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Crimean-Congo hemorrhagic fever (CCHF) is a potentially severe or fatal disease caused by CCHF virus (CCHFV; species Orthonairovirus haemorrhagiae), a tickborne virus of the family Nairoviridae, order Bunyavirales. CCHF has [...]

The natural disturbance-based management (NDBM) aims to maintain specific structural and compositional attributes of natural forests in managed stands. Operationally, NDBM relies on diversifying and adapting silvicultural practices, including partial harvesting (PC), to expand the range of options beyond that of simply clearcuts (CC). Established in 1998, the Sylviculture et Amenagement Forestier Ecosystemique (SAFE) project evaluates this potential in hardwood, mixedwood, and coniferous stands in northwestern Quebec, Canada. Our results confirmed a part of the NDBM objectives, i.e., PC allowed the maintenance of stands with mixed structure and composition, constituting an interesting complement to CC, which reset stand regeneration. However, PC did not accelerate the stand transition to later stages with less intensive harvesting or to earlier stages with more intensive harvesting. We essentially had an initial impact, delaying or stopping the stand evolution that dissipates over time and more quickly with less intensive harvesting. Furthermore, our results did not support the ability of PC to enhance the development of old-growth attributes like deadwood. Despite the 20-year horizon of this study, further field surveys will be required in the future to better understand the impact of different silvicultural treatments on forest productivity and biodiversity preservation throughout a forest rotation. Key words: natural disturbance-based management (NDBM), mixed stands, boreal forest, partial cuts, clearcuts, 1. Introduction Natural disturbance-based management (NDBM) has been widely advocated as a means to maintain healthy and resilient forest ecosystems by reducing differences between natural and managed landscapes throughout North [...]

Almost half of all women experience a sexual pain disorder in their lifetime, including dyspareunia, vaginismus, vulvodynia, and provoked vestibulodynia. Despite significant negative consequences across quality of life indices, few [...]

Wildfire is the predominant natural disturbance in the boreal forests of western Canada. Natural disturbance based forest management involves the use of retention harvesting to retain stand structural diversity after harvest; however, unlike fire, this partial harvesting technique does not cause combustion of the forest floor. Application of prescribed burning to areas treated with retention harvesting might emulate the influence of wildfires more effectively than harvesting alone. We compared understory vascular plant diversity, abundance, and composition between forest stands subjected to dispersed retention harvesting (10% retention) with and without prescribed burning 1, 6, and 11 or 12 years after burning. Untreated forest was included as a reference. Research was conducted in conifer-dominated, mixedwood, and deciduous-dominated boreal forest stands in northwestern Alberta, Canada. In deciduous-dominated stands, burned areas of retention harvested stands had higher species richness and greater cover than did unburned areas. In all three forest cover types, effects of harvest with and without burn on species richness, cover, and composition were still evident a decade after disturbance. Fire-adapted species benefited most from the prescribed burn treatment. The combination of prescribed burning with retention harvesting can be considered a useful option in forest management that aims to emulate natural disturbance. Key words: prescribed burning, retention harvesting, fire, understory vascular plants, boreal forest. Les perturbations qui dominent dans les forets boreales de l'ouest du Canada sont causees par les feux de foret. L'amenagement forestier qui s'inspire des perturbations naturelles inclut l'utilisation de la coupe avec retention pour conserver la diversite structurale a la suite de la recolte. Cependant, cette methode de coupe partielle n'entraine pas la combustion de la couverture morte comme c'est le cas avec le feu. Le recours au brulage dirige dans les zones soumises a une coupe avec retention pourrait imiter l'effet des feux de foret plus efficacement que la coupe seule. Nous avons compare la composition, l'abondance et la diversite des plantes vasculaires en sous-etage dans des peuplements forestiers soumis a une coupe avec retention des arbres disperses (10 % de retention) avec et sans brulage dirige 1, 6 et 11 ou 12 ans apres le brulage. Une foret non traitee a ete incluse comme reference. Cette etude a ete realisee dans le nord-ouest de l'Alberta, au Canada, dans des peuplements de foret boreale domines soit par des resineux soit par des feuillus et dans des peuplements mixtes. Dans les peuplements domines par des feuillus soumis a une coupe avec retention, la richesse en especes et la couverture etaient plus grandes dans les zones brulees que dans les zones non brulees. Dans les trois types de couvert forestier, les effets de la recolte avec et sans brulage sur la richesse en especes, la couverture et la composition etaient encore evidents 10 ans apres la perturbation. Les especes adaptees au feu ont le plus beneficie du brulage dirige. La combinaison du brulage dirige et de la coupe avec retention peut etre consideree comme une option utile pour l'amenagement forestier qui cherche a imiter les perturbations naturelles. [Traduit par la Redaction] Mots-cles: brulage dirige, coupe avec retention, feu, sous-etage, plantes vasculaires, foret boreale., Introduction Wildfire is the predominant stand-replacing natural disturbance in the boreal forest and it drives the region's vegetation dynamics (Johnson 1992; Payette 1992). The understory vegetation layer hosts most of [...]

Understanding swimming performance of native freshwater fishes has implications for ecology, conservation, and management. In particular, this type of information has practical importance for improving the understanding of fish dispersal, occurrence, migration, and invasive potential. The objective of this study was to characterize swimming performance of 2 taxa from the comparatively understudied minnow family (Cyprinidae) and test for potential drivers as a function of total length, sex, habitat, morphology, or some combination.The study assessed Spotfin Shiner (Cyprinella spiloptera; n = 66) and Bluntnose Minnow (Pimephalesnotatus;n = 24) populations from an ontogenic range of male and female individuals from lentic and lotic habitats in Indiana and Ohio. Akaike information criterion (AIC) model selection identified the most parsimonious linear regression model to predict swimming performance of Spotfin Shiner and Bluntnose Minnow independently. Overall, larger Spotfin Shiners were superior swimmers compared with smaller individuals. In both species, individuals having more streamlined heads and elongated caudal regions were better swimmers. Additionally, Spotfin Shiners that were collected from lotic environments were generally better swimmers than individuals from lentic environments. Models did not recover sex-specific effects in either species--or meaningful total length, or habitat effects, in Bluntnose Minnows. Overall, this study provides evidence of a complex series of swimming performance covariates when assessing or understanding performance. This has implications for aquatic population, assemblage, and community ecology as well as management and conservation efforts., INTRODUCTION Alterations to flow regimes are almost ubiquitous globally (Poff et al. 1997). Dams constitute the most obvious and recognizable form of these alterations; however, while dams do act as [...]

ABSTRACTS The common explanation for the progression of the rainy season over Africa is the seasonal excursion of the ITCZ. The ITCZ paradigm stems from a time when tropical rainfall [...]

We tested the response of species composition of three dominant litter-dwelling arthropod taxa (carabid beetles, spiders, and rove beetles) to wildfire and harvest. This study was conducted in north-central Ontario (47[degrees]42'N, 83[degrees]36'W) in jack pine (Pinus banksiana Lamb.) dominated stands in 2013 using pitfall trapping. Using 222 species (12 015 individuals), we compared the effects of disturbance using recently burned (3 years since fire) and clearcut sites (3 years since harvest; tree length, full tree, stump removal, and blading), as well as older, closed-canopy stands that have regenerated following clearcutting (51 years since harvest) and fire (92 years since fire), with multivariate regression trees. Taxa were more similar in the three controls (including recent fire) than between controls and harvest treatments, with increased forest floor disturbance in harvested plots being a likely explanation. In addition, taxa were different in the younger (51 years) harvest-origin plots than in the older (92 years) fire-origin plots, suggesting that communities had not yet recovered from the harvest disturbance possibly due to insufficient coarse woody debris in the younger stand. These results indicate that forest management practices that match natural forest floor disturbance could ameliorate short-term effects, whereas the maintenance of more coarse woody debris could reduce the recovery time of epigaeic communities. Key words: natural disturbance emulation, ecosystem management, carabid beetle, rove beetle, ground spider. Nous avons etudie l'impact des feux de foret et de la recolte sur la composition en especes de trois taxons dominants d'arthropodes qui vivent dans la litiere (carabes, araignees et staphylins). Cette etude a ete realisee en 2013 dans le centre-nord de l'Ontario (47[degrees]42'N, 83[degrees]36'O), dans des peuplements domines parle pin gris (Pinus banksiana Lamb.), au moyen du piegeage dans des trappes. A l'aide de 222 especes (12 015 individus), nous avons compare les effets de la perturbation en utilisant des sites recemment brules (3 ans apres un feu) et des sites coupes a blanc (3 ans apres la recolte; bois en longueur, arbre entier, enlevement des souches et coupe a la cisaille), ainsi que des peuplements plus vieux a couvert ferme qui se sont regeneres apres une coupe a blanc (51 ans apres la recolte) ou un feu (92 ans apres le feu) en utilisant des arbres de regression multivariee. Les taxons etaient plus semblables dans les trois temoins (incluant le feu recent) que entre les temoins et les traitements impliquant une coupe, ce qui s'explique vraisemblablement par la perturbation accrue de la couverture morte dans les parcelles recoltees. De plus, les taxons etaient differents dans les parcelles plus vieilles (92 ans) issues de feux comparativement aux plus jeunes (51 ans) issues d'une coupe, ce qui indique que les communautes n'avaient pas encore recupere a la suite de la perturbation due a la recolte, probablement a cause du manque de debris ligneux grossiers dans le peuplement plus jeune. Ces resultats indiquent que les pratiques d'amenagement forestier qui correspondent a une perturbation naturelle de la couverture morte pourraient ameliorer les effets a court terme tandis que le maintien de plus de debris ligneux grossiers pourrait reduire la periode de recuperation des communautes epigees. [Traduit par la Redaction] Mots-cles: imitation des perturbations naturelles, amenagement de l'ecosysteme, carabe, staphylin, araignee qui vit au sol., 1. Introduction Ecological comparisons of resident biota between managed and naturally disturbed sites are the premise of natural disturbance based approaches to forest management. Natural disturbance based management is founded [...]

Sustainable forest management implies successful regeneration following disturbances. Tree regeneration in subarctic ecosystems can, however, be constrained by limitations to seedling establishment related to cold soils, slow decomposition rates, and competition by ericaceous species. We established a field trial at the northern limit of commercial forests in Quebec, Canada, to evaluate to what extent mechanical site preparation (MSP) and planting of a nurse [N.sub.2]-fixing species could promote conifer establishment on a site burned in 2007. The experiment comprised four treatments applied in 2010: standard MSP (disc trenching), standard MSP plus planting of Alnus crispa, intensive MSP, with larger furrows than standard MSP, and a control. Main plots were divided and planted in 2011 with Picea mariana (Mill.) Britton, Stearns & Poggenb. or Pinus banksiana Lamb. We monitored seedling survival, growth, nutrition, and microsite over a 3-year period. Results revealed interactions between treatments and planted species. Mechanical site preparation resulted in higher conifer growth relative to the control conditions, and planting Alnus resulted in growth gains similar to those obtained from intensive MSP. We measured competitive interactions between Alnus and the conifers that might eventually cancel out the initial benefits derived from facilitation by planting the nurse species. Longer term monitoring of interspecific interactions is needed to unravel the mechanisms responsible for the facilitative effect and identify the best management practices. Key words: reforestation, restoration, boreal forest, conifer, nutrition, competition, regeneration. L'amenagement durable des forets implique que la regeneration forestiere s'etablisse avec succes apres les perturbations. La regeneration forestiere dans les ecosystemes subarctiques peut toutefois etre problematique en raison des limitations que les sols froids, les faibles taux de decomposition, et la vegetation concurrente dominee par les ericacees imposent a l'etablissement des semis et a la productivite vegetale. Nous avons effectue une experience sur le terrain a la limite nordique des forets commerciales du Quebec, au Canada, pour evaluer dans quelle mesure la preparation mecanique du sol (PM) et la plantation d'une espece de soutien fixatrice d'azote pouvait ameliorer l'etablissement des coniferes sur un site recemment brule. L'experience comprenait quatre traitements appliques en 2010 : PM standard (scarifiage a disques), PM standard plus plantation d'Alnus crispa, PM intensive avec des sillons plus larges que la PM standard et un temoin. Les parcelles principales ont ete divisees et plantees en 2011 avec Picea mariana (Mill.) Britton, Stearns & Poggenb. ou Pinus banksiana Lamb. Nous avons mesure la survie, la croissance et la nutrition des plants, ainsi que les caracteristiques des microsites oU ils avaient ete plantes, sur une periode de 3 ans. Les resultats ont revele des interactions entre la PM et l'espece plantee. La PM a stimule la croissance des coniferes par rapport au temoin et la plantation d'Alnus a engendre des gains de croissance similaires a ceux associes a la PM intensive. Nous avons mesure des interactions competitives entre Alnus et les coniferes, lesquelles pourraient eventuellement annuler les effets benefiques initiaux de facilitation s'il advenait qu'Alnus domine la station. Un suivi a plus long terme de meme que l'etude des interactions interspecifiques sont necessaires afin d'elucider les mecanismes responsables de l'effet de facilitation et d'identifier les meilleures pratiques d'amenagement. Mots-cles : reboisement, restauration, foret boreale, conifere, nutrition, competition, regeneration., Introduction Tree density and stocking are critical factors that determine forest productivity (Drew and Flewelling 1979). They both depend directly upon successful tree regeneration following natural and anthropogenic disturbances (Burton [...]

Abstract: Canada's boreal biome is a mosaic of forests and peatlands. These ecosystems have developed dynamically, periodically affected by disturbance events of significant spatial extent and variable severity, reducing ecosystem [...]

Understanding vegetation recovery patterns following wildfire and logging disturbance is essential for long-term planning in sustainable forestry. Plot-scale studies indicate differences in revegetation rates and postdisturbance composition in Labrador, Canada, following fire in comparison with harvest but do not necessarily capture the full range of relevant landscape variability. Using a satellite-based land cover classification that distinguishes forest, woodland, shrub, lichen, and bare ground, we applied partial least-squared regression (PLS) to derive empirical models of vegetation dynamics following fire and harvest. Forest recovery rates were found to be generally slow and sensitive to predisturbance land condition and site quality (potential productivity). We found that, although disturbance type was not specifically retained in the model, estimated rates of vegetation recovery were faster for a typical harvest compared with a typical fire (i.e., 50% recovery at 14 years versus 33 years, respectively). Indeed, the model predicts important regeneration delay following fire that appears sensitive to both site quality and area burned. Understanding factors affecting broad-scale vegetation recovery relationships can help guide future sustainable forestry and wildlife habitat initiatives in the region, in part by parameterizing landscape simulation models used for strategic decision support. Key words: Canada, disturbance patch attributes, land cover, partial least-squared regression (PLS), site productivity. Il est essentiel de comprendre les schemas de retablissement de la vegetation a la suite d'un feu de foret ou d'une perturbation causee par l'exploitation forestiere pour planifier a long terme dans un contexte de foresterie durable. Des etudes a l'echelle de la parcelle au Labrador, Canada, montrent que le taux de revegetalisation et la composition different apres une perturbation selon qu'elle ait ete causee par le feu ou la coupe. Cependant, ces etudes ne detectent pas necessairement toute l'amplitude de la variabilite pertinente du paysage. A l'aide d'une classification de la couverture du sol, etablie sur la base de donnees satellitaires et capable de distinguer la foret, les terrains boises, les arbustes, les lichens et le sol nu, nous avons applique l'analyse de regression partielle par les moindres carres pour deriver des modeles de dynamique de la vegetation a la suite d'un feu ou d'une coupe. Les taux de retablissement de la foret se sont generalement averes lents et sensibles a l'etat du terrain avant la perturbation ainsi qu'a la qualite de la station (productivite potentielle). Bien que le type de perturbation n'ait pas ete specifiquement considere dans le modele, nous avons trouve que les taux estimes de retablissement de la vegetation etaient plus rapides dans le cas d'une recolte typique comparativement a un feu typique (c.-a-d. 50 % de retablissement respectivement a 14 ans versus 33 ans). En effet, a la suite d'un feu le modele predit un important decalage de la regeneration qui semble sensible tant a la qualite de la station qu'a la superficie brulee. La connaissance des facteurs qui influencent le retablissement de la vegetation a grande echelle peut aider a orienter la foresterie durable dans l'avenir et les initiatives concernant l'habitat de la faune dans la region, en partie en parametrant les modeles de simulation du paysage utilises comme outils d'aide a la prise de decisions strategiques. [Traduit par la Redaction] Mots-cles: Canada, attributs des parcelles perturbees, couverture du sol, regression partielle par les moindres carres, productivite de la station., Introduction There is a growing awareness that natural disturbances are an integral component of functioning ecosystems and, as such, need to be accounted for when planning future timber supply and [...]

Ecosystem-based management advocates that forestry disturbances should aim to emulate natural disturbances to mitigate the landscape-level impact of forest management. This study compares the impact of clear-cuts followed by a prescribed burn (CCPB) with clear-cuts alone (CC) and current careful logging practices (CLAAG: 'careful logging around advanced growth') on understory composition within black spruce (Picea mariana Miller (BSP)) paludified forest stands at the plot, site, and treatment levels using a functional-type approach. Vascular and nonvascular taxa showed significant differences in composition at the plot level among treatments. We found that pioneer taxa occurred mainly in CCPB sites, while late-successional taxa characterized CC sites. CLAAG sites had higher taxa richness than CCPB and CC sites, and we found that CCPB treatments were most likely to promote vascular taxa compositions that are more similar to those observed after natural disturbances. Additionally, the relative abundance of Sphagnum spp., responsible for paludification, was significantly reduced in sites treated by prescribed burning. This study therefore presents results suggesting that prescribed burning might represent a sustainable alternative to current harvesting techniques in the Clay Belt of eastern Canada that could help in preserving biodiversity (in terms of understory species assemblage) while maintaining or even enhancing forest productivity. Key words: boreal forest ecosystem, black spruce forest stands, prescribed fire, clear-cut, biodiversity, understory composition, conservation management, paludification. Les strategies d'amenagement forestier ecosystemique preconisent d'imiter les effets des perturbations naturelles pour attenuer l'impact de traitements sylvicoles a l'echelle du paysage. Cette etude compare les effets de coupe totale suivie de brulage dirige (CCPB) avec ceux de coupe totale (CC) et de pratique sylvicole appliquee limitant la perturbation du sol (CLAAG : << careful logging around advanced growth >>) sur la composition des especes de sous-bois, au sein de peuplements d'epinette noire (Picea mariana Miller (BSP)) touches par la paludification. Les analyses, effectuees a l'echelle de la placette, du site et du traitement ont permis via l'analyse des taxons et des types fonctionnels d'examiner les effets respectifs de chaque traitement. Des differences de composition significatives parmi les especes vasculaires et non-vasculaires ont ete observees a l'echelle de la placette selon le type de traitement considere. Nous avons constate que les especes pionnieres etaient associees aux sites CCPB tandis que les especes de fin de succession etaient caracteristiques des sites CC. Une richesse specifique plus elevee a ete observee parmi les sites CLAAG que dans les sites CCPB et CC. Nous avons par ailleurs trouve que les traitements CCPB etaient davantage enclin a promouvoir des patrons de composition d'especes vasculaires similaires a ceux observes apres des perturbations naturelles comme les feux de foret. Nous avons egalement constate une abondance relative plus faible des especes de sphaigne, responsible du phenomene de paludification, au sein des sites traites par brulage dirige. Les resultats de cette etude suggerent ainsi que le brulage dirige represente une alternative durable aux pratiques sylvicoles actuelles en permettant de conserver la biodiversite (en termes d'assemblages d'especes) et de maintenir voire d'augmenter la productivite des peuplements exploites. Mots-cles: ecosysteme forestier boreal, peuplements d'epinette noire, brulage dirige, coupe totale, biodiversite, composition des especes de sous-bois, gestion de la conservation, paludification., Introduction In boreal forests, stand-replacing wildfires are considered to be the primary disturbances that drive natural forest dynamics (Bergeron et al. 2001; Harvey et al. 2002, Bouchard et al. 2008; [...]

Greater opportunity now exists compared to 35 years ago for civil engineers to apply river ice knowledge to practical problems of planning, designing, and operating hydro-power facilities, water intakes, bridges, and other infrastructure along ice-covered rivers. This is due to major advancements made during this period in understanding the physical processes of river ice formation, growth and breakup, in developing instrumentation for acquisition of information on winter environments, and in developing numerical modelling tools. An increasing number of journal articles, as well as papers presented at the river ice workshops of the CGU Committee on River Ice Processes and the Environment (CRIPE) and the ice symposia of the International Association for Hydro-Environment Engineering and Research (IAHR) attest to the advancement in river ice science and engineering knowledge that has occurred during the past 35 years. This paper reviews the developments in river ice science and engineering from a Canadian perspective and briefly discusses future directions. Key words: river ice, river ice processes, instrumentation, modelling, mitigation, civil engineering. Les ingenieurs civils ont plus souvent l'occasion aujourd'hui qu'il y a 35 ans d'appliquer les connaissances disponibles sur la glace de riviere a la resolution des problemes pratiques de planification, de conception et de fonctionnement lies aux installations hydroelectriques, ouvrages de prise d'eau, ponts et autres infrastructures installees le long des rivieres couvertes de glace. Cela est du aux avancees majeures realisees au cours des 35 dernieres annees dans la comprehension des phenomenes physiques de la formation, du developpement et de la rupture de la glace de riviere, dans la conception d'instruments d'acquisition de donnees sur les conditions hivernales et dans le developpement d'outils de modelisation numerique. De plus en plus d'articles de revues scientifiques et de publications, presentes dans le cadre des ateliers du CRIPE (Committee on River Ice Processes and the Environment) organises par l'Union Geophysique Canadienne (UGC) et lors des symposiums sur la glace de l'IAHR (International Association for Hydro-Environment Engineering and Research), attestent les progres des connaissances, accomplis ces 35 dernieres annees, en science et en ingenierie specialisees dans la glace de riviere. Le present article decrit ces avancees du point de vue canadien et traite brievement des perspectives d'avenir dans ce domaine. [Traduit par la Redaction] Mots-cles: glace de riviere, processus lies a la glace de riviere, instruments, modelisation, mesures d'attenuation, ingenierie civile., Introduction During the past 35 years, great strides have been made in river ice hydraulics. Canadian engineers and scientists have been forefront in developing a greater understanding of river ice [...]

It is acknowledged that natural forest fires cannot and even should not be eliminated from the North American boreal forest. Forest fires produce immediate losses of wood volume, disrupt the conversion of the actual forest age structure into a target structure, and prevent planned timber supply (PTS) levels from being achieved. In this paper, we explore the extent to which periodic shortfalls in available timber under various burn rates can be mitigated through salvage logging and the tolerance of forest managers to a given level of shortfall, both as a function of forest age class structure. Simulations are done using both a deterministic and a stochastic representation of burn rate over time. Results show that the frequency of shortfall events can be reduced by salvage logging and by the introduction of measures that generate a tolerance to shortfall and that this mitigation potential is influenced by initial forest age class structure and burn rate. Results also show that even a 100% rate of salvage logging cannot fully compensate for timber losses to fire and eliminate fire-induced timber shortfalls. Furthermore, interannual burn rate variability reduces the efficiency of both mitigation measures. As the PTS is never realized under fire risk, the real cost of opting for different PTS scenarios should be estimated not from the difference in PTS but rather from the more realistic difference in realized timber harvest. Key words: natural disturbances, sustained yield, boreal forest, stochastic processes. Il est reconnu que les feux de foret d'origine naturelle ne peuvent pas et meme ne doivent pas etre elimines de la foret boreale nord-americaine. Les feux de foret occasionnent des pertes immediates de volume de bois, perturbent la conversion de la structure courante d'age de la foret vers une structure cible et empechent l'approvisionnement planifie en bois (APB) d'etre atteint de maniere constante. Dans cet article, nous explorons dans quelle mesure les deficits periodiques en bois disponible causes par divers risques de feux peuvent etre attenues par la coupe de recuperation et par le degre de tolerance des gestionnaires forestiers face a ces deficits, et ceci en fonction de la structure d'age des forets. Les simulations sont faites en utilisant une representation temporelle deterministe et stochastique des feux. Les resultats montrent que la frequence des periodes en deficit de bois peut etre reduite par la coupe de recuperation et par l'introduction de mesures de tolerance a ces deficits, et que ce potentiel d'attenuation est influence par la structure d'age de la foret initiale et par le niveau de pertes par le feu. Les resultats montrent egalement que meme un taux de coupe de recuperation a 100 % ne peut pas compenser entierement les pertes de bois par le feu et eliminer les deficits periodiques qui en resultent. En outre, l'ajout de la variabilite interannuelle des feux reduit l'efficacite des deux mesures d'attenuation. Enfin, puisque l'APB n'est en fait jamais realise dans les forets sujettes aux feux, le cout reel d'une reduction l'APB doit etre estime non pas par la difference l'APB, mais plutot par la difference plus realiste de recolte de bois realisee. Mots-cles: perturbations naturelles, rendement soutenu, foret boreale, processus stochastiques., Introduction In the boreal forests of North America, fires may cause important losses of goods and services, including timber supply (Van Wagner 1983; Martell 1994). Meanwhile, total fire exclusion is [...]

Life is dependent on catalysis, as many chemical transformations essential for cellular function are kinetically sluggish and/or thermodynamically disfavoured under ambient conditions. The emergence of a catalyst (or catalytic system) [...], The emergence of catalysis in early genetic polymers such as RNA is considered a key transition in the origin of life (1), pre-dating the appearance of protein enzymes. DNA also demonstrates the capacity to fold into three-dimensional structures and form catalysts in vitro (2). However, to what degree these natural biopolymers comprise functionally privileged chemical scaffolds (3) for folding or the evolution of catalysis is not known. The ability of synthetic genetic polymers (XNAs) with alternative backbone chemistries not found in nature to fold into defined structures and bind ligands (4) raises the possibility that these too might be capable of forming catalysts (XNAzymes). Here we report the discovery of such XNAzymes, elaborated in four different chemistries (arabino nucleic acids, ANA (5); 2'-fluoroarabino nucleic acids, FANA (6); hexitol nucleic acids, HNA; and cyclohexene nucleic acids, CeNA (7)) directly from random XNA oligomer pools, exhibiting in transRNA endonuclease and ligase activities. We also describe an XNA-XNA ligase metalloenzyme in the FANA framework, establishing catalysis in an entirely synthetic system and enabling the synthesis of FANA oligomers and an active RNA endonuclease FANAzyme from its constituent parts. These results extend catalysis beyond biopolymers and establish technologies for the discovery of catalysts in a wide range of polymer scaffolds not found in nature (8). Evolution of catalysis independent of any natural polymer has implications for the definition of chemical boundary conditions for the emergence of life on Earth and elsewhere in the Universe (9).

Much of Canada's terrestrial biodiversity is supported by boreal forests. Natural resource development in boreal forests poses risks to this biodiversity. This paper reviews the scientific literature to assess the effects of natural resource development on terrestrial biodiversity in Canadian boreal forests. We address four questions: (1) To what extent have Canadian boreal forests changed due to natural resource development? (2) How has biodiversity responded to these changes? (3) Will the biodiversity of second-growth forests converge with that of primary boreal forests? (4) Are we losing species from boreal forests? We focus on trees, understory plants, insects, fungi, selected mammals, and songbirds because these groups have been most studied. We review more than 600 studies and found that changes in community composition are prevalent in response to large-scale conversion of forest types, changes in stand structures and age distributions, and altered landscape structure resulting from forest management and habitat loss associated with other developments such as oil and gas, hydroelectric, and mining. The southern boreal forest has been more highly impacted than the north due to more extensive forest management and the cumulative effects of multiple forms of development. There is abundant evidence that most species are not in danger of being extirpated from the boreal forest due to these anthropogenic changes. A few species, including woodland caribou (Rangifer tarandus) and grizzly bear (Ursus arctos), have, however, undergone long-term range contractions. Significant gaps in our ability to assess the effects of natural resource development on biodiversity in the boreal zone are the lack of long-term spatial and population data to monitor the impact of forest changes on ecosystems and species. Key words: terrestrial biodiversity, boreal forest, natural resource development, forest management, forest conversion. Une bonne partie de la biodiversite du Canada se retrouve en foret boreale. Le developpement des ressources naturelles dans des forets boreales presente des risques pour cette biodiversite. Les auteurs presentent une revue de la litterature pour evaluer les effets du developpement des ressources naturelles sur la biodiversite terrestre dans les forets boreales canadiennes. Ils ont souleve quatre questions: (1) jusqu'il quel point les forets boreales canadiennes se sont vues modifiees par le developpement des ressources naturelles ? (2) Comment la biodiversite a-t-elle reagi a ces changements ? (3) Y aura-t-il convergence de la biodiversite des forets de seconde venue avec celle des forets boreales primaires ? (4) Subissons-nous des pertes d'especes en forets boreales ? Les auteurs se sont interesses en particulier aux arbres, aux plantes de sous-bois, aux insectes, aux champignons, a des mammiferes et oiseaux chanteurs selectionnes, car ces groupes ont ete les plus etudies. Ils ont suivi plus de 600 especes et ont constate que les changements de composition prevalent en reaction a des modifications a grande echelle des types forestiers, des changements de la structure, des classes d'age, des modifications aux structures des paysages resultant de l'amenagement forestier, ainsi que des pertes d'habitat associees avec d'autres developpements comme l'huile, le gaz, l'hydroelectricite et les mines. La partie meridionale de la foret boreale a recu plus d'impacts que la partie nordique suite a des amenagements forestiers plus intensifs et aux effets cumulatifs des diverses formes de developpement. Il y a beaucoup de preuves que la plupart des especes ne se retrouvent pas en danger d'extinction en forets boreales sous l'influence de modifications anthropogenes. Quelques especes, incluant le caribou forestier (Rangifer tarandus) et l'ours grizzly (Ursus arctos) ont cependant subi des contractions d'habitat a long terme. On observe des deficiences significatives dans notre capacite a evaluer les effets du developpement des ressources naturelles sur la biodiversite dans la zone boreale, du a l'absence de donnees spatiales et a long terme sur les populations, pour suivre l'impact des modifications forestieres sur les ecosystemes et les especes. [Traduit par la Redaction] Mots-cles: biodiversite terrestre, foret boreale, developpement des ressources naturelles, amenagement forestier, conversion des forets., 1. Introduction Biodiversity, broadly defined as the variety of life and its processes, including genes, species, communities, and ecosystems and the ecological and evolutionary processes that keep them functioning (Noss [...]

Atlases Cros, A., R. Venegas-Li, S. J. Teoh, N. Peterson, W. Wen, and N. A. Fatan. 2014. 'Spatial Data Quality Control for the Coral Triangle Atlas.' Coastal Management 42 (2): [...]

Canada's National Forest Inventory (NFI) sampling program is designed to support reporting on forests at the national scale. On the other hand, continuous maps of forest attributes are required to support strategic analyses of regional policy and management issues. We have therefore produced maps covering 4.03 x [10.sup.6] [km.sup.2] of inventoried forest area for the 2001 base year using standardised observations from the NFI photo plots (PP) as reference data. We used the k nearest neighbours (kNN) method with 26 geospatial data layers including MODIS spectral data and climatic and topographic variables to produce maps of 127 forest attributes at a 250 x 250 m resolution. The stand-level attributes include land cover, structure, and tree species relative abundance. In this article, we report only on total live aboveground tree biomass, with all other attributes covered in the supplementary data (http://nrcresearchpress.com/doi/suppl/10.1139/cjfr-2013-0401). In general, deviations in predicted pixel-level values from those in a PP validation set are greater in mountainous regions and in areas with either low biomass or sparse PP sampling. Predicted pixel-level values are overestimated at small observed values and underestimated at large ones. Accuracy measures are improved through the spatial aggregation of pixels to 1 [km.sup.2] and beyond. Overall, these new products provide unique baseline information for strategic-level analyses of forests (https://nfi.nfis.org). Key words: nonparametric method, remote sensing, boreal forest, stand attribute, biomass, composition, national baseline inventory. L'Inventaire forestier national (IFN) du Canada est un programme d'echantillonnage concu pour appuyer la production de rapports sur les forets a l'echelle nationale. D'autre part, les cartes continues d'attributs forestiers sont necessaires pour appuyer les analyses strategiques des problematiques regionales de politique et d'amenagement. Nous avons donc produit des cartes couvrant 4,03 x [10.sup.6] [km.sup.2] de surface forestiere inventoriee en 2001 a partir d'observations normalisees provenant des placettes photos de l'IFN utilisees comme donnees de reference. Nous avons utilise la methode des k plus proches voisins (kNN) avec 26 couches de donnees geospatiales, y compris les donnees spectrales MODIS et les variables climatiques et topographiques, pour produire les cartes de 127 attributs forestiers a une resolution de 250 x 250 m. Les attributs a l'echelle du peuplement comprennent le type de couverture terrestre, la structure et l'abondance relative des especes d'arbres. Dans cet article, nous rapportons seulement la biomasse totale aerienne et vivante des arbres. Tous les autres attributs abordes sont presentes dans la section materiel supplementaire (http://nrcresearchpress.com/doi/suppl/10.1139/cjfr- 2013-0401). En general, les ecarts des valeurs predites a l'echelle du pixel par rapport a celles des placettes photos de validation, sont plus importants dans les regions montagneuses et dans les zones ou, soit la biomasse, soit le taux d'echantillonnage de placettes photos est faible. Les valeurs predites a l'echelle du pixel sont surestimees lorsque les valeurs observees sont petites et sous-estimees lorsqu'elles sont grandes. Les mesures de precision sont ameliorees grace a l'agregation spatiale des pixels sur 1 [km.sup.2] et plus. Dans l'ensemble, ces nouveaux produits fournissent des informations de base uniques pour les analyses strategiques des forets (https://nfi.nfis.org). [Traduit par la Redaction] Mots-cles: methode non parametrique, teledetection, foret boreale, attribut de peuplement, biomasse, composition, inventaire national de reference., Introduction Canada's forests and wooded lands cover 40% of its territory and constitute one-tenth of the world's forest area (National Forest Inventory 2010). Provincial and territorial governments are responsible for [...]

Data are limited regarding 2 new human polyomaviruses, KI polyomavirus (KIPyV) and WU polyomavirus (WUPyV), in immunocompromised patients. We used realtime PCR to test for these and 12 respiratory viruses [...]

BK and JC polyomaviruses are known to infect humans (1,2). Recently, the novel KI polyomavirus (KIPyV) and WU polyomavirus (WUPyV) have been identified in respiratory secretions of children with signs [...]

WU polyomavirus (WUPyV) (1) and K1 polyomavirus (KIPyV) (2) are newly described human polyomaviruses most closely related to JC virus (JCV) and BK virus (BKV). JCV and BKV are human [...]

Introduction Lipoprotein lipase (LPL) deficiency (MIM database 238600) is a rare autosomal recessive disorder with an estimated prevalence of 1 in [10.sup.6] (Hayden and Ma 1992). In some areas of [...], Lipoprotein lipase (LPL) is a key enzyme involved with hydrolysis and removal of triglycerides from plasma. LPL deficiency is a rare condition with an estimated prevalence of 1 in [10.sup.6]. It is characterized biochemically by elevated triglycerides and lowered HDL in the plasma and clinically by a constellation of signs and symptoms during childhood including failure to thrive, lipemia retinalis, eruptive xanthomas, hepatosplenomegaly, and acute pancreatitis. Nearly 100 mutations in the LPL gene have been associated with LPL deficiency. Here we report 2 unrelated pedigrees with LPL deficiency from 2 novel disease-causing LPL mutations: a G1y159G1u missense mutation in exon 5 and a 4-bp ACGG deletion at the 3' boundary of exon 2. We present molecular findings of these 2 cases and review the biochemical, clinical, and genetic features of LPL deficiency. Key words: chylomicronemia, LPL, LPL deficiency, triglyceride, type I hyperlipoproteinemia. La lipoproteine lipase (LPL) est une enzyme importante dans l'hydrolyse et l'elimination des triglycerides du plasma. Le deficit en LPL est une pathologie rare dont la prevalence est estimee a 1 sur [10.sup.6]. Il est caracterise biochimiquement par augmentation des triglycerides et une diminution du taux de HDL dans le plasma, et cliniquement par une multitude de signes et de symptomes durant l'enfance, dont le deficit de croissance, la lipemie retinienne, les xanthomes eruptifs, l'hepatosplenomegalie et la pancreatite aigue. Pres de 100 mutations dans le gene LPL ont ete associees a un defi cit en LPL. Ici nous rendons compte de 2 pedigrees independants presentant un deficit en LPL de 2 nouvelles mutations LPL a l'origine de l'affection : une mutation faux-sens G1y159G1u dans l'exon 5 et une deletion de 4 paires de bases ACGG a l'extremite 3' de l'exon 2. Nous presentons les resultats moleculaires de ces 2 cas et passons en revue les caracteristique biochimiques, clinique et genetiques du deficit en LPL. Mots-cles : chylomicronemie, LPL, deficit en LPL, triglyceride, hyperlipoproteinemie de type I. [Traduit par la Redaction]

Extensive logging of the boreal forest rejuvenates landscapes once dominated by old-growth stands. As black bear (Ursus americanus Pallas, 1780) fitness and behavior are known to be primarily related to the abundance of shadeintolerant soft mast species in northern forests, we hypothesized that logging will influence habitat and space use patterns of black bears. We used VHF telemetry on 12 female black bears in the Reserve faunique des Laurentides (Quebec, Canada) to investigate seasonal patterns of habitat selection in an exploited heterogeneous boreal landscape at different spatial scales. Habitat characterization based on seven forest cover types allowed us to compare the productivity of key forage species in various post-logging age classes. Regenerating stands (6-20 years old) had the uppermost ground vegetation cover, providing both the highest density and a high biomass of berries. Black bears preferred regenerating stands (6-20 years old) and avoided mature coniferous forests inside their home range. Homerange size was inversely related to the proportion of regenerating stands (6-20 years old). Intensive logging influenced black bear habitat and space use patterns, and presumably their population dynamics. An increase in the habitat quality of an opportunistic predator poses great concern for conservation, especially for forest-dwelling woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)). L'exploitation forestiere intensive de la foret boreale rajeunit des paysages autrefois domines par des peuplements matures et surannes. Dans les forets septentrionales, il est reconnu que l'ecologie de l'ours noir (Ursus americanus Pallas, 1780) est influencee par la productivite des arbustes fruitiers, generalement intolerants ' l'ombre. Nous avons donc emis l'hypothese selon laquelle l'exploitation forestiere influence la selection de l'habitat et l'utilisation de l'espace par l'ours noir. Le suivi telemetrique VHF de 12 ourses dans la Reserve faunique des Laurentides (Quebec, Canada) a permis d'analyser les patrons saisonniers de selection d'habitat dans un paysage heterogene boreal soumis ' l'exploitation ' fferentes echelles spatiales. L'habitat fut caracterise en sept types de couverts forestiers afin de comparer la productivite en petits fruits de peuplements de differents stades successionnels apres la coupe. Les parterres en regeneration (6-20 ans) supportaient la plus abondante vegetation au sol, ainsi que la plus forte densite et une biomasse elevee de petits fruits. Les ourses ont prefere les parterres en regeneration (6-20 ans) et evitaient les peuplements resineux matures (>50 ans) dans leur domaine vital. La taille des domaines vitaux etait inversement proportionnelle ' leur proportion en parterres de coupe en regeneration (6-20 ans). L'exploitation forestiere intensive a influence les patrons d'utilisation de l'espace et de l'habitat chez l'ours noir, et possiblement la dynamique des populations. L'augmentation de la qualite de l'habitat de ce predateur opportuniste pourrait avoir des consequences pour la conservation, notamment celle du caribou forestier (Rangifer tarandus caribou (Gmelin, 1788))., Introduction The boreal forest covers nearly 90% of Canada's productive forested land and most of interior Alaska. These forests were once dominated by old-growth stands, where historically the mosaic of [...]

Abstract: Disturbance effects on plant communities largely reflect the degree of overstory removal, soil disturbance, and attendant vegetation destruction. We examined initial harvest-related impacts of partial and complete canopy removal, [...]

We compared understory vegetation composition and richness in aspen-dominated boreal mixedwood forest stands in Alberta, Canada, that had been burned by wildfire with those that burned and were subsequently salvage logged. Stands were examined at early and midsuccessional (2 and 34 years after disturbance(s), respectively) developmental stages. In comparison with wildfire stands, understory communities of early successional salvage-logged stands were characterized by greater species richness, weedy species presence, higher shrub abundance, and lower abundances of fire- specialist seed bank species. In constrained ordination, the understory community of early successional wildfire stands was related to greater canopy cover, sapling density, and moss depth, whereas that of salvage- logged stands was related to greater light, volume of downed deadwood, and litter and organic matter. Longer term effects of salvage logging on the understory community were minimal and, instead, reflected the influence of forest canopy redevelopment. In midsuccessional stands, understory composition was related to conifer density, litter cover, soil moisture, organic layer depth, tall shrub density, and bryophyte-covered microsite cover. Postfire salvage logging can have substantial short- term effects on the postfire understory plant community; in the longer term, effects will depend to a large extent on the influence of harvesting and subsequent management on canopy redevelopment. Nous avons compare la composition et la richesse de la vegetation en sous-etage dans des peuplements de foret boreale mixte domines par le peuplier faux-tremble en Alberta, au Canada, qui avaient et. [Traduit par la Redaction], Introduction Early postfire forest stands are characterized by a distinctive combination of environmental and stand attributes that influence the initial establishment phase of the plant community and have important long-term [...]

To the Editor: Two novel polyomaviruses (PyVs), KIPyV and WUPyV, were identified in respiratory and fecal specimens from children with signs and symptoms of respiratory tract infection (1,2). A review [...]

To the Editor: Before 2007, two human polyomaviruses were known to infect humans: BK virus and JC virus (1,2). Recently, 2 novel polyomaviruses, KI polyomavirus (KIPyV) and WU polyomavirus (WUPyV), [...]