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In Canada, over 300 heavy vehicles equipped with central tire inflation systems are being used in forestry, mining, and grain hauling. Since 1995, Saskatchewan Highways and Transportation has permitted truck fleets to operate with primary highway axle loads on secondary highways under a partnership program. This paper reports on the comparison of rutting progression on an accelerated field experiment utilizing standard and reduced tire pressures. The experiment was conducted by Saskatchewan Highways and Transportation in the Big Quill Lake area of southern Saskatchewan. The vehicles used in the experiment were nine-axle B trains, eight-axle B trains, and six-axle semi-trailers. The statistical analysis of rutting data presented in the paper shows that reduced tire pressures can effectively extend the pavement service life of gravel and thin membrane surfaced roads. On the thin membrane pavements, there was less rutting on the low-pressure lane until twice as many vehicles had trafficked the road, and rutting was no worse on the low-pressure lane even when 10 times as many vehicles had trafficked the road. On the gravel surface, rut depth was lower on the low-pressure lane until twice as many trucks had trafficked that lane.Key words: rutting, pavement, central tire inflation, tire pressure, low-volume roads, unsurfaced roads.Au Canada, plus de 300 véhicules lourds équipés de systèmes centraux de gonflement des pneus sont en usage dans les secteurs forestier et minier et pour le transport de grains. Depuis 1995, le département des autoroutes et des transports de la Saskatchewan (« Saskatchewan Highways and Transportation ») a permis aux flottes de camions d'opérer sur des autoroutes secondaires avec des charges aux essieux pour autoroutes primaires dans le cadre d'un programme de partenariat. Cet article se penche sur la comparaison de la progression de l'orniérage lors d'un essai accéléré sur le terrain en utilisant des pressions normales et réduites pour les pneus. L'essai a été conduit par le département des autoroutes et des transports de la Saskatchewan dans la région du lac Big Quill, dans le sud de la province. Les véhicules employés durant l'essai ont été des trains routiers de type B à neuf essieux, des trains routiers de type B à huit essieux et des semi-remorques à six essieux. Les analyses statistique des données sur l'orniérage présentées dans cet article montrent que des pressions réduites pour les pneus peuvent de fait étendre la durée de vie de la chaussée pour des routes de gravier et à membrane mince. Sur les chaussées à membrane mince, il y a moins d'orniérage sur la voie employée avec des pneus à pression réduite jusqu'à ce que le traffic de véhicules soit deux fois plus élevé, et l'orniérage n'est pas plus mauvais sur la voie dédiée pour les pneus à pression réduite même lorsque le traffic de véhicules est dix fois plus élevé. Sur la surface de gravier, la profondeur des ornières est plus basse sur la voie pour les pneus à pression réduite jusqu'à ce que le traffic de camions soit deux plus élevé.Mots clés : orniérage, chaussée, gonflement de pneus central, pression de pneus, routes à volume réduit, routes non-pavées.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing 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 Earth Sciences is the property of Canadian Science Publishing 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 Science is the property of Canadian Science Publishing 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 Earth Sciences is the property of Canadian Science Publishing 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 Earth Sciences is the property of Canadian Science Publishing 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.)

Presents a study that determined how the architectural development of the crooked clone of Populus (P.) tremuloides differed from the wild type in Saskatchewan. Causal observation of the crooked aspens or P. tremuloides; Materials and methodology; Possible explanations for the bending of shoots.

Studies the post-wildfire establishment of jack pine (Pinus banksiana Lamb.), black spruce (Picea mariana (Mill.) BSP), and white spruce (Picea glauca (Moench) Voss) in the southern mixedwood boreal forest of Saskatchewan, Canada. Introduction; Methods; Survivorship as a function of seedbeds and species identification; Age-specific survivorship and time-since-fire; Possible causes of early mortality; Abscission schedule and variation in age structures; Comparison of these results to those of other studies; Conclusions.

The recovery of identifiable plant remains intimately associated with a skeleton of Tyrannosaurus rex in southwestern Saskatchewan, Canada, provides the basis for interpreting the latest Maastrichtian (65.5–65 Ma) paleoenvironment of the region. Fossil plants from the site are described, and fruits formerly known as Aesculus antiquus Dawson or Ficus ceratops Knowlton are transferred to a new taxon, Spinifructus antiquus (Dawson) comb. nov. Study of the sediments of the Frenchman Formation that host the bones and plants, in combination with analysis of the plants, indicates that the regional climate was mesothermal and without winter frost, but with seasonal drought. The T. rex is believed to have roamed a broad river valley abundantly vegetated by a largely deciduous flora. The deciduous nature of the Saskatchewan paleovegetation, interpreted as a response to low winter light levels at high latitude, contrasts strongly with the contemporaneous vegetation of a few degrees latitude further south and leads to questions about how a dinosaur fauna survived in a region where the bulk of the vegetation entered an extended period of dormancy.La collecte de restes de plantes identifiables intimement associées à un squelette de Tyrannosaurus rex dans le sud-ouest de la Saskatchewan, au Canada, constitue la base pour interpréter le paléoenvironnement du Maastrichtien terminal (65,5 à 65 Ma) de la région. Des plantes fossiles du site sont décrites et des fruits antérieurement connus comme Aesculus antiquus Dawson ou Ficus ceratops Knowlton sont transférés à un nouveau taxon Spinifructus antiquus (Dawson) comb. nov. L'étude des sédiments de la Formation de Frenchman qui contient les os et les plantes, combinée à l'analyse des plantes, indique que le climat régional était mésothermique et sans gelée hivernale mais avec des sécheresses saisonnières. On croit que T. rex se déplaçait dans une large vallée de rivière où la végétation abondante était surtout à flore décidue. La nature décidue de la paléovégétation de la Saskatchewan, interprétée comme une réponse aux faibles niveaux de lumière en hiver à haute latitude, contraste fortement avec la végétation contemporaine présente à quelques degrés de latitude plus au sud et porte à remettre en question le fait qu'une faune de dinosaures ait survécu dans une région où la plus grande part de la végétation entrait dans une période de dormance étendue.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Zoology is the property of Canadian Science Publishing 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.)

Examines the soil carbon dioxide emission and net carbon dioxide exchange after photosynthetic uptake by ground-cover plants in Prince Albert, Saskatchewan. Simulations of sol respiration; Value of the standard deviation of measured flux; Relation between temperature and flux.

An augened, strongly flasered, and multiply folded monzonitic gneiss occurs in a structural dome in the Black Bear Island Lake region of northern Saskatchewan, within the ca. 1850 Ma Paleoproterozoic southern Rottenstone Domain of the Trans-Hudson Orogen (THO). A sample of this rock has yielded thermal ionization mass spectrometry (TIMS) and sensitive high-resolution ion microprobe (SHRIMP) zircon data consistent with a formation age of at least 2500 Ma. Zircons also show somewhat younger, ca. 2380 Ma overgrowths, indicating a complex history. The Nd model age (T[sub DM] ) of 2726 Ma also confirms the late Archean age of the rock, as does the isotopic composition of common Pb from a K-feldspar sample. U–Pb analyses of titanites yield ages of ca. 1800 Ma, indicating recrystallization during terminal closure of the THO. It is unlikely that the Archean rocks are a part of the Archean Sask craton in the Glennie Domain, for Lithoprobe seismic sections indicate that the Sask craton dips westward beneath the La Ronge and Rottenstone domains. It is more likely that the rocks are part of a klippen of Hearne Province crust emplaced during closure of the THO, a large pendant in the ca. 1850 Ma Wathaman batholith, or a crustal fragment exotic to the orogen. Further study should shed light on the tectonic and paleogeographic history of the THO.Un gneiss à monzonite, œillé, fortement filandreux et à plis multiples se retrouve dans un dôme structural dans la région du lac Black Bear Island dans le nord de la Saskatchewan, à l'intérieur du domaine Rottenstone sud (Paléoprotérozoïque, ca. 1850 Ma) de l'orogène trans-hudsonien (THO). Un échantillon de cette roche a été soumis à la spectrométrie de masse à ionisation thermique (TIMS) et à la microsonde ionique à haute résolution et à haut niveau de sensibilité (SHRIMP); les données fournies sur du zircon concordent avec un âge de formation d'au moins 2500 Ma. Les zircons montrent aussi des accroissements secondaires un peu plus jeunes, ca. 2380 Ma, indiquant un historique complexe. L'âge modèle Nd (T[sub DM] ) de 2726 Ma confirme aussi l'âge de la roche comme Archéen tardif, ce qui est appuyé par la composition isotopique de la forme commune du Pb d'un échantillon de feldspath K. Des analyses U–Pb de titanites donnent des âges de ca. 1800 Ma, indiquant une recristallisation à la fin définitive de l'orogène trans-hudsonien. Il est peu probable que les roches archéennes forment une partie du craton archéen de Sask dans le domaine de Glennie, car les sections séismiques Lithoprobe indiquent que le craton Sask plonge vers l'ouest sous les domaines de La Ronge et de Rottenstone. Il est plus probable que les roches font partie d'un klippe de la croûte de la province de Hearne, mis en place à la fin de THO, ou d'un grand pendant dans le batholite de Wathaman, ca. 1850, ou encore d'un fragment de la croûte exotique à l'orogène. Des études ultérieures devraient aider à déterminer l'historique tectonique et paléogéographique de THO.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Economic base analysis is a limited but useful tool for measuring forest dependence. It cannot measure the full range of forest values (e.g., subsistence, amenity, bequest, and existence values). However, economic base analysis utilizes widely available census data to provide accurate measures of communities dependent on industrial forest activity. This analysis includes Indian reserves and rural census subdivisions previously excluded in studies of economic base dependence. Economic base dependence measures are further improved by including a transfer payment sector. This paper presents findings of forest industry dependence measures using 1991 census data. Results show that including Indian reserves and other rural census subdivisions in the analysis increases the number of forest industry dependent places and population in the Prairie Provinces. The addition of the transfer payment sector to the economic base provides a more comprehensive account of the sources that contribute to the economic diversity of rural locations. These geographical and sectoral refinements to economic base calculations result in a more accurate accounting of forest industry dependence. [ABSTRACT FROM AUTHOR]