Beef production in the arid Southwest depends on range forages. Forage quality and quantity primarily results from amount, intensity and timing of precipitation. Twenty-three years (1978-2000) of precipitation and animal production data were evaluated. Two major questions addressed were: Does rainfall timing affect number and weight of calves weaned? Does grazing system reduce immediate drought impact on calf production? Three grazing systems were evaluated: Year-round grazing, Savory rotational grazing and Santa Rita rotational grazing (50-60hd, 80-150hd and 50-65hd/year respectively). Winter (P < 0.05), summer (P < 0.01) and previous fall (P < 0.01) precipitation affected calf crop. Only summer precipitation (P < 0.01) had a significant effect on weaning weight. Calf crop did vary between grazing systems (P < 0.01). Savory system had the heaviest weaning weight, total production, and lowest maintenance cost; followed by Santa Rita and year-round respectively (P < 0.01). Maintenance cost per kg calf weaned was similar between rotational systems, but higher in year-round (P < 0.01).

I investigated the effects of winter prescribed burning on relative abundance and species richness of birds in mesquite (Prosopis glandulosa)-grassland at the Welder Wildlife Foundation Refuge, Texas, from June 1995 to August 1996. Relative abundance (P=0.246) and species richness (P=0.622) of breeding birds were not different, but mourning doves (Zendaida macroura) (P=0.058) and great-tailed grackles (Quiscalus mexicanus) (P=0.084) increased, and black-bellied whistling ducks (Dendrocygna autumnalis) (P=0.040) declined in burned treatments. Relative abundance of wintering birds was greater (P=0.002) in burned treatments, but species richness was not different (P=0.602). Mourning doves (P < 0.001) and savannah sparrows (Passerculus sandwichensis) (P=0.001) increased, but grasshopper sparrows (Ammondramus savannarum) (P=0.009), Le Conte's sparrows (Ammondramus leconteii) (P=0.001), and sedge wrens (Cistothorus platensis) (P=0.001) declined in burned treatments in winter.

I studied 1,472 locations of desert mule deer (Odocoileus hemionus crooki) (1M, 6F) before completion of the Hayden-Rhodes Aqueduct (HRA) (pre-HRA, 1981-1984), and 2,300 locations (6M, 10F) after completion of the Hayden-Rhodes Aqueduct (post-HRA, 1989-1991) to examine habitat use. I used a Geographic Information System to measure and analyze deer locations by season, sex, and year. I compared home-range size, distance to water catchments, distance to washes, vegetation use versus availability and deer interactions ≤1 km from the canal between the periods. Home-range sizes did not change significantly (P≤0.05) as a result of completion and operation of the HRA. Deer were closer to water catchments in the warmer seasons before completion of the HRA, but farther from water in the warmer seasons after completion of the HRA. Deer locations ≤1 km from the HRA increased after completion and operation of the HRA. Deer were probably relying on areas ≤1 km from the canal for forage and thermal cover.

No description available.

No description available.

No description available.

No description available.

Less diversity and more homogenization in the media`s news range is the subject for our bachelor thesis. By analyzing and comparing three separate weeks in two of Sweden's largest evening newspapers Aftonbladet and Expressen we wanted to discoverhow the diversity between the two newspapers had changed over the years, more precisely from 1993 until now. Had there been a homogenization or not? We wanted to study this because it is a long going debate about the news stories becoming more and more the same. An important debate because less diversity in news events and news presentation may lead to less diversity in public opinions and knowledge. When it comes to our result we found out that the diversity in the week of 2013 in comparison tothe week of 1993 was better for Expressen, but not for Aftonbladet. At the same time, our second analyzing week took place in 2003 and in comparison to that week both newspapers had greater diversity in 2013. So when we make a conclusion after looking at these three weeks we could say that homogenization was a problem in 2003, but is not anymore. Except for when it comes to public affairs. When we divided the news intodomestic, foreign, public and non-public affairs we discovered that the foreign news for every week had less diversity than domestic news, we found the same result in public affairs in comparison to non-public affairs. But unlike foreign news where the diversity increased in 2013, the diversity of public affairs kept decreasing. If the weeks we selected reflects the two newspapers news range on a greater scale this could be a democratic problem, because if there are some news that can contribute to more public opinions and wider knowledge it is public affairs.

Every species has a limit to its geographic distribution. The problem is that we don’t really know why. Classical explanations propose that range limits occur where the ecological conditions overwhelm adaptation and populations are no longer self-sustaining. It is generally expected that population abundance and fitness decline towards range margins across a gradient of declining habitat quality. Current evolutionary and theoretical explanations of range limits predict that this geographic pattern of demography will result in genetic constraints in marginal populations, such that range expansion is thwarted by reduced evolutionary potential. In this thesis, I tested the key assumptions and predictions of range limit theory through an empirical evaluation of two coastal dune, endemic plants; Camissonia cheiranthifolia (Spreng.) Raim. (Onagraceae) and Abronia umbellata L. (Nyctaginaceae). In geographic wide surveys of a large proportion of populations across both species’ ranges, neither species exhibited declining abundance or performance towards its range limits. Central populations of C. cheiranthifolia tended to have a higher production of seeds per unit area than marginal populations. Although this pattern demonstrated the potential for gene flow from central sites to swamp selection in marginal sites, results from a transplant experiment suggested that this was unlikely. Experimental populations of C. cheiranthifolia originating from ≥ 675 km south of the northern range limit exhibited similar levels of fitness when planted at the range margin. Along a 200 km transect across the limit, and in contrast to expectations, fitness of all populations increased towards the limit and generally remained high beyond the limit. Individuals from all populations reproduced and matured fruit beyond the limit, suggesting that if individuals dispersed beyond the limit that populations would establish. The species’ abrupt distributional limit also did not correspond to an abrupt shift in ecological conditions, despite the association of fitness with plant community and microhabitat variables. Overall, ecological tolerances to fitness or niche-based explanations to range limits do not adequately describe the distributions of either species. Constraints on dispersal rate, the influence of anthropogenic factors on habitat dispersion and limited genetic variability for fitness related traits are addressed. / Thesis (Ph.D, Biology) -- Queen's University, 2007-05-13 16:45:44.456

The Livingstone Range anticlinorium (LRA) is a long (>65 km) narrow (<5 km) structural culmination that coincides with a major hanging-wall ramp across which the Livingstone thrust cuts ~1000 m up-section eastward from a regional décollement in the upper part of Devonian Palliser Formation to another regional décollement within Jurassic Fernie Formation. The presence of Precambrian basement fluids prior to thrusting and folding is recorded in the LRA by deformed jasper+/-fluorite+/-sphalerite veins, and adjacent haloes of altered dolomitic host rock with high 87Sr/86Sr ratios (0.7094 to 0.7100) relative to most host rocks. Basement fluids are a possible source for anomalously radiogenic strontium that occurs in the diagenetically altered Paleozoic carbonate rocks in the LRA and throughout the Western Canada Sedimentary Basin, but underlying thick shale strata such as the Exshaw Formation are also a possible source. The earliest stages of thrusting deformation involved the development of distinctive chevron-style, flexural-slip thrust-propagation folds that have conspicuous blind thrust faults along their hinge zones. The hinge-zone thrust system of the Centre Peak anticline consists of a series of stacked detachment thrusts, each of which emerges from a different zone of interbed slip in the backlimb of the anticline and deflects the hinge zone eastward. Each successively higher detachment thrust dies out in the hinge zone at approximately the same stratigraphic level at which an overlying detachment thrust fault emerges from a bedding detachment zone in the backlimb. Fluid flow during thrust-propagation folding is recorded by dolomite+/-calcite veins with isotopic compositions that are similar to those of host rocks. Fluid flow occurred along faults related to thrust-propagation folding, and also along many tear faults and larger thrust faults. Veins in these fault zones have slightly higher 87Sr/86Sr ratios relative to adjacent host rocks and are interpreted to have formed from a mixture of formation fluids and hotter basement fluids in a rock-dominated system. Oxygen isotope thermometry of four syn-folding veins indicates they precipitated at anomalously high temperatures (>250°C). The youngest episode of fluid flow along thrust faults and tear faults is recorded by calcite veins with very low δ18O values (-18 to -9‰ PDB), which are interpreted to have precipitated along faults that were active while the LRA was being transported eastward and elevated by underlying thrust faults, and cooled by infiltrating meteoric water. The conduits along which significant meteoric fluid circulation occurred are marked by visibly altered host rocks that have anomalously low δ18O values and slightly lower δ13C values relative to most host rocks. Rapid cooling due to deep infiltration of meteoric water into the shallow brittle surface of the deforming earth is almost certainly not restricted to thrust and fold belts, nor is its thermal effect necessarily restricted to the upper few kilometers. This model for fluid flow has significant implications for predicting thermal conditions in deep metamorphic rocks that lie beneath the brittle crust, the most obvious effect being to push down the brittle/ductile transition zone, which would enhance even deeper meteoric fluid circulation and cause the deflection of underlying isotherms. / Thesis (Ph.D, Geological Sciences & Geological Engineering) -- Queen's University, 2007-11-01 15:25:23.854