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This paper deals with work done last century and early this century on a problem of fundamental ontology from within the broad process relational 'research program'. This is the problem usually termed in process circles 'the problem of compound individuals'. The viewpoints taken by the following are outlined briefly: Whitehead and Donald Sherburne (all real entities microscopic); Hartshorne/Cobb (large events with regional inclusion); Joseph Bracken (equiprimordial fields); George Wolf (large events without regional inclusion: marbles in jelly); Lewis Ford both early (sub-occasions) and recent (included and inclusive occasions); and also some non-Whiteheadian and even anti-Whiteheadian process views (Ivor Leclerc, Nicholas Rescher, Reto Lezius Fetz, George Lucas, James Felt). It concludes, very provisionally, that events seem to be moving in the direction of a layered or multi-level ontology, to allow ontologically 'equiprimordial' realities of different levels and sizes with dependencies going in all directions. This seems to fit with some recent work done in process circles in Australia (esp. Gare and Douglas) and also Europe. Finally, there are some remarks on the importance of the question well beyond fundamental ontology, for application to the mind-body problem, in social and political theory and with respect to various questions in theology. [ABSTRACT FROM AUTHOR]

Abstract Background Recent endeavours in metagenomics, exemplified by projects such as the human microbiome project and TARA Oceans, have illuminated the complexities of microbial biomes. A robust bioinformatic pipeline and meticulous evaluation of their methodology have contributed to the success of these projects. The soil environment, however, with its unique challenges, requires a specialized methodological exploration to maximize microbial insights. A notable limitation in soil microbiome studies is the dearth of soil-specific reference databases available to classifiers that emulate the complexity of soil communities. There is also a lack of in-vitro mock communities derived from soil strains that can be assessed for taxonomic classification accuracy. Results In this study, we generated a custom in-silico mock community containing microbial genomes commonly observed in the soil microbiome. Using this mock community, we simulated shotgun sequencing data to evaluate the performance of three leading metagenomic classifiers: Kraken2 (supplemented with Bracken, using a custom database derived from GTDB-TK genomes along with its own default database), Kaiju, and MetaPhlAn, utilizing their respective default databases for a robust analysis. Our results highlight the importance of optimizing taxonomic classification parameters, database selection, as well as analysing trimmed reads and contigs. Our study showed that classifiers tailored to the specific taxa present in our samples led to fewer errors compared to broader databases including microbial eukaryotes, protozoa, or human genomes, highlighting the effectiveness of targeted taxonomic classification. Notably, an optimal classifier performance was achieved when applying a relative abundance threshold of 0.001% or 0.005%. The Kraken2 supplemented with bracken, with a custom database demonstrated superior precision, sensitivity, F1 score, and overall sequence classification. Using a custom database, this classifier classified 99% of in-silico reads and 58% of real-world soil shotgun reads, with the latter identifying previously overlooked phyla using a custom database. Conclusion This study underscores the potential advantages of in-silico methodological optimization in metagenomic analyses, especially when deciphering the complexities of soil microbiomes. We demonstrate that the choice of classifier and database significantly impacts microbial taxonomic profiling. Our findings suggest that employing Kraken2 with Bracken, coupled with a custom database of GTDB-TK genomes and fungal genomes at a relative abundance threshold of 0.001% provides optimal accuracy in soil shotgun metagenome analysis.

Background: Recent endeavours in metagenomics, exemplified by projects such as the human microbiome project and TARA Oceans, have illuminated the complexities of microbial biomes. A robust bioinformatic pipeline and meticulous evaluation of their methodology have contributed to the success of these projects. The soil environment, however, with its unique challenges, requires a specialized methodological exploration to maximize microbial insights. A notable limitation in soil microbiome studies is the dearth of soil-specific reference databases available to classifiers that emulate the complexity of soil communities. There is also a lack of in-vitro mock communities derived from soil strains that can be assessed for taxonomic classification accuracy. Results: In this study, we generated a custom in-silico mock community containing microbial genomes commonly observed in the soil microbiome. Using this mock community, we simulated shotgun sequencing data to evaluate the performance of three leading metagenomic classifiers: Kraken2 (supplemented with Bracken, using a custom database derived from GTDB-TK genomes along with its own default database), Kaiju, and MetaPhlAn, utilizing their respective default databases for a robust analysis. Our results highlight the importance of optimizing taxonomic classification parameters, database selection, as well as analysing trimmed reads and contigs. Our study showed that classifiers tailored to the specific taxa present in our samples led to fewer errors compared to broader databases including microbial eukaryotes, protozoa, or human genomes, highlighting the effectiveness of targeted taxonomic classification. Notably, an optimal classifier performance was achieved when applying a relative abundance threshold of 0.001% or 0.005%. The Kraken2 supplemented with bracken, with a custom database demonstrated superior precision, sensitivity, F1 score, and overall sequence classification. Using a custom database, this classifier classified 99% of in-silico reads and 58% of real-world soil shotgun reads, with the latter identifying previously overlooked phyla using a custom database. Conclusion: This study underscores the potential advantages of in-silico methodological optimization in metagenomic analyses, especially when deciphering the complexities of soil microbiomes. We demonstrate that the choice of classifier and database significantly impacts microbial taxonomic profiling. Our findings suggest that employing Kraken2 with Bracken, coupled with a custom database of GTDB-TK genomes and fungal genomes at a relative abundance threshold of 0.001% provides optimal accuracy in soil shotgun metagenome analysis. [ABSTRACT FROM AUTHOR]

In this experiment, dried bracken was used as the raw material, and an ultrasound-assisted method was used to extract and calculate the extraction rate of bracken crude polysaccharides. The bracken polysaccharides were then purified using the Sevage method, macroporous resin, and dialysis method. Chemical composition and physicochemical properties of bracken polysaccharides were determined. Infrared spectroscopy, Congo red test, high performance liquid chromatography, periodic acid oxidation, iodine-potassium iodide reaction, and other methods were used to characterize the structure of bracken polysaccharides, and the antioxidant capacity of bracken polysaccharides on DPPH free radicals, ABTS+ free radical scavenging ability, and FRAP ability were measured in vitro. The extraction rate of bracken crude polysaccharides was 8.91%, the content of purified bracken polysaccharides was 76.95%, the total phenolic content was 1.03%, the content of flavonoids was 1.90%, the sulfate content was 21.38%, and the content of uronic acid was 29.26%, according to the experimental results. The infrared spectroscopy results revealed that bracken polysaccharides had typical polysaccharide absorption peaks, as well as uronic acid and partial pyranose. The monosaccharide composition results revealed that bracken polysaccharide was a heteropolysaccharide made up of ten monosaccharides. Long side chains, more branched chains, complex chain structure, and no three-stranded helix structure of bracken polysaccharide. In vitro antioxidant testing revealed that bracken polysaccharides had a high ABTS+ radical scavenging ability (up to 92.61%), a good iron ion reduction ability (40.15±1.40 mg/g in Trolox equivalent), and a high DPPH free radical scavenging ability. The above findings will serve as a foundation for further research into the structure-activity relationship of bracken polysaccharides, as well as a theoretical reference for the rational use of bracken resources.

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The objective of the present study was to investigate the effects of 1-methylcyclopropene (1-MCP) combined with tea polyphenols coating (TPC) treatments on overall quality and cell wall metabolism of bracken (Pteridium aquilinum var. latiusculum) stored at 4 ± 1 °C. In comparison with the control group, 1-MCP + TPC treatment maintained overall quality, retarded the degradation of cell wall polysaccharides, and inhibited the activities of cell wall degrading enzymes. Low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) analysis revealed that 1-MCP + TPC treatment affected the distribution and migration of water in postharvest bracken. Furthermore, fourier-transform infrared spectroscopy (FTIR) indicated that the characteristic peaks of cell wall polysaccharides were influenced by 1-MCP + TPC treatment during storage. In conclusion, the combined treatment of 1-MCP + TPC may be a promising approach to delay senescence and quality deterioration of postharvest bracken. [ABSTRACT FROM AUTHOR]

The survival of butterfly populations depends on successful oviposition strategies. The limited mobility of early life stages requires females to select sites that reflect larval requirements. However, as land use and climate changes are altering habitat conditions and micro-climate, some species may adapt ovipositing strategies and flourish while others, with narrow niche requirements, may be unable to respond. Oviposition site selection and micro-habitat niche is examined for two closely related butterfly species—the specialist High Brown Fritillary (Fabriciana adippe) and relative generalist Dark Green Fritillary (Speyeria aglaja) through field observations of egg-laying females and analysis of micro-habitat characteristics. A total of 104 oviposition behaviour observations across both species were recorded in 69 1 m2 quadrats, with the habitat characteristics compared to randomly selected quadrats in the same area. Results show that higher host plant density was a positively significant factor for oviposition site selection only for the High Brown Fritillary. Moreover, the cover of live Bracken (Pteridium aquilinum) and grass were important for site selection in both species, with High Brown Fritillaries tolerating less live Bracken and grass cover than Dark Green Fritillaries. This confirms the more specific requirements and narrower micro-habitat niche of the High Brown Fritillary, which appears to be more sensitive to micro-habitat cooling. Implications for insect conservation: The management of Bracken mosaic habitats for these two species should aim to supress grass growth and maintain Bracken density within limits, by opening the Bracken canopy on a rotation through grazing or manual cutting, ensuring a continuous supply of suitable micro-habitat. [ABSTRACT FROM AUTHOR]

In the tropical dry forest of the Yucatan Peninsula in southern Mexico, as in many parts of the Neotropics, deforested areas have been colonized by the highly competitive invasive bracken (Pteridium arachnoideum), which inhabits naturally regenerated and successional forests on abandoned farmland. The purpose of this study was to compare the efficiency of different treatments for the control of ferns through the mechanical removal of their fronds in rocky soils of the Yucatan Peninsula. In 2013, we implemented an experiment using different frequencies of cutting of ferns (cutting ferns every 30, 60, 90, and 120 days and control). One year after establishing experiment, data was gathered regarding bracken rhizome biomass, basal area, height, density, and species richness of naturally regenerating vegetation for all treatments. As expected, the lowest rhizome biomass was achieved with the 30- and 60-day cutting treatments and the fern control had a positive effect on the regeneration of woody species. We conclude that promotion of natural regeneration following agricultural land use may be essential for long-term elimination of bracken.

Hexavalent chromium (Cr VI) is a highly toxic environmental pollutant produced as a byproduct of stainless steel manufacture and leather tanning. Several vegetal Cr VI-accumulating species have been investigated in phytoremediation, a promising technology to remove heavy metals from soils and water bodies. The aim of this work was to test the sensitivity, accumulation and remotion of Cr VI in both life cycle phases of the fern Pteridium aquilinum. Both gametophytes and sporophytes were obtained (in vitro) and evaluated (in vitro and using hydroponics) under controlled temperature, photoperiod and humidity conditions. One-month gametophytes were exposed in vitro to K2Cr2O7 (0, 50, 200, 600 and 800 µM). Four-month sporophytes were exposed to K2Cr2O7 (0, 800, 1600 and 6400 µM) under hydroponic conditions. Both phases were harvested at 24, 28, 72 and 168 h post-exposure, and biomass, chlorophyll content (a and b) and the amount of Cr in tissues and culture medium were tested. The results indicate that both phases of the cycle are not sensitive to Cr VI, since chlorosis and reduction in biomass were not observed. The gametophytes accumulated up to 915 mg of Cr×Kg−1 DW, while the sporophytes accumulated up to 11,854 of Cr×kg−1 DW in the underground parts. The sporophytes showed higher Cr uptake in rhizomes and adventitious roots, and despite having a low translocation index toward the leaves, these reached high concentrations as well (2240 mg Cr×Kg−1 DW). Given the uptake capacity in sporophytes, this fern places within the top five species with highest Cr accumulation, and it may be successfully used in phytoremediation methods. [ABSTRACT FROM AUTHOR]

Contemporary human diet is poor in proteins. Therefore, the modern food science should find new sources of high-grade protein. The bracken fern is rich in proteins can be an unconventional solution to this problem. The research objective was to study the protein contents of Pteridium aquilinum (L.) Kuhn, which grows on the territory of the Krasnoyarsk Region. The study featured Pteridium aquilinum (L.) Kuhn harvested in several districts of the Kozulka, Kuragino and Shushenskoye districts Krasnoyarsk Region in May 2021. Spectrophotometry and chromatography were used to assess the proteins and amino acids, respectively. The protein content in the dried fern samples ranged from 24 to 27%. All the samples contained fifteen amino acids, including seven essential ones, mostly represented by phenylalanine+tyrosine (2.17 g/100 g of protein). Glutamine was the dominating essential amino acid (4.98 g/100 g of protein). The score of all the essential amino acids was more than 100%. The limiting amino acid was represented by methionine+cystine. From the total of fifteen amino acids, twelve belonged to various classes of aliphatic amino acids, one – to aromatic amino acids, and two – to heterocyclic amino acids. In terms of biological value, the samples collected in the Kuragino district surpassed those from the Kozulka and Shushenskoye districts because they had a lower value of amino acid score difference coefficient (78) and the highest value of coefficient of amino acid utility (0.55). The index of essential amino acids for all the fresh fern samples ranged from 1.04 to 1.1, which indicates a greater value of the total of essential amino acids than in the reference protein. The qualitative and quantitative composition of amino acids of the bracken fern in the Krasnoyarsk Region showed that it can be used in food industry as an additional source of protein.

The study of microorganisms is a field of great interest due to their environmental (e.g., soil contamination) and biomedical (e.g., parasitic diseases, autism) importance. The advent of revolutionary next-generation sequencing techniques, and their application to the hypervariable regions of the 16S, 18S or 23S ribosomal subunits, have allowed the research of a large variety of organisms more in-depth, including bacteria, archaea, eukaryotes and fungi. Additionally, together with the development of analysis software, the creation of specific databases (e.g., SILVA or RDP) has boosted the enormous growth of these studies. As the cost of sequencing per sample has continuously decreased, new protocols have also emerged, such as shotgun sequencing, which allows the profiling of all taxonomic domains in a sample. The sequencing of hypervariable regions and shotgun sequencing are technologies that enable the taxonomic classification of microorganisms from the DNA present in microbial communities. However, they are not capable of measuring what is actively expressed. Conversely, we advocate that metatranscriptomics is a "new" technology that makes the identification of the mRNAs of a microbial community possible, quantifying gene expression levels and active biological pathways. Furthermore, it can be also used to characterise symbiotic interactions between the host and its microbiome. In this manuscript, we examine the three technologies above, and discuss the implementation of different software and databases, which greatly impact the obtaining of reliable results. Finally, we have developed two easy-to-use pipelines leveraging Nextflow technology. These aim to provide everything required for an average user to perform a metagenomic analysis of marker genes with QIMME2 and a metatranscriptomic study using Kraken2/Bracken. [ABSTRACT FROM AUTHOR]

Metagenomics analysis is now routinely used for clinical diagnosis in several diseases, and we need confidence in interpreting metagenomics analysis of microbiota. Particularly from the side of clinical microbiology, we consider that it would be a major milestone to further advance microbiota studies with an innovative and significant approach consisting of processing steps and quality assessment for interpreting metagenomics data used for diagnosis. Here, we propose a methodology for taxon identification and abundance assessment of shotgun sequencing data of microbes that are well fitted for clinical setup. Processing steps of quality controls have been developed in order (i) to avoid low-quality reads and sequences, (ii) to optimize abundance thresholds and profiles, (iii) to combine classifiers and reference databases for best classification of species and abundance profiles for both prokaryotic and eukaryotic sequences, and (iv) to introduce external positive control. We find that the best strategy is to use a pipeline composed of a combination of different but complementary classifiers such as Kraken2/Bracken and Kaiju. Such improved quality assessment will have a major impact on the robustness of biological and clinical conclusions drawn from metagenomic studies. [ABSTRACT FROM AUTHOR]

Management of upland land‐use has considerable potential for mitigating flood risk by increasing topsoil storage and slowing overland flow. Recent work has highlighted the potential for vegetation to impact the velocity of saturation‐excess overland flow. Woodland creation is widely proposed for Natural Flood Management (NFM), but data on saturation‐excess overland flow in woodland habitats is lacking. Here we measure soil properties and overland flow velocities in established broadleaf woodland and wood pasture with an understorey dominated by either grass or bracken. We show that wood pasture dominated by bracken has overland flow velocity 12–20% lower than established broadleaf woodland and 19–27% lower than grass‐dominated wood pasture. Established woodland soils exhibited eight times higher saturated hydraulic conductivity than bracken‐dominated wood pasture and 80 times higher than grass‐dominated wood pasture. We conclude that upland habitats can be managed to reduce flood risk, first by storing storm water in the soil and then by reducing overland flow velocity through rough surface vegetation. These factors combine to reduce floods by delaying the onset of overland flow runoff and slowing its delivery to streams. It is clear than Manning's n is far from constant in these shallow overland flows, the development of overland flow datasets is, therefore, also beneficial for improving the theory and practice of hillslope rainfall‐runoff modelling. [ABSTRACT FROM AUTHOR]

The sheep tick, Ixodes ricinus L. (Acari: Ixodidae), is an important vector of many pathogens of medical and veterinary significance. Determining vector abundance is a requisite of assessing potential vector‐borne disease risk. Estimation of tick abundance is often conducted by blanket drag sampling a site, conducted at one time point during the day. The time of day chosen for sampling can vary, is not widely standardized and is often unreported by the investigator. This study investigated whether the time of day chosen for sampling had an effect on tick collection at an open grassland coastal site in North Devon, U.K., during May 2019 to July 2019. Tick abundance for both adults and nymphs in the evening period was more than twice that found in the mid‐day sampling period. Overall abundance differed with site aspect, ground temperature and relative humidity. This study shows that for this open grassland recreational site, the time of day chosen for sampling has important implications for tick collection and the assessment of the relative risk of human exposure to ticks and tick‐borne infections. [ABSTRACT FROM AUTHOR]

Study region: Cathedral Peak Research Catchments, uKhahlamba Drakensberg mountain range, South Africa. Study focus: The focus was to determine the seasonal pattern of evapotranspiration (ET) over a bracken canopy, which is a product of degradation within the montane grasslands of the uKhahlamba Drakensberg mountains. Surface renewal (SR) was investigated as a viable alternative to eddy covariance for long-term estimation of ET within a remote high rainfall montane landscape. The SR dissipation method was used to observe ET over the bracken canopy for 23 months, across two consecutive years with variable seasonal rainfall timing and amounts. Besides ET, rainfall and energy flux components were observed. New hydrological insights for the region: The SR dissipation method was shown to be adequate for the long-term estimation of evapotranspiration over a bracken canopy within a remote high summer rainfall montane landscape. The bracken canopy was found to have a distinct seasonal cycle. Autumn was most sensitive to rainfall amount and timing, as late annual rainfall during autumn decreases bracken ET compared to higher summer rainfall followed by a lower autumn rainfall. Comparing the evapotranspiration of bracken from this study to the evapotranspiration of natural grassland in previous studies, the largest difference in evapotranspiration between the canopies occurs in winter.

Hexavalent chromium (Cr VI) is a highly toxic environmental pollutant produced as a byproduct of stainless steel manufacture and leather tanning. Several vegetal Cr VI-accumulating species have been investigated in phytoremediation, a promising technology to remove heavy metals from soils and water bodies. The aim of this work was to test the sensitivity, accumulation and remotion of Cr VI in both life cycle phases of the fern Pteridium aquilinum. Both gametophytes and sporophytes were obtained (in vitro) and evaluated (in vitro and using hydroponics) under controlled temperature, photoperiod and humidity conditions. One-month gametophytes were exposed in vitro to K2Cr2O7 (0, 50, 200, 600 and 800 µM). Four-month sporophytes were exposed to K2Cr2O7 (0, 800, 1600 and 6400 µM) under hydroponic conditions. Both phases were harvested at 24, 28, 72 and 168 h post-exposure, and biomass, chlorophyll content (a and b) and the amount of Cr in tissues and culture medium were tested. The results indicate that both phases of the cycle are not sensitive to Cr VI, since chlorosis and reduction in biomass were not observed. The gametophytes accumulated up to 915 mg of Cr×Kg−1 DW, while the sporophytes accumulated up to 11,854 of Cr×kg−1 DW in the underground parts. The sporophytes showed higher Cr uptake in rhizomes and adventitious roots, and despite having a low translocation index toward the leaves, these reached high concentrations as well (2240 mg Cr×Kg−1 DW). Given the uptake capacity in sporophytes, this fern places within the top five species with highest Cr accumulation, and it may be successfully used in phytoremediation methods.

Pteridium aquilinum (Dennstaedtiaceae) colonization affects ecological and restoration processes. The knowledge of the impacts on the ecological succession by this species allows the use of restoration strategies in invaded environments. This work aimed to evaluate the floristic composition, diversity, structure, density, basal area, height, and diameter of natural regeneration in three areas of the Atlantic Forest in the Serra do Espinhaço Biosphere Reserve in an area invaded by P. aquilinum after a fire. Three environments with different coverage intensities by P. aquilinum were studied, and the plants over 10 cm in height or 5 cm in canopy diameter were measured. The floristic composition and diversity were analyzed using indices presented by Chao, Fisher, Margalef, Pielou, Shannon-Weaver, and Simpson, and similarity was evaluated by the Jaccard index. Species density, basal area, height, and canopy diameter classes were also evaluated. The floristic composition, diversity, structure of natural regeneration, density, and basal area were higher in post-fire areas with a lower coverage by P. aquilinum. The topsoil coverage with plant litter and the possible effect of P. aquilinum allelopathy probably reduced the species richness and diversity. The proportion of plants from the lowest height and canopy diameter classes was higher under moderate coverage by P. aquilinum. The reduction in the floristic composition, diversity, number of species, and basal area in post-fire areas colonized by P. aquilinum is probably due to this species aggressiveness. The population of this plant is high, accumulating large quantities of plant litter as a physical barrier preventing light and propagules from reaching the soil, reducing the germination of the seed bank and, consequently, the natural regeneration. The floristic composition, diversity, structure of natural regeneration, density, and basal area were lower in areas with higher coverage by P. aquilinum. The proportion of plants in the most significant height and canopy diameter classes was higher with reduced coverage by P. aquilinum. The P. aquilinum reduced forest succession in areas after a fire. [ABSTRACT FROM AUTHOR]

An outbreak of new disease with leaf and stem blight symptom occurred at bracken-growing fields in Namhae-gun, Gyeongsangnam-do, Korea during the last 4 years. This new disease caused significant yield losses on bracken production in this area. We have collected diseased leaves and stems showing the blight symptom in May, July, and October 2018 to investigate causal pathogens. A total of 92 fungal isolates were obtained from the diseased samples and their pathogenicity was tested on healthy bracken leaves. From the total isolates, 22 isolates were able to produce the leaf blight symptom similar to the original one found in the fields. To identify two fungal pathogens which showed higher virulence levels compared to other pathogenic isolates, we constructed phylogenetic trees using the nucleotide sequences of genes for ribosomal RNA, RNA polymerase beta subunit, beta tubulin, and internal transcribed region. Most phylogenetic trees constructed indicate that both isolates, which are identical to each other, reside in a clade of the genus Didymella and possibly similar to D. rumicicola or D. acetosellae. Nevertheless, the exact identification of these pathogens at the species level needs further investigations. This is the first report of a blight disease on bracken by Didymella sp.

Growing anthropogenic impacts on natural and semi-natural ecosystems have created a network of degraded sites throughout the world. These disturbed ecosystems are often colonized by invasive plants such as Pteridium aquilinum, which is one of the most widespread plants worldwide. In northern Iran, P. aquilinum is often found invading newly-created habitats formed after anthropogenic disturbance. This study aimed to assess the relationship between P. aquilinum performance and a range of environmental factors (soils, climate, topography and land-use) in northern Iran. In fifteen sites dominated by P. aquilinum, that spanned the regional distribution of P. aquilinum, we measured its cover, density and biomass. Pteridium aquilinum was found to occur in a variety of land-uses including abandoned agricultural lands, degraded forests and upland rangelands. The performance of P. aquilinum varied significantly between the sites and it performed better in a moderate-Mediterranean climate. Variation partitioning confirmed the importance of climate followed by soil and land-use in explaining the performance of P. aquilinum. Topographic variables did not show any significant effect on P. aquilinum. Both temperature and rainfall affected P. aquilinum performance. Density was correlated positively with early-spring rainfall whereas biomass and cover were found to have positive correlation with temperature. There was also a gradient of soil texture/pH/N/P influencing P. aquilinum. Frond density and biomass were correlated positively with sand content, N and P, but negatively with pH, lime and bulk density. Thus, soil conditions alongside temperature in spring and early summer could explain P. aquilinum cover, but for density, rainfall in early spring was the most important factor, suggesting that in northern Iran P. aquilinum performance appears to be intermediate compared to responses reported for temperate (temperature-controlled) and tropical climates (rainfall-controlled). [ABSTRACT FROM AUTHOR]

The textual analysis of the materials about the paporotnik bez serdca (“fern/bracken without a heart”) made it possible to distinguish two main varieties of this text, their chronology and the relationship of sub-variants. In the 17th and 18th centuries, the text about the paporotnik bez serdca contained details typical for the tradition of Russian herbals (herb “without a heart”, collection on the Kupala Night, a ritual with using precious metal, coins or an object with a hole). In the 18th century, some text fragments of the paporotnik bez serdca were transformed as scribes adapted the text from books to their real knowledge. For example, a new description of the appearance of the plant appeared (leaves like those of rowan, the root like a bear’s claw), thanks to which the fern/bracken becomes quite recognisable. In addition, folklore motifs from the oral tradition gradually penetrated into the herbals (fern flowering; the appearance of the figure of a priest and a new function “for luck”). This trend developed already in the 19th century, when a number of new lengthy texts about the paporotnik bez serdca, saturated with folklore topics, appeared. [ABSTRACT FROM AUTHOR]

Plant growth in nitrogen (N)-limited, unfertilised terrestrial ecosystems should respond to additional N inputs from atmospheric deposition (Ndep). We investigated this for sites in Great Britain (GB) by compiling 796 estimates of net primary productivity (NPP) from measured biomass production over the period 1932–2014, although the great majority were for 1990 onwards. The sites were largely vegetated with shrubs, grass and bracken, and had a wide range of Ndep (0.5–3.3 gN m−2 a−1 in 2000). The measured NPP estimates were compared with calculated values from the biogeochemical ecosystem model N14CP, which predicts that NPP depends strongly upon Ndep. The measured and modelled average total NPP values (gC m−2 a−1) from all data were 387 (standard deviation, SD = 193) and 377 (SD = 72) respectively. Measured and modelled averages for vegetation classes followed the sequence: broadleaved trees ~ needle-leaved trees > herbs (rough grassland + bracken) ~ shrubs. After averaging measured values for sites in individual model grid cells (5 km × 5 km) with 10 or more replicates, the measured and modelled NPP values were correlated (n = 26, r2 = 0.22, p = 0.011), with a slope close to unity. Significant linear relationships were found between measured ln NPP and cumulative Ndep for both herbs (n = 298, p = 0.021) and shrubs (n = 473, p = 0.006), with slopes comparable to those predicted with the model. The results suggest that semi-natural NPP in GB depends positively upon Ndep, in a manner that agrees quantitatively with N14CP predictions. Calculations with the model, using modelled temporal variation in Ndep, indicate that fertilisation by Ndep caused average increases in semi-natural NPP over the period 1800 to 2010 of 30% for shrubs, 71% for herbs, and 91% for broadleaved trees. Combined with previous published results for forests, our findings suggest a general and widespread vegetation response to fertilisation by Ndep. [ABSTRACT FROM AUTHOR]

Whether management intervention is required to control biological invasions depends primarily on demonstrating species losses resulting from such invasions. Brackens of the Pteridium genus are currently regarded as a problem species that act as important ecological filters in the assembly of invaded communities. We investigated the effects of Pteridium arachnoideum invasion on the diversity, structure, floristic composition, and functional traits of cerradão in Assis, São Paulo, Brazil. We compared an invaded site with an adjacent non-invaded site. Bracken constrained the establishment of tree species, resulting in a community structure remarkably distinct from the non-invaded area. The density and basal area of the arboreal community were higher in non-invaded areas, but large trees were more frequent in the invaded areas. However, bracken did not reduce tree species diversity. Both richness and diversity were higher in the invaded area, indicating that over time, tree species richness and diversity naturally recovered, albeit slowly, in the invaded area. Therefore, one cannot attribute the loss of richness in the Cerrado vegetation to bracken invasion. Hence, we argue that, in this system, eradication of this invasive species is not likely to be cost effective, and thus, it should be a low management priority.

Graphical abstract Highlights • A new pterosin glycoside and a new seco -illudoid sesquiterpene were isolated from the Pteridium aquilinum. • Compounds 1 and 2 showed inhibitory activity against BACE1 and cholinesterase. • Compound 2 was a mixed-type inhibitor against human BACE1 binding to active sites of corresponding enzymes. • Structure elucidation was based on spectroscopic data (1D, 2D NMR and HRMS). Abstract Bioassay-guided fractionation of the ethanolic extract from the whole plants of Pteridium aquilinum has resulted in the isolation of a new pterosin glycoside, (‒)-pteroside N (1), and a new seco -illudoid sesquiterpene, pterosinone (2). Their structures were identified by analysis of the spectroscopic data including extensive 2D NMR. All of the isolates were evaluated for the anti-Alzheimer disease (anti-AD) activity through enzyme inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1). (‒)-Pteroside N (1) showed moderate BACE1 inhibitory activity (IC 50 value: 30.6 μM), but exhibited potent inhibitory activity against AChE and BChE (IC 50 values: 4.47 and 7.39 μM, respectively). On the other hand, pterosinone (2) showed mild AChE and BChE inhibitory activity (IC 50 value: 87.7 and 72.9 μM), but exhibited potent inhibitory activity against BACE1 (IC 50 value: 19.4 μM). The results of the present study demonstrate that sesquiterpenoids from P. aquilinum might be beneficial in the treatment of AD. [ABSTRACT FROM AUTHOR]

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Copyright of Wood Industry / Drvna Industrija is the property of Drvna Industrija 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.)

In order to identify the effect of P. arachnoideum, we studied 11 native tree species commonly used in reforestation projects. Bioassays were conducted in laboratory to evaluate the effect of bracken leachate on the germination and morphology of seedlings. Juveniles of some of these species were planted in two adjacent but contrasting areas in relation to the dominance of P. arachnoideum. The evaluation of growth and survivorship was performed after six and twelve months. This study reveals that for some pioneer and secondary trees P. arachnoideum leachate exerted an inhibitory effect on seed germination and seedling morphology. Field experiments revealed that pioneers are apparently more resistant to P. arachnoideum leachate than secondary species.Na tentativa de identificar o efeito de P. arachnoideum, estudamos 11 espécies nativas comumente utilizadas em projetos de reflorestamento. Bioensaios foram conduzidos em laboratório para avaliar o efeito do extrato aquoso do samambaião sobre a germinação e morfologia de plântulas. Plantas jovens de algumas destas espécies foram plantadas em duas áreas adjacentes, porém contrastantes em relação à dominância de P. arachnoideum. A avaliação do crescimento e sobrevivência foi realizada após seis e doze meses. Este estudo revela que, para algumas espécies pioneiras e secundárias tropicais, P. arachnoideum exerce um efeito inibidor sobre a germinação de sementes e a morfologia de plântulas. Experimentos de campo mostram que as espécies pioneiras são aparentemente mais resistentes ao P. arachnoideum do que as espécies secundárias.

To predict ecosystem responses to anthropogenic change it is important to understand how and where plant productivity is limited by macronutrient availability. Nitrogen (N) is required in large quantities for plant growth, and is readily lost through leaching or gas fluxes, but reactive nitrogen can be obtained through dinitrogen fixation, and phosphorus (P) is often considered a more fundamental long-term constraint to growth and carbon sequestration in terrestrial ecosystems. Phosphorus limitation may be becoming more prevalent due to widespread pollution by atmospheric N. Assessments of the effects of macronutrient availability on productivity in natural ecosystems are however scarce. We measured standing biomass of bracken Pteridium aquilinum as a proxy for productivity across sites with similar climate but varied geology. Total above-ground biomass varied from 404 to 1947 g m − 2 , yet despite 12-fold to 281-fold variation in soil macronutrient stocks these were remarkably poor at explaining variation in productivity. Soil total nitrogen, organic phosphorus, calcium, magnesium and zinc had no relationship with productivity, whether expressed as concentrations, stocks or element/C ratios, and nor did foliar N/P. Soil potassium (K) and molybdenum stocks both showed weak relationships with productivity. The stock of K in bracken biomass was considerably greater as a proportion of soil stock than for other nutrient elements, suggesting that this nutrient element can be important in determining productivity. Moisture availability, as indicated by environmental trait scores for plant species present, explained considerably more of the variation in productivity than did K stock, with less production in wetter sites. Soil N/C ratio and organic P stock were relatively unimportant in determining productivity across these bracken sites. It is possible that more-direct measures of N and P availability would explain variation in productivity, but the study shows the importance of considering other essential elements and other environmental factors when predicting productivity. [ABSTRACT FROM AUTHOR]