Boreal Zone Research Articles

Ancistrocerus shibuyai (Yasumatsu, 1938), stat. restit. (Hymenoptera: Vespidae: Eumeninae), an overlooked trans-Palaearctic species

Ancistrocerus shibuyai (Yasumatsu, 1938), stat. restit. was hitherto considered a subspecies of A. trifasciatus (Müller, 1776) distributed in Russia (Eastern Siberia, Far East), Mongolia, China (North-East), Korean Peninsula, and Japan, while A. trifasciatus trifasciatus was known to have a nearly trans-Palaearctic distribution. Due to minor but distinct morphological differences between A. shibuyai and A. trifasciatus, the former one is hereby recognized as a separate species. Based on the extensive material examined, A. shibuyai is shown to be widely distributed in the boreal zone of the Palaearctic region; particularly, the species is recorded for the first time from Austria, Ukraine, European part of Russia, Urals, Western Siberia, and Kazakhstan. Ancistrocerus trifasciatus var. moeschleri Blüthgen, 1938, syn. nov. and A. balticus Budrys & Orlovskytė, 2023, syn. nov. are synonymized with A. shibuyai. Distribution and biology of both A. shibuyai and A. trifasciatus are briefly discussed. A lectotype is designated for Odynerus trifasciatus orientalis Kostylev, 1938.

River restoration effects on dispersal and the development of riparian seed bank: do poor seed banks limit restoration of boreal riparian zones?

In boreal streams, restoration after channelization typically consists of increasing instream geomorphic complexity with no other active restoration measures (e.g. planting) as it mainly targets fish. Unsurprisingly, this restoration fails to restore riparian vegetation within the time frames needed to meet biodiversity goals. To understand the potential role of dispersal and seed banks in the poor restoration results, we compared deposition patterns from a seed release experiment conducted during spring flood and summer low flow conditions to seed bank‐ and vegetation composition. The experiment was conducted across seven boreal streams, each differing in time since restoration (0–22 years). We found that seed deposition increased due to low flow and local flow obstruction, suggesting the importance of instream boulders. Locations where there was a high deposition likelihood in our seed release experiment had higher Shannon diversity compared to locations with a low seed deposition likelihood. Riparian vegetation composition is related to flow obstruction, while seed bank species composition is correlated to spring flood seed deposition. In general, the sampled riparian seed banks contained few seeds and species. We therefore conclude that (1) restoration of hydrogeomorphic complexity (especially instream boulders) can enhance seed deposition with some effects on species composition of the vegetation and seed bank diversity, and (2) the importance of these generally species poor seed banks for the return of species after restoration boreal streams is questionable. Other (active) methods or more time may therefore be needed to meet biodiversity goals within riparian vegetation restoration.

Late Glacial and Holocene history of climate, vegetation landscapes and fires in South Taiga of Western Siberia based on radiocarbon dating and multi-proxy palaeoecological research of sediments from Shchuchye Lake

Abstract To investigate long-term relationships between climate, vegetation, landscape geochemistry and fires in the boreal forest zone of Western Siberia, a sediment core of 345 cm was collected from Shchuchye Lake (located in south taiga zone of southeast part of West Siberian plain) and investigated by spore-pollen, radiocarbon, LOI and charcoal analyses. Quantitative palaeoclimate was reconstructed based on pollen data. Investigation revealed 13.2 cal ka history of vegetation, climate, landscapes and fires. In the dry climate of Late Glacial, the landscape was treeless. Continuous permafrost existed in the soil. In the middle of the YD cooling 12.4–12.2 cal ka BP, our data showed warming that caused degradation of permafrost in soils and settlement of spruce in moist places. Later, thawing and accumulation of moisture in a local lowering in relief increased and a lake was formed. With the beginning of the Holocene, the climate sharply changed to warmer and wetter. Intensified surface flow caused accumulation of mineral and carbonate fraction in the lake. Dense birch forests spread on drylands. As a result, the leaching regime initiated the formation of podzols in the soil. At about 10.0 cal ka BP, Scots pine (Pinus sylvestris) quickly spread in the area of investigation. Fires became more frequent and more intense during the dry Late Glacial time, sharply decreasing with increased precipitation in the Early Holocene, and again moderately increasing with spread of pine forests in the mid Holocene. With the transition to Late Holocene (after 6.0 cal ka BP), the intensity of regional background fires and number of local fires decreased.

Projected Increasing Negative Impact of Extreme Events on Gross Primary Productivity During the 21st Century in CMIP6 Models

AbstractIn the context of increasingly frequent and severe climate extremes, an understanding of the impacts of these events on gross primary production (GPP) and thus on land carbon uptake is crucial. However, research utilizing new model outputs to assess the future trends, characteristics, and driving factors of GPP reduction associated with extreme events remains limited. Here, we use model outputs from Phase Six of the Coupled Model Intercomparison Project (CMIP6) to investigate the spatiotemporal patterns of negative GPP extreme events during the 21st century. We find a notable increase in negative GPP extremes globally under the SSP5‐8.5 scenario. They are characterized by longer durations and larger sizes, despite the smaller number of events. Under the SSP1‐2.6 scenario, while the total negative GPP extremes remain relatively stable, hotspots, including tropical forests, southern China, and boreal forest zones, still experience increases in negative extremes. By attributing these GPP extremes to climate conditions, we identified compound hot and dry conditions, which contributed to over 40% of the negative GPP extremes under both scenarios, as the dominant driver, followed by single‐driver dry conditions. Under SSP5‐8.5, the increasing contribution of compound hot and dry conditions leads to greater GPP reductions through prolonged and intensified negative extreme events. Compared with CMIP5 models, CMIP6 models project an asymmetry of negative and positive GPP extreme events that favors more negative extremes across most regions. Our findings highlight the escalating damage from climate extremes on future ecosystem productivity, emphasizing the urgent need for effective mitigation and adaptation actions.

A Coupled Model of Hydraulic Eco-Physiology and Cambial Growth - Accounting for Biophysical Limitations and Phenology Improves Stem Diameter Prediction at High Temporal Resolution.

Traditional photosynthesis-driven growth models have considerable uncertainties in predicting tree growth under changing climates, partially because sink activities are directly affected by the environment but not adequately addressed in growth modelling. Therefore, we developed a semi-mechanistic model coupling stomatal optimality, temperature control of enzymatic activities and phenology of cambial growth. Parameterized using Bayesian inference and measured data on Picea abies and Pinus sylvestris in peatland and mineral soils in Finland, the coupled model simulates transpiration and assimilation rates and stem radial dimension (SRD) simultaneously at 30 min resolution. The results suggest that both the sink and phenological formulations with environmental effects are indispensable for capturing SRD dynamics across hourly to seasonal scales. Simulated using the model, growth was more sensitive than assimilation to temperature and soil water, suggesting carbon gain is not driving growth at the current temporal scale. Also, leaf-specific production was occasionally positively correlated with growth duration but not with growth onset timing or annual cambial area increment. Thus, as it is hardly explained by carbon gain, phenology itself should be included in sink-driven growth models of the trees in the boreal zone and possibly other environments where sink activities and photosynthesis are both restrained by harsh conditions.

Satellites Reveal Global Migration Patterns of Natural Mountain Treelines during Periods of Rapid Warming

Profound global transformations in the Anthropocene epoch are hastening shifts in species ranges, with natural mountain treeline migration playing a crucial role in this overarching species movement. The varied reactions of mountain treelines to climatic conditions across diverse climatic zones, when compounded by local disturbances, result in distinct migration patterns. Usually, warming encourages mountain treelines to migrate to higher elevations. Nevertheless, in a period of rapid warming, it remains unclear whether the natural mountain treeline in global thermal climatic zones and subclimatic zones has expedited its upward movement. Here, we employed remote sensing observations and the random forest algorithm to investigate the natural treeline dynamics across 24 major mountain ranges worldwide amidst a period of rapid warming (1990–2020). Our research shows substantial disparities in the migration patterns of natural mountain treelines across the global thermal zone. The natural mountain treeline in tropical and subtropical zones descends by an average of 1.1 and 0.8 m per year, respectively. Only 18.8 and 35.5% of the natural mountain treelines in these regions had undergone upward migration, respectively. The average migration rates of natural mountain treelines in temperate and boreal zones were 0.7 m per year. Correspondingly, 47 and 33.2% of the natural mountain treelines in these zones had already shifted to higher elevations. The highest average migration rate of natural mountain treelines occurs in temperate continental climates (1.7 m per year). The loss or degradation of alpine species habitats, a direct consequence of the upward movement of the treeline, highlights the necessity for increased monitoring and protection of alpine species in temperate and boreal zones in the future.

Challenges in using 0.45 µm filters to assess potentially bioavailable trace elements in the dissolved fraction of river and peat bog waters of the Boreal Zone

Passing through a 0.45 µm filter can significantly alter the concentrations of dissolved trace elements (TEs) in organic-rich waters of the Boreal Zone. However, little evidence has been provided about the impacts of filtration on the size distribution of dissolved TEs. This limitation hinders our comprehension of how filtration affects the assessment of the potentially bioavailable forms of dissolved TEs (i.e. ions and small molecules). Using AF4-UV-ICP-MS, this study systematically investigates such artefacts and their influence on the concentrations of dissolved, primarily ionic, and colloid-associated TEs in river waters and peat bog waters of the Boreal Zone. In river waters (circumneutral pH), membrane filtration had a significant impact on TEs that are associated with inorganic colloids such as Al, Mn, Fe, As, the rare earth elements, Pb, and Th. Approximately 20–80 % of primarily ionic TEs (< 0.5 kDa) and 100 % of large inorganic (ca. 40–300 nm) TEs were excluded from the filtrates under clogged conditions. In contrast, little impact of filtration was observed for bog waters (pH 4). Similarly, cartridge filtration of river waters also led to a decrease in concentrations and size distributions of dissolved TEs. However, cartridge filtration demonstrated a higher efficiency in allowing the passage of ions and excluding colloids than membrane filtration. On average, the ratio of the dissolved concentrations between a cartridge and a membrane filtrate was 1.0 ± 0.2. For primarily ionic species, the average ratio was 1.4 ± 0.4, while for colloidal species, it was 0.4 ± 0.1. Therefore, despite having similar dissolved concentrations, filtration methods with the same nominal pore size can yield different concentrations of bioavailable forms of TEs. These findings may be important for studies of the environmental relevance of dissolved TEs in surface waters of the Boreal Zone, and organic-rich waters elsewhere.

Meta-analysis: Global patterns and drivers of denitrification, anammox and DNRA rates in wetland and marine ecosystems

Nitrogen cycling is one of the most important biogeochemical processes on Earth, and denitrification, anammox and DNRA processes are important nitrogen cycling processes in estuarine ecosystems. However, due to the large input of anthropogenic nitrogen sources, a large number of environmental problems have now occurred in the estuary. But the global patterns and controlling factors of denitrification, anammox and DNRA rates in wetland marine ecosystems are not yet known. We reached our conclusions through a global synthesis of 546 observation sites from 78 peer-reviewed papers: The three rates were generally higher in areas near wetlands than in coastal areas. The rate of denitrification was highest in the subtropical region the seasonal variability was not significant; and TOC was the main factor controlling denitrification. The rate of anammox was significantly higher in the subtropical region than in the tropical and boreal zones, and the seasonal variability was significant; and at the same time, TN was the main driver of the anammox rate of the wetland ocean. DNRA rates were significantly higher in the tropics than in the subtropics and temperate zones; and the main driver of DNRA rates was temperature. Nitrogen cycle functional genes also had an indirect effect on their rates. With NH4 + -N significantly affecting nirK abundance and TN significantly affecting the gene abundance of nirS; TOC and TN had a greater effect on hzo abundance, which indirectly affected anammox rates; for DNRA, C/N significantly affects the gene abundance of nrfA, which indirectly affects the DNRA rate. Therefore, the findings of this study indicate that physicochemical indicators about N and climatic characteristics have a profound effect on the nitrogen cycling process, which provides a good feedback for studying the role of denitrification and provides a positive impact on global climate and environmental governance.

The diversity and taxonomy of Tomentella (Thelephoraceae, Thelephorales) with descriptions of four new species from Southwestern China.

Taxonomy plays a central role in understanding the diversity of life, translating the products of biological exploration and discovery specimens and observations into systems of names that settle a "classification home" to taxa. Up to this point, studies on the taxonomy and phylogeny of the basidiomycetous genus Tomentella stemmed mainly from the temperate to boreal zones of the North Hemisphere, but were scarce in tropical Asia. In this study, four new species, viz. Tomentellaolivaceobasidiosa, T.velutina, T.wumenshanensis and T.yunnanensis from China, are described and illustrated based on the morphological characteristics and molecular phylogenetic analyses, in which the sequences of ITS+nLSU+mtSSU+RPB2 genes were used for the phylogenetic analyses using Maximum Likelihood, Maximum Parsimony and Bayesian Inference methods. All the new species can be well recognised by their macroscopical and anatomical characteristics. The four new species, closely related taxa in the phylogenetic tree and morphologically similar species are discussed.

Modelling and mapping the abundance of lingonberry (Vaccinium vitis-idaea L.) in Norway

Lingonberry (Vaccinium vitis-idaea L.) grows in a range of nature types in the boreal zone, and understanding factors affecting the abundance of the plant, as well as mapping its spatial distribution, is important. The abundance of the species can be an indicator of ecosystem changes, and lingonberry can also be a source for commercial utilisation of berry resources. Using country-wide data from 6404 field plots of the Norwegian national forest inventory (NFI), we modelled the relationship between lingonberry cover and airborne laser scanning (ALS) and satellite metrics and bioclimatic variables describing the forest structure, terrain, soil properties and climate using a generalised mixed-effects model with a quasipoisson distribution. The validation carried out with an independent set of 2124 NFI plots indicated no obvious bias in predictions. The most important predictors were found to be interactions between dominant tree species, stand basal area and latitude, as well as the reflectance in the near-infrared band from Sentinel-2 satellite imagery, the dominant height based on the ALS variable and the long-term mean summer (June–August) temperature. The results provide an indicator of the effects of global warming, as well as the possibility of giving forest management prescriptions that favour lingonberry and locating the most abundant lingonberry sites in Norwegian forests.

Predicting plants in the wild: Mapping arctic and boreal plants with UAS-based visible and near infrared reflectance spectra

Biophysical changes in the Arctic and boreal zones drive shifts in vegetation, such as increasing shrub cover from warming soil or loss of living mat species due to fire. Understanding current and future responses to these factors requires mapping vegetation at a fine taxonomic resolution and landscape scale. Plants vary in size and spectral signatures, which hampers mapping of meaningful functional groups at coarse spatial resolution. Fine spatial grain of remotely sensed data (<10 cm pixels) is often necessary to resolve patches of many Arctic and boreal plant groups, such as bryophytes and lichens, which are significant components of terrestrial vegetation cover. Separation of co-occurring small vegetation patches in images also requires high spectral resolution. Our goal here was to test the capabilities of UAS-based imaging spectroscopy for mapping plant functional types (PFT) using high spatial and spectral resolution data over Arctic and boreal vegetation at four sites in central Alaska. We then tested several Machine and Deep learning models of PFT cover using the reflectance spectra. The best models were very simple, balancing both bias (overfitting caused by imbalance sample sizes) and variance (fit to the independent validation data), explaining > 50 % of the independent ground cover estimation and > 84 % accuracy in estimating validation pixels. We explored the impact of spectral resolution on PFT mapping by including vegetation indices and a gradient of narrow (5 nm) to wide (50 nm) band features in our classification models across. Vegetation indices were the most important predictors for classifying PFTs, while including band features improved models, with narrow and wide bandwidths having similar importance but models with wide bandwidths performing slightly better. We conclude that Arctic and boreal PFT reflectance can be pooled across sites for mapping with relatively few labeled pixels. Underfit, simple algorithms outperformed deep learning, at least with these small sample sizes, in classifying PFTs by balancing bias and variance. Future work should aim to increase the number of labeled pixels and the detail of labels to further improve mapping taxonomic precision.

Nomenclature notes on vegetation of the Salicetea purpureae Moor 1958 class in Ukraine

A brief history of the syntaxonomic studies of floodplain vegetation of the Salicetea purpureae class in Ukraine is presented and the tasks of further research are established. Our study has shown that the vegetation of the class includes more than 30 associations, which belong to 6 alliances and 2 orders. According to the ecological peculiarities, they are divided into willow shrubs on the gravel banks of streams in the montane and subalpine belts of the temperate and boreal zones of Europe and the Caucasus (Salicion eleagno-daphnoidis), willow and poplar forests of lowland and foothill rivers formed on alluvium in the nemoral zone of Europe and at high altitudes in the Mediterranean region (Salicion albae), willow shrubs on the sandy-loamy soils of the river banks of lowlands and foothills of the nemoral zone of Europe (Salicion triandrae), willow shrubs on riverine dunes in central Ukraine (Artemisio dniproicae-Salicion acutifoliae), shrubs on temporarily flooded clay soils in central Ukraine (Rubo caesi-Amorphion fruticosae). The problems of using the phytosociological nomenclature during the analysis of the Salicetea purpureae vegetation on the territory of Ukraine are highlighted. It was found that half of the syntaxa listed in Ukrainian geobotanical literature are synonyms, published invalidly, or need typification. Every syntaxon is accompanied by explanations of its non-validity with citations of the relevant articles published in the 4th edition of the International Code of Phytosociological Nomenclature. In addition to the incorrectly cited associations, two of the six alliances (Artemisio dniproicae-Salicion acutifoliae, Rubo caesii-Amorphion fruticosae) also require correction because their description was based on the invalid nomenclatural types formed by the selection of species which are invalid according to The Euro+Med PlantBase. In this paper, we aimed to analyze the studies on the vegetation of the Salicetea purpureae class on the territory of Ukraine using the Braun–Blanquet approach, determine the issues that require more detailed research in the future, and make some notes on nomenclature discordances. Such review makes it possible to determine all mismatches in phytosociological nomenclature.

Biogeochemical stability of organic covers and mine wastes under climate change simulated mesocosms.

Mine environments in boreal and sub-boreal zones are expected to experience extreme weather events, increases in temperature, and shifts in precipitation patterns. Climate change impacts on geochemical stability of tailings contaminants and reclamation structures have been identified as important climate-related challenges to Canadian mining sector. Adapting current reclamation strategies for climate change will improve long-term efficiency and viability of mine tailings remediation/restoration strategies under a changing climate. Accordingly, mesocosm experiments were conducted to investigate associations of climate-driven shifts in microbial communities and functions with changes in the geochemistry of organic covers and underlying tailings. Our results show that warming appears to significantly reduce C:N of organic cover and promote infiltration of nitrogen into deeper, unoxidized strata of underlying tailings. We also observed an increase in the abundance of some nitrate reducers and sulfide oxidizers in microbial communities in underlying tailings. These results raise the concern that warming might trigger oxidation of sulfide minerals (linked to nitrate reduction) in deeper unoxidized strata where the oxygen has been eliminated. Therefore, it would be necessary to have monitoring programs to track functionality of covers in response to climate change conditions. These findings have implications for development of climate resilient mine tailings remediation/restoration strategies.

Relation of Changes in CO2 Concentration over Large Water Areas of the Boreal and Subarctic Zones of the Northern Hemisphere with Their Phenological Phases Determined from SMOS Satellite Data

Relation of Changes in CO2 Concentration over Large Water Areas of the Boreal and Subarctic Zones of the Northern Hemisphere with Their Phenological Phases Determined from SMOS Satellite Data

Применение методов пространственного анализа при оценке степени горимости лесов Хабаровского края

Forest fires are the dominant factor in the transformation of natural landscapes in the boreal zone. The area of the Khabarovsk Territory, 93.6 % of which belongs to the forest fund lands, currently has a forest cover of only 66.5 %, which is largely due to forest fires. This makes urgent the problem of reducing the forest fire frequency in the region, including in terms of assessing the actual fire frequency for predicting the risks of landscape fires. The article shows the possibilities of using spatial analysis methods of the Spatial Analyst module of the ArcGIS 10.8 software package to assess the degree of actual forest fire frequency based on calculating the number of fires per 1 million and 250 thousand ha and the area of fires per 1000 ha for a sliding window of a given size. Based on the data from the Remote Monitoring Information System of the Federal Forestry Agency for 2000–2020 and the data on the number of fires from the Fire Information for Resource Management System website for 2000–2021, an assessment of the actual fire frequency for the Khabarovsk Territory has been carried out. The analysis of the results reflects the high spatial and seasonal heterogeneity of the spread of landscape fires in the territory and their proximity to transport and residential structures. Areas with high fire frequency often do not coincide with the boundaries of forestry enterprises, and the maximum indicators are typical for non-forest areas that are not covered by forestry statistics. For different seasons of the year, along with quantitative differences, spatial shifts of firing points and areas with their high density are also observed. Most of the lands in the region (88.3 %) in terms of fire danger belong to the “low” and “below medium” fire frequency categories, which is primarily due to the low degree of development of these areas. The assessment of the degree of fire frequency in the territory on the basis of annual and seasonal maps of the density of firing points, calculated using the sliding window method, makes it possible to fairly objectively and in detail reflect the average long-term risk of fire occurence outside of reference to forestry boundaries. In combination with a map of the distribution of forests by natural fire hazard classes based on pyrological characteristics, the results of the reseаrch can become the basis for calculating the background fire risk, reflecting the risk of fire occurrence and development.

Stand biomass of Pinus sylvestris var. mongolica plantations benefits from high density monocultures in the boreal zone

Pinus sylvestris var. mongolica (P. sylvestris) plantations are extensively established in the boreal zone. Increasing stand biomass of these plantations can effectively enhance carbon stock, which is crucial for mitigating climate change. However, the current understanding of optimizing plantation strategies to maximize stand biomass is primarily derived from experiments in tropical and subtropical zones, which is difficult to extend to the boreal due to substantial climatic differences. Based on a comprehensive dataset from 1,076 sample plots of P. sylvestris plantations in the boreal zone of China, we evaluated the effects of tree species richness and stand density on tree height, diameter at breast height (DBH), and stand biomass to investigate the optimal plantation strategy. Furthermore, we examined how these effects changed with stand age and investigated their relative importance. We found that monocultures at a high stand density of 2,000–2,500 ​ha−1 were the optimal plantation strategy to maximize stand biomass (107.5 ​Mg·ha−1), and this held true at almost all stand ages. Unfortunately, this strategy resulted in low species richness and small individual trees (10.6 ​m height and 9.8 ​cm DBH), thus presenting a trade-off. In addition, as stand age increased, the effect of tree species richness on stand biomass shifted from positive to negative, but the effect of stand density was always positive. Overall, stand age had the greatest effect on stand biomass, followed by stand density and then tree species richness. Our findings reveal a distinct plantation strategy for optimizing stand biomass of P. sylvestris plantations in the boreal zone. More importantly, this study highlights that (1) maximizing stand biomass in the boreal zone may compromise tree species richness; (2) net effects of tree species richness on stand biomass are not always positive, as negative selection effects offset positive complementary effects.

Host specificity in the fungal plant parasite Anthracoidea sempervirentis (Anthracoideaceae, Ustilaginales) reveals three new species and indicates a potential split in the host plant Carex sempervirens.

The smut fungal genus Anthracoidea contains more than 100 species that parasitize hosts predominantly in the sedge genus Carex. Anthracoidea species are mainly found in the boreal zones of the Northern Hemisphere and many species have an arctic-alpine distribution. Recent re-organization of the taxonomy of the main host genus Carex questions current understanding of host associations in Anthracoidea. Host specificity for many of the species in this genus is considered to be quite broad and a host spectrum of over 10 host species is common. One aim of the study is to understand the potential influence that host taxonomy has on the evolutionary patterns of Anthracoidea. Additionally, by including more specimens, we clarify host specificity and species delimitation in Anthracoidea sempervirentis, a prevalent species occurring on different host species in different Carex subgroups using molecular data. Host colonization patterns within Anthracoidea are complex, and different subclades of Carex have been colonized several times independently, whereas clades of related Anthracoidea species often occur on Carex species from the same host clade. Parasites previously thought to be Anthracoidea sempervirentis occurring on the different Carex host are shown to be at least four distinct species that are restricted to individual host species. Three new species, Anthracoidea ferrugineae on Carex ferruginea from the Alps and the Carpathians, A. firmae on Carex firma from the Alps, and A. kitaibelianae on Carex kitaibeliana from mountains in the Balkan Peninsula, are described and illustrated. An emended description of Anthracoidea sempervirentis is also provided. Anthracoidea sempervirentis in its emended circumscription consists of two clades that correspond to respective clades within Carex sempervirens. The study shows that host colonization in Anthracoidea is more complex than current host taxonomy suggests. Further, including several specimens per host species results in a much higher diversity within Anthracoidea than previously assumed. Citation: Kemler M, Denchev TT, Feige A, Denchev CM, Begerow D (2024). Host specificity in the fungal plant parasite Anthracoidea sempervirentis (Anthracoideaceae, Ustilaginales) reveals three new species and indicates a potential split in the host plant Carex sempervirens. Fungal Systematics and Evolution 13: 91-110. doi: 10.3114/fuse.2024.13.04.

Maskwio’mi (Birch Bark Extract): A Case Study Exploring The Use Of A Traditional L’nu Medicine On Skin Conditions

According to the Canadian Dermatology Association, more than 1 in 4 Canadians live with chronic skin conditions. There are many different treatment options, including prescription medications, over-the-counter drugs, natural remedies, and herbal folk medicines. Folk medicines have a long history, and birch trees (genus betula) have shown great utility for treating skin conditions in societies of temperate and boreal climate zones and have been listed in pharmacopoeias for several centuries. Maskwio’mi (maskwi = birch, o’mi = gathering or oil) is such a traditional skin remedy from the L’nu (Mi’kmaq) people of Atlantic Canada. This case study is part of a larger study and the first to document usage of maskwio’mi for skin conditions, with a goal of future in-depth clinical studies and hopes of recognizing it as a natural health product.

Иглоподобные листовые органы хвойных. Часть I. Моделирование периметра поперечного сечения иглы

Despite the availability of measuring systems for estimating the surface area of leaf organs of higher plants, the need for simple standard methods for determining this indicator area remains relevant for plant physiologists. The methods for estimating the surface area of needle-like leaf organs of conifers, based on the geometry of an individual needle rest on the general principle of calculating the needle surface area as the product of its length by the perimeter of its cross-section. This makes the cross-section perimeter one of the most important parameters needed to characterize the needle surface area. The strong variability of this parameter depending on the species necessitates the development of individual models of the cross-section of individual needles. The aim of this study has been to create a universal model for estimating the needle cross-section perimeter, irrespective of the tree species. For the practical implementation of the aim, a method was proposed for estimating the perimeter of the needle cross-section, based on the well-known fact that any closed line is transformable into an equivalent circle, while the length of the closed line does not change. The perimeter of the equivalent circle can be related to the parameters of the geometric figure before the transformation. This approach allows us to relate the width and thickness of the needle cross-section to its perimeter. The developed universal model of the needle cross-section has been verified on cross-sections of Siberian fir (Abies sibirica L.) and common juniper (Juniperus communis L.) needles. The samples of needles of these woody plants have been collected from a bilberry-sphagnum spruce forest in the boreal zone of the north-east of the European part of Russia (Knyazhpogostkiy district, the Komi Republic). Statistical analysis has shown the significance and adequacy of the model. It can be used to assess the perimeter of coniferous needles, irrespective of their species. In this case, the accuracy of perimeter estimation is comparable to the accuracy of direct perimeter measurement by the piecewise linear approximation method.

The ABoVE L-band and P-band airborne synthetic aperture radar surveys

Abstract. Permafrost-affected ecosystems of the Arctic–boreal zone in northwestern North America are undergoing profound transformation due to rapid climate change. NASA's Arctic Boreal Vulnerability Experiment (ABoVE) is investigating characteristics that make these ecosystems vulnerable or resilient to this change. ABoVE employs airborne synthetic aperture radar (SAR) as a powerful tool to characterize tundra, taiga, peatlands, and fens. Here, we present an annotated guide to the L-band and P-band airborne SAR data acquired during the 2017, 2018, 2019, and 2022 ABoVE airborne campaigns. We summarize the ∼80 SAR flight lines and how they fit into the ABoVE experimental design (Miller et al., 2023; https://doi.org/10.3334/ORNLDAAC/2150). The Supplement provides hyperlinks to extensive maps, tables, and every flight plan as well as individual flight lines. We illustrate the interdisciplinary nature of airborne SAR data with examples of preliminary results from ABoVE studies including boreal forest canopy structure from TomoSAR data over Delta Junction, AK, and the Boreal Ecosystem Research and Monitoring Sites (BERMS) area in northern Saskatchewan and active layer thickness and soil moisture data product validation. This paper is presented as a guide to enable interested readers to fully explore the ABoVE L- and P-band airborne SAR data (https://uavsar.jpl.nasa.gov/cgi-bin/data.pl).