In arid and semiarid environments, various natural and anthropogenic stressors have resulted in land cover change that has negatively impacted the ecological integrity of the landscape. Society, however, relies on many ecological processes and functions provided by the landscape to enhance its wellbeing. The direct and indirect benefits society receives from the landscape are collectively termed "ecosystem services." The overarching goal of this thesis was to examine how the landscape has changed and to analyze how these changes impact the ecosystem services supplied by the landscape. The Upper San Pedro watershed in southeastern Arizona and northern Sonora was used as a case study to link land cover change with an array of ecosystem services to understand the spatiotemporal dynamics of ecosystem service supply. To accomplish this, a multitemporal land cover dataset for the watershed was updated to extend the temporal coverage to 37 years across 5 land cover datasets. Indicators serving as proxy variables for a variety of ecosystem services were assessed for each land cover class. This linkage between land cover and ecosystem services enabled an analysis of the tradeoffs and synergies within the array of services each land cover class can provide. Combined with the multitemporal land cover dataset, the spatiotemporal dynamics of potential ecosystem service supply were analyzed across the watershed for a 37 year period. Rather than examining the impacts of land cover change on the biophysical aspects of the environment, this approach enables land managers and decision makers to explore the implications of a changing landscape on human wellbeing.

Evapotranspiration dominates the water budget in drylands, exerting important controls not only on the dynamics of water, but also on the amount and distribution of vegetation on a landscape. The spatial and temporal variability of vegetation cover imposes constraints on key ecohydrological processes that feedback to the dynamics of evapotranspiration and, most importantly, its partitioning between direct evaporation and transpiration from plants, one of the most significant ecohydrological challenges. Yet, lacking are systematic evaluations of how variations in woody plant cover--a fundamental vegetation attribute of landscapes that can vary spatially with amount of cover and temporally with leaf phenology-- influence the dynamics of soil microclimate and ultimately the partitioning of evapotranspiration into its components. This study presents the results of field experiments that systematically evaluated the effects of amount of canopy cover and its seasonality in both surface microclimate and soil evaporation. These field observations are complemented by controlled experiments that directly evaluate the relationship between amount of canopy cover and the partitioning of evapotranspiration, with an assessment of its larger-scale implications using a regional land surface-atmosphere model. Finally, this study presents a classroom-adaptation of the evapotranspiration partitioning experiment that was used to effectively translate new scientific concepts and information into k-12 classrooms. Overall, the results from this study provide a comprehensive understanding about the interactive ways in which canopy cover, canopy structure attributes and plant phenology influence soil surface microclimate--characterized by near-ground solar radiation and soil temperature--and soil evaporation. More specifically, the results illustrate how the main control of deciduous-woody vegetation on soil evaporation is the addition of litter to the surface. However, in absence of litter, attributes of woody cover influence soil evaporation variably with season and phenology. Further, The results from this study illustrate how the partitioning of evapotranspiration exhibits a non-linear response to amount of woody canopy cover. Notably, when incorporated into a regional surface-atmosphere model, this non-linearity strongly affects water fluxes, highlighting the potential implications for ecological, hydrological, and atmospheric processes associated with the partitioning of evapotranspiration, providing important insights for natural resource management.

Impervious surfaces negatively affect urban hydrology by altering the depth, frequency and seasonal distribution of stormwater runoff. To assess the imperviousness of green roofs, a mathematical model was developed to simulate the stormwater response of a hypothetical green roof. The model is based on the physical processes that affect the green roof stormwater response and uses historic climate data. The results show that green roof imperviousness fluctuated according to climate conditions and precipitation sequence. Only 29% of the total precipitation received by the green roof resulted in runoff, however, the response varied substantially when evaluated at a daily interval. Runoff was eliminated during 82% of days with rain and a higher proportion of runoff disturbances were eliminated during the spring and summer compared to the fall. In comparison to an impervious surface, the green roof showed a reduction in the depth and frequency of runoff thereby improving urban hydrology.

The effect of cover crops on N and weed dynamics was assessed within a pea (Pisum sativum L.) – cover crop – sweet corn (Zea mays L.) rotation. Cover crops of oat (Avena sativa L.), perennial rye (rye) (Secale cereale L.), oilseed radish (OSR) (Raphanus sativus L. var. oleoferus Metzg Stokes), and OSR plus perennial rye (OSR+rye) increased plant available N (PAN) over the cover crop growing season compared to the no cover control at the Bothwell site only. However, at neither site did cover crops result in increased PAN for the sweet corn, indicating that these cover crops will not reduce required N fertilizer applications. Also, cover crops posed neither an increased or decreased need for weed management during sweet corn production. However, OSR may be useful in pesticide reduced programs due to its potential ability to reduce fall herbicide applications, provided it does not set viable seed.

<p>The complex nature and composition of regolith cover in Southern Africa is a major challenge to geochemical mapping for concealed mineralization. Some of the setbacks to successful geochemical exploration may be ascribed to the use of various partial extraction techniques,without a profound understanding of the regolith components and their composition. This investigation therefore focuses on the use of hydroxylamine partial extraction geochemistry for geochemical mapping in regolith over two contrasting environments viz / aeolian sand-calcrete regolith over Au mineralization at Amalia Blue Dot Mine in South Africa and lateritic regolith covering the Ni-Cu deposit at Kabanga Main and Luhuma in Tanzania. Regolith samples from the above areas were sieved and extracted with hydroxylamine hydrochloride solution and analyzed for multi-element by AAS and ICP-MS techniques. A stepwise optimization of the hydroxylamine extraction technique of samples from both areas was carried out and incorporated into the analytical programme (in a pilot study). Results of hydroxylamine partial extraction generally gave better anomaly contrast and reflection of bedrock mineralization than the conventional aqua regia techniques that were previously used in the region. The results however show that lateritic regolith may be best extracted using 0.25M hydroxylamine while 0.1M concentration appears most suitable for extraction of aeolian-calcrete regolith. The above results are corroborated by principal component analysis of the analytical data that show various element associations, e.g. with Fe-Mn oxides while others possibly belong to the loosely adsorbed or exchangeable group. The&nbsp / gochemical maps in the pilot study areas at Amalia, Kabanga and Luhuma show elevated element contents or clusters of anomalies of diverse elements associated with Fe-Mn oxides. Geochemical mapping at Kabanga with deeply concealed mineralization however shows variability of subdued element patterns over mineralized areas. Geochemical signatures associated with hydroxylamine hydrochloride partial leach are therefore characterized by a lower geochemical background than that using conventional aqua regia leach. This study leads recommending for further investigations into partial extraction of the exchangeable group of elements, possibly using ammonium acetate.</p>

Impression management (IM) handlar om enmedveten eller omedveten process att styra intrycken av sig själv som ges tillomgivningen i syfte att imponera och söka erkännande. Tidigare forskning har istor utsträckning berört anställningsrekommendation utifrån intervjuer och demest framgångsrika resultaten har visat sig vara självförbättrande IM taktik.Studiens syfte vara att undersöka hur självförbättrande IM taktik i personligtbrev, två kvalitéer av meriter, påverkar ett beslut omanställningsrekommendation, samt undersöka hur en uppsättning personliga egenskaperrelaterar till självförbättrande IM taktik. Deltagarna var studenter, 57kvinnor och 32 män. Studien var experimentell 2 x 2 x 2 mellangruppsdesign. Deviktigaste fynden var att, högre kvalité av meriter innebar högre skattning avanställningsrekommendation samt att högre skattning av egenskaper vidsjälvförbättrande IM taktik skattats. Meriters kvalité visades viktig,egenskaper visade samband med IM dock satte IM trovärdighet på spel.Könsskillnader påträffades även och vidare forskning förslås göras mellankönen.

Problems with storm water runoff are becoming more frequent, and the main cause is the increase of impervious cover (IC). The imperviousness increases stream peak flows, changes peak times, and so changes the flood distribution. Several policies are used to manage flows and flooding; however most have been reported to be inefficient because land owners do not have correct exposure to price incentives and risk. The main contributions of this thesis are an investigation into market mechanisms to price and allocate impervious cover allowances, while managing flood distribution. The market mechanisms are based on the electricity and gas markets which use linear programming formulations. This thesis develops three net pool market mechanisms: Det_MarketIC is a capped and deterministic market for IC, and Sto_MarketIC and Sto_MarketIC_Risk are stochastic market models with flood component penalties and risk positions representing the desired risk from the community respectively. Additionally, a gross pool market was extended under rainfall uncertainty, Gross_MarketIC. The market design is an auction system with operational constraints and bids for IC allowances from participants. The system relates physical routed flows at nodal or control points to these bids. The models clear the market by creating a demand (supply) curve for increments (reductions) in flows at specific places, and accounts for marginal changes in the expected flood damage and flood damage components. The market formulations estimate efficient allocations and prices. Decomposed prices from the market models are shown based on duality, as applied in electricity markets. The dual prices show spatial and temporal effects of flows, which impact at flooding areas. With Sto_MarketIC and Gross_MarketIC, prices account for changes in flood distribution. With Sto_MarketIC_Risk, prices also account for the risk as CVaR in flooding areas. Thus, prices increase as binding risk conditions are tightened. Finally, the net pool models are illustrated using hydrological and hydraulic simulators based on a small catchment located in Canterbury, New Zealand. Allocations and prices varied with the different models. Participants would face increasing prices in their IC allowances due to increments in flood damage.

This dissertation examines subfunctors of Ext relative to covering (enveloping) classes and the theory of covering (enveloping) ideals. The notion of covers and envelopes by modules was introduced independently by Auslander-Smalø and Enochs and has proven to be beneficial for module theory as well as for representation theory. The first few chapters examine the subfunctors of Ext and their properties. It is showed how the class of precoverings give us subfunctors of Ext. Furthermore, the characterization of these subfunctors and some examples are given. In the latter chapters ideals, the subfunctors of Hom, are investigated. The definition of cover and envelope carry over to the ideals naturally. Classical conditions for existence theorems for covers led to similar approaches in the ideal case. Even though some theorems such as Salce’s Lemma were proven to extend to ideals, most of the theorems do not directly apply to the new case. It is showed how Eklof & Trlifaj’s result can partially be extended to the ideals generated by a set. In that case, one also obtains a significant result about the orthogonal complement of the ideal. We relate the existence theorems for covering ideals of morphisms by identifying the morphisms with objects in A2 (which is the category of all representations of 2-quiver by R-modules) and obtain a sufficient condition for the existence of covering ideals in a more general setting. We finish with applying this result to the class of phantom morphisms.

The use of high N fertilizer in sweet corn (Zea mays L.) and wheat (Triticum aestivium L.) production often results in leaching losses and contamination of ground water. Cover crops planted after harvest of sweet corn and wheat may reduce residual soil NO$ sp- sb3$-N levels by crop N uptake and subsequently minimize NO$ sp- sb3$-N content in gravitational water. Field experiments were conducted on a Ste. Rosalie heavy clay (Humic Gleysol) and a St. Bernard sandy clay loam (Melanic Brunisol) to determine the contribution of the six cover crops to nutrient uptake, subsequent N release, leaching losses, denitrification rates and soil properties such as aggregate stability, organic matter. The cover crops were red clover (Trifolium pratense L.), crimson clover (Trifolium incarnatum L.), forage radish (Raphanus sativus L.), canola (Brassica rapa L.), barley (Hordeum vulgare L.), annual rye grass (Lolium multiflorum L.). Three replicates were used in a split plot arrangement of a randomized complete block experiment. Sweet corn and wheat were grown at three fertilizer N rates, 0-75-150 kg N ha$ sp{-1}$ for sweet corn and 0-45-90 kg N ha$ sp{-1}$ for wheat. Cover crop of forage radish, canola and barley were more effective at absorption or soil N than rye grass and clover species at all sample times. Levels of soluble N in the soil were reduced with cover crop in the off-season. Cover crop plots had higher NO$ sp- sb3$-N levels than control plots in the spring, indicating net mineralization and nitrification. Gravitational water NO$ sp- sb3$-N contents were higher in the control plots relative to cover crop plots at both sites. Therefore growing cover crops after harvest of sweet corn and wheat can reduce residual NO$ sb3$-N level in the soil and thus restrict ground water contamination with fertilizer N.

Enhanced understanding of forest stocks and dynamics can be gained through improved forest measurement, which is required to assist with sustainable forest management decisions, meet Australian and international reporting needs, and improve research efforts to better respond to a changing climate. Integrated sampling schemes that utilise a multi-scale approach, with a range of data sourced from both field and remote sensing, have been identified as a way to generate the required forest information. Given the multi-scale approach proposed by these schemes, it is important to understand how scale potentially affects the interpretation and reporting of forest from a range of data. ¶ To provide improved forest assessment at a range of scales, this research has developed a strategy for facilitating tree and stand level retrieval of structural attributes within an integrated multi-scale analysis framework. The research investigated the use of fine-scale (~1m) airborne Light Detection and Ranging (LiDAR) data (1,125 ha in central Queensland, and 60,000 ha in NE Victoria) to calibrate other remotely sensed data at the two study sites. The strategy refines forest structure mapping through three-dimensional (3D) modelling combined with empirical relationships, allowing improved estimation of maximum and predominant height, as well as foliage and crown cover at multiple scales. Tree stems (including those in the sub-canopy) were located using a height scaled crown openness index (HSCOI), which integrated the 3D density of canopy elements within the vertical profile into a two-dimensional spatial layer. The HSCOI modelling also facilitated the reconstruction of the 3D distribution of foliage and branches (of varying size and orientation) within the forest volume. ¶ Comparisons between forests at the Queensland and NE Victorian study sites indicated that accurate and consistent retrieval of cover and height metrics could be achieved at multiple scales, with the algorithms applicable for semi-automated use in other forests with similar structure. This information has facilitated interpretation and evaluation of Landsat imagery and ICESat satellite laser data for forest height and canopy cover retrieval. The development of a forest cover translation matrix allows a range of data and metrics to be compared at the plot scale, and has initiated the development of continuous transfer functions between the metrics and datasets. These data have been used subsequently to support interpretation of SAR data, by providing valuable input to 2D and 3D radar simulation models. Scale effects have been identified as being significant enough to influence national forest class reporting in more heterogeneous forests, thus allowing the most appropriate use and integration of remote sensed data at a range of scales. An empirically based forest minimum mapping area of 1 ha for reporting is suggested. The research has concluded that LiDAR can provide calibration information just as detailed and possibly more accurately than field measurements for many required forest attributes. Therefore the use of LiDAR data offers a unique opportunity to bridge the gap between accurate field plot structural information and stand to landscape scale sampling, to provide enhanced forest assessment in Australia.