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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Inter- And Intra-Specific Interactions In Germination And Seedling Establishment Of Cheatgrass And Russian Wildrye, Erin K. Espeland
Inter- And Intra-Specific Interactions In Germination And Seedling Establishment Of Cheatgrass And Russian Wildrye, Erin K. Espeland
The Prairie Naturalist
Cheatgrass (Bromus tectorum) is an invasive species in the arid and semi-arid west of the USA, and is weedy in disturbed prairie landscapes. Perennial Russian wildrye (Psathyrostachys juncea) limits population growth of cheatgrass, but the mechanism is unclear. I conducted glasshouse and greenhouse experiments to test if intra- and interspecific competitive interactions of seeds and seedlings of cheatgrass and Russian wildrye were different across a geographic soil gradient with different cultivation legacies in eastern Montana, USA. Seed-seed interactions occurred in both species. Cheatgrass and Russian wildrye inhibited one another’s emergence in one edaphic condition in one experiment. Cheatgrass growth was …
Association Of Soil Conditions And Grass Species With Variable Cover Of Leafy Spurge, Terence P. Mcgonigle, Jeremy L. Timmer
Association Of Soil Conditions And Grass Species With Variable Cover Of Leafy Spurge, Terence P. Mcgonigle, Jeremy L. Timmer
The Prairie Naturalist
Variation in soil conditions and grass cover was assessed across a range of leafy spurge (Euphorbia esula L.) cover values on a sandy rangeland in Manitoba, Canada. Soil conditions varied by site but not in relation to cover of leafy spurge. We observed a significant negative relationship between total grass cover and increasing cover of leafy spurge. Only porcupine grass (Hesperostipa spartea [Trin.] Barkworth) had a negative relationship with leafy spurge, falling from high cover at low weed occurrence to only trace levels at the highest leafy spurge abundance. Neither prairie Junegrass (Koeleria macrantha [Ledeb.] Schult.), rough …
Grass And Canada Goldenrod (Solidago Canadensis) Competition And Implications For Management In The Northern Tallgrass Prairie, Alexander J. Smart, Gary E. Larson, Peter J. Bauman
Grass And Canada Goldenrod (Solidago Canadensis) Competition And Implications For Management In The Northern Tallgrass Prairie, Alexander J. Smart, Gary E. Larson, Peter J. Bauman
The Prairie Naturalist
Canada goldenrod (Solidago canadensis L.) is a native perennial forb that can form dense clonal patches and become weedy in pastures of the Northern Tallgrass Prairie Ecoregion. Our objectives were to determine 1) the competitive effects between Canada goldenrod and grass, 2) the relationship between Canada goldenrod stem density and grass biomass, and 3) the distribution of Canada goldenrod stem density at the pasture scale. We used regression analysis to develop a relationship between Canada goldenrod stem density and grass biomass. Additionally, we estimated the frequency distribution of Canada goldenrod stem density categories using three evenly distributed 100 × 100-m …
Patterns Of Age-0 Gizzard Shad Abundance And Food Habits In A Nebraska Irrigation Reservoir, Christopher L. Sullivan, Casey W. Schoenebeck, Keith D. Koupal, W. Wyatt Hoback, Brian C. Peterson
Patterns Of Age-0 Gizzard Shad Abundance And Food Habits In A Nebraska Irrigation Reservoir, Christopher L. Sullivan, Casey W. Schoenebeck, Keith D. Koupal, W. Wyatt Hoback, Brian C. Peterson
The Prairie Naturalist
Gizzard shad (Dorosoma cepedianum) are prolific spawners that can influence reservoir communities. Larval gizzard shad may compete with larval recreational fish for zooplankton resources. Therefore, it is necessary to determine larval gizzard shad dynamics and food habits to better understand their potential for competition with larval recreational fish. Our study examined age-0 gizzard shad abundance in Harlan County Reservoir during late spring/summer from 2002–2010 and food habits and prey electivity of age-0 gizzard shad during late spring/summer 2008 and 2009. The annual peak age-0 gizzard shad density 3 from 2002–2010 ranged from 50 to 380/100 m , which …
Effects Of Species, Water, And Nitrogen On Competition Among Three Prairie Grasses, Jerry L. Weatherford, Randall W. Myster
Effects Of Species, Water, And Nitrogen On Competition Among Three Prairie Grasses, Jerry L. Weatherford, Randall W. Myster
The Prairie Naturalist
We conducted an experiment to investigate effects of species, water (W), and nitrogen (N) on competition among little bluestem (Schizachyrium scoparium), sideoats grama (Bouteloua curtipendula), and indiangrass (Sorghastrum nutans). All biomass parameters and the root:shoot ratio of little bluestem were reduced by the presence off 1 of 2 other species, and its shoot biomass and total biomass were both increased by addition of N. Root and shoot biomass of sideoats grama were reduced by the presence of indiangrass and its total biomass was reduced by the presence of itself, whereas its shoot biomass was increased by addition of W at …
Potential Importance Of Competition, Predation, And Prey On Yellow Perch Growth From Two Dissimilar Population Types, Casey W. Schoenebeck, Michael L. Brown
Potential Importance Of Competition, Predation, And Prey On Yellow Perch Growth From Two Dissimilar Population Types, Casey W. Schoenebeck, Michael L. Brown
The Prairie Naturalist
Our objective was to describe the influence of population dynamics, inter- and intra-specific competition, predation, prey abundance, and prey size structure on yellow perch (Perca flavescens) growth for two perch population types (high-quality and low-quality) commonly found in South Dakota glacial lakes. We selected Lake Cochrane as a low quality yellow perch population and Lake Madison as a high quality perch population. Sunfish (Lepomis spp.) relative abundance was greater (P < 0.05) in Lake Cochrane than Lake Madison, suggesting interspecific competition may have a large influence on yellow perch growth. Indices of available sizes and densities of zooplankton were lower (P < 0.05) in Lake Cochrane than Lake Madison, suggesting that increased competition for large zooplankton may have reduced zooplankton size structure and density. Zooplankton may be a limiting resource in South Dakota glacial lakes when both yellow perch and sunfish are feeding primarily on zooplankton which may explain differences in perch growth rates between population types .
Studies Concerning The Elimination Of Experimental Error In Comparative Crop Tests, T. A. Kiesselbach
Studies Concerning The Elimination Of Experimental Error In Comparative Crop Tests, T. A. Kiesselbach
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
It is apparent that many sources of error have unconsciously entered into comparative crop yield tests. The very important matter of overcoming variation in soil conditions as a source of experimental error has been quite extensively studied and reported by various investigators during the past decade. The means suggested for reducing such error have been (1) repetition of plats and (2) correction of yields according to check plats planted to a uniform variety or treatment at stated intervals. Both methods have proved of value and a combination of both may often be used advantageously. Some danger always exists of error …