<p>The increased focus on the importance of active travel within a community to improved social, economic and environmental sustainability has facilitated discussion and questions about how to best encourage those who take a personal automobile to switch to an active mode of travel. In attempting to answer this question, it is first important to understand that there are a variety of factors that impact an individual’s decision to take a certain mode of transportation. This study attempts to determine which factors have the largest impact on students’ decisions to take an active mode of transportation within a university setting.</p> <p>Through investigation of socio-demographic and attitudinal variables of university students, a comparison of ideal versus actual commute time was modeled. Regression analysis was applied to test the relationship between the ratio of ideal to actual commute time and the individual’s socio-demographic variables and attitudinal scores. Research using discrete choice analysis further provided more detailed evidence of specific factors affecting student’s decision to choose an active mode of travel based on the level of utility they obtained by each mode as a function of attitudes, the built environment and socio-demographic variables.</p> <p>The results obtained from this study contribute insight and support for initiatives aimed to increasing active modes of travel by students in university settings. Recommendations are provided that can be adopted at the institutional and municipal level of both policy and planning to increase uptake of active modes of travel.</p> / Master of Arts (MA)

<p>The Community Intervention Trial for Smoking Cessation (COMMIT) was the largest community-based effort to date aimed specifically at the reduction of smoking. COMMIT involved 11 matched pairs of intervention and comparison communities from geographically diverse regions of North America. One community from each of the matched pairs was randomly allocated to receive a standardized intervention protocol implemented between 1989 and 1993. The main trial goal was to achieve higher quit rates amongst heavy smokers in the intervention communities compared to the comparison communities.</p> <p>Intermediate trial goals were to increase the priority of smoking as a public health problem and increase social norms that support nonsmoking in the intervention communities. These goals were informed by contemporary health promotion theory which suggests that longstanding changes in behaviour are best achieved by altering social environments to support healthy choices. This thesis presents a conceptualization of the links between attributes of individuals, communities and attitudes toward smoking which provides the basis for empirical investigations of COMMIT's success in promoting attitude change; the nature of the relationship between attitude and behaviour change for smoking; and the role of community context in constructing attitudes.</p> <p>Intermediate trial goals were to increase the priority of smoking as a public health problem and increase social norms that support nonsmoking in the intervention communities. These goals were informed by contemporary health promotion theory which suggests that longstanding changes in behaviour are best achieved by altering social environments to support healthy choices. This thesis presents a conceptualization of the links between attributes of individuals, communities and attitudes toward smoking which provides the basis for empirical investigations of COMMIT's success in promoting attitude change; the nature of the relationship between attitude and behaviour change for smoking; and the role of community context in constructing attitudes.</p> <p>Attitude change was assessed primarily from prevalence surveys administered in 1989 (n=9,875) and 1993 (n=14,117). Data from cohorts of smokers and nonsmokers (n=5,450) were also used to examine covariates of attitude change and for the analysis of the attitude change -behaviour change relationship. Community profile data and legislative tracking were employed in the descriptive analyses of the relationship between community context and smoking attitudes.</p> <p>Valid and reliable measures representing the primary constructs ofbeliefin the priority of smoking as a public health problem and norms and values concerning smoking were developed. Attitude change, assessed by a cross-sectional approach, revealed that there were substantial changes in favour of stronger anti-smoking attitudes in both the intervention and comparison communities. Intervention effects were limited to changes in heavy smokers' beliefs about the seriousness of smoking as a public health problem. The strongest covariate of attitude change was shown to be quitting smoking during the trial for both measures, while changes in beliefs about smoking as a public health problem were demonstrated to be greater for less educated groups in the intervention communities. The attitude change -behaviour change analyses revealed support for traditional theoretical positions in the debate. Conclusions reached, however, suggest that the type of behaviour change being measured (i.e., quitting or starting smoking) and the measure of attitude affect the results of attitude behaviour analyses. Lastly, 'place' was shown have an important independent effect on attitudes toward smoking. Through case studies of several COMMIT communities, place attributes identified to have an important impact on individual smoking attitudes were economic reliance on the tobacco industry, socio-economic and cultural composition and legislative/political climates.</p> / Doctor of Philosophy (PhD)

Coffea arabica is a species with far-reaching impacts on the global economy. Nevertheless, climate-related challenges threaten the coffee industry at its source: its growing regions. The coffee industry is a significant economic driver in Guatemala, but farmers are increasingly reporting losses in crop yield and arable land due to climate-related challenges. Ecological niche modeling (ENM) can be employed to make predictions about the current and future suitability of regions for a species by identifying significant biotic or abiotic indicators. An ENM was used to project suitable land into the future using climate change projection models known as representative concentration pathways (RCPs), for the coffee plant and a number of other species. Due to the potential of shade trees to lessen heat stress on coffee plants, common shade trees for the region were modeled. Additionally, a fungus species responsible for detrimental coffee leaf rust was modeled. Results of these models indicated potential for substantial climate-related habitat losses for the coffee plant in the coming decades. Examination of model predictions allow for greater understanding of the climate-related variables affecting the ecology of the coffee plant, and the potential risks to the industry, in a changing climate. Additionally, ENM models for coffee rust and shade trees can help Guatemalan farmers make informed decisions about farm management.

Coffea arabica is a species with far-reaching impacts on the global economy. Nevertheless, climate-related challenges threaten the coffee industry at its source: its growing regions. The coffee industry is a significant economic driver in Guatemala, but farmers are increasingly reporting losses in crop yield and arable land due to climate-related challenges. Ecological niche modeling (ENM) can be employed to make predictions about the current and future suitability of regions for a species by identifying significant biotic or abiotic indicators. An ENM was used to project suitable land into the future using climate change projection models known as representative concentration pathways (RCPs), for the coffee plant and a number of other species. Due to the potential of shade trees to lessen heat stress on coffee plants, common shade trees for the region were modeled. Additionally, a fungus species responsible for detrimental coffee leaf rust was modeled. Results of these models indicated potential for substantial climate-related habitat losses for the coffee plant in the coming decades. Examination of model predictions allow for greater understanding of the climate-related variables affecting the ecology of the coffee plant, and the potential risks to the industry, in a changing climate. Additionally, ENM models for coffee rust and shade trees can help Guatemalan farmers make informed decisions about farm management.

Aedes aegypti is the principal vector for dengue transmission across large areas of the world. Understanding where this critically important vector lives is paramount to preventing the continued expansion of dengue globally. Using 1981-2010 bioclimatic (bioclim) variables, as well as additional environmental variables and elevation data, multiple MaxEnt models were constructed for Ae. aegypti within the South American continent to identify ecologically important variables and areas of persistent high suitability. All models had acceptable AUC scores (> 0.70), indicating accurate model fitting. Annual mean precipitation and temperature were found to be important model variables; however, when added, humidity became the more predictive variable. Elevation had minimal, if any, impact on model construction predictability. When utilizing MaxEnt models, non-traditional climatic variables, i.e., humidity, were significantly more predictive for Ae. aegypti than the standard bioclim variables. Optimal variable selection is critical to understanding current and potential future areas of high transmission risk.

This paper looks at the intersections of nature and culture through a study of forest ecosystem restoration efforts in the Ouachita National Forest (Arkansas and Oklahoma). Ecosystem restoration goals are often informed by a pre-European settlement (PES) condition, with an implicit (and occasionally explicit) assertion that such conditions are both more natural than and preferable to the contemporary state. In many cases resuming pre-suppression fire regimes remains a key mechanism for achieving this restored condition. This study’s three main objectives include: (1) determining how PES benchmarks arose in restoration thought, (2) examining how the choice to use a PES benchmark is influenced by culture, and (3) evaluating the pragmatism of including a PES benchmark in restoration projects. The issues of the naturalness of PES conditions, along with the cultural implications of adopting a PES benchmark, are critically examined against the backdrop of historic legacies of fire suppression and paleoecological change. Normative balance-of-nature ideas are discussed in light of their influence on natural resource management paradigms. Linkages are drawn between PES conditions and forest health. Evidence supporting the ecological resilience associated with PES vegetation communities is considered alongside the anticipation of future forcing factors. The idea that restored forests represent an ecological archetype is addressed. Finally, an alternative explanation concerning the tendency of ecosystem restoration efforts to converge on a single historic reference condition – a point of equifinality – is weighed against notions of: (1) anthropic degradation, (2) a regional optimum, and (3) a socially-constructed yearning for a frontier ideal. Because of the unique convergence between historical human activities and natural processes, contemporary culture has conceived of the PES time period as a sort of frontier ideal. The creation of PES benchmarks appears to be an unintentional consequence of attempts to restore forest health rigorously defined by biometric standards. This study offers, to restoration thinking, a framework for critically evaluating the inclusion of historic reference conditions and a means of responding to criticism surrounding their use. This study's findings rest on evidence gathered from paleoecological and historical biogeography data, interviews, archival materials, cultural landscape interpretation, landscape and nature-based art, and complexity theory.

Digital Elevation Models (DEMs) are digital representations of surface topography or terrain. Collection of DEM data can be done directly through surveying and taking ground control point (GCP) data in the field or indirectly with remote sensing using a variety of techniques. The accuracies of DEM data can be problematic, especially in rugged terrain or when differing data acquisition techniques are combined. For the present study, ground data were taken in various protected areas in the mountainous regions of Nepal. Elevation, slope, and aspect were measured at nearly 2000 locations. These ground data were imported into a Geographic Information System (GIS) and compared to DEMs created by NASA researchers using two data sources: the Shuttle Radar Topography Mission (STRM) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). Slope and aspect were generated within a GIS and compared to the GCP ground reference data to evaluate the accuracy of the satellitederived DEMs, and to determine the utility of elevation and derived slope and aspect for research such as vegetation analysis and erosion management. The SRTM and ASTER DEMs each have benefits and drawbacks for various uses in environmental research, but generally the SRTM system was superior. Future research should focus on refining these methods to increase error discrimination.

Eastern Kentucky is a 35-county region that is a part of the Cumberland Plateau of the Appalachian Mountains. With mountaintop removal and associated land cover change (LCC) (primarily deforestation), it is hypothesized that there would be changes in various atmospheric boundary layer parameters and precipitation. In this research, we have conducted sensitivity experiments of atmospheric response of a significant flash flood-producing rainfall event by modifying land cover and topography. These reflect recent LCC, including mountaintop removal (MTR). We have used the Weather Research and Forecasting (WRF) model for this purpose. The study found changes in amount, location, and timing of precipitation. LCC also modified various surface fluxes, moist static energy, planetary boundary layer height, and local-scale circulation wind circulation. The key findings were the modification in fluxes and precipitation totals. With respect to sensible heat flux (H), there was an increase to bare soil (post-MTR) in comparison to pre-MTR conditions (increased elevation with no altered land cover). Allowing for growth of vegetation, the grass simulation resulted in a decrease in H. H increased when permitting the growth of forest land cover (LC) but not to the degree of bare soil. In regards to latent heat flux (LE), there was a dramatic decrease transitioning from pre-MTR to post-MTR simulations. Then with the subsequent grass and forest simulations, there was an increase in LE comparable to the pre-MTR simulation. Under pre-MTR conditions, the total precipitation was at its highest level overall. Then with the simulated loss of vegetation and elevation, there was a dramatic decrease in precipitation. With the grass LC, the precipitation increased in all areas of interest. Then forest LC was simulated allowing overall slightly higher precipitation than grass.

This study deals with the Holocene environmental dynamics experienced by a seasonally wet-dry landscape of tropical Columbia. In light of a high ecological sensitivity, the study area is also analyzed as the resource of man. This is done by intensive study area reconnaissance, mapping, altimeter survey, and radiocarbon dating of fluvial landforms. Also, samples of soil, pasture, and water were collected for later study, and several interviews were completed with local residents. The study area is a tropical lowland of northcentral Columbia at about 7 ½° north attitude. A maximum local relief about 600 m is maintained by a rather resistant lower Tertiary sandstone hogback. The well-faulted landform lies at an almost vertical attitude because of its boundary with the great Salinas fault, which was probably active during the Tertiary-Quaternary orogeny of the Cordillera Oriental. Through this landscape flows the Río Lebrija, a major local base level at about 180 m elevation. Draining about 2700 km2 of the Cordillera’s western flank, this valley contains relict evidence of major ecological fluctuations during Quaternary time. Midway through the Holocene, a marked thinning of plant cover, caused by peak Hypsithemal temperatures and resulting precipitation irregularities, permitted intense surface erosion of hillslopes. This process, maximized by the initiation of short wet periods delivered considerable quantities of weathered materials to aggrading valleys. The sands and gravels deposited in areas protected from stream migration have formed the alluvia terraces seen today. Charcoal, collected from compact coarse sandy alluvium lying 15 m above the present Río Lebrija, was dated at 6.2535+90 and 5.365+85 B.P., a much younger date than suggested for correlative basin landforms. It appears that there is a need for reassessment of the assumed magnitude and rapidity of the recent, as well as ancient, dynamics undergone by tropical flora, erosion surfaces and fluvial systems. An important environmental concept appears to be a direct correlation between valley aggradation and progressive warmth in continental, tropical wet-dry regions. Man’s activities are naturally destructive to this sensitive low-land environment. Great earthflows dated at 445+110 B.P. may have resulted from European-type deforestation of unstable slopes. The denudation of these rugged slopes continues today at an expanding rate. The message is reinforced after every heavy rain when the swift Lebrija swirls red-brown with yesterday’s soil. The initiation of high protein agriculture on the rich pastured bottomlands might lessen the human pressures upon the most sensitive landscapes and would enhance possibilities for supplemental irrigation. Also, the powerful current of the Río Lebrija is a potential source of hydroelectric energy. The harnessing of this power by a proposed waterwheel-barrage facility would deal minimal alteration to the fluvial system, while supplying the community with limited irrigation and domestic energy. If successful, the utilization of land and water resources would be optimized, and the local people would be in a better position to adjust to weather anomalies initiated by an evolving environment. KEY WORDS: Colombia, Cordillera Oriental, tropical wet-dry climate, alluvial terrace, Hypsithemal “environmental flux,” and land use.

The stability of Mammoth Cave’s microclimate has never undergone extensive investigation. The Snowball Dining Room area was chosen to measure the microclimate of the cave and to determine if food preparation, human presence and surface temperature variations alter this microclimate. Three portable weather stations containing a temperature / humidity probe, datalogger and microbarograph were placed in various locations along three passageways leading away from the dining room. Readings were taken 24 hours per day for four months. Plotting temperature readings in graph form show a correlation between temperature of the passageway and distance from the dining room.