Search

This study describes the seasonal changes in cell-to-cell transport in three selected angiosperm tree species, Acer pseudoplatanus (maple), Fraxinus excelsior (ash), and Populus tremula × tremuloides (poplar), with an emphasis on the living wood component, xylem parenchyma cells (XPCs). We performed anatomical studies, dye loading through the vascular system, measurements of non-structural carbohydrate content, immunocytochemistry, inhibitory assays and quantitative real-time PCR to analyse the transport mechanisms and seasonal variations in wood. The abundance of membrane dye in wood varied seasonally along with seasonally changing tree phenology, cambial activity, and non-structural carbohydrate content. Moreover, dyes internalized in vessel-associated cells and 'trapped' in the endomembrane system are transported farther between other XPCs via plasmodesmata. Finally, various transport mechanisms based on clathrin-mediated and clathrin-independent endocytosis, and membrane transporters, operate in wood, and their involvement is species and/or season dependent. Our study highlights the importance of XPCs in seasonally changing cell-to-cell transport in both ring-porous (ash) and diffuse-porous (maple, poplar) tree species, and demonstrates the involvement of both endocytosis and plasmodesmata in intercellular communication in angiosperm wood. [ABSTRACT FROM AUTHOR]

Equine atypical myopathy (AM also referred to as multiple acyl-CoA dehydrogenases deficiency [MADD]) is thought to be caused by toxins metabolized from hypoglycin A (HGA) and méthylènecyclopropylglycine (MCPrG). HGA is contained in the seeds and seedlings of the sycamore tree (Acer pseudoplatanus); MCPrG has so far only been confirmed in seeds. Among other things, these substances can disrupt the fatty acids β-oxidation pathway with the subsequent accumulation of certain acylcarnitines. The tentative diagnosis is based on anamnesis and clinical signs and can be verified by the detection of elevated creatine kinase activity, specific profile of acylcarnitines and the presence of HGA, MCPrG conjugates and/or their metabolites in peripheral blood and/or urine. Dry blood spots were collected for 15 days from a 3.5-year-old stallion which had been affected by AM and, as a control group, from twelve healthy horses. Two mass spectrometry methods were used for the analysis of 31 acylcarnitines, carnitine, HGA, MCPrG and their metabolites. HGA and six increased acylcarnitines were detected in the patient’s blood throughout the monitoring period. Nine acylcarnitines were strongly correlated with HGA. Multivariate statistical analysis showed a clear separation of samples from the AM horse, where the metabolic profile tended to normalization in the later days after intoxication. Due to the longer persistence in the blood, the detection of HGA and elevated acylcarnitines profile appear to be an appropriate tool to confirm the diagnosis of AM, compared to metabolic products of HGA and MCPrG even in advanced cases.

The paper presents an original laboratory method developed to determine and compare the light-induced colour changes of uncoated and coated wood surfaces, while also allowing the highlighting and evaluation of the individual contributions of the substrate and coating film to the global effect. Two types of wood test samples: V1 (uncoated) and V2 (coated) and coating films on 1mm thick clear glass slides were employed. The behaviour of the wood substrate under the coating film was simulated on uncoated substrate covered with a coated glass slide. European maple (Acer pseudoplatanus L.) and two types of transparent water-based varnishes with 2k formulations were used. The samples were exposed for up to 72 hours to artificial UV-VIS light in accelerated tests simulating natural light passing through window glass. Colour changes were measured in the CIELab system, as well as the chemical changes of the wood substrate and the coating films by FTIR analysis. Exposure of uncoated maple wood resulted in a total colour difference (ΔE) of 10.83 units and this was only slightly reduced by coating (9.29-9.81 units). Exposure through the glass slide reduced the colour changes of the uncoated and coated wood surfaces by 37-43%. Colour changes of 5.79-6.85 units were measured on the wood substrate exposed under coated glass slides, whilst the colour changes of the coating films on glass slides were only 0.64-1.0 units, which indicates a maximum contribution of the wood substrate to the light-induced colour changes of the coated surfaces. FTIR investigation confirmed this finding. [ABSTRACT FROM AUTHOR]

The objective of the research consisted in the analysis of the qualitative parameters of 380 lots of seeds of sycamore maple (Acer pseudoplatanus L.) originated from all over Romania, in the last 21 years (2003-2023). In the context of global warming, the influence of the main climatic factors (air temperature and atmospheric precipitations) on the qualitative parameters of the seeds of sycamore maple was studied for two leading counties regarding the tested seed lots, Caraș-Severin and Sibiu. The research was carried out in the forest seed testing laboratory of the INCDS "Marin Drăcea" Brașov Station. All laboratory analyses, carried out between 2003 and 2023, were made in according with the international rules established by ISTA and implemented in Romania by SR 1908/2004 standard. Average values for purity (94.4%), viability (72.9%) and mass of 1000 seeds (130.5 g) were obtained for the 380 analysed lots of sycamore maple seeds which places them in the 2nd class of quality, very close to the thresholds of the first class, where 40% of the lots are included. The highest values of seed viability were recorded in 2008, 2011 and 2012, and the leading counties were Mureș, Buzău and Timiș. Positive and highly significant correlations were obtained among the main qualitative traits of the seeds as well as a multiple correlation, also positive and highly significant, between purity, viability and mass of 1000 seeds. Heavier and higher purity seeds will have better viability. In both analysed counties (Sibiu and Caraș-Severin), regarding the influence of climatic factors on the seed’s quality parameters, in the year in which the highest temperature was recorded, and fell among the lowest amounts of precipitation (year 2019), a very low values for seeds viability were obtained (penultimate place, in Sibiu, and 15th out of 20, in Caraș-Severin). The obtained results indicate a possible risk of reducing the viability of the sycamore maple seeds in the future, in the context of climate warming, with negative effects on the existence of this important mixed species in the Romanian forests. [ABSTRACT FROM AUTHOR]

Global climate change continues to leave irreversible effects worldwide. With the increase in the effects of climate change, especially in recent years, the amount of UV-B radiation reaching the earth's surface is also likely to increase. With increasing temperatures, the amount of precipitation in the world has decreased, and the drought has started to alarm. This study is tried to understand how plants can respond to these stresses using ash-leaf maple (Acer negundo L.) and sycamore maple (Acer pseudoplatanus L.) species. The effects of these stress factors on plant leaf morphology were investigated by applying certain intensities of drought (moderate [T2] and severe drought [T3]) and UV-B (8 kJ m-2 h-1 [T4] and 12 kJ m-2 h-1 [T5]) stresses on these two species with T1 (control) treatment. As a result, leaf width in A. pseudoplatanus species was at the lowest levels in individuals exposed to T3 and T9. In A. negundo species, leaflet length in T1, T2, T3, T4 T5, T6 (modarete+T4), T7 (modarete+T5), T8 (severe drought+T4), and T9 (severe drought+T5) treatment were 8.800, 8.704, 8.075, 8.792, 8.823, 8.516, 8.317, 7.993, and 8.605 cm, respectively. According to these values, it was observed that the leaflet length was the shortest in T8 (7.993 cm) treatment. On the other hand, the leaflet length in T9 was close to the T1 group. As a result, individuals exposed to T4 were more affected than T5 in applications applied to UV-B stress and T3. Therefore, the increase of UV-B radiation positively affects the plant's resistance to drought stress.

The sooty bark disease (SBD) is an emerging disease affecting sycamore maple trees (Acer pseudoplatanus) in Europe. Cryptostroma corticale, the causal agent, putatively native to eastern North America, can be also pathogenic for humans causing pneumonitis. It was first detected in 1945 in Europe, with markedly increasing reports since 2000. Pathogen development appears to be linked to heat waves and drought episodes. Here, we analyse the conditions of the SBD emergence in Europe based on a three-decadal timeseries data set. We also assess the suitability of aerobiological samples using a species-specific quantitative PCR assay to inform the epidemiology of C. corticale, through a regional study in France comparing twoyear aerobiological and epidemiological data, and a continental study including 12 air samplers from six countries (Czechia, France, Italy, Portugal, Sweden and Switzerland). We found that an accumulated water deficit in spring and summer lower than -132 mm correlates with SBD outbreaks. Our results suggest that C. corticale is an efficient airborne pathogen which can disperse its conidia as far as 310 km from the site of the closest disease outbreak. Aerobiology of C. corticale followed the SBD distribution in Europe. Pathogen detection was high in countries within the host native area and with longer disease presence, such as France, Switzerland and Czech Republic, and sporadic in Italy, where the pathogen was reported just once. The pathogen was absent in samples from Portugal and Sweden, where the disease has not been reported yet. We conclude that aerobiological surveillance can inform the spatial distribution of the SBD, and contribute to early detection in pathogen-free countries. [ABSTRACT FROM AUTHOR]

Premise: Climate change may lead to C stress (negative C balance) in trees. Because nonstructural carbohydrates (NSC) are required during metabolic reactivation in the spring, C stress might delay budbreak timing. This effect is expected to be greater in shade‐intolerant than in shade‐tolerant species, owing to the faster C economy in the shade‐intolerant. Methods: We experimentally induced C stress in saplings of six temperate tree species that differed in their light requirements by exposing them to either full light or shade from summer to spring, then recorded the date of first budbreak for the individuals. Because the levels of C reserves that represent effective C stress may differ among species, we estimated the degree of C stress by recording survival during the experiment and measuring whole‐sapling NSC concentrations after budbreak. Results: Shade reduced NSC concentrations and increased the sugar fraction in the NSC in all species. In the shade, shade‐intolerant species had higher mortality and generally lower NSC concentrations than the shade‐tolerant species, indicating a trend for more severe C stress in species with faster C economy. In shade‐intolerant species, budbreak started earlier and proceeded faster in full light than in shade, but in shade‐tolerant species budbreak was delayed in full light. The effects of the light environments on budbreak were not greater in shade‐intolerant than in shade‐tolerant species. Conclusions: Our study reveals a correspondence between budbreak responses to light and the light requirements of the species. This finding confirms that C metabolism has a significant role in triggering budbreak and demonstrates that whether C stress accelerates or delays budbreak depends on the species' light requirements. [ABSTRACT FROM AUTHOR]

From 2018 to 2020, Germany experienced periods of exceptional weather conditions. Extremely high summer temperatures and precipitation deficits induced stress and mortality in forest trees. Acer pseudoplatanus (sycamore) was one of the affected tree species. Symptoms of sooty bark disease (SBD) and severe damage of entire stands, both caused by the fungal species Cryptostroma corticale, were reported more frequently. To explore the non-symptomatic distribution of C. corticale, wood cores from visibly healthy sycamore stems were sampled and all outgrowing fungi were identified and recorded. In total, 50 trees, aged 30–65 years, were sampled at five different forest stands, from which 91 endophytic filamentous morphotypes could be isolated. The fungal endophytic community in the woody tissue of the sycamore trees varied greatly at the different sites and between the trees. The number of isolated morphotypes at the different sites ranged from 13 to 44 and no morphotype was found at all sites. At 1.20-m stem height, 3.3 fungi could be isolated from woody tissue per tree on average. The most abundant species isolated from visibly healthy sycamore in regard to both occurrence at the studied sites and continuity was C. corticale. It was recorded at four of the studied forest stands, from 26% of all studied sycamore trees, and had a frequency of 7.85% relative to the 293 isolated filamentous strains that were isolated. The second most abundant species was Xylaria longipes followed by Lopadostoma turgidum. In this study clear evidence for the endophytic lifestyle of C. corticale is presented which thus appears to be spread further than expected based on visible SBD symptoms. [ABSTRACT FROM AUTHOR]

Norway maple and sycamore, two Acer genus species, have an important ecological value and different sensitivity to stressing factors being currently aggravated by climate change. Seedling growth is postulated to be the main barrier for successful plant establishment under the climate change scenarios. Therefore, the differences in redox regulation during the seedling performance of Norway maple and sycamore were investigated. Seeds of the two Acer species exhibited an identical high germination capacity, whereas seedling emergence was higher in sycamores. PCA analyses revealed that there is more diversification in the leaf characteristics than roots. Norway maple displayed a higher chlorophyll content index (CCI) with a similar leaf mass whereas sycamore seedlings exhibited a higher normalized difference vegetation index (NDVI), higher water content, higher root biomass and higher shoot height. Based on NDVI, sycamore seedlings appeared as very healthy plants, whereas Norway maple seedlings displayed a moderate healthy phenotype. Therefore, redox basis of seedling performance was investigated. The total pool of glutathione was four times higher in sycamore leaves than in Norway maple leaves and was reflected in highly reduced half-cell reduction potential of glutathione. Sycamore leaves contained more ascorbate because the content of its reduced form (AsA) was twice as high as in Norway maple. Therefore, the AsA/DHA ratio was balanced in sycamore leaves, reaching 1, and was halved in Norway maple leaves. Nicotinamide adenine dinucleotide phosphate content was twice as high in sycamore leaves than in Norway maples; however, its reduced form (NADPH) was predominant in Norway maple seedlings. Norway maple leaves exhibited the highest anabolic and catabolic redox charge. The higher reduction capacity and the activity of NADPH-dependent reductases in Norway maple leaves possibly resulted in higher CCI, whereas the larger root system contributed to higher NDVI in sycamore. The different methods of controlling redox parameters in Acer seedlings grown at controlled conditions provided here can be useful in understanding how tree species can cope with a changing environment in the future. [ABSTRACT FROM AUTHOR]

Pollen are an important food source for numerous insects and may be used as natural markers in ecological studies. However, to make inferences about the movement rates of insects based on their gut contents, information on pollen digestion rates is needed. Here, we assessed how the consumption and digestion rates of pollen ingested by Chrysoperla carnea Stephens (Neuroptera: Chrysopidae) adults are influenced by plant species, temperature, and sex. We offered pollen of two insect‐pollinated plants – Acer pseudoplatanus L. (Sapindaceae) and Helianthus annuus L. (Asteraceae) – and two wind‐pollinated plants – Fraxinus excelsior L. (Oleaceae) and Quercus rubra L. (Fagaceae) – differing in size and protein content, to adult lacewings at two temperatures, 20 and 25 °C. After feeding, lacewings were allowed to digest pollen for up to 14 days, sampled at 10 time intervals. At each of these intervals, lacewings were frozen and the internal pollen were obtained through acetolysis and quantified under a light microscope. The number of pollen grains decreased exponentially over time and declined faster for Acer than for the other three plant species. The half‐life and the time at which 95% of the pollen grains were digested were lower for Acer than for the other plant species. Lacewings consumed more pollen grains from Acer and Quercus than from Fraxinus and Helianthus. Male lacewings consumed 30% fewer pollen grains than females, but without differences in their digestion rates. Our results show that lacewings consumed higher amounts of high‐protein pollen (Acer and Quercus) and that digestion rates differed among plant species, which could be linked to their structural characteristics. The variable digestion rates of pollen grains may influence the study of lacewing diet composition. Studies that make inferences about the pollen diet or movement ecology of lacewings by analysing their gut contents should account for species‐specific pollen digestion rates. [ABSTRACT FROM AUTHOR]

Norway maple and sycamore belong to the Acer genus and produce desiccation-tolerant and desiccation-sensitive seeds, respectively. We investigated the seed germination process at the imbibed and germinated stages using metabolomic and proteomic approaches to determine why sycamore seeds germinate earlier and are more successful at establishing seedlings than Norway maple seeds under controlled conditions. Embryonic axes and embryonic axes with protruded radicles were analyzed at the imbibed and germinated stages, respectively. Among the 212 identified metabolites, 44 and 67 differentially abundant metabolites were found at the imbibed and germinated stages, respectively, in both Acer species. Higher levels of amines, growth and defense stimulants, including B vitamins, were found in sycamore. We identified 611 and 447 proteins specific to the imbibed and germinated stages, respectively, in addition to groups of proteins expressed at different levels. Functional analysis of significantly regulated proteins revealed that proteins with catalytic and binding activity were enriched during germination, and proteins possibly implicated in nitrogen metabolism and metabolite interconversion enzymes were the predominant classes. Proteins associated with the control of plant growth regulation and seed defense were observed in both species at both germination stages. Sycamore proteins possibly involved in abscisic acid signal transduction pathway, stress tolerance and alleviation, ion binding and oxygenase activities appeared to accompany germination in sycamore. We identified peptides containing methionine (Met) oxidized to methionine sulfoxide (MetO), and functional analyses of proteins with significantly regulated MetO sites revealed that translation, plant growth and development, and metabolism of nitrogen compounds were the main processes under Met/MetO redox control. We propose that higher levels of storage proteins and amines together with higher levels of B vitamins supported more efficient nitrogen utilization in sycamore, resulting in faster seedling growth. In conclusion, omic signatures identified in sycamore seem to predispose germinated sycamore seeds to better postgerminative growth., (© The Author(s) 2025. Published by Oxford University Press.)

Hypoglycin A (HGA) and methylenecyclpropylglycine (MCPrG) are formed by some maple trees (Acer species) and have been associated with incidences of atypical myopathy among horses in pastures. In this work, a simple and sensitive ultra-performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS) method without derivatization was developed for the quantification of HGA and MCPrG in maple samples and validated according to EU guidelines. The LOQ presented here for HGA (16.4 µg/kg) is considerably lower than the lowest published LOQ (500 µg/kg). This method confirms that sycamore and box elder maple contain considerable amounts of HGA and MCPrG. In addition, the presence of the dipeptides hypoglycin B and γ-glutamyl-MCPrG in these two maple species is shown using high-resolution MS. This is the first report on the presence of these dipeptides in maple since 1973. The presence of HGB and γ-glutamyl-MCPrG could change the way we understand animal intoxication following the ingestion of maple. [ABSTRACT FROM AUTHOR]

In spring, grazing equids may suffer from a severe rhabdomyolysis syndrome named atypical myopathy. This environmental intoxication results from ingestion of toxins contained in Acer pseudoplatanus seedlings. The aim of this study was to investigate the effectiveness of herbicide spraying and mowing to reduce the toxic pressure of sycamore seedlings. In a first experiment, the efficacy of three herbicides to eradicate seedlings was compared to mowing. In a second experiment, the influence of the mowing timing on pasture productivity was determined. In both experiments, sycamore seedling counting, grass height and botanical composition were determined. In experiment 2, the final harvest biomass and its nutritional value were also determined. Herbicides and mowing both reduced the number of seedlings, which nevertheless disappear naturally over time without intervention (i.e., in control areas). As opposed to mowing, herbicide spraying altered the composition of the pasture flora. Both sprayed and mowed seedlings remain toxic until full decomposition. Early mowing (i.e., early April) did not affect the harvest yield. Late mowing (i.e., end of April) reduced the harvest yield but its nutritional value fitted the horses' need. In conclusion, mowing is the best strategy to reduce the risk of Acer pseudoplatanus poisoning in grazing equids while preserving ecological sustainability and nutritional value of pastures. [ABSTRACT FROM AUTHOR]

Modifications of DNA nucleobases are present in all forms of life. The purpose of these modifications in eukaryotic cells, however, is not always clear. Although the role of 5-methylcytosine (m5C) in epigenetic regulation and the maintenance of stability in plant genomes is becoming better understood, knowledge pertaining to the origin and function of oxidized nucleobases is still scarce. The formation of 5-hydroxymetylcytosine (hm5C) in plant genomes is especially debatable. DNA modifications, functioning as regulatory factors or serving as DNA injury markers, may have an effect on DNA structure and the interaction of genomic DNA with proteins. Thus, these modifications can influence plant development and adaptation to environmental stress. Here, for the first time, the changes in DNA global levels of m5C, hm5C, and 8-oxo-7,8-dihydroguanine (8-oxoG) measured by ELISA have been documented in recalcitrant embryonic axes subjected to desiccation and accelerated aging. We demonstrated that tissue desiccation induces a similar trend in changes in the global level of hm5C and 8-oxoG, which may suggest that they both originate from the activity of reactive oxygen species (ROS). Our study supports the premise that m5C can serve as a marker of plant tissue viability whereas oxidized nucleobases, although indicating a cellular redox state, cannot. [ABSTRACT FROM AUTHOR]

Previous phytopathological studies of the fungal pathogen Nectria cinnabarina have been focused on its distribution and host diversity but little is known about the spread of this pathogen and the defence responses of forest trees to an infection inside host tissues. Histopathological alterations of bark, periderm, phloem and woody tissues were investigated in sycamore maple (Acer pseudoplatanus) branches following their natural attack by the advanced anamorph and teleomorph developmental stages of the fungus. Light, fluorescence, confocal laser scanning and scanning electron microscopy techniques supplemented by X-ray micro-computed tomography imaging were used to distinguish between healthy and disintegrated plant tissues. The intercellular spread of fungal hyphae was found primarily in the phelloderm. Expanding hyphae aggregations produced ruptures in the phellem and the disintegration of both phellogen and phellodermal parenchyma cells in close proximity to the expanding fruiting bodies of the fungus. Thicker hyphae of the teleomorph fungal stage heavily disintegrated the phelloderm tissues and also induced enhanced sclerification of the nearby phloem tissues that limited the spread of the infection into the sieve tubes. Both the intercellular and intracellular spread of hyphae inside the peripheral parts of sclereid clusters led to the disintegration of the compound middle lamellae but the hyphae were only rarely able to pass through these structural phloem barriers. The massive fungal colonization of both lumens and disintegrated tangential cell walls of ray parenchyma cells resulted in severe cambial necroses. Although the hyphae penetrated into the outermost annual growth rings of the xylem, no cell wall disintegration of the parenchyma cells, vessels and fibres was revealed. Despite the local cambial necroses and severe phloem ray disintegration, the bark remained attached to the examined branches and no bark cankers were formed. [ABSTRACT FROM AUTHOR]

Trees have a strong influence on the chemical properties of the soil in which they grow. Establishing plantations with different tree species combinations thus potentially leads to divergence in soil chemistry. To study the degree to which differentiation already occurs during the first years after establishment, we made use of a biodiversity–ecosystem functioning experiment in Belgium, FORBIO. The multi-site experiment replicates tree species richness (1–4 species) and composition in three sites. The sites represent contrasting site contexts, mostly land-use history, soil, and climate. Soil samples (0–10 cm) were taken at the time of planting and approximately 8 years later. We measured the total C and N concentration, the Olsen P, the pH-H2O, and the concentration of base and Al cations. The change in chemical composition was strongly dependent on site conditions including former land use. Afforestation on former cropland had a positive impact on total C and Olsen P and a negative effect on base cations and pH. On sites reforested after clear-cut, soil texture and particular site preparation played an important role. On top of that, we found several significant effects of species composition. Strongest composition effects were detected in the reforested site on loamy soil with little soil disturbance. This study highlights that species choice can already affect soil chemistry in early stages of forest development, but that the nature of the effects may strongly depend on the context in which the plantations are established. Further research is needed to identify the most important contextual factors. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Forestry Society of Croatia / Sumarski List Hrvatskoga Sumarskoga Drustva is the property of Forestry Society of Croatia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With ongoing climate change, episodes of severe flooding are predicted to become more frequent despite a general trend towards increasing summer drought. We investigated how wood growth of adult trees of two species characteristic of floodplain forests in Central Germany (Fraxinus excelsior L., Quercus robur L.) and two less-typical species (Acer pseudoplatanus L., Carpinus betulus L.) responded to both maximum stream water level and climate, with a special focus on the effects of the extraordinary flood of the Saale River in June 2013 and the extreme drought in summer 1976. Tree-ring widths were measured on wood cores, and standardized ARSTAN tree-ring chronologies were produced. Using variance partitioning as well as linear mixed-effects models, we compared the effects of monthly values for maximum water level, temperature and precipitation sum on tree-ring width. Further, we calculated resistance, resilience and recovery of the tree species to the extreme events of flooding in 2013 and drought in 1976. Wood growth of all species studied, and particularly of F. excelsior, responded positively to the extraordinary flooding in June 2013. However, in the best models for the characteristic floodplain forest species (F. excelsior and Q. robur), mainly precipitation (F. excelsior) or a combination of precipitation and wood growth of the previous year (Q. robur) acted as drivers of wood growth of the current year. In contrast, growth of the less habitat-specific species (A. pseudoplatanus) mainly showed a significant response to the combination of temperature and wood growth of the previous year. C. betulus was the only species studied that benefited from the extreme drought in 1976. However, two years afterwards, only the wood growth of A. pseudoplatanus was still reduced, while F. excelsior and Q. robur fully recovered. In comparison to other regions in Central Europe, the moderate flood regime of the Saale River seems to have the potential to mitigate effects of summer drought in this region, which is one of the driest in Germany. Thus, increased flooding frequency might, to some degree, reduce drought effects brought about by climate change as well.

In spring, grazing equids may suffer from a severe rhabdomyolysis syndrome named atypical myopathy. This environmental intoxication results from ingestion of toxins contained in Acer pseudoplatanus seedlings. The aim of this study was to investigate the effectiveness of herbicide spraying and mowing to reduce the toxic pressure of sycamore seedlings. In a first experiment, the efficacy of three herbicides to eradicate seedlings was compared to mowing. In a second experiment, the influence of the mowing timing on pasture productivity was determined. In both experiments, sycamore seedling counting, grass height and botanical composition were determined. In experiment 2, the final harvest biomass and its nutritional value were also determined. Herbicides and mowing both reduced the number of seedlings, which nevertheless disappear naturally over time without intervention (i.e., in control areas). As opposed to mowing, herbicide spraying altered the composition of the pasture flora. Both sprayed and mowed seedlings remain toxic until full decomposition. Early mowing (i.e., early April) did not affect the harvest yield. Late mowing (i.e., end of April) reduced the harvest yield but its nutritional value fitted the horses’ need. In conclusion, mowing is the best strategy to reduce the risk of Acer pseudoplatanus poisoning in grazing equids while preserving ecological sustainability and nutritional value of pastures.

Host preference of root endophytes of the three European tree species of Norway spruce (Picea abies), common ash (Fraxinus excelsior), and sycamore maple (Acer pseudoplatanus) were investigated in two forest stands near Zurich, Switzerland. The focus was placed on members of the Phialocephala fortinii s.l. (sensu lato)—Acephala applanata species complex (PAC), as well as other dark septate endopyhtes (DSE). PAC species were identified based on 13 microsatellite loci. Eleven PAC species were found, with Phialocephala helvetica, P. europaea being the most frequent. All but cryptic species 12 (CSP12) preferred Norway spruce as a host. Though very rare in general, CSP12 was most frequently isolated from maple roots. Regarding the abundant PAC species, P. helvetica and P. europaea, the preference of spruce as a host was least pronounced in P. europaea, as it was also often isolated from ash and maple. It is the first record of PAC found on common ash (Fraxinus excelsior). Cadophora orchidicola, a close relative of PAC, has frequently been isolated from ash. Various species of the Nectriaceae (Cylindrocarpon spp.) have often been isolated, particularly from maple roots. By comparison, Pezicula spp. (Cryptosporiopsis spp.) was found to be abundant on all three hosts. Phomopsis phaseoli exhibits a clear preference for spruce. [ABSTRACT FROM AUTHOR]

• Key message: Wavy grain, a rare figure type of wood, leads to highly priced timber in Acer pseudoplatanus L. The influence of this trait on growth performance and its causes are not known. Analyzed wavy and straight grain sycamore maple progenies show comparable growth performance in a field trial. Stability of wavy grain after vegetative propagation is confirmed and genetic inheritance indicated. • Context: Wavy grain is a rare figure type of wood resulting from undulating fiber growth that leads to a decorative and highly priced timber in Acer pseudoplatanus L. with top positions on auction sales. Nevertheless, neither the influence of this trait on growth performance is known, nor have the causes been disentangled. • Aims: Our objectives were to find out if wavy grain figure influences growth parameters essential for log quality and to gain insight into the causes of wavy grain by the analysis of a progeny trial and a seed orchard. • Methods: In a progeny trial with 30-year-old F-1-offspring from selected wavy grained and straight grained trees, trunk diameter, tree height, and trunk shape were evaluated. Additionally, 21 trees of the trial and selected plus tree-grafts of a seed orchard were felled and analyzed for occurrence and intensity of wavy grain structure. • Results: No effect of the wavy and straight grain parentage on growth was observed in the progeny trial. Of the felled trees, over 30% showed evidence of wavy grain compared to rare occurrence in natural stands. Wood structure analysis of plus tree scions confirmed the stability of wavy grain after vegetative propagation. • Conclusion: Wavy grain seems to be genetically inherited, and there seems to be no statistically significant difference in commercially relevant traits in the progeny. This highlights the value of including wavy grain as a desired attribute in breeding systems of maple. [ABSTRACT FROM AUTHOR]

The phyllosphere is a challenging microbial habitat in which microorganisms can flourish on organic carbon released by plant leaves but are also exposed to harsh environmental conditions. Here, we assessed the relative importance of canopy position—top, mid, and bottom at a height between 31 and 20 m—and tree species identity for shaping the phyllosphere microbiome in a floodplain hardwood forest. Leaf material was sampled from three tree species—maple (Acer pseudoplatanus L.), oak (Quercus robur L.), and linden (Tilia cordata MILL.)—at the Leipzig canopy crane facility (Germany). Estimated bacterial species richness (Chao1) and bacterial abundances approximated by quantitative PCR of 16S rRNA genes exhibited clear vertical trends with a strong increase from the top to the mid and bottom position of the canopy. Thirty operational taxonomic units (OTUs) formed the core microbiome, which accounted for 77% of all sequence reads. These core OTUs showed contrasting trends in their vertical distribution within the canopy, pointing to different ecological preferences and tolerance to presumably more extreme conditions at the top position of the canopy. Co-occurrence analysis revealed distinct tree species-specific OTU networks, and 55–57% of the OTUs were unique to each tree species. Overall, the phyllosphere microbiome harbored surprisingly high fractions of Actinobacteria of up to 66%. Our results clearly demonstrate strong effects of the position in the canopy on phyllosphere bacterial communities in a floodplain hardwood forest and—in contrast to other temperate or tropical forests—a strong predominance of Actinobacteria. [ABSTRACT FROM AUTHOR]

The key selective pressure shaping the morphology of samaras is seen as enhancing primary wind‐borne dispersal from the parent plant to the ground. However, the consequences of the samara wing of primarily wind‐dispersed tree species for post‐dispersal processes has not been well studied. We explored whether the presence of this wing in Acer pseudoplatanus either deters or promotes predation after dispersal, either by increasing the time and energy required to predate the seed or by increasing the seed's visibility to predators. We found that wing‐removed fruits were preferred, suggesting that the presence of samaras makes seed handling more expensive for granivores. Further, we found that fewer seeds were consumed from treatments that contained the most winged seeds, thus there was no evidence of the samaras making seed finding easier for granivores. We conclude that the presence of the wing may offer an anti‐predatory benefit as well as aiding primary dispersal. [ABSTRACT FROM AUTHOR]

At a trial established in Cumbria, northern England, significant differences in growth rate between tree species were apparent, with cider gum (Eucalyptus gunnii) and alder (Alnus glutinosa) exhibiting most rapid volume and biomass accumulation. Estimations were made of leaf area, specific leaf area, leaf area ratio (based on stem mass not whole tree mass) and length of growing season. These measurements were undertaken to explain tree growth difference and developing a growth potential index based on growing season length and leaf area. The high leaf area of cider gum and alder explained some of their superior growth, while alder also had the longest period in leaf, compared with ash (Fraxinus excelsior) and sycamore (Acer pseudoplatanus). The slow growth of ash can be explained by the short period in leaf and also the relatively low leaf area ratio. Leaf area to stem weight also differed between species with that of ash being relatively low. Specific leaf area was also low for ash, a trait shared with cider gum, which suggests that these species invest highly in each unit of leaf area. Of the tree species assessed, the length of the growing season was longest for alder, enabling it to maintain growth for a longer period. By multiplying growing season by leaf area a resource capture index was calculated and this explained 56% of the variation in stem dry weight between trees. The potential and limitations for using this index are discussed.

The systematic killing of trees is usually aimed at eradicating pests or alien plant species susceptible to harm existing natural ecosystems. In some cases, trees may become the subject of dispute between neighbors, which sometimes ends in tree death after months or years of dispute. In this paper, we analyze a case of clandestine tree killing and look into ways through which evidence left by delinquents can be analyzed a posteriori with state-of-the-art approaches. The investigation presented here looks at a series of old-growth trees that were supposedly poisoned inside a protected, nineteenth century grove in Switzerland. After the sudden, unexplained death of several old Black poplar (Populus nigra) trees along the main alley in fall 2015 and their subsequent removal, the dying of five additional, neighboring Sycamore maple (Acer pseudoplatanus) and English walnut (Juglans regia) trees in 2016 promptly triggered a suite of criminal investigations at the property. During an initial inspection, a large number of boreholes was found in the root plates of the dying trees. We present findings obtained from tree-ring, wood anatomical and dendrogeochemical investigations performed on root, stem and leave material from the assumedly poisoned trees and show that massive amounts of chemical elements – supposedly in the form organic pesticides with high Al, As, Fe, Cr, Ni contents, aluminum phosphides or glyphosate-based pesticides – were injected into 36 boreholes drilled into the roots around September 2016. Results obtained in this study are currently used in criminal investigations, and are a nice example of how scientific detectives can help their “real World” colleagues in identifying delinquents.

The incorporation of Lucanus cervus (L.) in Annex 2 of the EU Habitats Directive imposed on EU member countries the obligation to prepare protection plans and undertake adequate measures aimed at the preservation of this species. A necessary precondition for their implementation was connected with the identification of current localities of L. cervus. This paper presents the distribution of L. cervus localities in Poland, identified on the basis of a survey conducted in the areas administered by the State Forests. Habitat preferences for the selection of biotopes by stag beetles were evaluated in terms of forest-site types. This will facilitate effective protection of L. cervus by indicating potential biotopes for this species, particularly in areas with high abundance. The survey showed the presence of L. cervus in 176 localities distributed in 47 forest districts. Most of them were found in three main areas comprising forests in the areas of Zielona Góra, Wrocław and the Świętokrzyskie Mts. They constitute large-scale refuges. In 98% of cases the development of L. cervus was associated with oaks Quercus robur and Quercus petraea. Other host plants included Fagus sylvatica and Acer pseudoplatanus. The age of trees colonised by stag beetles ranged from 70 to 248 years, 134 years on average. Lucanus cervus was most frequently found in deciduous mesic forest sites (41% of localities) and deciduous mixed mesic forest sites (24% of localities). Over 90% of recorded localities are situated in forested areas, understood to include stands, residual trees and stumps, as well as localities at forest edges and along roads in the vicinity of forests. [ABSTRACT FROM AUTHOR]

The structure of leaf veins is typically described by a hierarchical scheme (e.g. midrib, 1st order, 2nd order), which is used to predict variation in conduit diameter from one order to another whilst overlooking possible variation within the same order. We examined whether xylem conduit diameter changes within the same vein order, with resulting consequences for resistance to embolism. We measured the hydraulic diameter (D h), and number of vessels (V N) along the midrib and petioles of leaves of Acer pseudoplatanus , and estimated the leaf area supplied (A leaf-sup) at different points of the midrib and how variation in anatomical traits affected embolism resistance. We found that D h scales with distance from the midrib tip (path length, L) with a power of 0.42, and that V N scales with A leaf-sup with a power of 0.66. Total conductive area scales isometrically with A leaf-sup. Embolism events along the midrib occurred first in the basipetal part and then at the leaf tip where vessels are narrower. The distance from the midrib tip is a good predictor of the variation in vessel diameter along the 1st order veins in A. pseudoplatanus leaves and this anatomical pattern seems to have an effect on hydraulic integrity since wider vessels at the leaf base embolize first. [ABSTRACT FROM AUTHOR]

Summary: In trees, dead and living cells of secondary xylem (wood) function collectively, rendering cell‐to‐cell communication challenging. Water and solutes are transported over long distances from the roots to the above‐ground organs via vessels, the main component of wood, and then radially over short distances to the neighboring cells. This enables proper functioning of trees and integrates whole‐plant activity.In this study, tracer loading, immunolocalization experiments and inhibitor assays were used to decipher the mechanisms enabling transport in wood of Acer pseudoplatanus (maple), Fraxinus excelsior (ash) and Populus tremula × tremuloides (poplar) trees.We show that tracer uptake from dead water‐conducting vessels, elements of the apoplasm, to living vessel‐associated cells (VACs) of the xylem parenchyma of the symplasm system proceeds via the endocytic pathway, including clathrin‐mediated and clathrin‐independent processes.These findings enhance our understanding of the transport pathways in complex wood tissue, providing experimental evidence of the involvement of VACs and endocytosis in radial uptake from vessels. [ABSTRACT FROM AUTHOR]

Summary: The seedling stage is the most susceptible one during a tree′s life. Water relations may be crucial for seedlings due to their small roots, limited water buffers and the effects of drought on water transport. Despite obvious relevance, studies on seedling xylem hydraulics are scarce as respective methodical approaches are limited.Micro‐CT scans of intact Acer pseudoplatanus and Fagus sylvatica seedlings dehydrated to different water potentials (Ψ) allowed the simultaneous observation of gas‐filled versus water‐filled conduits and the calculation of percentage loss of conductivity (PLC) in stems, roots and leaves (petioles or main veins). Additionally, anatomical analyses were performed and stem PLC measured with hydraulic techniques.In A. pseudoplatanus, petioles showed a higher Ψ at 50% PLC (Ψ50 −1.13MPa) than stems (−2.51 MPa) and roots (−1.78 MPa). The main leaf veins of F. sylvatica had similar Ψ50 values (−2.26 MPa) to stems (−2.74 MPa) and roots (−2.75 MPa). In both species, no difference between root and stems was observed. Hydraulic measurements on stems closely matched the micro‐CT based PLC calculations.Micro‐CT analyses indicated a species‐specific hydraulic architecture. Vulnerability segmentation, enabling a disconnection of the hydraulic pathway upon drought, was observed in A. pseudoplatanus but not in the especially shade‐tolerant F. sylvatica. Hydraulic patterns could partly be related to xylem anatomical traits. [ABSTRACT FROM AUTHOR]

This paper shows the results of the analysis of the fruit morphometric characteristics of 29 trees of sycamore maple (Acer pseudoplatanus L.) and red - leaf sycamore maple (Acer pseudoplatanus ‘Аtropurpureum’ Späth.) in Novi Sad area. Based on the test trees, it can be concluded that the analyzed secondary population of sycamore maple has a high level of intra - populations variability, based on different degrees of variability of measured parameters and statistically significant differences of all analyzed parameters within the analysed genotypes. The results indicate that there are certain differences between fruit of sycamore maple and its red - leaf variety. Given that there is no statistically significant difference between sites and different urban spaces, it can be concluded that stress factors caused by a high degree of urbanity do not affect the morphometric characteristics of fruits in the analyzed test trees. Testing the symmetry of fruits indicates a high level of genetic variability within the analyzed population.

Two related tree species, Norway maple (Acer platanoides L.) and sycamore (Acer pseudoplatanus L.), produce desiccation-tolerant (orthodox) and desiccation-sensitive (recalcitrant) seeds, respectively. We compared the seeds of these two species to characterize the developmentally driven changes in the levels of peptide-bound methionine sulfoxide (MetO) and the abundance of methionine sulfoxide reductases (Msrs) B1 and B2, with respect to the cellular redox environment. Protein oxidation at the Met level was dynamic only in Norway maple seeds, and the reduced MsrB2 form was detected only in this species. Cell redox status, characterized by the levels of reduced and oxidized ascorbate, glutathione, and nicotinamide adenine dinucleotide (NAD)/phosphate (NADP), was clearly more reduced in the Norway maple seeds than in the sycamore seeds. Clear correlations between MetO levels, changes in water content and redox status were reported in orthodox Acer seeds. The abundance of Msrs was correlated in both species with redox determinants, mainly ascorbate and glutathione. Our data suggest that MsrB2 is associated with the acquisition of desiccation tolerance and that ascorbate might be involved in the redox pathway enabling the regeneration of Msr via intermediates that are not known yet.

Military activities have worldwide introduced toxic explosives into the environment with considerable effects on soil and plant-associated microbiota. Fortunately, these microorganisms, and their collective metabolic activities, can be harnessed for site restoration via in situ phytoremediation. We characterized the bacterial communities inhabiting the bulk soil and rhizosphere of sycamore maple (Acer pseudoplatanus) in two chronically 2,4,6-trinitrotoluene (TNT) polluted soils. Three hundred strains were isolated, purified and characterized, a majority of which showed multiple plant growth promoting (PGP) traits. Several isolates showed high nitroreductase enzyme activity and concurrent TNT-transformation. A 12-member bacterial consortium, comprising selected TNT-detoxifying and rhizobacterial strains, significantly enhanced TNT removal from soil compared to non-inoculated plants, increased root and shoot weight, and the plants were less stressed than the un-inoculated plants as estimated by the responses of antioxidative enzymes. The sycamore maple tree (SYCAM) culture collection is a significant resource of plant-associated strains with multiple PGP and catalytic properties, available for further genetic and phenotypic discovery and use in field applications.

European ash (Fraxinus excelsior) and sycamore maple (Acer pseudoplatanus) are considered amongst tree species as some of the most attractive forage for red deer (Cervus elaphus). The aim of this paper is to estimate branch and foliage mass browsing by red deer in young Sycamore maple and European ash in Central Slovakia and to analyze interspecific differences in browsing frequency and quantity. Altogether 665 ash trees and 701 maple trees were measured for height and stem diameter at the ground level. Red deer browsing, defined as leader shoot or lateral branch cropping, was recorded for all trees. A combination of the diameter of browsed branches and branch regression models allowed for the estimation of browsed (potentially consumed) mass by red deer. Results show that browsing occurred more frequently on maple (5 cases per tree) compared to ash (3 cases per tree); however, more total branch biomass was consumed in ash (10.7 g per tree) compared to maple (2.6 g per tree). This is because browsed branches were larger in ash than in maple. We assume that the difference in the size of browsed branches between ash and maple is relative to species-specific branch morphological and structural features.

Highlights • Sycamore maple in Central Europe (Germany) shows a longitudinal genetic structure. • Postglacial recolonization might account for this pattern of genetic variation. • An introgression zone points to genetic exchange after secondary contact. • Genetic exchange has been less in the South; mountains might have limited gene flow. • Genetic differentiation was observed among certain regions of provenance. Abstract Sycamore maple (Acer pseudoplatanus L.) is a broadleaved forest tree species mainly occurring in mountainous areas of Europe, preferring fresh to moist, deep, calcareous soils. As was the case with other important forest tree species, sycamore maple was absent from the area north of the Alps during the last ice age. Therefore, we investigated the origin of sycamore maple in this area and its genetic variation across the landscape as the result of its postglacial migration into this area. We compared our results with the current delineation of sycamore maple into regions of provenance in Germany. Altogether 1043 trees from Germany, but also, in few cases, from bordering countries, were analysed using 11 nuclear and one chloroplast microsatellite (SSR) markers. Both the analysis of chloroplast (cpDNA) haplotypes and the Bayesian cluster analysis based on nuclear SSR data revealed distinct genetic structures of sycamore maple in Germany, suggesting more than one origin. The spatial distribution of a particular cpDNA haplotype (haplotype '105') might be the result of a migration event with an eastern origin, probably along the Eastern Alps, which could have occurred during the Holocene. The other haplotype (haplotype '102') might be of (south-) western origin, representing a migration pathway along the Western Alps. This hypothesis is further supported by a Bayesian cluster analysis based on nuclear SSRs. We identified two clusters, one distributed in the western part of the study area and one in the eastern. Between them, a zone of genetic introgression occurs, where populations exhibit a mixed membership to both clusters. This zone of genetic admixture is narrower in the south. An analysis of the landscape shape confirms that average genetic differentiation per distance unit is higher in the south. This is also in agreement with higher genetic distances between regions of provenance in the south. The mountainous landscape of this region could have contributed to this higher genetic differentiation, by posing geographic barriers to gene flow. On the contrary, wide-scale seed movement, also beyond the limit of native range, as well as a flat relief could have resulted in a wider zone of admixture in the north. Based on our results, we argue that the current delineation of provenance regions for sycamore maple in Germany fits to the inferred patterns of genetic differentiation. [ABSTRACT FROM AUTHOR]

Temperate tree species differ in their physiological sensitivity to declining soil moisture and drought. Although species‐specific responses to drought have often been suggested to be the result of different water uptake depths, empirical evidence for such a mechanism is scarce.Here we test if differences in water uptake depths can explain previously observed species‐specific physiological responses of temperate trees to drought and if the water uptake depth of different species varies in response to declining soil moisture. For this purpose, we employed stable oxygen and hydrogen isotopes of soil and xylem water that we collected over the course of three growing seasons in a mature temperate forest in Switzerland.Our data show that all investigated species utilise water from shallow soil layers during times of sufficient soil water supply. However, Fraxinus excelsior, Fagus sylvatica and Acer pseudoplatanus were able to shift their water uptake to deeper soil layers when soil water availability decreased in the topsoil. In contrast, Picea abies, was not able to shift its water uptake to deeper soil layers.We conclude from our data that more drought‐resistant tree species are able to shift their water uptake to deeper soil layers when water availability in the topsoil is becoming scarce. In addition, we were able to show that water uptake depth of temperate tree species is a trait with high plasticity that needs to be characterised across a range of environmental conditions. [ABSTRACT FROM AUTHOR]

Military activities have worldwide introduced toxic explosives into the environment with considerable effects on soil and plant-associated microbiota. Fortunately, these microorganisms, and their collective metabolic activities, can be harnessed for site restoration via in situ phytoremediation. We characterized the bacterial communities inhabiting the bulk soil and rhizosphere of sycamore maple (Acer pseudoplatanus) in two chronically 2,4,6-trinitrotoluene (TNT) polluted soils. Three hundred strains were isolated, purified and characterized, a majority of which showed multiple plant growth promoting (PGP) traits. Several isolates showed high nitroreductase enzyme activity and concurrent TNT-transformation. A 12-member bacterial consortium, comprising selected TNT-detoxifying and rhizobacterial strains, significantly enhanced TNT removal from soil compared to non-inoculated plants, increased root and shoot weight, and the plants were less stressed than the un-inoculated plants as estimated by the responses of antioxidative enzymes. The sycamore maple tree (SYCAM) culture collection is a significant resource of plant-associated strains with multiple PGP and catalytic properties, available for further genetic and phenotypic discovery and use in field applications. [ABSTRACT FROM AUTHOR]

From 2004 until 2016, 21 Père David's deer (Elaphurus davidianus) have died for unknown reason at Zoo Duisburg. These deer, also known as milu, have succumbed from a myopathy that occurred seasonally in autumn and in spring. The clinical signs shown by the animals closely resembles those of a disease called equine atypical myopathy (EAM), which is formerly known in horses. The cause for EAM in Europe was found in the ingestion of hypoglycin A, contained in samaras and seedlings of the sycamore maple tree (Acer pseudoplatanus). To test the hypothesis that the mortality of milus was caused by ingestion of hypoglycin A, 79 sera from all zoos and wildlife parks that have kept milus in Germany and Austria, including 19 diseased and 60 healthy animals, were used. Selected biochemical values and additionally hypoglycin A, methylenecyclopropyl acetic acid-carnitine (MCPA-carnitine), and acylcarnitines, which have been found in horses suffering from EAM, were determined. The results showed greater values of serum activities of creatine kinase (P < 0.001) and aspartate aminotransferase (P < 0.001) in diseased milus comparing to healthy ones confirming a myopathy in affected animals. Moreover, hypoglycin A and MCPA-carnitine were found in the blood of Père David's deer and thus, hypoglycin A intoxication was considered to be a potential cause for the myopathies by ingestion of sycamore maple samaras that were present in the enclosure of the affected animals. Hypoglycin A values were greater in diseased animals (P < 0.01) as well as MCPA-carnitine levels (P < 0.05). Additionally, affected milus showed greater C5-OH-carnitine (P < 0.01) and C6-carnitine (P < 0.001) values. Until now hypoglycin A intoxication was only known in the family of Equidae, in humans, and in laboratory rats, and it has not been previously described in other zoological families. Comparing to horses, ruminants do have a different digestive tract and it will need further investigation to find out if several factors are involved to trigger an outbreak in ruminants. [ABSTRACT FROM AUTHOR]

Poor storability of recalcitrant seeds is due to their inability to tolerate low moisture content. Understanding the processes underlying their recalcitrance is a prerequisite to developing a maintenance strategy and prolonging their lifespan. Multiple studies have investigated the differences between orthodox (desiccation-tolerant) and recalcitrant (desiccation-sensitive) seeds. Information on epigenetic regulation, however, is lacking and thus limits our understanding of the processes defining the physiology of seeds. In the present comparative study, changes in the global levels of 5-methylcytosine (m5C) in orthodox and recalcitrant seeds of Acer platanoides L. and Acer pseudoplatanus L. were characterized during progressive stages of severe drying. Concomitant with their differential sensitivity to desiccation stress, we demonstrate variation in the response of embryonic axes and cotyledons to water deficit at the level of DNA methylation. Results indicate that desiccation-induced changes in m5C are both tissue and seed category-specific and are highly correlated with recalcitrant seed viability. Moreover, we demonstrate that m5C global changes in response to desiccation are not retained in DNA isolated from seedlings, except in seedlings that are derived from strongly desiccated orthodox seeds (moisture content of 3.5%). Finally, the potential utilization of m5C status as a universal seed viability marker is discussed. [ABSTRACT FROM AUTHOR]

The health condition of the sycamore maple growing in different urban environmental conditions was evaluated. A location did not affect the concentration of phosphorus, potassium, magnesium, and calcium in leaves. However, the plants differed in the nitrogen content. Trees growing along a heavy-traffic route were more numerously inhabited by insects and more susceptible to pathogenic fungi than trees growing along a road with pedestrian traffic. Four orders of insects, mites, and slugs were identified on the sycamore maple. The dominant insect species was Drepanosiphum platanoidis (Schrank, 1801). Two species of pathogenic fungi have been identified: Sawadea bicornis and Rhytisma acerinum. [ABSTRACT FROM AUTHOR]