Characterizing the long-term variability of snow-cover extent over the interior of North America

Historical and reconstructed snow-cover data show evidence of a gradual increase in snow cover over the continental interior of North America (NA) during much of the 20th century, primarily in response to increasing snowfall. A rapid decrease in Canadian-prairies snow cover after 1970 is not observed over the Great Plains. Analysis of snow-cover-climate relationships revealed systematic increases in the sensitivity of snow cover to Northern Hemisphere (NH) temperatures over the 1940-65 period. This change is mainly due to an increase in snowfall-temperature sensitivity during this period. Seasonal analysis revealed that the observed increase in snow-cover and snowfall temperature sensitivity is primarily a spring phenomenon. A marked increase in the importance of the spring period is observed around 1960, which coincides with a well-documented change in atmospheric circulation over NA. The post-1960 period is characterized by a significant inverse relationship between snow cover and hemispheric air temperature over the Canadian prairies and northern Great Plains regions.

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Rearing the wheat stem sawfly on an artificial diet

The Canadian Entomologist ◽

10.4039/n04-100 ◽

2005 ◽

Vol 137 (4) ◽

pp. 497-500 ◽

Cited By ~ 2

Author(s):

Tuilo B. Macedo ◽

Paula A. Macedo ◽

Robert K.D. Peterson ◽

David K. Weaver ◽

Wendell L. Morrill

Keyword(s):

Great Plains ◽

Cropping Systems ◽

Insect Pest ◽

The United States ◽

Northern Great Plains ◽

Yield Losses ◽

Canadian Prairies ◽

Wheat Stem Sawfly ◽

Head Weight ◽

Harvest Efficiency

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), is an insect pest in dryland wheat cropping systems in the southern Canadian Prairies and the northern Great Plains of the United States (Morrill 1997). Yield losses caused by C. cinctus are due to reduced head weight (Holmes 1977; Morrill et al. 1992) and lodging, which decreases harvest efficiency. Estimates of yield losses in Montana alone are about US$25 million per year.

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Production characteristics of the mixed prairie: constraints and potential

Canadian Journal of Animal Science ◽

10.4141/cjas93-080 ◽

1993 ◽

Vol 73 (4) ◽

pp. 765-778 ◽

Cited By ~ 25

Author(s):

W. D. Willms ◽

P. G. Jefferson

Keyword(s):

Species Composition ◽

Great Plains ◽

Warm Season ◽

Bouteloua Gracilis ◽

Fertilizer Application ◽

Plant Litter ◽

Northern Great Plains ◽

Forage Production ◽

Canadian Prairies ◽

Mixed Prairie

The mixed prairie represents the most arid region of the Northern Great Plains in Canada. Approximately 6.5 M ha of the original total of 24 M ha have retained their native character. The native prairie supports about 5.3 M animal–unit–months or about 15% of all beef cattle present on the Canadian prairies. A large portion of the area is dominated by either needle-and-thread (Stipa comata Trin. + Rupr.) or western wheatgrass (Agropyron smithii Rydb.), both cool season grasses, and associated with blue grama [Bouteloua gracilis (H.B.K.) Lag. ex Steud.] a warm season grass. These species define the major plant communities of the mixed prairie and determine their production potential. However, their production is limited by available water during the growing season and by soil nutrients; factors which also influence their species composition. Grazing imposes a significant impact on the grasslands by altering the water and nutrient cycles, through defoliation and reduced plant litter, and eventually by affecting the species composition. Removing litter may reduce forage production by up to 60% and repeated defoliation will favour the more drought tolerant but less productive species. Forage production may be increased by seeding introduced species, which have a greater shoot to root ratio than native grasses, or with fertilizer application. Livestock production may be increased with the use of grazing systems. However, the benefits of each practice on the mixed prairie must be assessed in terms of their cost, their impact on the environment, and the reduced or lost value for other users. Key words: Biomass, above-ground, below-ground, water-use efficiency, reseeding, soil fertility, grazing efficiency

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Agro-morphology and forage nutritive value of white prairie clover [Dalea candida(Michx.) Willd.] populations native to the Canadian prairies

Canadian Journal of Plant Science ◽

10.1139/cjps-2017-0255 ◽

2018 ◽

Vol 98 (6) ◽

pp. 1234-1244

Author(s):

Nityananda Khanal ◽

Michael P. Schellenberg ◽

Bill Biligetu

Keyword(s):

Great Plains ◽

Seed Yield ◽

Nutritive Value ◽

Block Design ◽

Northern Great Plains ◽

Canadian Prairies ◽

Forage Crop ◽

Randomized Complete Block Design ◽

Acid Detergent Fibre ◽

Provincial Park

White prairie clover [Dalea candida (Michx.) Willd.] is native to the dry prairies and hillsides of the Northern Great Plains. A study was initiated in 2012 with six white prairie clover populations collected from the Canadian Prairies. Plant growth characteristics, forage biomass, seed yield, and forage nutritive values were evaluated using a randomized complete block design in a field near Swift Current, SK. Three populations from Argyle, Carlowrie, and Big Grass Marsh (NCP588) in Manitoba displayed erect-type growth while those from Douglas Provincial Park and Stewart Valley in Saskatchewan and Writing on Stone Provincial Park in Alberta exhibited prostrate growth. The populations did not differ for mean biomass yield (79–104 g plant−1, p = 0.54) and mean seed yield (6.6–9.1 g plant−1, p = 0.69); however, they differed for bloom stage nutritional parameters such as acid detergent fibre (25%–30%, p = 0.04), neutral detergent fibre (34%–41%, p < 0.01), crude proteins (15%–18%, p < 0.01), phosphorus (0.24%–0.29%, p = 0.02), and iron content (144–360 ppm, p = 0.01). To our knowledge, this is the first report of comparative phenotypic, nutritional, and propagation study of native white prairie clover populations of Canada. The constraints and opportunities for successful domestication of white prairie clover as a forage crop are discussed.

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Diversity dynamics of mammals in relation to tectonic and climatic history: comparison of three Neogene records from North America

Paleobiology ◽

10.1666/12024 ◽

2013 ◽

Vol 39 (3) ◽

pp. 373-399 ◽

Cited By ~ 27

Author(s):

Catherine Badgley ◽

John A. Finarelli

Keyword(s):

North America ◽

Pacific Northwest ◽

Great Plains ◽

Large Scale ◽

Landscape History ◽

Northern Great Plains ◽

Faunal Composition ◽

Topographic Complexity ◽

Depositional Processes ◽

Climatic Optimum

In modern ecosystems, regions of topographic heterogeneity, when compared with nearby topographically homogeneous regions, support high species densities of mammals and other groups. This biogeographic pattern could be explained by either greater diversification rates or greater accommodation of species in topographically complex regions. In this context, we assess the hypothesis that changes in landscape history have stimulated diversification in mammals. Landscape history includes tectonic and climatic processes that influence topographic complexity at regional scales. We evaluated the influence of changes in topographic complexity and climate on origination and extinction rates of rodents, the most diverse clade of mammals.We compared the Neogene records of rodent diversity for three regions in North America. The Columbia Basin of the Pacific Northwest (Region 1) and the northern Rocky Mountains (Region 2) were tectonically active over much of the Cenozoic and are characterized by high topographic complexity today. The northern Great Plains (Region 3) have been tectonically quiescent, with low relief, throughout the Cenozoic. These three regions have distinctive geologic histories and substantial fossil records. All three regions showed significant changes in diversification and faunal composition over the Neogene. In the montane regions, originations and extinctions peaked at the onset and close, respectively, of the Miocene Climatic Optimum (17–14 Ma), with significant changes in faunal composition accompanying these episodes of diversification. In the Great Plains, rodents showed considerable turnover but infrequent diversification. Peak Neogene diversity in the Great Plains occurred during cooling after the Miocene Climatic Optimum. These histories suggest that climatic changes interacting with increasing topographic complexity intensify macroevolutionary processes. In addition, close tracking of diversity and fossil productivity with the stratigraphic record suggests either large-scale sampling biases or the mutual response of diversity and depositional processes to changes in landscape history.

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Diatom Assemblages and Ionic Characterization of Lakes of the Northern Great Plains, North America: A Tool for Reconstructing Past Salinity and Climate Fluctuations

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f93-207 ◽

1993 ◽

Vol 50 (9) ◽

pp. 1844-1856 ◽

Cited By ~ 117

Author(s):

S. C. Fritz ◽

S. Juggins ◽

R. W. Battarbee

Keyword(s):

North America ◽

Great Plains ◽

Environmental Gradient ◽

Surface Sediments ◽

Weighted Averaging ◽

Northern Great Plains ◽

Climate Fluctuations ◽

Sulfate Salts ◽

Highly Correlated

The distribution of diatoms with respect to salinity and ionic gradients was studied in lakes of the northern Great Plains of North America. The lakes range from freshwater to hypersaline (0.65–270 g∙L−1) and include a variety of brine types, although the majority are dominated by sulfate salts. Canonical correspondence analysis of diatoms in the surface sediments of 66 lakes and associated water chemistry data indicates that diatom distributions are highly correlated with salinity. The ordination also suggests that brine type forms a significant environmental gradient and separates taxa characteristic of bicarbonate/carbonate lakes from those of sulfate-dominated systems. The salinityoptima and tolerances of diatom species are calculated by weighted averaging regression, and these data provide a tool for the reconstruction of past salinity and the inferance of climatic change in arid and semiarid regions.

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Evaluation of Elite Wheat Germ Plasm for Resistance to Tan Spot

Plant Disease ◽

10.1094/pd-90-1320 ◽

2006 ◽

Vol 90 (10) ◽

pp. 1320-1325 ◽

Cited By ~ 20

Author(s):

P. K. Singh ◽

M. Mergoum ◽

S. Ali ◽

T. B. Adhikari ◽

E. M. Elias ◽

...

Keyword(s):

North America ◽

Great Plains ◽

Wheat Germ ◽

Management Practices ◽

Germ Plasm ◽

The United States ◽

Tan Spot ◽

Northern Great Plains ◽

Breeding Lines ◽

Resistant Varieties

Tan spot, caused by Pyrenophora tritici-repentis, is a serious foliar disease of wheat (Triticum aestivum) in North America. Control of tan spot through management practices and fungicide application is possible; however, the use of resistant varieties is the most effective and economical means of controlling tan spot. This study was conducted to determine the disease reaction of 126 elite hard red spring, white, and durum wheat varieties and advanced breeding lines collected from the northern Great Plains of the United States and Canada to individual races/toxins of P. tritici-repentis. Seedling evaluation of the 126 genotypes was done under controlled environmental conditions with virulent races 2, 3, and 5 of P. tritici-repentis and toxins Ptr ToxA and Ptr ToxB. Based on disease reactions, two resistant varieties and two advanced breeding lines adapted to the northern Great Plains were found to be resistant to all the races and insensitive to the toxins tested. Additionally, six genetically diverse lines/varieties were identified to be resistant to tan spot; however, these sources may not be well adapted to the northern Great Plains. These results suggest that the wheat germ plasm contains a broad genetic base for resistance to the most prevalent races of P. tritici-repentis in North America, and the resistant sources identified in this study may be utilized in wheat breeding programs to develop tan spot resistant varieties.

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