In the Intermountain West, aspen (Populus tremuloides) has declined mainly due to a combination of successional processes, fire suppression and long-term use of ungulates which has led to replacement by conifers, sagebrush or other shrub communities. Conifer encroachment is believed to cause critical changes in the ecosystem properties. In order to understand the impacts of conifer encroachment on soil properties such as soil organic carbon (SOC) storage, soil morphology, and soil chemical properties, and the implications of such changes, it is very important to assess the soil properties under the two vegetation types. The objectives of this study were to i) quantify SOC stocks and their variability in pure aspen forests; ii) evaluate the role of various biotic and abiotic site parameters as drivers of this SOC; iii) evaluate the effect of conifer encroachment on SOC storage, soil morphology, soil microclimate and soil chemical properties. The study was conducted in three catchments in Northern Utah in two phases: i) a transect study with 33 sampling points in a pure aspen community; ii) a paired plot study based on comparing six plots in to aspen and nearby conifer plots as representatives of end-member communities. Soils under aspen were mainly Mollisols, whereas the soils associated with conifers were classified as Alfisols, Inceptisols and Entisols. Even under pure aspen there was a significant SOC variability among sampling points and aspects, and SOC was negatively correlated with soil moisture index and average tree diameter and positively correlated with vegetation density. The paired plot comparison showed that SOC in the mineral soil (0-60 cm) was significantly higher under aspen, while O horizon thickness and C content was higher under conifers. The total SOC (O layer + mineral soil) was not significantly different among the vegetation types, suggesting an upward redistribution of SOC in conifer soils. The soil moisture in summer was also higher under aspen compared to conifers. Other chemical properties were not affected by vegetation types. Our study indicates that i) no differences in SOC can be detected in surface soil horizons (<20 >cm); ii) SOC is highly variable and greatly influenced by soil moisture and forest characteristics; iii) conifer encroachment is likely to alter soil microclimatic and SOC amount and distribution.

No description available.

The purpose of this study is to further quantify adult ovine ovariectomized bone for new remodeling characteristics to obtain a better understanding of how remodeling is occurring and the effectiveness of this animal model for the study of postmenopausal osteoporosis. Postmenopausal osteoporosis is a major health concern and animal models to test new treatment options are needed. The ovine model is a good option because the ewes undergo Haversian remodeling, are a large sized animal, and have a similar hormone profile to humans. Ewes, however, do not undergo a natural menopause, so an ovariectomy surgery was conducted in the sheep to simulate the decreased levels in estrogen. Columbia-Rambouillet sheep were used in this study: some that have been ovariectomized as a model for postmenopausal osteoporosis and some that underwent a sham surgery to serve as a control. The sheep were sacrificed 12 months post operatively in the month of August, so the seasonal effects of remodeling were accounted for. The left radius was then processed into microradiographs of 6 regional cortical beams, where the cranial (tensile side) and caudal (compressive side) anatomical sections were analyzed in this study to determine regional differences in remodeling. Previous students’ theses have analyzed the similar samples for basic bone remodeling histology measurements, resulting in some significant seasonal, anatomical, and treatment differences. However, most of the results showed no particular increase in the amount of remodeled area for the ovariectomized sheep compared to the sham sheep, even though an ovariectomy is believed to cause a burst of remodeling in bone due to the decreased levels in estrogen. In this study, a new repeatable method was developed that further examines secondary bone by quantifying the extent to which secondary osteons encroach on previously-existing secondary osteons. Encroached and unencroached secondary osteons were quantified using two different methods: a point count method that measured the percentage of the area the encroached and unencroached secondary osteons inhabited and an osteon count method that measured the number of encroached and unencroached secondary osteons per area. These raw measurements were calculated into 18 parameters and 2-way repeated measures ANOVAs were run to determine the effects of surgery and anatomical region on each of the bone remodeling parameters. The results found significant effects from estrogen deletion which were different depending on if the bone region was predominately in compression or tension. The ovariectomy surgery caused an increase in remodeling, which was mostly confined on the compressive side to areas that have been previously remodeled, but on the tensile side, bone remodeling expanded into areas that used to be primary bone. The new secondary osteons, as a result of the ovariectomy surgery, were larger than in the control animals. There however, was not an increase in porosity from the ovariectomy surgery, which is one of the main characteristics of osteoporosis. The model could be further studied to determine what sheep are doing that prevents them from losing bone and that knowledge could be greatly beneficial for human treatment plans of postmenopausal osteoporosis.

Linbana som kollektivt transportmedel i tätbebyggt område är i Sverige ett nytt fenomen. Med hänsyn till samhällets urbanisering och ambition att tillgodose bostadsbehovet genom förtätning, framstår linbana som ett lämpligt komplement till att förstärka befintlig infrastruktur. Framförallt på grund av det marginella "fotavtryck" anläggningen utgör på miljön. Linbanor är energieffektiva och miljövänliga transportalternativ som även ger framkomlighet i miljöer där andra transportsätt är för svåra eller för dyra att anlägga. I studien har frågor kring ersättning av markintrång och störningar som en linbana kan medföra granskats. Studien redogör för de generella ersättnings- och värderingsprinciper som berör detta område, samt hur dessa kan appliceras på linbanor i tätbebyggt område. Studien har genomförts med en juridisk metod, som innebär en fördjupning i lagtext, förarbeten och doktrin. För att kunna bedöma inverkan av störningarna har även vägledande rättsfall och praxis använts. Intervjuer har gjorts med en förrättningslantmätare samt ett tekniskt råd på avdelning 6, Svea hovrätt (mark- och miljööverdomstolen) för att vidga studiens referensramar av de tolkningar som gjorts. Av studien framgår att regler för intrångsersättning i expropriationslagen ska tillämpas, oavsett vilket lagrum som används för markåtkomsten. Avgörande där är den marknadsvärdeförändring intrånget medför. Effekten på marknadsvärdet av markintrång som utgörs av enbart vajer mellan stationer och pelarstöd, är svårare att bedöma än det intrång som görs för stationer och pelarstöd. Svårigheten ligger i bedömningen av hur marknadsvärdet förändras när fastigheten "urholkas" för linbanan. En linbana kan anläggas på höga höjder, vilket innebär att fastighetens möjlighet att nyttja utrymmet under vajern i de fallen inte begränsas i någon större utsträckning. Bedömning måste dock göras i det enskilda fallet. Gällande störningar framkommer problem kring hur olika störningar kan uppfattas samt hur dess sammantagna effekt ska bedömas. Då linbana som kollektivt transportmedel i tätbebyggt område är nytt inom Sverige har ännu inga rättsfall kring markintrång eller störningar prövats. För att kunna göra en bedömning av störningar har en rättsfallsanalys gjorts av rättsfall med verksamheter vars störning liknar de som kan uppkomma från linbanor. Resultatet visar att ämnet är svårbedömt. Att pröva linbanan i detaljplan kan därför vara en nödvändig åtgärd. Linbanan blir då prövad i sin helhet, och inom ramen för detaljplan främjas en bra dialog med berörda sakägare och medborgare i allmänhet. / A gondola lift as a means of public transportation system is a new phenomenon in Sweden. In view of the urbanization and society’s ambition to accommodate the urgent need of housing through a concentration of the city, a gondola lift stands out as a suitable compliment for the existing infrastructure. Above all because of the small "footprint" the structure makes on the environment. As a transportation system, gondola lifts are energy efficient, environmentally friendly and provides accessibility where other transportation systems are too difficult or too expensive to build. The study has looked at questions of compensation for the property encroachments and environmental disturbances a gondola lift might cause. The study gives further details about the general principles of compensation and valuation regarding this area, and also how these principles can be applied to gondola lifts in urban areas. The study has been done using a legal methodology, which involves a deeper understanding of the law, government bills and doctrine. Guiding- and precedent court cases has been analyzed in order to make an assessment about the influence of the environmental disturbances. Interviews has been done with a cadastral surveyor at the Gothenburg municipality office and with a technical adviser at the environmental court of appeal, in order to broaden the perspectives of the interpretations made in the study. The study infers that the compensation rules of encroachment in the law of expropriation should be applied, no matter which law is used to expropriate for the gondola lift. Decisive when determining the compensation is the change in market value caused by the encroachment. It´s harder to estimate the effect on market value caused by encroachment of the cable only, than for encroachment of the station buildings and pillars. The difficulty lies in the estimation of the change in market value when the expropriated property is "hollowed" in favor of the gondola cable. A gondola lift can be built very high, which means that a property in those cases aren´t restricted in any large extent regarding the use of the property directly below the cable. Although, assessments must be done for each individual case. Regarding the different disturbances, problems occur around the way they are perceived and how the overall effect of different disturbances should be assessed. Because gondola lifts as a public transportation is so new, there hasn´t been any legal cases tried about its encroachment or disturbances. In order to make an assessment about disturbances, a court case analysis has been done using cases about activities which disturbances are comparably similar to the once caused by a gondola lift. The result of the study shows that this assessment is hard to do. A necessary proceeding might be to try out the gondola lift in a detailed zoning plan. The gondola lift is then tested as a whole, including the effects of disturbances and encroachment. The framework of a detailed zoning plan also promotes the dialog with the parties concerned as well as with the other citizens.

La présente thèse se propose d’aborder l’intelligence singulière de Marguerite Duras et pour ce faire, elle retient l’ensemble des écrits : romans, textes de théâtre, écrits journalistiques, scénarios, textes divers. Elle prend en compte le difficile héritage de la Shoah et du stalinisme, et à partir de l'extrême déshumanisation qui a marqué le XXe siècle, elle s’interroge sur le nihilisme propre à la modernité, plus particulièrement sur la manière dont le nihilisme est susceptible de gagner la littérature puisqu’il appert qu’il entre fortement en résonance avec l’univers durassien. La réflexion ne saurait s’en tenir à la sphère historique et elle investit nécessairement le champ philosophique. Le plus important néanmoins n’est peut-être pas tant de révéler le phénomène que de chercher à saisir comment l’œuvre se débat face au néant qui la guette et par conséquent résiste. Dès lors se fait jour un anti-nihilisme au sein de la littérature et la notion de sensible devient par là-même centrale. C’est en effet à une déperdition du sensible que l’on assiste quand le nihilisme se manifeste ; mais le sensible ne se borne pas à jouer le rôle d’un indicateur ; il est bien plus le principe permettant de combattre le néant. Par lui, le cogito brusquement se tait et l’empiétement, figure que notre analyse emprunte à Merleau-Ponty, advient ; par lui, l’intelligence se dérobe à l’intelligible, admet la contradiction et prend le large ; par lui, le désir, expression d’« un plus fort que », se trouve établi au fondement de l’homme, garant de son humanité ; par lui enfin la transcendance est ramenée vers l’immanence de façon qu’il devient possible d’envisager la métaphysique à partir de la chair. / The present thesis aims to examine the unique intelligence emerging in Marguerite Duras's works, and to showcase this, it encompasses a range of her writings including novels, plays, newspaper articles, scenarios and other essays. It takes into account the difficult heritage of the Shoah and Stalinism, and from the extreme dehumanisation that marked the 20th century, it questions itself on nihilism in relation to modernity, specifically the manner in which nihilism is likely to influence literature as it would appear that it is very much present in the Duras universe. The reflection doesn't just cover the historical aspect, it expands fundamentally into a philosophical dimension. The most important thing, however, is probably not so much to reveal the phenomenon but to try and understand how the works struggle to face the coming emptiness and therefore resists. From then on, anti-nihilism rises within literature and as a result, sensitivity becomes central. Indeed, a loss of sensitivity is observed when nihilism manifests itself, however, sensitivity is not just an indicator; it is rather the enabling principle to combat emptiness. With it, the cogito disappears suddenly and the encroachment, thought borrowed from Merleau-Ponty, appears. With it, intelligence shies away from the intelligible, admits contradiction and takes off. With it, desire, the expression of something beyond our control, establishes itself as the foundation of the human being, guaranteeing his humanity. With it finally, transcendence returns to immanence so that it becomes possible to consider metaphysics from the flesh.

No description available.

This study tested the performance of classification, regression, and ordination techniques to evaluate the spatiotemporal dynamics of threats to big sagebrush ecological sites. The research was focused on invasion by annual exotic grasses and encroachment by woodlands. We sought to identify those areas that have had a persistent coverage of cheatgrass (Bromus tectorum) in big sagebrush ecological sites. We took advantage of the contrast in greenness between multi-temporal (within one year) remotely sensed vegetation indices captured in the spring and summer to find a distinct phenological signature that allowed mapping cheatgrass. We utilized support vector machines (SVM) to classify three temporal scenarios for which field data sets were available. SVM performed very well with accuracies of 70% (producer's) and 95% (user's) for the class of interest (presence of cheatgrass). This was the focus of chapter 2. In chapter 3 we report the development of vegetation continuous fields (VCF) for three years of interest 1996, 2001, and 2007 in order to detect active woodland encroachment. We prepared VCF for shrubs, trees, herbaceous vegetation, and bare ground using a suite of remotely sensed spectral reflectance, vegetation indices, and transformations. We compared the performance of multivariate regression trees (MRT) and random forests (RF) to develop the VCF multi-temporal series. RF outperformed MRT in both accuracy and ability to appropriately map the continuum of percent cover across large landscapes. We estimate that 17,570 hectares of big sagebrush lands showed encroachment by woodlands. Our goal in chapter 4 was to develop a similarity index for large rangeland landscapes. Trend assessments field sites and a long-term annual series (1984 - 2008) of remotely sensed imagery were used in conjunction with multidimensional scaling (MDS) to measure ecological distance to undesired states such as invasion by exotic annuals and encroachment by woodlands. In this chapter our units of analysis were soil-mapping units, which were predominantly composed of one ecological site (>60%). Our MDS results show that different ecological sites can be identified in the reduced MDS statistical space. The observed transitions and trajectories of mountain, Wyoming, and basin big sagebrush sites correlated well with the ecological expectation in semiarid lands. We anticipate that managers can use our protocols to update ecological site descriptions and state and transition models from a remotely sensed perspective.

Thesis (M.Sc.)--University of Adelaide, Dept. of Geology and Geophysics, 2003. / Includes bibliographical references (leaves 112-115).

Increasing sea levels and anthropogenic disturbances have caused the world’s coastal vegetation to decline 25-50% in the past 50 years. Future sea level rise (SLR) rates are expected to increase, further threatening coastal habitats. In combination with SLR, the Everglades ecosystem has undergone large-scale drainage and restoration changing Florida’s coastal vegetation. Everglades National Park (ENP) has 21 coastal plant species threatened by SLR. My dissertation focuses on three aspects of coastal plant community change related to SLR and dehydration. 1) I assessed the extent and direction coastal communities—three harboring rare plant species—shifted from 1978 to 2011. I created a classified vegetation map and compared it to a 1978 map. I hypothesized coastal communities transitioned from less salt- and inundation-tolerant to more salt- and inundation-tolerant communities. I found communities shifted as hypothesized, suggesting the site became saltier and wetter. Additionally, all three communities harboring rare plants shrunk in size. 2) I evaluated invading halophyte (salt-tolerant) plant influence on soil salinity via a replacement series greenhouse experiment. I used two halophytes and two glycophytes (non-salt-tolerant) to look at soil salinity over time under 26 and 38‰ groundwater. I hypothesized that halophytes increase soil salinity as compared to glycophytes through continued transpiration during dry, highly saline periods. My results supported halophytic influence on soil salinity; however, not from higher transpiration rates. Osmotic or ionic stress likely decreased glycophytic biomass resulting in less overall plant transpiration. 3) I assessed the best plant life-stage to use for on-the-ground plot-based community change monitoring. I tested the effects of increasing salinity (0, 5, 15, 30, and 45‰) on seed germination and seedling establishment of five coastal species, and compared my results to salinity effects on one-year olds and adults of the same species. I hypothesized that seedling establishment was the most vulnerable life-stage to salt stress. The results supported my hypothesis; seedling establishment is the life-stage best monitored for community change. Additionally, I determined the federally endangered plant Chromolaena frustrata’s salinity tolerance. The species was sensitive to salinity >5‰ at all developmental stages suggesting C. frustrata is highly threatened by SLR.

Thesis (MSc. Agriculture (Pasture Science)) -- University of Limpopo, 2016. / The relationships between tree age, growth rings, and stem circumference correlated with establishment patterns may be a valuable instrument to reveal the functioning of woody species in the Savanna Biome. A study on tree age and establishment patterns of Acacia tortilis in the semi-arid regions of the Limpopo Province was conducted to aid an understanding of the causes of encroachment in savanna vegetation. This study aimed to determine the periodicity of growth ring formation at two study areas, correlate the number of growth rings with different tree characteristics and document tree population establishment patterns of Acacia tortilis, using stem circumferences. This was done in order to predict long-term bush encroachment using the interaction between rainfall and soil on the age, growth and establishment patterns of Acacia tortilis. Data was collected at three sites representing two study areas, two sites at the University of Limpopo’s Syferkuil Agricultural Experimental Farm and one site at the Sondela Nature Reserve in the Limpopo Province. The study incorporated two different soil forms and two rainfall regimes. Trees were divided into five height classes; namely, <0.5 m, >0.5 – 1.5 m, >1.5 – 2.0 m, >2.0 – 3.0 m and >3m. Fifty trees (ten in each class) were felled at each site, and the following recordings were made: tree height, stem circumference and crown diameter. Furthermore, each felled stump was taken to the laboratory and examined for growth rings. The results indicated that growth pattern of Acacia tortilis stems were more influenced by soil form than the amount of rainfall. Tree height was not significantly affected by soil form. However, rainfall proved to have a significant effect on the final height of the plant. Both rainfall and soil form did not have a substantial effect on the number of growth rings. Crown diameter was affected by soil form but rainfall did not prove to have the same effect. Correlations between growth rings and stem circumferences, tree height and crown diameter, proved to have significant relationships. However, the relationship between stem circumference and the number of growth rings was the most significant. iv A prediction model was created using the relationship between stem size and growth rings. Using this model tree age can be determined in a non-destructive manner. However, the absence of a correlation between rainfall and establishment strongly suggests that rainfall cannot be used, on its own, to determine the establishment sequence and the pattern of bush encroachment. The study suggests that natural developments responsible for establishment patterns and population dynamics of woody species are complex, and their effects are visible after an extensive period. Therefore, to understand these influential processes comprehensively, several seasons of observations and monitoring would be recommended. Future research on this particular topic should include more than one encroaching species, because this will provide a broader perspective on the encroachment patterns of bush communities. However, the focus should be on studying the influence of growth limiting factors such as soil and climatic impacts, as well as area-specific environmental factors on the growth of encroaching species, such as Acacia tortilis. Key words: Bush encroachment, dendrochronology, growth rings, tree age, savanna, stem circumference Note: The candidate and the supervisors are aware of the fact that the Acacia genus has been revised. However, in this dissertation, the genus and species Acacia tortilis is still used. Relevant changes will be used in future publications. / University of Limpopo’s Department of Agriculture and National Research Foundation