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Question and Location: How does soil burn severity and early post-fire tree composition affect long-term understorey vegetation dynamics in the coniferous forests of eastern Canada? Method: Vegetation dynamics were assessed using paleoecological methods and a chronosequence analysis of extant stands. The relation between environmental factors and succession was evaluated using ordination techniques on the chronosequence data. Understorey succession was studied by regression analysis on the chronosequence data and through within-site Markovian transition probabilities between successive 1-cm layers of plant macroremains from soil organic matter profiles. Results: Initial tree composition (Picea mariana and Pinus banksiana) had little effect on understorey composition. Soil burn severity (measured as the thickness of the residual forest floor humus) significantly affected temporal changes in understorey species. Following fires of high severity, stands underwent a gradual paludification with a net increase in Sphagnum and ericaceous shrubs (Ledum groenlandicum), and a decrease in feathermosses. Paludification was accelerated after low severity fires, which led to the dominance of Sphagnum less than 200 years after fire, and of L. groenlandicum shortly after fire. In situ paleo-ecological work confirmed results obtained with the chronosequence analysis. Conclusions: One vegetation gradient related to time after disturbance is insufficient to account for the full complexity of longterm changes in understorey composition following fire. Current forestry practices that protect the forest floor humus may induce a premature paludification. [ABSTRACT FROM AUTHOR]

Northern peatlands are substantial sinks of carbon (C), yet the sources of carbon dioxide (CO2) emitted from peatlands are largely unknown. Since the relationship between roots and peat in C cycling is important, vascular plants growing on the surface of peat deposits should influence CO2 efflux from the peat surface and the overall C balance in peatlands. In our study, 30-cm peat cores were removed from an ombrotrophic bog in boreal, continental western Canada. Surface vegetation in the cores remained intact and included a continuous bryophyte cover dominated by Sphagnum fuscum. In addition, some cores were collected such that either ericaceous shrubs (Ledum groenlandicum) or sedges (Eriopho rum vaginatum) were present. We investigated how the presence of each vegetation type influenced soil respiration and the microbial mineralization of root exudates using a pulse 14C labeling of vegetation in the intact peat cores. The role of root biomass and root respiration in CO2 emission and C allocation was quantified for each type of vegetation and compared through both measurement and modeling. Our results show that vascular plants contributed 35-57% of total CO2 efflux from the peat surface, primarily derived from rhizosphere processes, including root respiration as well as microbial mineralization of root exudates. The mineralization of root exudates contributed 14-53 μmol C-CO2∙m-2d-1 (17- 24% of total) to CO2 efflux, depending on vegetation type and moisture conditions. The type of vegetation present did not influence the total amount of photosynthetic fixation over the course of the study, but did affect how C was allocated within and between both the aboveground and belowground components of the peat column. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) is a lethal malignancy with high morbidity and mortality but lacks effective treatments thus far. Despite the introduction of immune checkpoint inhibitors (ICIs) (including PD-1/PD-L1 inhibitors), durable and optimal clinical benefits still remain elusive for a considerable number of BC patients. To break through such a dilemma, novel ICI-based combination therapy has been explored for enhancing the therapeutic effect. Recent evidence has just pointed out that the HDAC2 inhibitor (HDAC2i), which has been proven to exhibit an anti-cancer effect, can act as a sensitizer for ICIs therapy. Simultaneously, dietary intervention, as a crucial supportive therapy, has been reported to provide ingredients containing HDAC2 inhibitory activity. Thus, the novel integration of dietary intervention with ICIs therapy may offer promising possibilities for improving treatment outcomes. In this study, we first conducted the differential expression and prognostic analyses of HDAC2 and BC patients using the GENT2 and Kaplan–Meier plotter platform. Then, we summarized the potential diet candidates for such an integrated therapeutic strategy. This article not only provides a whole new therapeutic strategy for an HDAC2i-containing diet combined with PD-1/PD-L1 inhibitors for BC treatment, but also aims to ignite enthusiasm for exploring this field. [ABSTRACT FROM AUTHOR]

Background. The Drought Code (DC) of the Canadian Fire Weather Index System (CFWIS) has been intuitively regarded by fire managers in Alaska, USA, as poorly representing the moisture content in the forest floor in lowland taiga forests on permafrost soils. Aims. The aim of this study was to evaluate the DC using its own framework of water balance as cumulative additions of daily precipitation and substractions of actual evaporation. Methods. We used eddy covariance measurements (EC) from three flux towers in Interior Alaska as a benchmark of natural evaporation. Key results. The DC water balance model overpredicted drought for all 14 site-years that we analysed. Errors in water balance cumulated to 109 mm by the end of the season, which was 54% of the soil water storage capacity of the DC model. Median daily water balance was 6.3 times lower than that measured by EC. Conclusions. About half the error in the model was due to correction of precipitation for canopy effects. The other half was due to dependence of the actual evaporation rate on the proportional 'fullness' of soil water storage in the DC model. Implications. Fire danger situational awareness is improved by ignoring the DC in the CFWIS for boreal forests occurring on permafrost. [ABSTRACT FROM AUTHOR]

Seismic lines are cleared corridors for the location mapping of subsurface bitumen. After use, the lines can be left to regenerate naturally with varying success. Wildfires, another prominent disturbance in the Boreal region, are propagated by continuous fuel distribution (coarse/fine), meteorological variables (e.g., wind speed, temperature, and precipitation), and the moisture content of the fuel and soil. However, little is known about seismic lines and the potential risk and severity of wildfires. This work presents a case study of wildfire variables on two paired (seismic line and adjacent natural area) sites near Fort McMurray, Alberta, Canada. Wind speed was increased on seismic lines, and the dominant wind direction changed. Higher precipitation, air temperature, and soil moisture and reduced water table depths were observed on seismic lines. Coarse fuel distribution was not continuous on seismic lines; however, fine fuels were. Although the Fire Weather Index (FWI) indicated an enhanced wildfire potential on one line (NS orientation), peat smouldering and ignition models (Hcomb/Hign) showed increased smouldering potential on both seismic lines compared to adjacent natural areas. Future work should focus on expanding the diversity of seismic line characterization, working towards the landscape-scale modelling of these variables. [ABSTRACT FROM AUTHOR]

We analysed whether Phacelia secunda populations from different elevations exhibit intrinsic traits associated with diffusive and biochemical components of photosynthesis, and if they differ in acclimation of photosynthesis to warmer temperatures. We hypothesized that P. secunda will have similar photosynthetic performance regardless of altitudinal provenance and that plants from high elevations will have a lower photosynthetic acclimation capacity to higher temperature than plants from low elevations.Plants from 1600, 2800 and 3600 m a.s.l. in the central Chilean Andes were collected and grown under two temperature regimes (20/16 °C and 30/26 °C day/night). The following photosynthetic traits were measured in each plant for the two temperature regimes: AN, gs, gm, Jmax, Vcmax, Rubisco carboxylation kcatc.Under a common growth environment, plants from the highest elevation had slightly lower CO2 assimilation rates compared to lower elevation plants. While diffusive components of photosynthesis increased with elevation provenance, the biochemical component decreased, suggesting compensation that explains the similar rates of photosynthesis among elevation provenances. Plants from high elevations had lower photosynthetic acclimation to warmer temperatures compared to plants from lower elevations, and these responses were related to elevational changes in diffusional and biochemical components of photosynthesis.Plants of P. secunda from different elevations maintain photosynthetic traits when grown in a common environment, suggesting low plasticity to respond to future climate changes. The fact that high elevation plants had lower photosynthetic acclimation to warmer temperature suggests higher susceptibility to increases in temperature associated with global warming. [ABSTRACT FROM AUTHOR]

Microfade testing (MFT) was used to examine standardized wool samples dyed with 14 natural historic dyes, each prepared with five different mordants, to determine whether the lightfastness and colourimetric properties of these dyes vary as a function of the mordant. The addition of mordants changed the original colour of the dyes as well as potential patterns corresponding to ΔL*, Δa*, and Δb* such that the variation of lightfastness ranges from 0.25–0.70 units of Blue Wool Equivalence (BWE). Disregarding the effect of mordants, MFT showed that all dyes have lightfastness equivalent to BW3, indicating that they belong in the category of 'high sensitivity to light'. All dye-mordant combinations vary in lightfastness, such that even the least lightfast dye will have a mordant combination that is more lightfast than the most lightfast dye combined with a mordant that renders it less lightfast. The effect of mordants varies by dye: while one dye may demonstrate a difference in lightfastness of 0.56 units of BWE between the least and most lightfast mordant combination, another may show little or no difference (as low as 0.07 units of BWE). Overall, alum based mordants tend to produce the least lightfast combinations, followed by tin and iron, with copper and chromium producing the most lightfast combinations. This paper shows that there are no simplistic patterns of lightfastness between mordant-dye combinations with these 14 natural dyes. Identifying both dye and mordant is useful to better estimate the lightfastness of a dyed textile. [ABSTRACT FROM AUTHOR]

Oil sands mining in northeastern Alberta, Canada, generates tailings containing sand, silt, clay, water, and residual bitumen with hydrocarbons. The impact of tailings on revegetation is a major environmental concern and poses a significant land reclamation challenge. Oil sands companies have recently developed technologies that use thickeners in combination with carbon dioxide to produce non‐segregating tailings (NST), to accelerate the consolidation of tailings while sequestering greenhouse gases. Effects of these tailings on plant re‐establishment have yet to be determined. We investigated the impact of NST on biomass and physiology of 20 boreal woody plant species grown in environmentally controlled growth rooms. The seedlings were grown for 8 weeks in NST capped with boreal forest topsoil or peat‐mineral soil mix or petroleum coke in 50‐cm‐long polyvinyl chloride pipes. We found that the biomass of balsam fir, beaked hazelnut, blueberry, green alder, Labrador tea, lowbush cranberry, paper birch, and raspberry was severely reduced by NST, while the effects on balsam poplar, Bebb's willow, chokecherry, dogwood, saskatoon, and white spruce were relatively weak. This was also the case for jack pine, which showed poor survival in NST. The negative impact of NST on plants can be largely explained by elevated sodium and decreased foliar nutrient concentrations. The impact of NST capping with petroleum coke on plant growth was non‐significant. Differences among species in their survival and biomass responses to NST appeared to be partly a reflection of their natural habitats. Findings from this study can help guide revegetation oil sands reclamation strategies. [ABSTRACT FROM AUTHOR]

Our study delved into the relationship between root-associated fungi, gene expression and plant morphology in Norway spruce cuttings derived from both slow-and fast-growing trees. We found no clear link between the gene expression patterns of adventitious roots and the growth phenotype, suggesting no fundamental differences in the receptiveness to fungal symbionts between the phenotypes. Interestingly, saplings from slow-growing parental trees exhibited a higher richness of ectomycorrhizal species and larger roots. Some ectomycorrhizal species, typically found on mature spruces, were more prevalent on saplings from slow-growing spruces. The ericoid mycorrhizal fungus, Hyaloscypha hepaticola, showed a stronger association with saplings from fast-growing spruces. Moreover, saplings from slow-growing spruces had a greater number of Ascomycete taxa and free-living saprotrophic fungi. Aboveground sapling stems displayed some phenotypic variation; saplings from fast-growing phenotypes had longer branches but fewer whorls in their stems compared to those from the slow-growing group. In conclusion, the observed root-associated fungi and phenotypic characteristics in young Norway spruces may play a role in their long-term growth rate. This suggests that the early interactions between spruces and fungi could potentially influence their growth trajectory., (© 2024 The Author(s). Environmental Microbiology published by John Wiley & Sons Ltd.)

Forty‐two plant foods known to have been used in the past by native people of the Nuxalk Nation, Bella Coola, British Columbia, Canada, were studied. To estimate the availability of the most prominent plant food resources, field estimates were made using modifications of standard techniques for quantifying plant species. Assessments of accessibility, abundance and frequency of food species were made. In addition, harvesting efficiency of 24 species was determined. Twenty species were selected as being the most readily available food resources, and therefore good candidates for nutritional research and promotion. These included the trees: Populus trichocarpa, Pyrus fusca, Tsuga heterophylla; the shrubs: Amelanchier alnifolia, Ledum groenlandicum, Ribes divaricatum, Rosa nutkana, Rubus idaeus, R. parviflorus, R. spectabilis, Sambucus racemosa, Vaccinium ovalifolium, V. parvifolium, Viburnum edule, and the herbs: Cornus canadensis, Epilobium angustifolium, Heracleum lanatwn, Maianthemum dilatatum, Potentilla pacifica, Trifolium wormskioldii. It was concluded that the variety and quantity of plant food resources of the Nuxalk Nation in the Bella Coola Valley are substantial. [ABSTRACT FROM PUBLISHER]

Ericaceous shrubs often interfere with the growth of black spruce seedlings on regenerating forest sites in Eastern Canada. Mechanical site preparation such as scarification may improve this situation, but it is uncertain whether this is solely due to a reduction in direct competition from the shrubs, or also from a sustained improvement in nutritional site quality. We sampled experimental plots in two boreal climate regions (i.e. warmer-drier Abitibi vs. cooler-wetter Côte-Nord) where scarification, performed 18 years earlier, had increased the growth of black spruce relative to non-scarified plots. Trees of scarified plots had closed the canopy more than trees of non-scarified plots in Côte-Nord, but not in Abitibi. Total ground cover of ericaceous shrubs was lower in scarified plots at both sites, the main species being Kalmia angustifolia (i.e. Kalmia) in Abitibi and Rhododendron groenlandicum (i.e. Labrador tea) in Côte-Nord. Scarified plots at both sites had significantly shorter current-year ericaceous rhizomes than non-scarified plots, but the difference between treatments was significantly greater in Côte-Nord than in Abitibi. In Côte-Nord, ericaceous shrubs on scarified plots had a lower specific rhizome mass, higher specific leaf area, lower tannin and higher N concentrations in leaves and litter, and lower N use efficiency than on non-scarified plots. By comparison, scarification in Abitibi affected only one foliar property, namely a reduction in the C:N ratio of Kalmia leaf litter. Forest floor N mineralization rates and black spruce needle N concentrations were higher in scarified than non-scarified plots across both sites. Taken collectively, results suggest that mechanical scarification on ericaceous shrub-dominated cutovers can reduce competitive traits of boreal ericaceous shrubs and improve nutritional site quality, especially in cooler-wetter climates. Highlights Mechanical scarification increased growth rates of black spruce saplings. Scarified plots showed less above- and below-ground growth of ericaceous shrubs. Foliar and rhizomatous traits suggested higher soil fertility on scarified plots. Soil N mineralization and spruce needle N were higher on scarified plots. Positive effects of scarification can be higher in wetter cooler maritime climate. [ABSTRACT FROM AUTHOR]

Summary: Ericaceous shrubs adapt to the nutrient‐poor conditions in ombrotrophic peatlands by forming symbiotic associations with ericoid mycorrhizal (ERM) fungi. Increased nutrient availability may diminish the role of ERM pathways in shrub nutrient uptake, consequently altering the biogeochemical cycling within bogs.To explore the significance of ERM fungi in ombrotrophic peatlands, we developed the model MWMmic (a peat cohort‐based biogeochemical model) into MWMmic‐NP by explicitly incorporating plant‐soil nitrogen (N) and phosphorus (P) cycling and ERM fungi processes. The new model was applied to simulate the biogeochemical cycles in the Mer Bleue (MB) bog in Ontario, Canada, and their responses to fertilization.MWMmic_NP reproduced the carbon(C)–N–P cycles and vegetation dynamics observed in the MB bog, and their responses to fertilization. Our simulations showed that fertilization increased shrub biomass by reducing the C allocation to ERM fungi, subsequently suppressing the growth of underlying Sphagnum mosses, and decreasing the peatland C sequestration. Our species removal simulation further demonstrated that ERM fungi were key to maintaining the shrub–moss coexistence and C sink function of bogs.Our results suggest that ERM fungi play a significant role in the biogeochemical cycles in ombrotrophic peatlands and should be considered in future modeling efforts. See also the Commentary on this article by Barel & Robroek, 238: 5–7. [ABSTRACT FROM AUTHOR]

Climate fluctuations and landscape evolution, with their associated impacts on northern coastal ecosystems, likely influenced human populations of Nunatsiavut who have inhabited the region for nearly 7000 years. As part of an interdisciplinary research initiative within the Nain Archipelago on the subarctic coast of Labrador, this project sought to reconstruct the postglacial palaeoclimatic and palaeoenvironmental variability of Dog Island and document its impacts on the evolution of lakes located in the vicinity of significant archaeological sites. To address these questions, we analysed physical, geochemical, and biological indicators preserved in sediment cores of two lakes. Results from Oakes Bay West Lake revealed gradual acidification since ca. 4900 cal. yr BP, coherent with terrestrial vegetation development and/or neoglacial cooling, interrupted by periods of milder climatic conditions (ca. 4900–3640 cal. yr BP and ca. 1520 cal. yr BP—present) that favoured large sediment inputs. Evilik Lake revealed the classic sequence of isolation of the basin in three major phases in response to glacio-isostatic rebound. These complementary results allowed for the development of a local palaeoenvironmental framework that contributes to a better understanding of how landscape evolution and climate have influenced human societies through site availability and proximity to marine resources, and how, in turn, they impacted their immediate environment through activities, such as wood harvesting and its associated effects on nutrients and lake sediment inputs. [ABSTRACT FROM AUTHOR]

Myrica gale L. (Myricaceae) is an essential oil-bearing plant that is rare in Lithuania and naturally grows only in the western part of the country. The aim of this study was to analyze the composition of essential oils of Myrica gale in different habitats in Lithuania and in different parts of the plant, as well as evaluate the local knowledge about M. gale as a medicinal and aromatic plant. Samples of fruits and leaves (from one and three M. gale populations, respectively) were studied separately. Essential oils were isolated from dried fruits and leaves by hydrodistillation and analyzed by GC/FID and GC/MS methods. Results showed that M. gale fruits accumulated 4.03 ± 2.13% essential oils, meanwhile leaves—up to 19 times less. A total of 85 compounds were identified in the essential oils of the M. gale. Monoterpene hydrocarbons accounted for about half of the total essential oil content; meanwhile, either monoterpene hydrocarbons or sesquiterpene hydrocarbons (depending on habitat) dominated in leaves. The main compounds (depending on habitat) in essential oils of fruits and leaves were α-pinene, 1,8-cineole, limonene, δ-cadinene, and (E)-nerolidol. The high variation in the composition of M. gale essential oils suggests the presence of different chemotypes within the studied habitats of this plant. Evaluation of local knowledge of M. gale through the survey of 74 residents of 15 villages in western Lithuania showed that only 7% of respondents knew this plant. Poor knowledge of M. gale could be related to the narrow range of the natural species' distribution in Lithuania. [ABSTRACT FROM AUTHOR]

Consumption of edible oils is a significant part of the dietary pattern in the developed and developing world. Marine and vegetable oils are assumed to be part of a healthy food pattern, especially if one takes into account their potential role in protecting against inflammation, cardiovascular disease, and metabolic syndrome due to the presence of polyunsaturated fatty acids and minor bioactive compounds. Exploring the potential effect of edible fats and oils on health and chronic diseases is an emerging field worldwide. This study reviews the current knowledge of the in vitro, ex vivo, and in vivo effect of edible oils in contact with various cell types and aims to demonstrate which nutritional and bioactive components of a variety of edible oils present biocompatibility, antimicrobial properties, antitumor activity, anti-angiogenic activity, and antioxidant activity. Through this review, a wide variety of cell interactions with edible oils and their potential to counteract oxidative stress in pathological conditions are presented as well. Moreover, the gaps in current knowledge are also highlighted, and future perspectives on edible oils and their health benefits and potential to counteract a wide variety of diseases through possible molecular mechanisms are also discussed. [ABSTRACT FROM AUTHOR]

Rust fungi in the order Pucciniales represent one of the largest groups of phytopathogens, which occur on mosses, ferns to advanced monocots and dicots. Seven suborders and 18 families have been reported so far, however recent phylogenetic studies have revealed para- or polyphyly of several morphologically defined suborders and families, particularly in Melampsorineae. In this study, a comprehensive phylogenetic framework was constructed based on a molecular phylogeny inferred from rDNA sequences of 160 species belonging to 16 genera in Melampsorineae (i.e. Chrysomyxa, Cerospora, Coleopuccinia, Coleosporium, Cronartium, Hylospora, Melampsora, Melampsorella, Melampsoridium, Milesina, Naohidemyces, Pucciniastrum, Quasipucciniastrum, Rossmanomyces, Thekopsora, Uredinopsis). Our phylogenetic inference indicated that 13 genera are monophyletic with strong supports, while Pucciniastrum is apparently polyphyletic. A new genus, Nothopucciniastrum was therefore established and segregated from Pucciniastrum, with ten new combinations proposed. At the family level, this study further demonstrates the importance of applying morphologies of spore-producing structures (basidia, spermogonia, aecia, uredinia and telia) in higher rank taxonomy, while those traditionally applied spore morphologies (basidiospores, spermatia, aeciospores, urediniospores and teliospores) represent later diverged characters that are more suitable for the taxonomy at generic and species levels. Three new families, Hyalopsoraceae, Nothopucciniastraceae and Thekopsoraceae were proposed based on phylogenetic and morphological distinctions, towards a further revision of Pucciniales in line with the phylogenetic relationships. [ABSTRACT FROM AUTHOR]

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Reproductive interference between sympatric-related species often causes adverse impacts on rare species, which increases the risk of local extinction, particularly in small and isolated populations. To evaluate the congeneric interactions in alpine plants, we compared the ecological and genetic properties and assessed the reproductive interference between tetraploid Rhododendron diversipilosum (widespread species) and diploid Rhododendron subarcticum (rare species in alpine fellfields) in northern Japan. In alpine fellfields, R. diversipilosum is commonly distributed close to shrubby patches, whereas R. subarcticum tends to grow in more exposed places, although they are sometimes mixed. R. subarcticum initiated flowering one week earlier; however, the flowering periods overlapped between species, indicating incomplete phenological isolation. The pollination experiment showed that both species were self-incompatible. Furthermore, heterospecific pollination occurred only for R. subarcticum; however, hybrid seeds seldom germinated. These results indicate that reproductive interference is asymmetric between species, where only the rare R. subarcticum may suffer from heterospecific pollination. Genetic analysis showed that R. subarcticum populations had lower genetic diversity but higher divergence among populations than R. diversipilosum. Although spatiotemporal niche separations may mitigate reproductive interference, the risk of local extinction could be higher in R. subarcticum populations because of isolated distributions with low genetic diversity. [ABSTRACT FROM AUTHOR]

The Yellowknife City Gold Project (YCGP), located close to the city of Yellowknife, Northwest Territories, Canada, is exploring and drilling the extension of the Au-bearing shear zones that host the Giant and Con Mines. A biogeochemical survey was conducted over the Crestaurum and Barney deposits, which are hosted within two well-known high Au grade shear zones at the YCGP. A total of 625 samples were collected from the alder (Alnus incana) (n = 76), Labrador tea (Ledum groenlandicum) (n = 40), black spruce (Picea mariana) (n = 189), and juniper (Juniperus) (n = 320), and analyzed using ICP-MS. Robust statistical analyses were applied to biogeochemical data to (1) identify the biogeochemical response in plant samples with respect to the underlying mineralogy, (2) detect the most preferred plant species in the study area, and (3) identify Au pathfinder elements and subsequently zones of Au enrichment. Principal component analysis (PCA) and K-means clustering analysis were employed to achieve these objectives. The preliminary statistical analysis showed that plant samples can successfully accumulate anomalous Au values up to 147 ppb. Also, it showed that black spruce and Labrador tea can accumulate higher concentrations of Au than alder and juniper. According to the PCA, mineralization/geological (PC1) and physiological (PC2) factors control the distribution of elements in plant samples. According to K-means clustering, plant samples were classified into three clusters based on the vegetation type and their affinity to accumulate suites of elements. Black spruce samples were identified as the optimum sample media for biogeochemical exploration at the YCGP as they were clustered in proximity to the mineralization/geological factor (PC1) responsible for loading vectors of Au, Ag, As, Se, Bi, Pb, Cu, Co, Fe, Zn, Cd, Tl, and Cr. Au is strongly correlated with its pathfinder elements (Ag, As, Se, Bi, Tl and Sb), specifically in the south of the Crestaurum Shear. The presented results in this study demonstrate that zones of Au enrichment can be detected using biogeochemical and robust statistical methods. • Plant species optimizations for biogeochemical exploration at the Yellowknife City Gold Project. • Application of principal component analysis and clustering analysis to biogeochemical exploration. • Biogeochemical prospecting for gold at the Crestauruma and Barney Shears. • Plant-substrate relationship using principal component analysis. • Geochemical factors controlling the distribution of elements in plant samples. [ABSTRACT FROM AUTHOR]

In the context of increasing heat periods and recurrence of droughts, and thus higher soil water depletion, we explored and quantified the role of understorey vegetation in ecosystem evapotranspiration in boreal and temperate forests. We reviewed and analysed about 200 papers that explicitly gave figures of understorey vegetation evapotranspiration relative to different stand features and traits. Understorey vegetation accounted on average for one-third of total ecosystem evapotranspiration during the growing season. Overstorey leaf area index (LAI) is the main variable that drives understorey evapotranspiration through radiation interception. Most data show that below an overstorey LAI of 2–3, the contribution of the understorey vegetation to ecosystem evapotranspiration increases exponentially, following the exponential increase of the climatic demand, i.e. potential evapotranspiration. Different factors have the potential to modulate this effect such as species composition and phenology, root distribution, and interaction with droughts. Consequently, managers must be aware that depending on understorey species present on site and stand structure, understorey vegetation can contribute significantly to a negative stand water balance. [ABSTRACT FROM AUTHOR]

Northern peatlands are globally important long‐term sinks of carbon due to their predominantly saturated conditions. However, these ecosystems are expected to become drier with climate change, potentially leading to shrubification. As such, the response of the shrubification–evapotranspiration (ET) feedback may be of critical importance to future peatland energy, water and carbon dynamics. We examined the effect of multi‐decadal peatland water table (WT) alteration at three adjacent sites with increasing depth to WT (WET, INTermediate, and DRY). In order to better understand the WT–shrubification–ET feedback, we measured peatland vegetation composition, microtopography and ET partitioning, where ET was measured at the ecosystem, microform, and leaf level using eddy covariance (EC), chambers and porometry, respectively. Averaged across microforms and WT treatments, there was a difference in the median measured leaf resistance (rleaf) between plant functional types ranging from 213 s m−1 for erect dwarf shrubs, 325 s m−1 for graminoids/sedges, and 520 s m−1 for prostrate dwarf shrubs. Scaled based on LAI, the low rleaf of erect dwarf shrubs dominated hummocks, where sites with a higher proportion of hummocks had lower median canopy resistance (rv) of 141, 133 and 130 s m−1 at the WET, INT and DRY sites respectively. Nevertheless, ET was highest at the WET site and similar between the INT and DRY sites, with greater evaporation from the moss surface at the WET site. Porometry and EC data along with a three‐source model were used to independently assess the evaporative contribution from the moss surface, which ranged from 17% to 40%. For moderate and persistent changes in WT from land‐use or climate change, our results suggest vegetation succession is minimal, but the microtopographic development and the concomitant differences in LAI for the various plant functional types is key to understanding changes in total ET and partitioning. [ABSTRACT FROM AUTHOR]

Plant litter decomposition is a biogeochemical process underlying the carbon cycle in terrestrial ecosystems and between the biosphere and the atmosphere. For the latter, it serves as one of the most important sources of not only carbon dioxide but also volatile organic compounds (VOCs), which have not yet been taken into account in atmospheric models for various purposes and scales, from local to regional and global. This review owes its appearance to the growing interest in decaying leaf litter and living forest floor cover as a hitherto unaccounted for source of photochemically active components of the Earth's atmosphere. This interest is understandable if we take into account the size of this source: for terrestrial ecosystems, the global production of litter is 10 × 10 16 g dry matter. The living vegetation cover of the soil on the forest floor, mainly comprising mosses and small shrubs, should also be regarded as a potentially significant source of atmospheric VOCs, as its total biomass may be comparable to or even exceed that of canopy foliage, which is considered the main source of these compounds. This implies a need to integrate these sources into biogenic VOC emission models, which in turn requires extensive research on these sources to understand the conditions and factors that influence VOC emissions. The decomposition of leaf litter, accompanied by the release of VOCs, is a very complex process that depends on a number of biological, chemical and physical environmental factors, but little information is currently available on the role each plays. Equally limited is information on the chemical composition and emission rates of VOCs from these sources. The review focuses on the main gaps in our knowledge of the sources of biogenic VOCs under the forest canopy, and we are confident that filling them will make a significant contribution to solving such an important task as closing the global organic carbon budget. [ABSTRACT FROM AUTHOR]

Stand tending using glyphosate to promote coniferous overstory trees has been a common practice in the boreal forests of Alberta. However, there are concerns about the impact of this practice on biodiversity of understory species. This study examined the impact of broadcast glyphosate application during the active reforestation phase, two to several years post-harvest, on forest plant diversity 25 to 40 years post-harvest. Herbicide treatments had the desired effect of shifting tree layer dominance from deciduous to coniferous species, driven by a 25-fold reduction in the density of trembling aspen (3927 vs. 154 stems·ha−1, untreated and treated, respectively). However, understory plant diversity was not significantly different between treated and untreated sites as examined by the Shannon–Wiener (H) and evenness (E) indices. Shared plant species (beta) across sites was high. Of the seven site-indicator species examined, three had significantly lower cover on treated sites: Wild sarsaparilla, low bush-cranberry and oak fern. Total understory plant cover was significantly greater in the treated portion (98.0%) versus untreated (71.4%); however, this difference was not significant when bryophytes were excluded in the analysis. The establishment, maintenance and monitoring of larger long-term trials is strongly recommended. [ABSTRACT FROM AUTHOR]

Maintaining healthy skin is important for a healthy body. At present, skin diseases are numerous, representing a major health problem affecting all ages from neonates to the elderly worldwide. Many people may develop diseases that affect the skin, including cancer, herpes, and cellulitis. Long-term conventional treatment creates complicated disorders in vital organs of the body. It also imposes socioeconomic burdens on patients. Natural treatment is cheap and claimed to be safe. The use of plants is as old as mankind. Many medicinal plants and their parts are frequently used to treat these diseases, and they are also suitable raw materials for the production of new synthetic agents. A review of some plant families, viz., Fabaceae, Asteraceae, Lamiaceae, etc., used in the treatment of skin diseases is provided with their most common compounds and in silico studies that summarize the recent data that have been collected in this area. [ABSTRACT FROM AUTHOR]

Pollen, spore, macrofossil and carbon data from a peatland near Cordova, Alaska, reveal insights into the climate–vegetation–carbon interactions from the initiation of the Holocene, c. the last 11.5 ka, to the present (1 ka = 1000 calibrated years before present where 0 = 1950 CE). The Holocene period is characterized by early deposition of gyttja in a pond environment with aquatics such as Nuphar polysepalum and Potamogeton , and a significant regional presence of Alnus crispa subsp. sinuata . Carbon accumulation (50 g/m 2 /a) was high for a short interval in the early Holocene when Sphagnum peat accumulated, but was followed by a major decline to 13 g/m 2 /a from 7 to 3.7 ka when Cyperaceae and ericads such as Rhododendron (formerly Ledum ) groenlandicum expanded. This shift to sedge growth is representative of many peatlands throughout the south-central region of Alaska, and indicates a drier, more evaporative environment with a large decline in carbon storage. The subsequent return to Sphagnum peat after 4 ka in the Neoglacial represents a widespread shift to moister, cooler conditions, which favored a resurgence of ericads, such as Andromeda polifolia, and increased carbon accumulation rate. The sustained Alnus expansion visible in the top 10 cm of the peat profile is correlative with glacial retreat and warming of the region in the last century, and suggests this colonization will continue as temperature increases and ice melts. [ABSTRACT FROM AUTHOR]

Ombrotrophic bogs receive new inputs of elements solely through atmospheric deposition, except for N where inputs are predominantly through N2-fixation, at least in low N deposition environments. At various locations across the globe, including the Athabasca Oil Sands Region (AOSR) of northern Alberta, Canada, element atmospheric deposition has increased as a result of anthropogenic activities. Regional and/or global deposition gradients offer an opportunity to examine questions related to nutrient limitation and element stoichiometry, i.e., the maintenance of relatively constant element ratios in bog lichen/plant tissues despite differing element deposition/availability. Using a dataset of tissue element concentrations in eight lichen/plant species in six AOSR bogs, supplemented with literature data from other sites globally, this synthesis asks: is there evidence of element stoichiometric homeostasis in lichen or plant species in AOSR bogs; if so, do stoichiometric homeostasis relationships extend globally beyond the AOSR, and; do element ratios provide insight into element limitation for the eight species? Mean element ratios and their coefficients of variation, ternary NPK and CaMgK plots, and scaling coefficients revealed widespread evidence of stoichiometric homeostasis. Stoichiometric relationships generally were unaffected by differences in element deposition among the AOSR bogs. Stoichiometric relationships sometimes extended to a species globally, but sometimes did not. Element ratios and ternary diagrams suggested a combination of N-, P-, and K-limitation, both within and beyond the AOSR bogs. Regionally high atmospheric N deposition may have shifted some species from N-limitation prior to the Industrial Revolution to P- or K-limitation today. [ABSTRACT FROM AUTHOR]

At the edge of alpine and Arctic ecosystems all over the world, a transition zone exists beyond which it is either infeasible or unfavorable for trees to exist, colloquially identified as the treeline. We explore the possibility of a thermodynamic basis behind this demarcation in vegetation by considering ecosystems as open systems driven by thermodynamic advantage—defined by vegetation's ability to dissipate heat from the earth's surface to the air above the canopy. To deduce whether forests would be more thermodynamically advantageous than existing ecosystems beyond treelines, we construct and examine counterfactual scenarios in which trees exist beyond a treeline instead of the existing alpine meadow or Arctic tundra. Meteorological data from the Italian Alps, United States Rocky Mountains, and Western Canadian Taiga-Tundra are used as forcing for model computation of ecosystem work and temperature gradients at sites on both sides of each treeline with and without trees. Model results indicate that the alpine sites do not support trees beyond the treeline, as their presence would result in excessive CO 2 loss and extended periods of snowpack due to temperature inversions (i.e., positive temperature gradient from the earth surface to the atmosphere). Further, both Arctic and alpine sites exhibit negative work resulting in positive feedback between vegetation heat dissipation and temperature gradient, thereby extending the duration of temperature inversions. These conditions demonstrate thermodynamic infeasibility associated with the counterfactual scenario of trees existing beyond a treeline. Thus, we conclude that, in addition to resource constraints, a treeline is an outcome of an ecosystem's ability to self-organize towards the most advantageous vegetation structure facilitated by thermodynamic feasibility. [ABSTRACT FROM AUTHOR]

In the mid-1960s, 27 muskoxen were translocated from Northeast Greenland to Tatsip Ataa near Kangerlussuaq in West Greenland. In just a few decades, these 27 individuals reproduced to become a population of many thousand – now the largest population of muskoxen in Greenland. This article examines human–muskox relations in present-day Kangerlussuaq and Greenland as biosocial multiplications. Muskox–human encounters shape muskoxen as well as human sociality in Kangerlussuaq, and – ultimately – they take part in the shaping of Kangerlussuaq as a place. The article ethnographically unfolds the processes through which muskoxen and humans shape each other and multiply. Diverse relations, meanings, and values come out of muskox–human encounters, and only some result in the muskox becoming a resource, understood as an element that can be utilized in a rational way, where the outcome can be measured in a specific (economic) value. Some of the meanings and values embedded in muskox–human encounters and the relations that come out of them overlap with the notion of resource, while others exceed it. Understanding how muskoxen become a resource, and how they do not, is crucial when wanting to understand human–muskox relations and to manage muskoxen sustainably. [ABSTRACT FROM AUTHOR]

A comprehensive account of fungal classification from freshwater habitats is outlined and discussed in the present review based on literature of biodiversity studies and recent morpho-phylogenetic analyses. A total of 3,870 freshwater fungal species are listed with additional details on the isolation source, habitat, geographical distribution, and molecular data. The Ascomycota (2,968 species, 1,018 genera) dominated the freshwater fungal taxa wherein Sordariomycetes (823 species, 298 genera) had the largest number, followed by Dothideomycetes (677 species, 229 genera), Eurotiomycetes (276 species, 49 genera), and Leotiomycetes (260 species, 83 genera). Other phyla included in the updated classification of freshwater fungi are: Chytridiomycota (333 species, 97 genera), Rozellomycota (221 species, 105 genera), Basidiomycota (218 species, 100 genera), Blastocladiomycota (47 species, 10 genera), Monoblepharomycota (29 species, 6 genera), Mucoromycota (19 species, 10 genera), Aphelidiomycota (15 species, 3 genera), Entomophthoromycota (6 species, 4 genera), Mortierellomycota (5 species, 3 genera), Olpidiomycota (4 species, 1 genus), Zoopagomycota (3 species, 2 genera), and Sanchytriomycota (2 species, 2 genera). The freshwater fungi belong to 1,361 genera, 386 families and 145 orders. The Pleosporales and Laboulbeniaceae are the largest freshwater fungal order and family comprised of 391 and 185 species, respectively. The most speciose genera are Chitonomyces (87, Laboulbeniomycetes), Verrucaria (50, Eurotiomycetes), Rhizophydium (52, Rhizophydiomycetes), Penicillium (47, Eurotiomycetes), and Candida (42, Saccharomycetes). [ABSTRACT FROM AUTHOR]

Boreal peatlands of Alberta (Canada) are heavily dissected by a large network of linear disturbances, including seismic lines used for Oil and Gas exploration. Edge effects resulting from these linear disturbances can increase their footprint and affect wildlife habitat, including the quality and quantity of plant and lichen forage. In 2012, seismic line restoration became a priority in Alberta, under the realm of restoration of habitat of threatened boreal woodland caribou. More accurate understanding of biotic and abiotic interactions leading to edge effects can be important in choosing appropriate restoration practices and prompting natural regeneration. We assessed the extent of edge effects of seismic lines on the adjacent boreal peatland near Peace River, northwestern Alberta. We compared plant and lichen community composition and environmental conditions on seismic lines and along 22 transects, which extended perpendicularly 75 m into the peatland from both lines edges. Soil moisture and light were higher on the lines, but frozen ground was less frequent than in the adjacent peatland. Seismic lines were also subsided by approximately 1.2 cm. Lichens were less abundant in the 2–25 m zone from the edge—indicating edge effects. On the lines, Sphagnum constituted a nearly 100% cover while lichens, trees, herbs, and other bryophytes were less abundant than in the peatland. We demonstrate how knowledge of edge effects on plants and lichens could be applied in assessing caribou habitat quality based on forage availability and predation risk, and how such knowledge could inform restoration practices of seismic lines in peatlands. [ABSTRACT FROM AUTHOR]

This research compared early nineteenth-century species lists from the Elgin Botanic Garden, New York; Cambridge Botanic Garden, Massachusetts; Botanick Garden of South-Carolina; Botanical Garden of Transylvania University, Kentucky; and Bartram's Botanic Garden, Pennsylvania (two lists). Diversity was shown by more species being unique in each botanical garden than species common to the five botanical gardens. Global representation was demonstrated with species from all of the continents (excluding Antarctica) and the Cape of Good Hope region in the botanical gardens except the Botanick Garden of South-Carolina, which did not have Australian species. Only Bartram's Botanic Garden US market list did not have twice as many species reported to be hardy in the New York City climate than species requiring a greenhouse. There were more herbaceous than woody plants in five of the six lists with the exception again being the Bartram's Botanic Garden US market list. Among the uses agriculture, arts, diet, and medicine, only medicine comprised more than 25% of the species in the five botanical gardens except the Botanical Garden of Transylvania University. For all six lists, the historical information on hardiness and duration matched modern information for more than 75% of the species; however, native region matches were less than 75% for African species. [ABSTRACT FROM AUTHOR]

Many nutrient-poor coarse-textured Kalmia L.–black spruce forest sites in eastern Canada turn to ericaceous heath dominated by Kalmia angustifolia L. after clearcutting and fire. While the mechanisms of post-fire forest and heath formation have been well documented, the origin of shrub savanna vegetation has received limited attention. This study demonstrates the significance of post-fire island regeneration of black spruce in Kalmia heath to the origin of shrub savannah alternate state. The study was conducted in Three Brooks, 10 km west of Grand Falls-Windsor, Newfoundland (48°51′ N; 55°37′ E). Black spruce forest in the site was clearcut, then a wildfire burned the area, and the site was subsequently planted with black spruce. Plant species cover, black spruce growth (stem density, stem height, basal diameter, and yearly volume increment), and foliar nutrients of planted spruce and soil properties (pH, humus and Ae horizon depth, and nutrients) in tree islands were compared with adjacent Kalmia heath. Black spruce islands had significantly lower cover of Kalmia and higher stem density of black spruce compared to Kalmia heath (7100 stems/ha in islands vs. 1920 stems/ha in heath). Height, basal diameter, and yearly volume increment of black spruce were more than three times higher in spruce islands than in Kalmia heath. Foliar nutrients of black spruce growing in Kalmia heath had significantly lower N and Mg (33 and 38%, respectively) but had significantly higher Mn and Zn (46 and 33%, respectively) than in black spruce islands. Black spruce growth inhibition in Kalmia heath is attributed to soil nutrient imbalance due to Kalmia evidenced by reduced concentrations of N and Mg and increased concentrations of Al, Fe, and other inorganic ions in the foliage. These results suggest that post-fire black spruce islands in severely burned patches provide "safe sites" for spruce regeneration, whereas Kalmia heath developing in non-severe burn area inhibits spruce regeneration and creates shrub savannah community as an alternate vegetation state. [ABSTRACT FROM AUTHOR]

Northern peatlands are substantial sinks of carbon (C), yet the sources of carbon dioxide (C[O.sub.2]) emitted from peatlands are largely unknown. Since the relationship between roots and peat in C cycling is important, vascular plants growing on the surface of peat deposits should influence C[O.sub.2] efflux from the peat surface and the overall C balance in peatlands. In our study, 30-cm peat cores were removed from an ombrotrophic bog in boreal,' continental western Canada. Surface vegetation in the cores remained intact and included a continuous bryophyte cover dominated by Sphagnum fuscum. In addition, some cores were collected such that either ericaceous shrubs (Ledum groenlandicum) or sedges (Eriophorum vaginatum) were present. We investigated how the presence of each vegetation type influenced soil respiration and the microbial mineralization of root exudates using a pulse [sup.14]C labeling of vegetation in the intact peat cores. The role of root biomass and root respiration in C[O.sub.2] emission and C allocation was quantified for each type of vegetation and compared through both measurement and modeling. Our results show that vascular plants contributed 35-57% of total C[O.sub.2] efflux from the peat surface, primarily derived from rhizosphere processes, including root respiration as well as microbial mineralization of root exudates. The mineralization of root exudates contributed 14-53 [micro]mol C-C[O.sub.2]*[m.sup.-2]*[d.sup.-1] (17-24% of total) to C[O.sub.2] efflux, depending on vegetation type and moisture conditions. The type of vegetation present did not influence the total amount of photosynthetic fixation over the course of the study, but did affect how C was allocated within and between both the aboveground and belowground components of the peat column. Key words: boreal; Canada; carbon balance; Eriophorum vaginatum; Ledum groenlandicum; ombrotrophic bog; peatlands; root exudation; Sphagnum fuscum.

Wildfire decision support systems combine fuel maps with other fire environment variables to predict fire behaviour and guide management actions. Until recently, financial and technological constraints have limited provincial fuel maps to relatively coarse spatial resolutions. Airborne Laser Scanning (ALS), a remote sensing technology that uses LiDAR (Light Detection and Ranging), is becoming an increasingly affordable and pragmatic tool for mapping fuels across localised and broad areas. Few studies have used ALS in boreal forest regions to describe structural attributes such as fuel load at a fine resolution (i.e.,100m² cell resolution). We usedALS to predict five forest attributes relevant to fire behaviour in black spruce (Picea mariana) stands inAlberta, Canada: canopy bulk density, canopy fuel load, stem density, canopy height and canopy base height. Least absolute shrinkage and selection operator (lasso) regression models indicated statistically significant relationships betweenALS data and the forest metrics of interest (R²≥ 0.81 for all metrics except canopy base height which had a R² value of 0.63). Performance of the regression models was acceptable and consistent with prior studies when applied to test datasets; however, regression models presented in this study mapped stand attributes at a much finer resolution (40 m²). [ABSTRACT FROM AUTHOR]

Questions: Edge influence on forest biodiversity is an important environmental effect associated with habitat fragmentation, but extrapolating the influence of edges across the broader landscape has been difficult, especially for situations where multiple edges exist in close proximity. We asked whether there were differences in edge effects between two types (3 m vs 8 m width) of low‐severity linear disturbance (seismic lines) and whether there were interactions of edge effects when seismic lines occur in dense networks; that is, do multiple narrow seismic lines have a stronger or weaker edge influence than a single narrow seismic line. Location: Treed peatlands in northeastern Alberta, Canada. Methods: Seismic lines are created during oil and gas exploration and are responsible for dissection of boreal forests in western Canada. We sampled vascular plants along transects perpendicular to seismic lines in moderate‐rich and poor treed fens. We used the "Randomization Test of Edge Influence" (RTEI) to calculate the magnitude and distance of edge effects and then compared these between narrower (3 m) versus wider (8 m) lines and between single narrow lines versus multiple narrow lines (parallel and ~50 m apart). Results: In moderate‐rich fens, we found a positive edge influence on understorey diversity from both wide and narrow seismic lines. We also found a weakening edge interaction on diversity, that is, single narrow seismic lines had a stronger edge influence on diversity than did multiple narrow seismic lines. In treed poor fens, multiple narrow seismic lines had a negative edge effect on tree density, understorey abundance, richness, and composition. In addition, we found strengthening edge interactions in treed poor fens on tree density, graminoid cover, and understorey composition. Conclusions: Even narrow linear disturbances, such as seismic lines, can have significant edge effects and these are exacerbated when lines occur in dense networks. [ABSTRACT FROM AUTHOR]

Abstract: The root system of forest trees account for a significant proportion of the total forest biomass. However, data is particularly limited for forests in permafrost regions. In this study, therefore, we estimated the above- and belowground biomass of a black spruce (Picea mariana) stand underlain with permafrost in interior Alaska. Allometric equations were established using 4–6 sample trees to estimate the biomass of the aboveground parts and the coarse roots (roots >5 mm in diameter) of P. mariana trees. The aboveground biomass of understory plants and the fine-root biomass were estimated by destructive sampling. The aboveground and coarse-root biomasses of the P. mariana trees were estimated to be 3.97 and 2.31 kg m−2, respectively. The aboveground biomass of understory vascular plants such as Ledum groenlandicum and the biomass of forest floor mosses and lichens were 0.10 and 0.62 kg m−2, respectively. The biomass of fine roots <5 mm in diameter was 1.27 kg m−2. Thus, the above- and belowground biomasses of vascular plants in the P. mariana stand were estimated to be 4.07 and 3.58 kg m−2, respectively, indicating that belowground biomass accounted for 47% of the total biomass of vascular plants. Fine-root biomass was 36% of the total root biomass, of which 90% was accumulated in the surface organic layer. Thus, this P. mariana stand can be characterized as having extremely high belowground biomass allocation, which would make it possible to grow on permafrost with limited soil resource availability. [Copyright &y& Elsevier]

Abstract: This study examines the recovery of the microbial compartment following active restoration of a North American ombrotrophic peatland extracted for horticultural peat-based substrates and restored by the Sphagnum moss transfer method. We used phospholipid fatty acids (PLFAs) to portrait the microbial community structure and Community Level Physiological Profiles (CLPP) to describe the functional diversity of the microbial communities. Our results indicate that the PLFA profiles were different between the beginning and the end of the growing season, but that it was impossible to distinguish five different vegetation classes found along the disturbance-recovery gradient on the basis of the microbial community structure. The pH, the cover of mosses, Ledum groenlandicum and Eriophorum vaginatum var. spissum were the best environmental predictors for the PLFA composition. The newly formed peat found in aerobic conditions beneath restored Sphagnum carpets had the highest decomposition capacity, whereas the lowest rates were found in the surface samples of non-restored conditions or in the deepest horizons of the natural samples. A large proportion of the variation in the physiological profiles was explained with variables related to the vegetation cover, the physicochemical environment and the microbial structure of the community, which is very promising for future monitoring studies. Overall, this study demonstrates that the recovery of particular plant groups, namely mosses and shrubs in restored peatlands might be the driver of changes occurring in the structure of the microbial communities in restored peatlands. [Copyright &y& Elsevier]

Twelve Alaska native plants were propagated from softwood and semi-hardwood stem cuttings collected from late June through August. Cuttings of new growth were treated with 0.3% indole-3-butyric acid powder and propagated in horticultural grade perlite and vermiculite (1:1 by vol) under intermittent mist with bottom heat [26C (79F)] in a greenhouse with a minimum night temperature of 15C (59F). After 6 weeks, cuttings were harvested and evaluated for rooting percentage and root quantity. Four species rooted poorly (< 25%) regardless of collection date: Siberian alder (Alnus viridis ssp.fruticosa), silverberry (Elaeagnus commutata), Bebb willow (Salix bebbiana) and shrub birch (Betula glandulosa). Best rooting (> 80%) occurred June 20 for: Beauverd spiraea (Spiraea stevenii), sweetgale (Myrica gale), and thinleaf alder (Alnus incana ssp. tenuifolia). Peak rooting for dwarf birch (Betula nana), feltleaf willow (Salix alaxensis), balsam poplar (Populus balsamifera), Labrador tea (Ledum groenlandicum) and littletree (Salix arbusculoides) was early to mid July. During peak rooting times, all successful species developed adequate root quantities for survival following transplanting. [ABSTRACT FROM AUTHOR]

We studied the pollination biology of 18 common insect-pollinated plant species on Kent Island, a boreal island in the Bay of Fundy. New Brunswick, Canada. Under natural conditions, fruit set was relatively high in most of the species studied [although it was very low (<1%) in Maianthemum canadense]. Hand-pollination increased fruit set in five of seven species examined (71%), indicating that fruit set may commonly be limited by the availability or behavior of pollinators on Kent Island. Twelve of 17 species examined (71 %) were capable of substantial autonomous self-pollination (autogamy in the absence of pollinators), although fruit set averaged higher in open-pollinated flowers (65.7%) than in flowers from which insects were experimentally excluded (49.6%). The number of seeds per fruit was also less in autonomously self-pollinated flowers in two species (Rhododendron canadense and Ledum groenlandicum). In at least one species (Iris versicolor), rates of autonomous selfing were higher on Kent Island than on the mainland. Stamen-excision experiments in I. versicolor demonstrated that fruit set required pollen transfer in the absence of pollinators (i.e., agamospermy did not occur). In hand-pollination experiments, five of six species (83%) (R. canadense, L. groenlandicum, Smilacina trifolia, S. stellata and I. versicolor) showed no evidence of inbreeding depression in terms of percent fruit set, fruit size or number of seeds per fruit. Overall, our results demonstrate that for many insert-pollinated plant species on Kent Island, pollinators are likely to be limiting, autogamy is common and inbreeding depression is negligible. Although pollinator limitation and autogamy regularly occur in mainland habitats as well, a review of the literature suggests that they may be more common on islands such as Kent Island. If such island-mainland differences are general, they may arise because genotypes and species capable of self-fertilization are more likely than obligate outcrossers to colonize and become established in isolated habitats. [ABSTRACT FROM AUTHOR]

Summer diets are crucial for large herbivores in the subarctic and are affected by weather, harassment from insects and a variety of environmental changes linked to climate. Yet, understanding foraging behavior and diet of large herbivores is challenging in the subarctic because of their remote ranges. We used GPS video‐camera collars to observe behaviors and summer diets of the migratory Fortymile Caribou Herd (Rangifer tarandus granti) across Alaska, USA and the Yukon, Canada. First, we characterized caribou behavior. Second, we tested if videos could be used to quantify changes in the probability of eating events. Third, we estimated summer diets at the finest taxonomic resolution possible through videos. Finally, we compared summer diet estimates from video collars to microhistological analysis of fecal pellets. We classified 18,134 videos from 30 female caribou over two summers (2018 and 2019). Caribou behaviors included eating (mean = 43.5%), ruminating (25.6%), travelling (14.0%), stationary awake (11.3%) and napping (5.1%). Eating was restricted by insect harassment. We classified forage(s) consumed in 5,549 videos where diet composition (monthly) highlighted a strong tradeoff between lichens and shrubs; shrubs dominated diets in June and July when lichen use declined. We identified 63 species, 70 genus and 33 family groups of summer forages from videos. After adjusting for digestibility, monthly estimates of diet composition were strongly correlated at the scale of the forage functional type (i.e., forage groups composed of forbs, graminoids, mosses, shrubs and lichens; r = 0.79, p <.01). Using video collars, we identified (1) a pronounced tradeoff in summer foraging between lichens and shrubs and (2) the costs of insect harassment on eating. Understanding caribou foraging ecology is needed to plan for their long‐term conservation across the circumpolar north, and video collars can provide a powerful approach across remote regions. [ABSTRACT FROM AUTHOR]

Vegetation phenology and productivity drive resource use by wildlife. Vegetation dynamics also reveal patterns of habitat disturbance and recovery. Monitoring these fine‐scale vegetation patterns over large spatiotemporal extents can be difficult, but camera traps (CTs) commonly used to survey wildlife populations also collect data on local habitat conditions. We used CTs (n = 73) from 2016 to 2019 to assess impacts of habitat change in a boreal landscape of northern Canada, where seismic lines for petroleum exploration disturbed wildlife habitat and prompted vegetation restoration efforts. First, we quantified vegetation dynamics from CTs, comparing them to satellite‐based estimates that are typically used to monitor vegetation at broad spatial scales. We then used understory phenology and productivity estimated from CT time‐lapse images to assess vegetation recovery on seismic lines. Finally, we related vegetation dynamics with the habitat use of three wildlife species: sandhill cranes Grus canadensis, woodland caribou Rangifer tarandus, and white‐tailed deer Odocoileus virginianus. CTs provided unique insight into vegetation dynamics that were different from signals measured by satellites, with temporally inconsistent and even some negative correlations between CT and satellite metrics. We found some indication of vegetation recovery on seismic lines that had received restoration treatment, with understory patterns more similar to undisturbed habitat than to seismic lines that did not receive restoration treatment. CTs also provided inferences about wildlife activity related to vegetation resources, which approaches using satellite data failed to detect. Wildlife habitat use tracked vegetation phenology, but did not always increase with vegetation productivity at weekly, 16‐day, or annual intervals. Instead, associations with vegetation productivity depended on species, temporal scale, and productivity metrics. Given the widespread and growing use of CTs to monitor terrestrial wildlife, we recommend their use to simultaneously monitor habitat conditions to better understand the mechanisms that govern wildlife habitat use in changing environments. [ABSTRACT FROM AUTHOR]

Mining and processing of lead (Pb)/zinc (Zn) ore at the Anvil Range mine occurred near the town of Faro in the Yukon Territory, Canada, for approximately 30 years, beginning in 1968. A study was undertaken to examine whether the mining activities had left a detectable “footprint” on the environment in the way of heavy metal phytoaccumulation. Foliage of three native plant species was sampled: bog blueberry (Vaccinium uliginosum), Labrador tea (Ledum groenlandicum), and willow (Salix sp.), at approximately 0.25, 2.5, 12, 30, and 200 (control) km distant from the mill (ore-processing facility at the mine). Foliage samples were oven-dried, wet- or dry-ashed, and analyzed for metal content using ICP-AES. In addition to Pb and Zn, the primary ore constituents, copper (Cu), iron (Fe), and cadmium (Cd), were also assayed. As expected, foliar Pb and Zn concentrations were elevated in plants at the sites closest to the mill, i.e., 0.25 and 2.5 km from the mine facility. Copper and Fe, both essential nutrients for plants, were also elevated in foliage at the sites closest to the mill, but not to a level that would be of concern. Foliar Cd levels were highest in Salix relative to the other species but were not affected by proximity to the mill. Results suggest that Ledum may be the best indicator of high environmental concentrations of Pb, while Salix may be the best indicator of elevated Zn and Cd. [Copyright &y& Elsevier]