Tesis sobre el tema "Spatial variation"
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West, R. M. "Statistical aspects of spatial variation". Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382715.
Texto completoFik, Timothy Joseph. "Price variation in spatial oligopolies". Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184708.
Texto completoThrippleton, Michael Jonathan. "New NMR techniques employing spatial variation". Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616058.
Texto completoHunter, Sally E. "Spatial and temporal variation in contourite sedimentation : link to variations in palaeocirculation". Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/145875/.
Texto completoTopcu, Metin. "Spatial Variation Of Apartment Housing In Ankara". Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605726/index.pdf.
Texto completoand producers&rsquo
apartment housing choice. As a dominant housing provision type, apartment housing is produced every location in urban space in Ankara. Therefore the study begins with investigating the formation and growth of apartment housing in Ankara by introducing spatial variation of apartment housing. With the help of building and population censuses, distribution of 400 quarters in the Greater Ankara Municipality borders with respect to building and population density, building features, share of apartment housing and average number of storeys are analyzed. FAR values are calculated and analyzed from the CBD to western direction to introduce the change in building densities. Lastly a questionnaire survey is done to find out whether differentiation of building and environment attributes of apartment housing that are produced in different location of urban area are well-matched with their residents&rsquo
preferences. At the end of the analysis differentiation of housing structure of the city clearly comes out. While it is expected that the height of housing structure is decreasing by going far away from the CBD, it is found increasing along certain directions such as western and south-western. However by moving at western direction FAR decreases from 2 to 0,75 which states different characteristics of housing structure even if high average number of storey. As a result apartment housing provisions at different locations offer different lifestyles with their building and environmental characteristics.
Zhang, Wangyang. "IC Spatial Variation Modeling: Algorithms and Applications". Research Showcase @ CMU, 2012. http://repository.cmu.edu/dissertations/136.
Texto completoWalford, Hannah Louise. "Spatial and temporal variation of African epeirogeny". Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620082.
Texto completoLee, Ho Young. "Diagnosing spatial variation patterns in manufacturing processes". Diss., Texas A&M University, 2003. http://hdl.handle.net/1969/122.
Texto completoPhoenix, Joseph D. "Spatial Temperature Variation in Refrigerated Road Transport". DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4418.
Texto completoLau, Mandy Hang Man. "Spatial planning, meta-governance and sub-regional variation". Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608284.
Texto completoCrowder, David W. "Sampling spatial sediment variation in gravel-bed streams". Thesis, Virginia Tech, 1995. http://hdl.handle.net/10919/45064.
Texto completoMohamed-Ghouse, Mohamed Zaffar Sadiq. "Modeling spatial variation of data quality in databases /". Connect to thesis, 2008. http://repository.unimelb.edu.au/10187/3544.
Texto completoWoodward, Tim. "Variation in 'Hayward' kiwifruit quality characteristics". The University of Waikato, 2007. http://hdl.handle.net/10289/2640.
Texto completoNavarro, Toro Agustín Alfonso. "Angular variation as a monocular cue for spatial percepcion". Doctoral thesis, Universitat Politècnica de Catalunya, 2009. http://hdl.handle.net/10803/48632.
Texto completoLas señales monoculares son entradas sensoriales capturadas exclusivamente por un solo ojo que ayudan a la percepción de distancia o espacio. Son en su mayoría características estáticas que proveen información de profundidad y son muy utilizadas en arte gráfico para crear apariencias reales de una escena. Dado que la información espacial contenida en dichas señales son extraídas de la retina, la existencia de una relación entre esta extracción de información y la teoría de percepción directa puede ser convenientemente asumida. De acuerdo a esta teoría, la información espacial de todo le que vemos está directamente contenido en el arreglo óptico. Por lo tanto, esta suposición hace posible el modelado de procesos de percepción visual a través de enfoques computacionales. En esta tesis doctoral, la variación angular es considerada como una señal monocular, y el concepto de percepción directa adoptado por un enfoque basado en algoritmos de visión por computador que lo consideran un principio apropiado para el desarrollo de nuevas técnicas de cálculo de información espacial. La información espacial esperada a obtener de esta señal monocular es la posición y orientación de un objeto con respecto al observador, lo cual en visión por computador es un conocido campo de investigación llamado estimación de la pose 2D-3D. En esta tesis doctoral, establecer la variación angular como señal monocular y conseguir un modelo matemático que describa la percepción directa, se lleva a cabo mediante el desarrollo de un grupo de métodos de estimación de la pose. Partiendo de estrategias convencionales, un primer enfoque implanta restricciones geométricas en ecuaciones para relacionar características del objeto y la imagen. En este caso, dos algoritmos basados en el análisis de movimientos de rotación de una línea recta fueron desarrollados. Estos algoritmos exitosamente proveen información de la pose. Sin embargo, dependen fuertemente de condiciones de la escena. Para superar esta limitación, un segundo enfoque inspirado en los procesos biológicos ejecutados por el sistema visual humano fue desarrollado. Está basado en el propio contenido de la imagen y define un enfoque computacional a la percepción directa. El grupo de algoritmos desarrollados analiza las propiedades visuales suministradas por variaciones angulares. El propósito principal es el de reunir datos de importancia con los cuales la información espacial pueda ser obtenida y utilizada para emular procesos de percepción visual mediante el establecimiento de relaciones métricas 2D- 3D. Debido a que dicha relación es considerada fundamental en la coordinación visuomotora y consecuentemente esencial para interactuar con lo que nos rodea, un efecto cognitivo significativo puede ser producido por la aplicación de métodos de L estimación de pose en entornos mediados tecnológicamente. En esta tesis doctoral, este efecto cognitivo ha sido demostrado por un estudio experimental en el cual un número de participantes fueron invitados a ejecutar una tarea de acción-percepción. El propósito principal de este estudio fue el análisis de la conducta guiada visualmente en teleoperación y el efecto cognitivo causado por la inclusión de información 3D. Los resultados han presentado una influencia notable de la ayuda 3D en la mejora de la habilidad, así como un aumento de la sensación de presencia.
Huang, Fang. "Modeling patterns of small scale spatial variation in soil". Link to electronic thesis, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-011106-155345/.
Texto completoKeywords: spatial variations; nested random effects models; semivariogram models; kriging methods; multiple logistic regression models; missing; multiple imputation. Includes bibliographical references (p. 35-36).
Rossouw, Marius Wilhelmus. "Spatial variation in plant nutrient composition on Marion Island". Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86405.
Texto completoENGLISH ABSTRACT: To estimate nutrient budgets and model nutrient cycling at a whole ecosystem level on sub-Antarctic Marion Island requires information on the spatial variability of plant nutrient concentrations on the island. The complexity of constructing budgets and models will also be reduced if, instead of considering each plant species individually, the species can be grouped on the basis of their similarities/differences in nutrient concentrations. This thesis presents the results of an investigation into both these aspects. Altitude and distance from the sea are highly correlated with each other and thus influence the concentrations of all the nutrients considered (N, P, K, Ca, Mg and Na) very similarly. Concentrations of N, P and Na in living leaves, dead leaves, stems and roots decrease going inland, due to a decline in the influence of animal manuring and of sea spray. Ca concentration increases going inland, away from the organic peats characteristic of the lowland regions toward the mineral rawmark inland soils. Declining sea spray and increasing soil minerality going inland both affect plant Mg concentration; the net effect is a slight decrease in Mg concentration going away from the coast. K concentration in living leaves and roots did not change going inland; dead leaf and stem K concentrations showed a weak decline. Bryophyte shoot nutrient concentrations do not show such marked patterns of change going inland. Considering the bryophyte species as a whole, the only significant effect is that shoot Na concentration decreases, and Ca concentration increases, going inland. Although information on nutrient concentrations in all plant organs from all four (N, E, W and S) sides of the island was available for only a few species, and in many instances the between-side effect was not significant for individual species, the pattern of between-side differences is quite clear. Living leaf N, P and Mg concentrations are higher in west side than east side plants, with south and north side plants having intermediate concentrations. Leaf K concentrations are highest on the north and lowest on the west side, with east and south side concentrations being intermediate. Leaf Ca concentrations are highest on the south side and lowest on the north side, with east and west side Ca concentrations being intermediate. Leaf Na concentration declines more sharply with distance inland on the island's western and southern sides than on its eastern and northern sides, so that closer than 450 m from the shore leaf Na concentration is higher on the west and south than on the east or north sides, but further inland than that the difference lessens. There was sufficient information for dead leaf, stem and root nutrient concentrations only for the west and east sides of the island. West-east differences in nutrient concentrations of dead leaves are the same as for living leaves. Stem and root west-east concentration differences are also similar to those for living leaves, except for P and Mg concentrations, which were similar on the two sides. All organs showed the same steeper decline in Na concentration on the west than on the east side of the island. Bryophytes show somewhat different between-side nutrient concentration patterns to the vascular plants. South side (not west) bryophytes have highest N and P concentrations but, like for the vascular plants, east side bryophytes have the lowest N and P concentrations. Also similar to the vascular plants, bryophyte K concentration is highest on the north side and lowest on the west side, although south side concentrations are nearly as high as the north side ones. Unlike the vascular plant leaves, bryophyte Mg concentration is highest on the south (not west) side and lowest on the north (not east) side, with east and west side concentrations being intermediate. South side bryophytes have highest Ca and Na concentrations, similar to the vascular plant pattern. Ordination and clustering analyses of leaf nutrient concentrations suggested five nutrient type clusters amongst the island's plant species. The clusters differ in the amount (low, moderate or high) of N, P, K and Na versus the amount of Ca and Mg. Species membership of the clusters is strongly related to what major taxonomic group (bryophyte, pteridophyte, monocot or dicot) the species belongs to, but habitat factors, especially the intensity of animal manuring, also play a role. Plant guilds compiled previously for the island and which have been suggested might prove useful for modeling nutrient standing stocks on a whole island basis associate poorly with the clusters. Where a particular guild does associate closely with a cluster it is mostly an effect of taxonomic group (the guild members are all from a single taxonomic group) or habitat (the guild members are typical for a particular habitat). It is suggested that in order to reduce the complexity and arduousness of constructing whole island plant nutrient standing stock budgets, the species should be grouped according to their taxonomy – as bryophytes, dicots, monocots, club mosses or pteridophytes (the ferns proper). Subgroups of these taxonomic groups can be constructed on the basis of habitat. Mostly, this will be necessary to distinguish plants from manured habitats from plants of the same species from unmanured ones.
AFRIKAANSE OPSOMMING: Ten einde die voedingstofvoorrade en modelvoedingstofsiklus op die sub-Antarktiese Marioneiland op 'n algehele ekosisteemvlak te raam, word inligting oor die ruimtelike variasie in plantvoedingstofkonsentrasies op die eiland benodig. Die raming van voorrade en die konstruksie van modelle sal ook minder ingewikkeld wees indien plantspesies op grond van hul ooreenkomste/verskille in voedingstofkonsentrasies gegroepeer word eerder as om elke spesie individueel te beskou. Hierdie tesis bied 'n uiteensetting van die ruimtelike variasie (hoogte, afstand van die see én kant van die eiland) in die chemiese samestelling (N, P, K, Ca, Mg en Na) van plante, en probeer die plantspesies op grond daarvan in voedingstoftipes klassifiseer. Hoogte en afstand van die see is nou verwant en beïnvloed dus voedingstofkonsentrasies op feitlik dieselfde manier. N-, P- en Na-konsentrasies in lewende blare, dooie blare, stingels en wortels neem af in die rigting van die binneland weens 'n afname in die invloed van dierebemesting en seesproei. Ca-konsentrasies styg weer namate daar vanaf die organiese veengrondkenmerke van die laagliggende streke na die mineraalryke binnelandse grond beweeg word. Sowel die afname in seesproei as die toename in grondmineraalgehalte in die rigting van die binneland beïnvloed die Mg-konsentrasie in plante; die netto uitwerking is 'n effense afname in Mg-konsentrasie namate daar wegbeweeg word van die kus. Die K-konsentrasie in lewende blare en wortels verander nie in die rigting van die binneland nie, terwyl dié in dooie blare en stingels 'n geringe afname toon. Die voedingstofkonsentrasies in briofietspruite toon egter nie dieselfde merkbare veranderingspatrone in die rigting van die binneland nie. Wat die briofietspesie in die geheel betref, is die enigste beduidende uitwerking dat die Na-konsentrasie in spruite afneem en die Ca-konsentrasie toeneem namate daar na die binneland beweeg word. Die N-, P- en Mg-konsentrasies in lewende blare is hoër by plante in die weste as in die ooste van die eiland, en plante in die suide en noorde toon tussenkonsentrasies. K-konsentrasies in blare is die hoogste in die noorde en die laagste in die weste, met tussenkonsentrasies in die ooste en suide. Ca-konsentrasies in blare is weer die hoogste in die suide en die laagste in die noorde, met tussenkonsentrasies in die ooste en weste. Aan die weste- en suidekant van die eiland toon Na-konsentrasies in blare 'n skerper afname namate daar verder van die see beweeg word as aan die ooste- en noordekant. Verskille in die voedingstofkonsentrasies van dooie blare in die weste en ooste is dieselfde as vir lewende blare. Konsentrasieverskille in stingels en wortels in die weste en ooste is ook soortgelyk aan dié in lewende blare, buiten P- en Mg-konsentrasies, wat dieselfde was aan albei kante. Alle plantorgane toon dieselfde skerper afname in Na-konsentrasies in die weste as in die ooste van die eiland. Die voedingstofkonsentrasiepatrone tussen die verskillende kante van die eiland was ietwat anders vir briofiete as vir vaatplante. Briofiete in die suide (nie die weste nie) het die hoogste N- en P-konsentrasies. Soos die vaatplante, het die briofiete in die ooste die laagste N- en P-konsentrasies. Óók soortgelyk aan die vaatplante, is die K-konsentrasie van briofiete die hoogste in die noorde en die laagste in die weste, hoewel konsentrasies in die suide bykans so hoog is as dié in die noorde. In teenstelling met die blare van vaatplante, is die Mg-konsentrasie van briofiete die hoogste in die suide (nie die weste nie) en die laagste in die noorde (nie die ooste nie), met tussenkonsentrasies in die ooste en weste. Briofiete in die suide het die hoogste Ca- en Na-konsentrasies, wat weer ooreenstem met die vaatplantpatroon. Ordinasie- en trosvormingsontledings van voedingstofkonsentrasies in blare dui op vyf voedingstoftipes onder die plantspesies op die eiland, op grond van die (klein, matige of groot) hoeveelheid N, P, K en Na teenoor die hoeveelheid Ca en Mg. Die klas waartoe 'n spesie behoort, hou sterk verband met sy hoof- taksonomiese groep (briofiet, pteridofiet, monokotiel of dikotiel), hoewel habitatfaktore (veral die intensiteit van dierebemesting) ook 'n rol speel. Die plantgildes wat voorheen vir die eiland opgestel is, toon weinig ooreenkoms met die klasse wat uit hierdie studie na vore kom.
Jiménez, Aguilera Helia Isabel. "Spatial variation of cyanobacteria in the Gulf of Bothnia". Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-171698.
Texto completoNordström, Jonas. "Temporal and spatial variation in predation on roe deer fawns /". Uppsala : Dept. of Ecology, Swedish University of Agricultural Sciences, 2010. http://epsilon.slu.se/201006.pdf.
Texto completoReverté, Saiz Sara. "Spatial variation in plant-pollinator relationships: consequences on pollination function". Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/669527.
Texto completoLos patrones de variabilidad espacial en comunidades naturales han sido habitualmente estudiados en escalas espaciales grandes, comparando hábitats, donde la distribución de especies está básicamente relacionada con factores ambientales. Aun así, dentro de un hábitat es posible encontrar variabilidad espacial a pequeña escala. La variación en la ocurrencia y abundancia de las especies a lo largo del espacio afectará la estructura de las interacciones ya que las diferentes especies varían en sus características y en el nombre e identidad de las especies con quien pueden interactuar. La variabilidad espacial en las comunidades puede tener también consecuencias ecológicas y evolutivas ya que la variación en la distribución de las especies afecta el funcionamiento de los ecosistemas. La polinización es un proceso clave en los ecosistemas terrestres, donde al menos el 90% de las especies de angiospermas dependen de la polinización por animales. El objetivo general de esta tesis es analizar la relación entre la estructura de las comunidades planta-polinizador, la función ecosistémica y los patrones de interacción a lo largo del espacio. Primero, queremos ver el grado de variabilidad espacial a escala local en una comunidad planta-polinizador en un hábitat uniforme y entender los factores que afectan dicha variabilidad. Con tal objetivo analizamos la heterogeneidad espacial de una comunidad de plantas y sus polinizadores en un matorral mediterráneo. Mostramos que, a pesar de la aparente uniformidad, tanto flores como polinizadores muestran unos elevados niveles de variabilidad resultando en un mosaico de comunidades locales. Los recursos no son limitantes, y la abeja de la miel no afecta la distribución de las comunidades de polinizadores silvestres. En general mostramos que la variabilidad en la comunidad floral no es el mayor predictor de la comunidad de polinizadores, indicando que otros factores son más importantes para explicar la distribución de los polinizadores a escala local. Segundo, aprovechamos la variabilidad espacial en la comunidad de polinizadores en el mismo matorral mediterráneo y analizamos los efectos en la función polinizadora y el éxito reproductivo de la especie ginodioica Thymus vulgaris. La deposición de polen se ve afectada por la estructura de la comunidad de polinizadores en los dos morfos, pero no hemos encontrado efectos de los polinizadores en el éxito reproductivo de ninguno de los dos morfos indicando que la polinización es adecuada en la mayoría de poblaciones estudiadas. Nuestro estudio muestra que la variabilidad local en la composición de los polinizadores puede tener consecuencias importantes en la función polinizadora, especialmente en las plantas que son más dependientes de los polinizadores. Finalmente estudiamos si hay una relación entre las características florales y las visitas de los polinizadores en comunidades naturales, centrándonos en el color. Aunque los polinizadores presentan preferencias de color innatas, la idea de que el color de la flor puede ser un predictor importante de sus principales polinizadores es muy controvertida ya que la elección de flor es dependiente del contexto. Encontramos asociaciones consistentes entre grupos de polinizadores y ciertos colores, y estas asociaciones coinciden con las predichas por la teoría de los síndromes de polinización. Aun así, las flores con colores similares no atraen ensamblajes de polinizadores similares. La explicación de este resultado paradójico seria que la mayoría de especies de flores son generalistas. Vemos que a pesar de que las preferencias de color de los polinizadores parece que condicionen las interacciones planta-polinizador, las fuerzas selectivas bajo estas preferencias no son suficientemente fuertes como para mediar la aparición y mantenimiento de asociaciones estrechas entre plantas y sus polinizadores basadas en el color.
Patterns of spatial variation in species communities have been usually studied at large spatial scales, comparing different habitats, where the distribution of species is mostly related to environmental factors. However, even within a habitat is possible to find important levels of spatial variability at the local scale. Variability in species occurrence and abundance across space will affect interaction structure because species differ in their functional traits and therefore in the number and identity of species with which they may interact. Furthermore, within-habitat spatial heterogeneity in species community structure may have far-reaching ecological and evolutionary consequences because variability in the spatial distribution of the species affects the functioning of ecosystems. Pollination is a key function in terrestrial ecosystems, with almost 90% of the angiosperm species depending on animal pollinators for sexual reproduction. The general objective of this thesis is to analyze the relationship between plant-pollinator community structure, ecological function, and interaction patterns across space. First, we aim to highlight the degree of spatial variation at the local scale in a plant-pollinator community across a uniform habitat and to understand the deterministic factors affecting this variation. For this purpose we analyse the spatial heterogeneity of a community of flowering plants and their pollinators within an uninterrupted Mediterranean scrubland. Also, since the study area is a honey producing area we want to know whether wild pollinator communities were affected by honey bee abundance. We show that, in spite of the apparent physiognomic uniformity, both flowers and pollinators display high levels of heterogeneity, resulting in a mosaic of idiosyncratic local communities. Resources appear to be non-limiting, and honey bee visitation rate did not affect the distribution of the wild pollinator community. Overall, our results show that the spatial variation of the flower community is not the main predictor of the pollinator community, indicating that other factors besides flower community composition are important to explain pollinator distribution at the local scale. Second, we take advantage of the spatial variability in local pollinator community across the same Mediterranean scrubland and analyse its effects on pollination function and reproductive success in the gynodioecious Thymus vulgaris. Pollen deposition is affected by pollinator assemblage structure and composition in both morphs, but we found no effect of the pollinator assemblage on plant reproductive success in either of the two morphs, showing that pollination appears to be adequate in most of the populations sampled. Our study shows that local variation in pollinator composition may have important consequences on pollination function, especially on plants that are more dependent on pollinators. Finally, we aim to establish whether there is a relationship between floral traits and pollinator visitation in natural communities, specifically focusing on floral colour. Although pollinators show innate colour preferences, the view that the colour of a flower may be considered an important predictor of its main pollinators is highly controversial because flower choice is highly context-dependent. We found consistent associations between pollinator groups and certain colours, and these associations matched predictions of the pollination syndrome theory. However, flowers with similar colours did not attract similar pollinator assemblages. The explanation for this paradoxical result is that most flower species are pollinator generalists. We conclude that although pollinator colour preferences seem to condition plant-pollinator interactions, the selective force behind these preferences has not been strong enough to mediate the appearance and maintenance of tight colour-based plant-pollinator associations.
Henriksen, Snorre. "Spatial and temporal variation in herbivore resources at northern latitudes". Doctoral thesis, Norwegian University of Science and Technology, Department of Biology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1877.
Texto completoHerbivores may affect plants directly through foraging, trampling and fertilization or indirectly through altered competitive relationships between plant species. In addition, herbivores may cause indirect interactions between species that do not compete for the same resources, but are object to grazing from a shared herbivore. A reintroduction of a large herbivore, the Svalbard reindeer (Rangifer tarandus platyrhynchus), was found to generate a strong trophic top-down effect on the vegetation, including a reduction in cover of mosses, vascular plants and lichens. This supports the “exploitation ecosystem hypothesis”. This caused a reduction in reindeer carrying capacity K and sustained reduction in herbivore densities. Plant groups differed in the rate of recovery after the reindeer population peak, and lichens did not show any sign of recovery. Consequently, the irruption caused a shift in the composition of the vegetation.
In addition to top-down effects of herbivores on plants, plant-herbivore interactions may work through variation in foraging resources caused by variation in environmental conditions. We investigated which climatic variables were able to explain local growth of two long-lived evergreen plant species Cassiope tetragona and juniper (Juniper communis), sampled over a large geographic area at Svalbard and Finnmark (Norway), respectively. Both species responded positively to high summer temperatures. C. tetragona growth was also negatively related to the summer Arctic Oscillation (AO) index and number of overcast days in July. Juniper growth was positively associated with a high winter AO, September temperature and precipitation. Juniper growth was positively correlated with a rapid phenological development and high net primary production (measures derived from satellite images), growing conditions that are generally recognised to decrease nutritional value of plants as forage for ungulates. Juniper with high average growth responded more to high a winter AO/NAO, summer temperature and derived spring NDVI than plants with low average growth. We found that juniper was able to capture important environmental factors and can thus be used as a proxy for foraging conditions.
Because temporal variation in climate affects plants at both temporal and spatial scales, it may cause synchronised population growth rates among plants and subsequently ungulate populations over large distances. We analysed whether growth of C. tetragona and juniper was correlated among localities and to what extent this correlation decreased with distance was performed. In addition, we analysed which climatic variables could be capable of generating synchronised growth. The spatial synchrony was high over large areas for C. tetragona. However, which climatic variable caused this synchrony was not possible to identify. The spatial correlation in juniper growth was on the other hand low and even increased slightly with increasing distance.
Body growth in ungulates is influenced by both demographic and environmental variability. The effect of demographic stochasticity is density dependent. Autumn body mass (measured as carcass weight) of semi-domesticated reindeer calves (R. t. tarandus) in Finnmark, northern Norway, was negatively affected by high population density. Furthermore, there was a negative relationship between calf body mass and unfavourable winter conditions (mainly through heavy snow accumulation), whereas body mass was positively associated with slow plant development during summer. Accounting for the within-herd variation in population density did not affect the relationship between environment variables and body mass to any extent. There was a negative relationship between calf body mass and juniper growth, indicating that juniper can capture environmental variation of importance for reindeer growth. Accounting for both density and juniper growth resulted in several changes in how environmental variables affected reindeer body mass, but still the general impression of negative effects of snow rich winters persisted.
Global climate is warming rapidly. One result of the change in global climate is the frequency of periods with temperature above 0°C during winter will increase in arctic regions. If above zero temperatures are combined with precipitation, this can cause formation of ground-ice or crusty, hard snow. This will directly affect forage availability for herbivores, but little is known about how it may affect plant species of importance for herbivores. We experimentally constructed ground-ice during early winter on high arctic heath vegetation to simulate the effect of an icing event on plant performance. Growth response of a small willow (Salix polaris) and a rush (Luzula confusa) was measured the following summer. Both species showed some response to icing. S. polaris that had been subject to experimental icing, showed increased growth later in season compared to the control groups. L. confusa showed a weak negative response throughout the summer to the experimental icing event.
Fliflet, Henrik Rasmussen. "Spatial and Temporal Variation in Moose- (Alces alces) Road Crossings". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for biologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19950.
Texto completoXing, Zhoujue. "Phase ambiguity reduction using spatial variation for two-dimensional navigation". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0021/MQ54761.pdf.
Texto completoInward, Kelly A. "Temporal and spatial variation in soil macrofauna of UK woodlands". Thesis, University of Reading, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553048.
Texto completoOldroyd, Alexander. "The spatial variation of diagnosis of osteoporosis in Morecambe Bay". Thesis, Lancaster University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.662194.
Texto completoPrice, Oliver Richard. "Spatial variation in pesticide/soil interactions at the field scale". Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409062.
Texto completoBaxter, Samantha Jayne. "The spatial variation of plant-available nitrogen within arable fields". Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272260.
Texto completoThickstun, Charles Russell. "Spatial Variation in Risk Factors for Malaria in Muleba, Tanzania". Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39082.
Texto completoPandit, Kavita K. "Temporal and spatial variation in sectoral labor allocation during development /". The Ohio State University, 1988. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487332636477126.
Texto completoBenitez, Lionel Ernesto Donatti. "SPATIAL VARIATION OF PHYSICAL PROPERTIES IN AN IRRIGATED FIELD (ARIZONA)". Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275402.
Texto completoRollins, Sarah. "The Salt Lake Tabernacle : acoustic characterization and study of spatial variation /". Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd1113.pdf.
Texto completoKing, Rachel y n/a. "Spatial Structure and Population Genetic Variation in a Eucalypt Species Complex". Griffith University. Australian School of Environmental Studies, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20050113.091713.
Texto completoWidén, Britta. "CO₂ exchange within a Swedish coniferous forest : spatial and temporal variation /". Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2001. http://epsilon.slu.se/avh/2001/91-576-6068-9.pdf.
Texto completoLinnerud, Marit. "Patterns in spatial and temporal variation in population abundances of vertebrates". Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for biologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-21308.
Texto completode, Roij Job. "Spatial variation in host-parasite interactions in the three-spined stickleback". Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/11993/.
Texto completoAteljevich, Eli Sava. "Seasonal variation and spatial organization of hydrologic fluxes over complex topography". Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/37015.
Texto completoMetcalfe, Helen. "Modelling the spatial variation in Alopecurus myosuroides for precision weed management". Thesis, University of Reading, 2017. http://centaur.reading.ac.uk/76006/.
Texto completoPastok, Daria. "Causes of spatial variation in parasite and pathogen pressure in insects". Thesis, University of Liverpool, 2015. http://livrepository.liverpool.ac.uk/2029362/.
Texto completoPantastico, Marissa Capistrano. "Competition in desert winter annuals: Effects of spatial and temporal variation". Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185362.
Texto completoKing, Rachel. "Spatial Structure and Population Genetic Variation in a Eucalypt Species Complex". Thesis, Griffith University, 2004. http://hdl.handle.net/10072/365496.
Texto completoThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
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Frogbrook, Zoe Louise. "Geostatistics as an aid to soil management for precision agriculture". Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314311.
Texto completoLloyd, Christopher David. "Non-stationary models for optimal sampling and mapping of terrain in Great Britain". Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323957.
Texto completoFranklin, Hannah Mayford. "Understanding Variation in Water Quality using a Riverscape Perspective". Thesis, University of Canterbury. Biological Sciences, 2010. http://hdl.handle.net/10092/5197.
Texto completoWilliamson, Laura. "Spatio-temporal variation in harbour porpoise distribution and activity". Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=239337.
Texto completoPowers, Sean D. Anderson Roger A. "How does spatial variation in climate cause spatiotemporal patterns in lizard energetics? /". Online version, 2010. http://content.wwu.edu/cdm4/item_viewer.php?CISOROOT=/theses&CISOPTR=346&CISOBOX=1&REC=7.
Texto completoSegers, Magrieta. "Spatial variation of coke quality in the non-recovery beehive coke ovens". Diss., Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-02082006-154944.
Texto completoTemnerud, Johan. "Spatial Variation of Dissolved Organic Carbon along Streams in Swedish Boreal Catchments". Doctoral thesis, Örebro University, Institutionen för naturvetenskap Department of Natural Sciences, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-116.
Texto completoDenna avhandling behandlar den småskaliga rumsliga variationen av löst organiskt kol (DOC, engelsk term: dissolved organic carbon), dess koncentration, masstransport och karaktär, i bäckar inom två barrskogsbeklädda avrinningsområden (delavrinningsområden 0,01-78 km²). Provtagningen gjordes uppströms och nedströms varje bäckförgrening under sommarbasflöde. Koncentrationen av DOC varierade inom en tiopotens (4-66 mg/l), liksom flera andra kemiska parametrar. Vid riksinventeringen av vattendrag för 2000 i norra Sverige noterades en snarlik spännvidd. Enligt Naturvårdverkets bedömningsgrunder för sjöar och vattendrag återfanns alla tillståndsklasser för DOC och pH, samt mänsklig påverkansgrad till försurningen inom de två studerade områdena. Den specifika avrinningen (flöde per areaenhet) varierade kraftigt i källflödena och inverkade på deras bidrag till kemin nedströms. Vattenkemin och specifika avrinningen var stabila i delavrinningsområden större än 15 km². Det kan vara nödvändigt att provta så stora områden om generella värden för landskapet önskas, men källflödenas kemi kommer då inte att kunna karakteriseras, ehuru källflödena utgör den största delen av bäcksträckan och det akvatiska ekosystemet.
Nedströms är DOC-koncentrationen, och många andra kemiska parametrar, lika med summan av bidragen från källflödena och nedströms utspädning av inflödande vatten. Tillkommer gör processer inom bäcken och vattnets utbyte med botten/grundvatten (den hyporheiska zonen), men även DOC-förluster/transformationer vid vissa bäckförgreningar och sjöar. Ovanstående resonemang förklarade bäckvattenkemins minskande variation och vanligen lägre DOC-koncentrationer nedströms i ett landskapsperspektiv. Längs bäcksträckorna observerades ingen generell minskning av DOC-koncentration eller ändring av dess karaktär. Skillnaden i DOC-koncentration och relaterade parametrar mellan källflöden och nedströms styrdes i hög grad av vilka landskapselement (myrar, sjöar och skogsmark) som vattnet hade passerat innan det hamnade i bäckarna, samt samspelseffekter med den specifik avrinningen och platserna med DOC-förlust. Prognoser med multivariata modeller baserade på kartinformation testades men kunde inte förutsäga det rumsliga mönstret eller DOC-koncentrationen med erforderlig precision.
Lämpliga rutiner inom miljöövervakningen för att övervaka den rumsliga variationen av kemin i ytvatten saknas alltjämt. Vid planering av terrestra och akvatiska skötselåtgärder bör man beakta bäckvattnets naturliga kemiska variation.
This thesis quantifies the small-scale spatial variation of dissolved organic carbon (DOC) concentrations, fluxes and character in two boreal catchments (subcatchments 0.01-78 km²) using ”snapshots” of summer base flow where samples were taken upstream and downstream from every node in the stream network. An order of magnitude variation was found in DOC-concentrations, and many other chemical parameters. The range was similar to that found in all of northern Sweden by the national stream survey in 2000. According to the official assessment tools used in Sweden, the entire range of environmental status for DOC, pH and human acidification influence existed within these two study catchments. A large variability in specific discharge had a major impact on the contribution of headwaters to downstream chemistry. The water chemistry parameters were relatively stable at catchment areas greater than 15 km². Sampling at that scale may be adequate if generalised values for the landscape are desired. However the chemistry of headwaters, where much of the stream length and aquatic ecosystem is found would not be characterized.
Downstream DOC-concentrations, as well as many other chemical parameters, are the sum of headwater inputs, in combination with progressive downstream dilution by inflowing water with its own DOC-concentration and character. Superimposed upon this are in-stream and hyporheic processes, as well as discrete loci of DOC loss/transformation at lakes and stream junctions. At the landscape scale, this results in a decreased downstream variation in stream water chemistry and often, but not necessarily, lower average DOC-concentrations. Along stream reaches there was not a loss of DOC-concentration or a consistent change in character. While the importance of in-stream/hyporheic processes that consistently alter DOC-concentrations along the channel network cannot be ruled out, the differences between headwater and downstream DOC-concentrations and related parameters depend largely on the mosaic of landscape elements (mires, lakes and forest soil) contributing water to the channel network, combined with patterns of specific discharge and discrete loci of DOC loss. Assessment would be facilitated by map information that could predict spatial patterns. Multivariate models using maps, however, did not give satisfactory predictions.
Appropriate procedures for dealing with spatial variation in the environmental assessment of surface waters are not yet established. An awareness of stream water chemistry’s natural spatial variability should be considered when planning aquatic and terrestrial management.
P, Hunt Leigh. "Spatial variation in the population dynamics of Atriplex vesicaria under sheep grazing /". Title page, contents and summary only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phh9412.pdf.
Texto completoTzala, Evangelia. "Multivariate analysis of spatial and temporal variation in cancer mortality in Greece". Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415589.
Texto completoYau, Monica M. "Hybridization in western trout : spatial variation and the role of environmental factors". Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45527.
Texto completoWatson, Sally. "Spatial variation in agricultural research, with particular reference to spaced plant experiments". Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282342.
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