Padre Island National Seashore provides important habitat for wintering grassland birds, which are declining throughout their breeding range, yet oil and gas development is widespread in the park. My objective was to evaluate the effects of resource extraction on the park's grassland birds and make management recommendations based on my findings. In January-March 2007 and 2008, I surveyed 5 active, 4 abandoned, and 4 road sites to investigate the relationship between distance from disturbance (well pads, access roads) and bird abundance. I also compared abundance among the 3 site types. At each site I recorded bird numbers and species in 10-m distance bands along all transects (4 transects/well, 2 transects/road), each extending 300 m from the road or pad. At road sites bird abundance was positively correlated with increased distance from road edge, but I found no linear relationship at active or abandoned well sites. However, mean bird abundance in the first (0-30-m) distance interval of active well transects was less than half that at the second interval, and was the lowest value for all active intervals except the ninth. First-interval abundance at active wells was lower than abundance at any abandoned well interval. Road transects likewise showed low abundance in the initial interval, although unlike at active wells abundance increased steadily with distance from the center of disturbance. This trend of lower overall numbers at the first interval of active well transects was driven largely by 1 species, the meadowlark. A combination of high noise levels near active well pads (up to 80 dB) and lack of tall vegetation (on average 30% lower than the 60-90-m interval) from which to sing may have contributed to low numbers of meadowlarks, which were the only birds to sing regularly during my study period. While most birds appear to be minimally affected by resource extraction at Padre Island, to ensure minimal impacts on sensitive species I recommend: 1) reducing noise at active sites, 2) limiting disturbance to vegetation near pads and roads, 3) maintaining existing perch sites, 4) restoring all vegetation to its pre-extraction condition, 5) limiting road construction.

Thesis (Ph. D.)--Helsinki University of Technology, 2001. / Includes bibliographical references (p. 49-55). Also available on the World Wide Web.

Thesis (M.A.)--University of Central Florida, 2009. / Adviser: Spencer Downing. Includes bibliographical references (p. 97-100).

I detta arbete studeras hur vinterklimatet i Sverige kommer att skilja sig åt mellan perioderna 2071-2100 och 1971-2000, med avseende på parametrarna temperatur, nederbörd, vind, snödjup och snöutbredning. Klimatmodelldata (CORDEX) i upplösningen 12.5 km baserade på tre olika strålningsdrivningsscenarier (RCP-scenarier) behandlades i Matlab och modellerades över Sverige. För att analysera upplösningens betydelse tillhandahölls även data i upplösningen 50 km för en tioårsperiod. Scenariot RCP 8.5 kan ge så mycket som 10 grader varmare vintrar, med uppemot 50% mer nederbörd. För RCP 2.6 förändras nederbörden med -5 till 20%, och temperaturen ökar med 1-4 grader. Antalet dygn med nederbördstillfällen kommer att vara oförändrat oavsett RCP-scenario; istället kommer mängden nederbörd per tillfälle generellt att bli större. Detta bekräftas av antalet dygn med kraftig nederbörd, som kommer att öka med 20%, 37% respektive 68% för RCP 2.6, 4.5 respektive 8.5. Temperaturökningen blir mer påtaglig i norr än i söder. Vinden uppvisar inga tydliga mönster, vilket korresponderar med historiska observationer. Även RCP 2.6 innebär en förminskning av snödjup och -utbredning, vilket kraftigt förstärks med RCP 8.5. Dessa förändringar kommer bland annat att medföra ökade vintervattenflöden och större risk för laviner och översvämningar, och snöberoende näringslivsaktörer som exempelvis skidanläggningar kommer att drabbas hårt av förändringarna. Regionala klimatmodeller med grövre upplösningar kan inte illustrera lokala geografiska variationer, vilket har i särklass störst betydelse för nederbörden och snödjupet. / How the winter climate in Sweden will differ between the time periods 2071-2100 and 1971-2000 is reviewed in this work. The investigated parameters are temperature, precipitation, wind, snow depth and snow distribution. Climate model data (CORDEX) with the resolution 12.5 km based on three different representative concentration pathways (RCP scenarios) were processed in Matlab and projected over Sweden. For a thorough analysis of the significance of the regional model resolution, data with the resolution 50 km was provided for a ten year period. The RCP 8.5 scenario could implicate a 10 degree increase in temperature, and upto 50% more precipitation. For the RCP 2.6 scenario, the precipitation alters with -5 to 20%, and the temperature increases with 1-4 degrees. The number of days with precipitation events remain unaltered regardless of RCP scenario, instead the amount of precipitation in general increases for each precipitation event. This is verified when looking at the amount of days with heavy precipitation, which will increase with 20%, 37% and 68% for RCP 2.6, 4.5 and 8.5, respectively. The temperature change will be more substantial in the north than in the south. The wind does not show any distinct patterns, which corresponds with historical observations. Even RCP 2.6 implies a diminishment of snow depth and snow distribution, which drastically amplifies for RCP 8.5. These changes will among others bring about increased winter water flow and a bigger risk for avalanches and floodings. Snow dependent businesses, for instance ski resorts, will be heavily affected by the changes. Regional low resolution climate models cannot illustrate local geographical variations, which by far has the biggest importance for modelling precipitation and snow depth.

Aphids (Hemiptera: Aphididae) are pests of multiple cropping systems, primarily due to the viruses they vector and direct crop damage that is exacerbated by their rapid population growth. In Kentucky, grain aphids (Rhopalosiphum padi and Sitobion avenae) cause significant yield loss to winter wheat as vectors of Barley Yellow Dwarf virus (BYDV), prompting the routine application of insecticides. Coupled with increasing human populations and decreasing arable land, it is increasingly evident that biological control services provided by natural enemies represent a viable long-term management option. Aphids are preyed upon by a diverse array of predators that can be exploited in conservation biological control. I designed a field experiment to monitor dispersal into and out of wheat fields, and how these movements were affected by the surrounding habitat. Analysis revealed there are significant movements of R. padi into the wheat in the fall, and S. avenae in spring, and that these movements are slowed down by forested edges. Natural, field-bordering weed strips were used as a conservation biological technique to enhance predator populations. Results showed that while weed strips did not affect the yield of the crop, aphid abundance, or BYDV incidence, it did significantly increase the abundance of natural enemies. Dominant predators included Coccinellidae, Anthocoridae, Chrysopidae larvae, and Braconidae. Using molecular gut-content analysis, I screened multiple species of predators and found strong trophic linkages between aphids and Orius insidiosus and multiple species of coccinellids, namely Coccinella septempunctata and Coleomegilla maculata. In aphidophagous systems, intraguild predation (IGP) can interfere with the biological control potential so I also screened coccinellids for IGP using newly designed primers. To identify intraguild prey DNA in coccinellids, I designed species-specific primers for C. maculata and C. septempunctata to use in PCR-based molecular gut-content analysis. Results revealed high frequencies of IGP between coccinellids that are significantly higher in weed strip plots. However, I observed no detectable impact on aphid predation during these increased times of IGP, suggesting it does not interfere with biological control of aphids in this system. I discuss the role of weed strips in winter wheat as part of an integrative pest management strategy.

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An environmental and cultural history of cities between 1870 and 1930s, "Winters in America" explores the changing material and cultural relationship that Americans formed with winter in the urban spaces of the country. During this period of immense demographic, social, and technological change most Americans encountered winter nature in the industrial city, and subsequently formed their environmental experiences and knowledge of the season through city life. Using case studies of five cities - Boston, Chicago, St. Paul, Tucson and Phoenix - this study shows how winter labor, leisure, and culture in the Gilded Age city not only informed built environments but was also marshaled by Americans to interpret the appearance of the season, resulting in an emerging urban environmental and seasonal culture. Indeed, the growth of cities in combination with social and technological changes played a significant role in reorienting how many residents experienced and understood winter in their lives. Access to and control over winter narratives were not inclusive, however, and the evolving culture of winter typically favored particular classes of citizens. Winter celebrations, employment aid, work, and winter health resorts, for example, shifted the experiences and social values injected into the season. Ultimately, an examination of winter in the city during this period demonstrates the continued environmental power of season in the lives of urban Americans, while exposing the cultural power many Americans ascribed to the coldest season.

The aim of this study was to investigate the importance of winter season for the production of carbon dioxide (CO2) and methane (CH4) in humic and clear-water boreal aquatic systems. The study was conducted in 16 experimental ponds in northern Sweden during the winter of 2013. Half of the ponds had a higher concentration of dissolved organic carbon (DOC). CO2, CH4, DOC and dissolved inorganic carbon (DIC) were measured repeatedly under the ice from January to April. The results show that CO2 was accumulated continually during winter. No difference in winter accumulation were found between humic and clear ponds. CH4 was rarely accumulated in neither humic nor clear ponds, and was not an important part of the gas flux at spring ice melt. At ice melt, the flux from humic ponds accounted for 1.6 g C m-2 and 1.7 g C m-2 from clear ponds, which was equivalent for 15.6% respective 100% of the annual gas emissions. On a whole-year basis humic ponds acted as a source of 10.3 g C m-2, while clear ponds acted as a sink of 14.7 g C m-2. 76 mg m-2 d-1 DOC was consumed in humic and 59 mg m-2 d-1 DOC in clear ponds while the DIC accumulation was 125 mg m-2 d-1 in humic and 118 mg m-2 d-1 in clear ponds. This study stresses the importance of ice-covered boreal aquatic systems as a significant parts of the global carbon cycling.

This thesis is concerned with the development of a new measurement device for the realistic assessment of braking capability of landing airplanes for winter runways. Landing represents one of the most safety-critical phases of aircraft operation. Aircraft runway excursion incidents occur due to the unpredictability of the runway pavement condition. This is especially true during winter time when the runway is often covered by deformable contaminants. Several accidents are discussed that list the deteriorated condition of the runway pavement and the inability to accurately report this condition as the main causes for the excursions. The accuracy of the approaches currently adopted by the airport authorities around the world to monitor the condition of the runway pavement are evaluated. The conventional and current practice of runway condition monitoring is focused on identifying the maximum tire-pavement frictional drag mu value and often neglects the characteristics of actual aircraft brake control system as well as the comprehensive effects coming from various factors such as deformable contaminants on the winter runway. The braking availability tester discussed here is designed to take a different approach for the realistic assessment of braking availability of landing aircrafts. The main idea of this device is to mimic the braking operation of actual aircrafts as closely as possible by incorporating the same brake mechanism and the brake control system used in existing aircrafts. The architecture of the device from the ground-up including the suite of sensors, the structure of the wheel, important actuators, and the real-time brake control system are discussed in detail. More importantly, the operational principles of the braking availability tester (BAT) are outlined which help one understand how the system works together. A new method to quantify the braking availability on the runway using the BAT is explained. The testing and data collection strategy for implementing this technique is also outlined. Additionally, the results from preliminary tests are presented to verify the functionality of the BAT. The results are used to verify that the BAT operates with the brake control system of an aircraft. Finally, experimental data sets from dry and contaminated pavement testing are presented to show the effect of different weather conditions on the operation of the BAT.

Traffic crashes tend to occur at relatively greater frequencies at particular locations, at particular time periods, and for particular subsets of drivers and vehicles. It is well recognized among the road safety community that crash-risk is highly elevated when inclement weather conditions occur in the winter. To present, most of the road safety studies focus on event-based analysis or seasonal analysis and give little attention to explore high-risk conditions at the daily temporal scale. The purpose of the study is to advance our understanding of high-risk crash conditions at the daily level and their occurrences in Southern Ontario, Canada. The study explores different definitions of high-crash days, and quantifies the influences of weather conditions, risk exposure, months and timing of precipitation on the likelihood of a high-crash day occurring using binary logistic regression model. Additionally, an approach for estimating the relative risk exposure using available traffic count data has also been developed. The results of the study show a small proportion of high-crash days are responsible for a considerable amount of traffic crashes during the winter. The risk of traffic crash is twice as high on high-crash days in comparison to non-high-crash days. The modeling approach well-fits the data and shows that winter weather conditions have significant influence on high-crash days with results being mostly consistent across the four study areas, Toronto, the Area Surrounding Toronto, London and the Area Surrounding London. Low temperature, heavy snowfalls, high wind speeds, high traffic volumes, early winter months, occurrence of precipitation in both morning and evening increase the odds of high-crash days to a large extent. The results of study could help to pre-schedule traffic operation and enforcement, to effectively distribute road safety resources and personnel, and to create situational awareness among road users and other stakeholders.