to genus (alders > birches) and CO2 (aCO2 > eCO2), and a significant genus × CO2 interaction, with alders downregulating foliar N less than did birches. Covariate analysis examining carbon efficiency traits in relation to foliar N showed clear functional responses. Both species in both genera were consistent in their ecophysiological and morphological responses to CO2 treatments. There was supporting evidence that assimilation was sink-driven, which is related to a plant organ's ability to continue to grow and incorporate assimilates. The alders used in this study are actinorhizal, and the additional available foliar N, paired with increased stem dry mass sink activity, appeared to be driving upregulation of the carbon efficiencies and growth in response to eCO2. Alders' greater carbon efficiencies and carbon sequestration in impoverished soils demonstrate that alders, as opposed to birches, should be used to accelerate ecological restoration in a world of increasing atmospheric CO2. [ABSTRACT FROM AUTHOR]

Due to land use change, green alder (Alnus alnobetula), formerly restricted to moist slopes, is now expanding to drier sun-exposed sites at the alpine treeline. The highly productive shrub is forming closed thickets, establishing nitrogen-saturated species poor shrublands. To evaluate wood anatomical adaptations to changing environmental conditions, we analyzed vessel characteristics (mean vessel area, MVA; vessel density, VD; and theoretic conductive area, TCA) and axial parenchyma abundance, as well as their distribution in the annual ring at a moist north-facing and a dry south-facing site at the alpine treeline on Mt. Patscherkofel (Central European Alps, Austria). Results revealed that lower soil water availability and enhanced evaporative demand did not affect MVA while VD and TCA were significantly reduced at the dry south-facing site. This suggests that in green alder, vessel size is a static trait whereas vessel number responds plastic. Limited water availability also triggered a significant increase in axial parenchyma, confirming the important role of xylem parenchyma in water relations. Harsh environmental conditions at the distributional limit of green alder may have affected xylogenesis, leading to a near semi-ring-porous distribution of vessels and an accumulation of parenchyma in the late growing season. We conclude that in a warmer and drier climate, growth limitation and physiological stress may set limits to the distribution of Alnus alnobetula at drought-prone sites in the alpine treeline ecotone. [ABSTRACT FROM AUTHOR]

Trees established in linear formations can be utilised as windbreak structures on farms as a form of agroforestry system. We present an extensive data package collected from an active berry farm located near Stellenbosch, South Africa considering hydrological, pedological, dendrological and meteorological measurements centred around an Italian alder (Alnus cordata (Loisel.) Duby) windbreak and a blackberry (Rubus fruticosus L. Var. 'Waldo') crop. Data was collected between September 2019 and June 2021. The data is available from Hassler et al. (2023) and includes: solar radiation, precipitation characteristics, vapour pressure deficit, air temperature, humidity, atmospheric pressure, wind speed and direction, gust speed, lightning strikes and distance recorded at 10 minute intervals; soil moisture and matric potential in two profiles at 15 minute intervals alongside soil samples at various depths describing soil texture, hydraulic conductivity and water retention parameters; soil profile description accompanied by 60 topsoil samples describing carbon and nitrogen and exchangeable base cation concentrations as well as potential cation exchange capacity and descriptions of soil texture; dendrological measurements present point cloud data for the study windbreak trees and surrounding features alongside cylinder models of the windbreak trees with volume and biomass data, foliage data as a product of an existing leaf creation algorithm is also given. The provided data is intended to explore the interaction between trees and crops in agroforestry landscapes. [ABSTRACT FROM AUTHOR]

Diels--Alder cycloaddition reactions between the biomass-derived platform molecule levoglucosenone (2) and various cyclic dienes such as α-terpinene produced a range of adducts, including compound 28. Manipulation of these adducts then afforded a series of derivatives. So, for example, reductions of the associated carbonyl groups delivered the corresponding alcohols including compound 29 and on reaction of these with diethylaminosulfur trifluoride rearranged fluorination products such as tetracycle 30 were obtained. An analogous suite of compounds was obtained by manipulation of the Diels--Alder adducts derived from reacting the same dienes with iso-levoglucosenone that was itself obtained through simple manipulation of levoglucosenone. Our earlier studies suggest that various of these derivatives could be used in the production, via ring-opening metathesis polymerisation (ROMP), of new bio-based polymers. [ABSTRACT FROM AUTHOR]

Tree-ring δ15N may depict site-specific, long-term patterns in nitrogen (N) dynamics under N2-fixing species, but field trials with N2-fixing tree species are lacking and the relationship of temporal patterns in tree-ring δ15N to soil N dynamics is controversial. We examined whether the tree-ring δ15N of N2-fixing red alder (Alnus rubra Bong.) would mirror N accretion rates and δ15N of soils and whether the influence of alder-fixed N could be observed in the wood of a neighboring conifer. We sampled a 27-year-old replacement series trial on south-eastern Vancouver Island, with red alder and coastal Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) planted in five proportions (0/100, 11/89, 25/75, 50/50 and 100/0) at a uniform stem density. An escalation in forest floor N content was evident with an increasing proportion of red alder, equivalent to a difference of ~750 kg N ha−1 between 100% Douglas-fir versus 100% alder. The forest floor horizon also had high δ15N values in treatments with more red alder. Red alder had a consistent quadratic fit in tree-ring δ15N over time, with a net increase of |$\sim$| 1.5‰, on average, from initial values, followed by a plateau or slight decline. Douglas-fir tree-ring δ15N, in contrast, was largely unchanged over time (in three of four plots) but was significantly higher in the 50/50 mix. The minor differences in current leaf litter N content and δ15N between alder and Douglas-fir, coupled with declining growth in red alder, suggests the plateau or declining trend in alder tree-ring δ15N could coincide with lower N2-fixation rates, potentially by loss in alder vigor at canopy closure, or down-regulation via nitrate availability. [ABSTRACT FROM AUTHOR]