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Climate drives ecosystem processes and impacts biodiversity. Biodiversity patterns over large areas, such as Canada's boreal, can be monitored using indirect indicators derived from remotely sensed imagery. In this paper, we characterized the historical space–time relationships between climate and a suite of indirect indicators of biodiversity, known as the Dynamic Habitat Index (DHI) to identify where climate variability is co-occurring with changes in biodiversity indicators. We represented biodiversity using three indirect indicators generated from 1987 to 2007 National Oceanic and Atmospheric Administration Advanced Very High Resolution Radiometer images. By quantifying and clustering temporal variability in climate data, we defined eight homogeneous climate variability zones, where we then analyzed the DHI. Results identified unique areas of change in climate, such as the Hudson Plains, that explain significant variations in DHI. Past variability in temperatures and growing season index had a strong influence on observed vegetation productivity and seasonality changes throughout Canada's boreal. Variation in precipitation, for most of the area, was not associated with DHI changes. The methodology presented here enables assessment of spatial–temporal relationships between biodiversity and climate variability and characterizes distinctive zones of variation that may be used for prioritization and planning to ensure long-term biodiversity conservation in Canada. [ABSTRACT FROM PUBLISHER]

Northern forested ecosystems are predicted to change dramatically in response to climate change during the next century. The purpose of this paper was to use logistic regression analysis to model the effects of climate and topography on the spatial distribution of the northern forest around Churchill, Manitoba, Canada. Climate maps were modeled using kriging interpolation of actual climate data collected from 34 long-term monitoring sites distributed throughout the study area, and topographic information was derived from commercially available digital elevation models. Five of the 18 independent variables contributed appreciably (p < 0.15) to the final logistic regression model: distance from the Hudson Bay coast, summer soil temperature, snow density, slope, and snow water equivalent. Current forest distribution was predicted with 66% accuracy using the final model, and Kappa statistics indicated significant agreement between modeled and actual forest extents. Significant explanatory variables demonstrate important synergistic effects of Hudson Bay, wind, and snow in determining forest distribution. Modeled forest extents were further south than actual forest limits, which suggest that the treeline is not likely in equilibrium with the present climate. [ABSTRACT FROM AUTHOR]

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

Copyright of Canadian Journal of Plant Pathology is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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

The microclimate of streamside habitats are protected from the effects of logging with buffer strips of retained trees. However, these buffer strips are often narrow due to their financial loss. Wider, selectively logged buffers might protect the microclimate while providing the same economic return. This study investigates the effects of logging on the microclimate and the growth of the bryophyte Hylocomium splendens on two streamside buffers: a standard unlogged narrow buffer (∼15 m) and a wider buffer (∼30 m) selectively logged with decreasing intensity towards the stream. The study was conducted in Central Finland on eight sites where the two buffers were logged next to each other. The near-stream change in air temperature and relative humidity was measured from pre-logging to post-logging. Additionally, post-logging microclimate gradients and the growth of H. splendens was measured on a 30 m transect away from the stream. The results showed no significant differences in the ability of the two kinds of buffers in maintaining streamside microclimate, and neither buffer seems to protect the microclimate from the negative effects of logging. The growth of H. splendens also decreased in both buffers. We conclude that wider, unlogged buffer strips are required to protect riparian forest microclimate. [ABSTRACT FROM AUTHOR]

This is a study about cultivated and 'wild' plants as components of the material heritage of crofters, an overlooked group of people in former agrarian landscapes. Despite abundant remains of crofts in Sweden, inhabited during the period from the eighteenth century until the 1940s, crofters have been subject to few studies. We used a survey conducted 1967 of botanical remains at abandoned croft as a basis for a re-survey in 2019. As with all biological traces of former human activities, cultivated plants and wild species favoured by former management ultimately disappear, but with long delays. We describe the patterns of this decline. In general, about a third of the species were gone after 52 years. The rate of disappearance of single species occurrences was about 1% annually. We discuss the interpretation of botanical remains from since long abandoned crofts in the context of heritage. In some cases, the botanical remains were the only material evidence left. We conclude that the material heritage of crofters deserves further studies and that botanical remains at abandoned crofts should be documented and at least at some sites protected. [ABSTRACT FROM AUTHOR]

Logging and forestry have traditionally been seen as a purely masculine sphere. The aim of this study is to analyze women's introduction into and situations in the forestry sector in twentieth century northern Sweden. We interviewed 30 women who worked as cooks between the 1930s and the 1960s, and examined written sources. We found that driving forces behind the emergence of a system involving forestry cooks included state investigations, rationalization of the forest sector, the effects of WW2, and overall modernization of society. Our informants were unmarried and young when they started working, and their introductions to the job were characterized by encouragement and pressure in their surroundings. They had prior knowledge of cooking, but few underwent formal training. They were, in most cases, hired by the forest workers, and portray the camps as egalitarian social systems. It is clear that the Swedish system was rather unusual internationally, and these women had a definite impact on modernizing a workspace far from cities and industries. For the women, the job entailed hardships, but also a sense of freedom. Conceivably, a seed of women's liberation in twentieth century Sweden was planted by these thousands of young women working in the northern forests. [ABSTRACT FROM AUTHOR]

Permafrost thawing could increase soil contaminant mobilization in the environment. Our objective was to quantify metal accumulation capacities for plant species and functional groups common to Alaskan military training ranges where elevated soil metal concentrations were likely to occur. Plant species across multiple military training range sites were collected. Metal content in shoots and roots was compared to soil metal concentrations to calculate bioconcentration and translocation factors. On average, grasses accumulated greater concentrations of Cr, Cu, Ni, Pb, Sb, and Zn relative to forbs or shrubs, and bioconcentrated greater concentrations of Ni and Pb. Shrubs bioconcentrated greater concentrations of Sb. Translocation to shoots was greatest among the forbs. Three native plants were identified as candidate species for use in metal phytostabilization applications. Elymus macrourus, a grass, bioconcentrated substantial concentrations of Cu, Pb, and Zn in roots with low translocation to shoots. Elaeagnus commutata, a shrub, bioconcentrated the greatest amounts of Sb, Ni, and Cr, with a low translocation factor. Solidago decumbens bioconcentrated the greatest amount of Sb among the forbs and translocated the least amount of metals. A combination of forb, shrub, and grass will likely enhance phytostabilization of heavy metals in interior Alaska soils through increased functional group diversity. [ABSTRACT FROM AUTHOR]

In the last decades a drastic increase in air temperature but a stable precipitation regime in Mongolia has led to gradual drying conditions. Thus, we evaluated the effect of spatial and climatic characteristics on the soil-plant nitrogen dynamics in three representative larch stands (Larix sibirica) with different geographical and climatic conditions using stable nitrogen isotopes. The results showed significant differences in the soil inorganic N content among sites and consequently a different isotopic composition in the plant-soil system. Litter, bark and wood had the lowest δ15N values for all sites, slightly higher δ15N values for needles, while the highest δ15N values were observed for roots and soil. These differences could be the result of the larch stands age themselves, but were in agreement with the spatial and climatic characteristics of the sites. Based on the δ15N value a higher reliance on ectomycorrhizal fungi (ECMF) was observed in the warmest and driest site, while lower dependency was shown in the cooler northern site with higher soil inorganic N content. In both sites, the rate of air temperature increase has been similar in the last decades; however, their soil-plant N dynamics showed different characteristics. [ABSTRACT FROM AUTHOR]

The vertical partitioning of fungi in forest soils regulates nutrient cycling. Chemical stress inhibits the organic matter turnover, and the role of fungal niche partitioning in this phenomenon needs exploration. Using next-generation sequencing, we studied fungal communities in organic and mineral soil horizons in control (unpolluted) and industrially polluted spruce-fir forests. Community composition and structure followed the pattern commonly observed in forest soils, with dominating ectomycorrhizal and saprotrophic mycelial fungi. In the control area, the ratio of ectomycorrhizal to saprotrophic fungal abundances was lower in the organic than in the mineral horizon. The strongest pollution-induced decrease of relative abundance and diversity was registered for saprotrophs, which are more exposed to heavy metals, and for those biotrophs, which lose most of their potential hosts. Therefore, the ratio of ectomycorrhizal to saprotrophic fungal abundances increased in the organic horizon in the polluted area, indicating a vertical repartition of fungal trophic guilds. [ABSTRACT FROM AUTHOR]

The article deals with various types of specially protected territories participating in preservation of biological diversity of boreal coniferous forests of the West Siberian Plain. Data are presented on species diversity of certain territories of Tomsk oblast established in various landscape and geographical conditions and under various conditions including areas within the Great Vasyugan Mire and the outskirts of Tomsk. The article reviews species of dominant plant families of rivers and lakes of the Polto system in the basin of the Tym river; and the condition of certain species of Orchidaceae, Empetraceae, Cupressaceae, Tiliaceae and Lamiaceae in other parts of the Tomsk region. There is also some analysis of species along with description of sites where 6 plant species were discovered (Orchis militaris,Orchis fuchsii,Juniperus communis,Empetrum nigrum,Tilia cordata,Stachys silvatica) that are protected in the area of study. [ABSTRACT FROM AUTHOR]

Historically, oak forests and woodlands intergraded with southern boreal forest, temperate mesic forest, and grassland biomes, forming complex fire-mediated relationships in the Great Lakes region of Minnesota, Wisconsin, and Michigan, USA. Variability in fire recurrence intervals allowed oaks to mix with grasses or with mesic forest species in areas with high (2–10 yr) or moderate (several decades) fire frequencies, respectively. In the southern boreal forest, oak colonization was limited by cold climate. In recent decades former savannas have been largely converted to agricultural fields and the fate of oak remnants is controlled by human fire use. In mesic temperate forests, fire exclusion, wetter climate, and deer browsing have led to mesophication and increasing maple dominance. With ongoing warming, however, mesophication could reverse due to increased drought and fire frequency, and earthworm invasion, which enhances the understory environment for oak seedlings. Oaks are also likely to invade large tracts of southern boreal forest. However, deer grazing on oak seedlings will partially negate the positive influence of warming and fire. On balance, oaks have a more positive future outlook in the Lake States, as the climate becomes more favorable to oaks compared to temperate mesic and boreal forests. [ABSTRACT FROM PUBLISHER]

The foliage biomass–sapwood relationship (the pipe model) is critical for tree growth and is used in tree growth models for understanding the implications of this structural relationship on the allocation of resources. In this research, we compared this relationship for two commercially important and sympatric species, black spruce (Picea mariana(Mill.) B.S.P.) and white spruce (Picea glauca(Moench) Voss). At locations in eastern Canada, 57 black and 50 white spruce trees were destructively sampled to obtain foliage biomass, crown structure, and tree stem measures. Using a model-based approach, we compared foliage biomass–branch basal area and foliage biomass–sapwood relationships at the tree and disk (i.e. along the tree stem) levels (i.e. pipe-model ratios) between these two species. We found that (i) branch foliage biomass–branch basal area was greater for black spruce than white spruce and (ii) pipe-model ratios along the tree stem given tree size were greater for black spruce than for white spruce. We attributed these differences to: (i) greater shade tolerance and leaf longevity of black spruce; (ii) slower growth rates of black spruce; and (iii) differing hydraulic strategies and mechanical requirements. [ABSTRACT FROM PUBLISHER]

Our objective was to automatically recognize the species composition of a boreal forest from high-resolution airborne winter imagery. The forest floor was covered by snow so that the contrast between the crowns and the background was maximized. The images were taken from a helicopter flying at low altitude so that fine details of the canopy structure could be distinguished. Segments created by an object-oriented image processing were used as a basis for a linear discriminant analysis, which aimed at separating the three dominant tree species occurring in the area: Scots pine, Norway spruce, and downy birch. In a cross validation, the classification showed an overall accuracy of 81.9%, and a kappa coefficient of 0.73. [ABSTRACT FROM AUTHOR]

The Late Pliocene (3.6–2.6 Ma) was a period of significant global warmth, considered a potential analogue for future anthropogenic climate change. Newly discovered fine-grained sediments from between the gold-bearing lower and upper White Channel Gravels show the presence of a wetland or lake within Bonanza Creek, Dawson Mining District, Yukon. This environment was surrounded by a diverse Pinaceae-dominated boreal forest with significant stands of angiosperms in favourable sites. Quantitative climate reconstructions derived from pollen and spores reveal a mean annual temperature at least 6 °C warmer than today with warm summers and relatively mild winters. Finally, the new pollen assemblage is used to discuss the age of the White Channel Gravels. [ABSTRACT FROM PUBLISHER]