Дисертації з теми "Spatial distribution of trophic resources"
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1
Lérault, Louise. "Impact de l'arrangement spatial des cultures associées sur la distribution des ressources trophiques pour les parasitoïdes et le contrôle biologique des pucerons." Thesis, Rennes, Agrocampus Ouest, 2022. http://www.theses.fr/2022NSARA090.
Анотація:
La distribution hétérogène des ressources trophiques dans l’environnement des organismes influence leurs patrons d’exploitation.Les agroécosystèmes ont une structuration spatiale marquée des ressources trophiques essentielles aux parasitoïdes, à savoir les hôtes et la nourriture sucrée.L’association d’une culture non productrice de nectar avec une culture nectarifère est un modèle intéressant pour étudier l’influence de l’apport de ressources trophiques au sein des parcelles,et pourrait favoriser le service écosystémique de régulation des ravageurs par les parasitoïdes. Ces cultures associées peuvent être agencées selon différents arrangements spatiaux, qui font varier la distribution spatiale des ressources.Dans la cadre de cette thèse, nous explorons l’influence de la distribution spatiale des ressources trophiques dans les cultures associées sur le comportement alimentaire des parasitoïdes et le parasitisme des pucerons.Dans un premier temps, nous étudions l’influence de la distance entre hôtes et nectar sur l’alimentation et le parasitisme de femelles Aphidius ervi. Nous observons que la présence d’hôtes influence la fréquence d’alimentation mais pas le taux de parasitisme. Dans un second temps, nous explorons la complémentarité potentielle entre l’apport d’hôtes alternatifs et de nectar et la portée spatiale de cet aménagement en inter-rang en verger. Nous n’observons pas d’effet de l’apport de chaque ressource ni de la combinaison des deux sur le parasitisme des pucerons. Enfin, nous étudions l’effet du mode d’arrangement spatial d’une association céréale-légumineuse, et le comparons avec une culture pure de céréale. Nous observons un effet opposé de l’association culturale sur les populations de pucerons selon la culture, avec moins de pucerons en association sur la légumineuse et plus sur la céréale dans les arrangements fins, mais sans lien avec l’activité des parasitoïdes. Nos résultats ne permettent pas de confirmer l’effet bénéfique des cultures associées sur le contrôle biologique des pucerons par les parasitoïdes. Déterminer les conditions environnementales de disponibilité de ressources dans lesquelles l’apport de nectar pourrait avoir un impact et la portée spatiale d’aménagement à une échelle plus large, permettrait peut-être d’expliquer cette absence d’effet de l’approvisionnement en ressources trophiques pour les parasitoïdesThe heterogeneous distribution of trophic resources in the environment of organisms influences their exploitation patterns. Agroecosystems have a marked spatial structuring of trophic resources that are essential to parasitoids, namely hosts and sugar-rich food. Intercropping a nectariless crop with a nectariferous crop is an interesting model to study the influence of the provision of trophic resources within plots, and could promote the ecosystem service of pest regulation by parasitoids. Intercrops can be distributed according to different spatial arrangements, which change the spatial distribution of parasitoid resources. In this PhD thesis, we explore the influence of the spatial distribution of trophic resources in intercrops on the feeding and parasitism behaviours of aphid parasitoids. First, we study the influence of the distance between hosts and nectar on the feeding and parasitism of Aphidius ervi females.We observe that the presence of hosts influences the feeding frequency but not the parasitism rate. Secondly, we explore the potential complementarity between providing alternative hosts and nectar along with the spatial range of their effect in an orchard. We do not observe any effect of the provision of each resource separately nor the combination of both on aphid parasitism. Finally, we study the effect of spatial arrangement of a cereal-legume intercropping system, and compare it with a cereal single crop. We observe an opposite effect of intercropping on aphid populations depending on the intercrop, with fewer legume aphids but more cereal aphids in the fine arrangements intercropping plots, and without a clear relation with parasitoid activity. Our results do not confirm the beneficial effect of intercrops on the biological control of aphids by parasitoids. Determining the environmental conditions of resource availability and its spatial range in which supplying nectar or alternative hosts could have an impact on a larger scale is required to explain the lack of effect of providing trophic resources for parasitoids
2
Desta, Assefa, and Aregai Tecle. "Modeling Spatial and Temporal Distribution of Precipitation in an Arizona Ponderosa Pine Forest Ecosystem." Arizona-Nevada Academy of Science, 2006. http://hdl.handle.net/10150/296643.
3
Huang, Jie. "Spatial and Temporal Analysis of Fecal Coliform Distribution in Virginia Coastal Waters." W&M ScholarWorks, 2011. https://scholarworks.wm.edu/etd/1539616702.
Анотація:
The collection of fecal coliform (FC) monitoring data in shellfish growing waters is primarily to assess public health risks from consumption of contaminated product. The data is also commonly used to assess the potential sources and loads of bacteria entering the aquatic system. This project is intended to extend traditional methods of developing these assessments, by applying an inverse modeling approach to improve the estimation of FC loads in the small watersheds typically contributing to shellfish growing waters in Virginia. Many fecal contamination studies in lower Chesapeake Bay, Virginia, have conveniently focused on analyses over relatively small spatial and temporal scales. The potential sources of bacteria are numerous and the magnitude of their contributions is commonly unknown (Hyer and Moyer, 2004). The effects of stochastic events merely complicate the already difficult task of quantifying sources and loads in an inherently variable system (White et al., 2008). Instead of identifying and quantifying individual fecal bacteria sources, like deer or raccoons or domestic animals, it is herein proposed to analyze spatial and temporal patterns of fecal contamination on relatively large scales and quantify FC loadings based on land cover. The result would make it easier for managers to assign land-cover-based accountability to restore fecal contaminated environments. Monitoring of FC concentrations throughout Virginia by the Division of Shellfish Sanitation (DSS) provided an opportunity to analyze FC levels from 1984 to the present and quantify FC loadings by type of land cover. There are three aspects in this study---spatial analysis of FC data, temporal analysis of FC data, and FC loadings quantification based on the findings from spatial and temporal analyses. GIS tools and a variety of statistical methods are used in combination with an inverse modeling approach. The modeling method was based on some basic concepts incorporated in the Watershed Management Model and the Tidal Prism Model currently used to develop Total Maximum Daily Load (TMDL) models for Virginia waters. The core contributions of this dissertation are: (1) This study provided a thorough examination of FC monitoring data in Virginia coastal waters and described how contamination levels are expressed at different spatial and temporal scales. Analyses examined tidal effects, regional effects, land condition effects, and climate effects. Results not only inform management decisions, but also provide guidance for the subsequent quantification of fecal bacteria loadings. (2) Fecal bacteria loadings are quantified as a function of land cover. The model developed in this study avoids the problems associated with using highly varied and poorly documented FC production rates and population numbers. Although the model is simple, the magnitude of Fecal Coliform Event Mean Concentration (FCMC) values based on land covers effectively distinguished the seasonal FC loadings.
4
Molotch, Noah P. "ESTIMATING THE SPATIAL DISTRIBUTION OF SNOW WATER EQUIVALENT AND SNOWMELT IN MOUNTAINOUS WATERSHEDS OF SEMI-ARID REGIONS." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/191275.
Анотація:
The processes controlling snowpack mass balance are highly variable in time and space, requiring remote sensing to observe regional processes and intensive field observations to observe hilislope-scale phenomena. This research aims to further understanding of the processes controlling snowpack mass balance through innovative applications of remotely sensed data and statistical interpolations of ground observations. Four advancements were obtained: 1) the sensitivity of regression tree snow distribution models to digital elevation data and independent variables was quanitified; 2) improved ability to upscale point snow water equivalent (SWE) measurements at snow telemetry (SNOTEL) stations was obtained by quantifying the small-scale SWE variability surrounding these stations; 3) spatially distributed snowmelt algorithms were improved by incorporating remotely sensed snow-surface albedo data into snowmelt modeling; and (4) the temporal and spatial continuity of regional-scale estimates of snow covered area (SCA) and SWE were improved by combining remotely sensed data and air temperature data to extend estimates beneath the cloud cover.
5
Dushimumuremyi, Jean Paul. "Spatial distribution of water resources and accessibility to water : the case of Bugesera district in Rwanda /." Göteborg : Kulturgeografiska institutionen, Handelshögskolan vid Göteborgs universitet, 2009. http://hdl.handle.net/2077/21260.
6
Kidder, Amí Lynne. "Ecohydrological Conditions Associated With The Distribution And Phenology Of The Pima Pineapple Cactus." Thesis, The University of Arizona, 2015. http://hdl.handle.net/10150/347323.
Анотація:
Climate changes in temperature and precipitation are already occurring and are projected to further exhibit increasing temperature and precipitation extremes and increasing variation. Such increased temperature variation and decreased precipitation are likely to have a profound impact on vegetation communities, particularly in regions that are dominated by extreme temperatures and strongly seasonal precipitation events. Both temperature and precipitation are tightly linked to vegetation growth and distribution, and in regions such as the U.S. desert southwest, there are a number of rare and endangered species that have a particularly tight knit relationship with their environment. Here, I examine the relationship between these ecohydrological drivers and a specific, little- researched cactus: the Pima Pineapple Cactus (Coryphantha scheeri var. robustispina). C. scheeri is a small, hemispherical cactus that resides in the Santa Cruz and Altar Valleys of Southern Arizona, and very little is known about the conditions that promote C. scheeri distribution and growth. To provide information that may aide in managing this species, I investigate aspects of the distribution and the phenology of this species. With respect to distribution, I hypothesize that (H1) C. scheeri locations are associated with spatial physical and climatic data within its geographic limits. A framework describing the climatic associations of C. scheeri would enable species managers to take advantage of suitable habitat when opportunities arise. With respect to phenology, within established C. scheeri habitat we lack a clear understanding of the impact ecohydrological factors can have on reproduction and size. Therefore, I also hypothesize (H2) that C. scheeri flowering phenology is triggered by available moisture, which may be in the form of precipitation, humidity, or soil moisture. My results indicate that through the use of the classification tree, C. scheeri habitat is strongly associated with climatic and physical variables at a state-wide scale; these associations indicate large losses of suitable habitat under future projected climate scenarios. Additionally, I find that C. scheeri flowering phenology appears to be associated with precipitation and the resulting increase of soil moisture; the data are also suggestive that bud formation might be associated with water-year growing degree day. Because the results indicate a tight coupling with climatic variables, with most suitable habitat within the current range in Arizona projected to be lost under future climate, I suggest managers may be inclined to increase monitoring C. scheeri in an ecohydrological context relative to the variables identified here and to consider conditions and locations where supplemental watering or microclimate amelioration could be beneficial for the species.
7
Dalle, Sarah Paule. "The spatial distribution of traditional plant resources on an indigenous territory (Darien, Panama) and implications for management /." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33389.
Анотація:
Ecological research aimed at the conservation of useful plants has rarely considered the spatial distribution of resources nor the potential implications for management. In this thesis I examined the spatial patterning of a group of 23 useful plant species on the 3,500 ha territory of a Kuna community in Darien, Panama. A systematic random sampling scheme was used to survey the distribution and abundance of the species, as well as the physical environment. A series of canonical analyses was conducted to evaluate the species-environment relationships and to identify spatial structures in the species distributions left unexplained by the environmental variables. Four distinct distribution patterns were identified among the species; these were most strongly explained by land-use, the degree of canopy closure and topography. Significant spatial structures, independent of the environmental variables, were related to anthropogenic pressures and an edaphic gradient. The habitat associations of the individual species are described and data on one species, Sabal mauritiiformis , is used to illustrate the utility of these data in the management of plant resources on human landscapes.
8
Cheatham, Rhodes Carolyn. "Spatial and Temporal Variation in Mangrove Distribution (1950-2014) in Tampa, Florida USA." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6813.
Анотація:
I carried out an observational study of historic high resolution aerial imagery spanning six decades (1950-2014) to identify recent and historic spatial extent of mangrove forests, within the municipal boundaries of the City of Tampa, Florida USA. My objectives were to map mangrove distribution and spatial extent and any change or patterns of change discernable. I observed variable patterns of change and rates of expansion varied between sites spatially as well as within sites between time intervals. I found notable changes in mangrove extent in the Tampa from historic and modern aerial imagery for the ~64-year period between 1950 and 2014. There were significant losses in areal extent between 1950 and 1973, much of which could be directly attributed to anthropogenic modification of the Tampa coastal landscape. All the regions observed had recovered or surpassed their original extent by the end of the period reviewed (1950-2014). It appears much of the recovery observed is a result of recolonization of created or modified shorelines. Results of these observations may contribute to the body of information used to inform conservation and management objectives in the City of Tampa and Tampa Bay.
9
Heller, Justin Henry. "Relative Abundance and Spatial Distribution of Lepomid Sunfishes in the Peace River." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3147.
Анотація:
This study examines spatially continuous sampling data in order to investigate patterns of abundance and distribution of three recreationally important sunfish species (bluegill, redear, and spotted sunfish) along the main-stem of the Peace River, a large softwater river located in southwest Florida. A total of 467 electrofishing transects were sampled biannually from spring 2008 to spring 2010. Sampling sites ranged from the headwaters of the Peace River in Polk County, FL to the oligohaline waters located in Charlotte County, FL. All fish were collected with boat mounted electrofishing gear, and aquatic habitat and physiochemical water quality measurements were recorded at each transect. Pearson's correlation coefficient and conical correspondence analysis were used to interpret relationships between sunfish abundance and associated environmental variables. Results showed that relative abundance of sunfish varied significantly between the upper, middle, and lower basins of the river. Distance from headwaters, conductivity and macrophyte coverage were all significant predictors of relative species abundance. Spotted sunfish were found closer to the headwaters and were positively associated with higher amounts of aquatic vegetation. Redear were most common in the middle basin and were most associated with changes in conductivity. Bluegill were relatively more abundant further downriver where conductivities were higher. Woody debris was strongly associated with fish abundance for all species but did not significantly explain the variance in species composition between locations in the river. The result of this study can be used by fisheries professionals to better manage sunfish populations in the Peace River and other lotic systems.
10
Sabesan, Aarthy. "Geo-spatial assessment of the impact of land cover dynamics and distribution of land resources on soil and water quality in the Santa Fe River watershed." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0007460.
11
Shepherd, Ashley Lauren. "Mapping of Sonoran Desert Vegetation Communities and Spatial Distribution Differences of Larrea Tridentata Seed Density in Relation to Ambrosia Dumosa and Ambrosia Deltoidea, San Cristobal Valley, Arizona." Thesis, The University of Arizona, 2011. http://hdl.handle.net/10150/217053.
Анотація:
Vegetation in the San Cristobal Valley of Barry M. Goldwater Range-East was mapped using a combination of field surveys and aerial imagery interpretation to contribute to ongoing inventory of natural resources for the BMGR-East as well as assist in resource management decisions. Eighteen vegetation associations were identified and mapped through collection of 186 samples to characterize vegetation associations. The most common vegetation association was Larrea tridentata monotype, covering 29% of the area mapped. Larrea tridentata is a widely spread shrub throughout the Sonoran, Chihuahuan and Mojave deserts; therefore understanding germination and seedling survival patterns is crucial. Ambrosia dumosa and A. deltoidea exhibit nurse plant-protégé interactions with L. tridentata. Seed density of L. tridentata was studied under Ambrosia species to determine factors controlling germination and seedling density. As expected seed density was greater under Ambrosia canopy than areas with no canopy. Ambrosia species and canopy type did not affect seed density.
12
Johnson, Gary Wayne. "Connecting Landscapes to People: Assessing the Distribution of Ecosystem Service Flows Using the SPAN Approach." ScholarWorks @ UVM, 2014. http://scholarworks.uvm.edu/graddis/301.
Анотація:
The Service Path Attribution Network (SPAN) framework provides a novel, user-centric, connectivity-based approach to ecosystem service assessment and valuation (ESAV). Ecosystem services are delivered to users through the simulated flow of some service medium (i.e., matter, energy, or information) from the ecosystems in which it originates (sources) to the people or assets which it affects (users). Along the way, the service medium may be absorbed by intervening landscape features (sinks) or captured by rival users.
Crucially, the service medium is not itself an ecosystem service or benefit but rather an agnostic transport mechanism which establishes connectivity between sources, sinks, rival users, and nonrival users within a delimited study region. Each user then receives benefits or harm from the encountered service medium depending on their specific relationship with it. For example, if surface water is the simulated service medium, it may increase productivity at a hydropower plant but damage farmers in floodplains by drowning their crops.
In the SPAN terminology, sources provide provisioning ecosystem services to users with a beneficial relationship with the service medium. Similarly, sinks provide preventive ecosystem services to users with a detrimental relationship with the service medium by reducing the amount flowing to their locations. Notably, within a single SPAN analysis, both sources and sinks may provide ecosystem services given a sufficiently heterogeneous pool of users.
The results of a SPAN ESAV analysis are myriad, totalling up to 30 output maps for some services. Taken together, these maps tell the story of which sources provide services to which users, which sinks protect users from harm, which users compete for the same resources (and who wins), and how all of the sources, sinks, rival users, and nonrival users affect one another. Additionally, a SPAN simulation produces maps of the flow paths taken by the service medium from sources to users as well as where and by how much the flow strength is reduced by sinks. Studying these flow paths can help decision makers identify those locations at which management actions would be maximized or minimized depending on their specific development goals.
A crowning achievement of this work is that for most ecosystem services the SPAN algorithm's complexity is guaranteed to be linear O(n) in both time and space with respect to the number of discrete locations analyzed. This makes it a viable option for high resolution landscape level ESAV studies using no more than commodity hardware.
This dissertation explores the SPAN framework in depth, from its novel conceptual terminology and computational algorithms through to the intended interpretation of its results. In addition to describing the conceptual and mathematical components of this system in detail, this work also provides a complete Literate Program demonstrating the application of the SPAN framework to an assessment of the scenic beauty ecosystem service in Chittenden County, Vermont.
13
Burnett, Anya Cheyenne. "Modeling habitat use of a fringe greater sage-grouse population at multiple spatial scales." Thesis, Utah State University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1543457.
Анотація:
While range-wide population declines have prompted extensive research on greater sage-grouse (Centrocercus urophasianus), basic information about southern periphery populations, such as the Bald Hills population in southern Utah, has not been documented. The objective of this research was to determine habitat preferences and space use patterns of the Bald Hills sage-grouse population which occurs in an area of high potential for renewable energy development. I tracked 66 birds via VHF telemetry in 2011 and 2012 and surveyed vegetation plots throughout the study area. I found that the population was primarily one-stage migratory with seasonal distributions that did not correspond well with previously developed suitable habitat maps (based on local biologist knowledge and lek data) for all seasons; I also found that mean home range sizes ranged from 82 km2 to 157 km2 .
Nesting hens did not select for any measured vegetation characteristics within the study area, while brood-rearing hens selected for high forb cover. Birds at summer sites (non-reproductive bird locations during the summer season) selected for greater grass and forb cover and lower shrub cover compared with random sites. Overall, Bald Hills sage-grouse used areas with greater shrub canopy cover and lower grass and forb cover than recommended in habitat guidelines.
Ten predictor variables were used to model suitable seasonal habitat using Maximum Entropy (maxent). All models were created for the Bald Hills population and projected to the Bureau of Land Management Cedar City Field Office management area and produced excellent model fit (AUC > 0.900). The Bald Hills population had similar nesting and winter habitat preferences as other populations but different brood-rearing and summer habitat preferences. I found local management techniques to be an important driver of seasonal habitat selection; birds selected for areas that had undergone habitat treatments (such as broadcast burn and crushing) within the previous 10 years. My results indicated the Bald Hills periphery population occupies marginal habitat and has adapted unique seasonal habitat preferences. Managers of isolated, fringe, and low-density populations should develop locally specific management guidelines to address the unique adaptations and ensure the persistence of these populations.
14
Bledsoe, April Dawn. "A Tale of Two Species: Black-tailed and White-tailed Prairie Dog Biogeography from the Last Interglacial to 2070." Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/etd/3764.
Анотація:
Ecological niche models (ENMs) were created for White-tailed and Black-tailed prairie dogs and projected into the Last Interglacial (LI), the Last Glacial Maximum (LGM), and mid-Holocene (mid-H) to discern possible past suitable habitat for both species. Additionally, ENMs were projected into the future year 2070 representative concentration pathways (RCPs) 2.6 and 8.5 to discern how climate change may affect future habitat suitability. Kernel density estimations, minimum convex polygons, and median distribution centers of White-tailed and Black-tailed occurrence records were examined between time-periods to discern the effects of anthropogenic westward expansion on both species’ distributions. Current ENMs were constructed from commonly used bioclimatic variables and non-traditional variables (including EPA level III Ecoregions) for White-tailed and Black-tailed prairie dogs for variable comparison performance in ENMs. Results indicate that both species respond to climate change and each occupy distinct ecological niches. Biogeographical changes coincident with westward expansion remain unknown.
15
Tomás, Nelson Ricardo Rodrigues Delgado. "Distribuição regional de médicos e de enfermeiros no SNS: escassez e/ou distribuição desequilibrada?" Master's thesis, Universidade de Évora, 2021. http://hdl.handle.net/10174/29946.
Анотація:
Esta dissertação visou analisar a evolução da distribuição de médicos e de enfermeiros, em Portugal, procurando evidenciar eventuais diferenças inter-regionais (NUTS III) estatisticamente significativas.
A líteratura considera a distribuição desequilíbrada de médicos e/ou enfermeiros com a geradora de situações de escassez ou de excesso desses recurses humanos, contribuindo para que problemas ao nível do acesso e da qualidade dos cuidados de saúde persistam. Porêm, muitos estudos limitam-se 'a calcular' 0 rácio desses profissionais de saúde por unidade populacional, 'ignorando' técnicas de econometria espacial que permitam uma melhor caracterização daquela distribuição.
Para alcançarmos OS objetivos propostos recolhemos dados sabre 0 número de médicos e de enfermeiros e a respetiva população residente; calculamos rácios por cada 1000/habitantes, aplicando-lhes o coeficiente de correlação I de Moran a fim de determinar se as eventuais diferenças, tendo por referência a respetiva localização espacial, se apresentam (ou nao) correlacionadas entre si do ponto de vista estatístico;
Regional distribution of doctors and nurses in the NHS: Scarcity and / or unbalanced distribution?
Abstract:
The aim of this study was to analyze the evolution of doctors and nurse's distribution in Portugal,trying to show any inter-regional (NUTS Ill) statistically significant differences.
The literature considers imbalanced distribution of doctors and/or nurses as generating scarcity or excess of these human resources, contributing to problems, in terms of access and quality of health care, to persist. However, many studies are limited to 'calculating' the ratio of those health care workers per 1000/inhabitants, thus 'ignoring' spatial econometrics techniques that allow a better characterization of that distribution.
In order to achieve the proposed objectives, we collected data about the number of doctors and nurses and the resident population; we calculated ratios per 1000/inhabitants, applying Moran's correlation coefficient I in order to determine whether any differences, with reference to their spatial location,are (or not) correlated, from a statistical point of view.
16
Garrouste, Manon. "Ressources scolaires et réactions individuelles : trois essais en économie de l'éducation." Thesis, Paris 1, 2015. http://www.theses.fr/2015PA010010/document.
Анотація:
L'objectif de cette thèse est d'étudier l'interdépendance des ressources scolaires et des ressources individuelles dans la production du capital humain. À travers trois cas d'études sur données françaises, différentes méthodes sont proposées pour analyser l'effet des politiques éducatives tout en tenant compte des comportements des individus. Le premier chapitre montre que les politiques d'éducation prioritaire sont susceptibles de conduire les familles, notamment les plus avantagées socialement, à contourner les établissements traités. Ces stratégies d'évitement sont de nature à contrebalancer les effets des moyens supplémentaires sur les résultats des élèves. Le deuxième chapitre cherche à savoir si les choix d'orientation des élèves sont contraints par J'offre scolaire locale. Nous montrons que l'ouverture d'un nouveau lycée augmente la proportion d'élèves qui poursuivent leurs études dans le second cycle, notamment en voie professionnelle. Enfin, le troisième chapitre montre que les étudiants tiennent compte de l'information contemporaine dont ils disposent sur leurs notes lorsqu'ils évaluent les qualités pédagogiques de leurs enseignantsThe main objective of this thesis is to study the interdependence of school resources and individual resources in human capital production. In three empirical analyses using French data, various methods arc proposed to evaluate the impact of educational policies, taking individual behaviors into account. The first chapter shows that compensatory education policies may result in individual sorting. The fact that socially more advantaged families tend to avoid treated schools cancels out additional resources positive effects on academic achievement. The second chapter examines whether pupils are constrained by local school supply. We find that opening a new high school increases the proportion of pupils who continue in upper secondary education, particularly in a vocational track. Studying how students evaluate teaching, the third chapter shows that they take contemporaneous information about their grades into account when they evaluate teachers' pedagogical qualities
17
Sibuet, Myriam. "Structure des peuplements benthiques en relation avec les conditions trophiques en milieu abyssal dans l'océan atlantique : cas particulier des échinodermes." Paris 6, 1987. http://www.theses.fr/1987PA066693.
18
Marvalin, Olivier. "ABONDANCEcr, BIOMASSE, ACTIVITE ET RELATIONS TROPHIQUES DES COMMUNAUTES BACTERIENNES HETEROTROPHES DU LAC D'AYDAT (PUY DE DOME) : contribution a l'etude du fonctionnement des systemes aquatiques." Clermont-Ferrand 2, 1988. http://www.theses.fr/1988CLF21086.
19
Hakizimana, Paul. "Analyse de la composition, de la structure spatiale et des ressources végétales naturelles prélevées dans la forêt dense de Kigwena et dans la forêt claire de Rumonge au Burundi." Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209727.
Анотація:
Dans cette étude, la composition taxonomique, la structure spatiale et les ressources végétales naturelles prélevées dans les forêts de Kigwena et de Rumonge ont été analysées. Les deux forêts sont situées au Sud-Ouest du Burundi, dans une région de forte densité de population. L’objectif global de l’étude était d’élucider des éléments de l’écologie de la forêt dense de Kigwena et de la forêt claire de Rumonge en vue de leur conservation optimale. Les résultats montrent que les deux forêts sont floristiquement différentes malgré leur proximité géographique. Les types biologiques sont dominés par les phanérophytes, les chaméphytes et les thérophytes ;ce qui traduit des adaptations des espèces aux conditions du milieu de vie forestier caractérisé par un stress hydrique et par d’importantes perturbations d’origine anthropique. Le spectre phytogéographique est en concordance avec la localisation des forêts étudiées dans le territoire phytogéographique du District du Mosso/Malagarazi, caractérisé par la présence des espèces à distribution soudano-zambézienne et des espèces de liaison soudano-zambézienne et guinéo-congolaise. La forêt dense de Kigwena et la forêt claire de Rumonge sont soumises aux mêmes influences phytogéographiques et n’ont donc pas connu d’isolement géographique. Dans la forêt dense de Kigwena, l’hétérogénéité spatiale de la végétation, reflétée par l’existence de quatre groupements végétaux distincts, obéit aux gradients d’humidité et d’anthropisation. Par contre, dans la forêt claire de Rumonge, l’hétérogénéité spatiale de la végétation se traduit par des variations stationnelles dans un même fond floristique. L’analyse de la distribution spatiale a montré que les arbres sont répartis selon le modèle spatial agrégé. Les ressources végétales prélevées dans les deux forêts par les populations riveraines servent en grande partie à des fins médicinales, matérielles, alimentaires, énergétiques et/ou socio-culturelles. Les prélèvements de ces ressources, l’agriculture intensive, l’exploitation des carrières, l’aménagement des infrastructures, les feux de forêt et les chablis ont été identifiés comme étant des facteurs de perturbation qui amplifiaient la dégradation et le risque de disparition des forêts de Kigwena et de Rumonge. En définitive, cette étude a montré que les forêts étudiées ont une richesse taxonomique et une valeur conservatoire considérables. Mais ces forêts sont menacées sous l’action d’une anthropisation croissante. Pour remédier à cette situation, des mesures et des actions de conservation ont été proposées pour un court terme. /The taxonomic composition, the spatial pattern and the botanical resources used by Man around the Kigwena and Rumonge forests were studied. Both forests are located in the south-western part of Burundi, in a zone characterized by a high population density. The overall objective of this study was to understand the ecology of the Kigwena and Rumonge forests in order to support their conservation. Results show that the flora of the two forests are different although their geographical proximity. The life forms are dominated by phanerophytes, chamaephytes and therophytes; this observation corresponds to an adaptation of the floras to water stress and anthropogenic disturbances. The phytogeographical spectrum is directly related to the presence of the forests in the Mosso/Malagarazi District. It is characterized by the presence of species with a soudano-zambezian distribution and by species of the soudano-zambezian/guineo-congolese connexion. No geographical isolation was evidenced which could have altered the composition of the Kigwena and Rumonge forests. In the Kigwena forest, the spatial floristic heterogeneity is shown by four different plant communities which occur according to anthropogenic disturbance and soil moisture gradients. But, in the Rumonge forest, the spatial floristic heterogeneity occurs with more common species, in the same flora. The analysis of the spatial pattern of the trees revealed a general tendency towards a clumped distribution. Many natural plant resources are removed from the Kigwena and Rumonge forests by neighbouring populations for medicinal use, material use, food use, energy use and cultural use. Removal of natural plant resources, intensive agriculture, quarry exploitation, infrastructure development, forest fires and windfall of trees have been identified as disturbance factors which amplify the degradation and the risk of disappearance of the forests of Kigwena and Rumonge. Ultimately, this study shows that the Kigwena and Rumonge forests are characterized by a high taxonomic richness as well as by their importance for conservation. Nevertheless, these forests are threatened by increasing anthropogenic activities. Consequently, short-term measures and actions for conservation are proposed.Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Clavier, Jacques. "Contribution a la mise en valeur des populations d'ormeaux (haliotis tuberculata l. )." Paris 6, 1987. http://www.theses.fr/1987PA066311.
21
Chen, Yu, and 程予. "Spatial-Temporal Distribution Pattern, in 1974-1989, of Groundfish Resources in Continental Shelves off Mainland China." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/99875111991604447004.
22
YANG, TSAI-HSUAN, and 楊采璇. "A Study on Relationships among the Cultural Policies, Creative Talents and Spatial Resources Distribution: a Case Study in Taipei." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/489xn6.
Анотація:
碩士中國文化大學
都市計劃與開發管理學系
107
Due to the cultural exchanges and economic development of globalization, the urban development patterns in many countries are gradually taking the cultural and creative thinking as the main development drive, and the creative and cultural industries establish a solid base for creative talents and enhance the competitiveness of the urban environment. As a consequence, this study intended to explore the cultural development policy of Taipei City over the past 2 decades, including the cultural policies and plans promoted by successive mayors that have been recorded by the Cultural Bureau, and learn about the characteristics of cultural development in terms of spatial distribution in Taipei City. However, few literatures had discussed the relationships between cultural policies and the aggregation of creative talents, which was important for public sectors to determine policy and budget investment. Thus, this study used the two axial spaces in the “Taipei Cultural Innovation Cluster Promotion Project” as the research areas to study the creative resources provided by the cultural policies of Taipei City Government, and the relationships between these resources and the spatial distribution of creative talents in Taipei City. By collecting the business registration data and adopting the definition and classification of the Ministry of Economic Affairs, the spatial distribution of creative talents in Taipei City was designated in digital maps. In order to examine the effectiveness of the governmental policies, the research focused on the governments’ long-term cumulative attentions. Using the Geographic Information System as a method to conduct spatial analysis, the spatial distribution of creative talents was analyzed through spatial autocorrelation approach. To understand the degree of clustering of creative talents, the cultural facilities, the influential areas of cultural facilities, and creative talents were analyzed by spatial overlapping, and the correlation and difference between the two were also examined. In short, this research was to examined the extent to which the resources provided by the cultural policy had succeeded in driving creative talents to gather. Moreover, this research also examined the different cultural facilities on the two axial spaces and different degrees of creative talent clustering. The empirical results showed that the development of the distribution of creative talents was not completely related to the two axial spaces of the “Taipei Cultural and Creative Group Promotion Project” implemented by the government. Moreover, the spatial overlapping analysis indicated that even though the governments paid attentions on specific cultural sites/areas in the long term, creative talents did not gather together as the governments excepted. Instead, there were a large number of random distributions and cold spots presenting in the spatial analysis results. Thus, this research suggested that governments need to review current plans and seek the causes of the inconsistency before issuing further policies.
23
LIN, YING-HONG, and 林穎鴻. "The Accessibility of Spatial Distribution and Location Selection of Community-based Day Care Resources - A Case of Taipei City." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/47ym8v.
Анотація:
碩士國立臺北科技大學
建築系建築與都市設計碩士班
107
As the proportion of the eldery population in Taiwan has rised rapidly, the demographic structure has changed to an aging society and the family care capacity has declined. The government department promotes the policy direction of Long-Term Care Plan 2.0 and expects to build a community-based care environment and implement the goal of aging in place. However, at present, the population that needs to be taken care of is increasing and there is a growing gap between the supply and demand for care resources, so the spatial distribution is a key factor. Therefore, this study explores how to rationally allocate resouces in space, and the need of population distribution should be considered in order to achieve the accessibility of service resources. Taking Taipei City as the scope, this study reviews the spatial distribution accessibility and location selection of day cares, conducts spatial analysis and calculation of geographic information system, and combines with in-depth interviews with experts and scholars to comprehensively analyze various spatial attributes and other major factors to explore their suitability. The conclusions of this study are: (1) The high population projection for day care in Taipei City is 2,115 people, and the number of approved housing service people is 846. The average day care service radius is 1,500 meters. (2) The spatial distribution of day care resources in Taipei City has a cluster phenomenon. There are 46 villages that have not been able to obtain day care resources within three kilometers of the road. Using the enhanced two-step floating catchment area method, the spatial distribution accessibility is 9.8. (3) By using the location selection mode calculation of the largest service area to do the location allocation of day care resources, it can improve the overall day care spatial distribution accessibility to 23.1. Based on the above results and the opinions from the interviewed experts and scholars, the principle of location selection of community-based day care resources is summarized, and the government or relevant departments are given reference for setting up day cares.
24
Bubnicki, Jakub. "Impact of biotic and abiotic factors on spatial distribution of ungulates in Białowieża Primeval Forest." Doctoral thesis, 2021. https://depotuw.ceon.pl/handle/item/3883.
25
Morris, Gabrielle Patricia. "A spatial decision support system evaluating energy and resources for wind turbine development: The case study of Iowa, USA." Master's thesis, 2021. http://hdl.handle.net/10362/113901.
Анотація:
Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial TechnologiesEnergy goals have been set to address climate change and mitigate greenhouse gas emissions in accordance with the Paris climate agreement, a result of the United Nations Convention on Climate Change in 2015. Wind turbines have received a fast-growing interest since they do not produce carbon emissions when converting wind energy to power. It is expected that wind turbines will make up 20 percent of the United States electricity market by 2030 and 35 percent by 2050. A spatial decision support system (SDSS) was developed for a quantitative research study, evaluating wind energy and resources through mathematical modeling and geographic information systems (GIS). The SDSS proposed in the study is comprised of four steps: acquisition of data, resource forecasting, simulation and analysis, and ranking of alternative strategies. The SDSS was then applied to a case study in Iowa, United States for the year 2013. Wind turbine and resource datasets were extracted from the U.S. Wind Turbine Database and WIND Toolkit, respectively. Resources were forecasted using Ordinary Kriging spatial interpolation and Weibull distribution modeling. Weibull parameters were estimated using the power density method. Wind power density, turbine rotor swept area, and the power coefficient were used to simulate power output and capacity factors of presently located wind turbines. Finally, alternative strategies for wind turbine development were ranked based on the estimated energy yields of presently located wind turbines. The results found that most of Iowa exhibits Class III wind speeds, as defined by the International Electrotechnical Commission. Overall, it can be determined that Iowa’s resources are economically suited for wind turbine development.
26
Prussin, Emrys Adain. "Spatial distribution of the nutrient plume emanating from an Integrated Multi-Trophic Aquaculture (IMTA) farm in British Columbia: use of an in-situ kelp bioassay to monitor nutrient loading." Thesis, 2012. http://hdl.handle.net/1828/3998.
Анотація:
To assess the spatial distribution of nutrient wastes around an open-water integrated fish/mollusk/kelp farm in-situ kelp bioassays were employed. Growth rates were measured over a four-month growing season and used as a proxy for relative nutrient concentrations. Seasonality and depth effects on growth rate were also assessed. Growth around the pens was 0.20 cm • day-1 higher than at the control, and reached a maximum of 1.4 cm • day-1. Optimal growth was achieved at 8 m. Growth at 8 m was significantly higher by 1.5 cm • day-1 compared to surface waters at 2 m. Early spring had the highest growth rates with a peak of 1.4 cm • day-1 recorded on June 21. This study re-iterates the fundamental benefits of IMTA and shows the potential of in-situ assay as an alternative to error-prone and costly water sampling to asses nutrient status in water.Graduate
27
Sokolic, Franko. "The use of satellite remote sensing to determine the spatial and temporal distribution of surface water on the eastern shores of Lake St. Lucia." Thesis, 2006. http://hdl.handle.net/10413/2305.
Анотація:
The Eastern Shores of Lake St Lucia forms part of the ecologically important Greater St Lucia Wetland Park, designated a World Heritage Site in 1999. The landscape is characterised by surface water, a high water table and numerous wetlands. Little is known about the distribution and temporal fluctuations of this surface water and its relationship to the wetlands. This study uses remote sensing to examine the relationship by mapping the extent of seasonal, ephemeral and permanent surface water on the Eastern Shores. Much of the surface water occurs in conjunction with emergent vegetation and is not easily mapped using hard classification methods. Neither a cluster analysis nor a maximum likelihood classification were able to map the subtle variations of the water-vegetation mix. Much more successful was the application of spectral mixture analysis using image endmembers of water, woody vegetation and non-woody vegetation. This technique was applied to seven Landsat Thematic Mapper images from 1991, 2001 and 2002. Steep slopes, forests and bare sand were masked out prior to classification. Maps of water extent were produced for each of the seven study dates. Mapping accuracy was verified against rainfall, with high correlations being obtained against rainfall accumulated over six months and longer. Long-term rainfall patterns were reflected in the surface water distribution, with inundation being more extensive when accumulated rainfall was high. Fire scars reduced the accuracy of the spectral mixture analysis but these scars could be identified from the thermal image bands. The largest open water body in the study area was Lake Bhangazi. Large extents of surface water were also found in the Mfabeni swamp and the wilderness area to the north where water concentrations of 90% were measured during wet periods. Surface water present near Brodies Crossing during wet periods was less evident when rainfall was lower. No inundation was recorded in the areas to the west and south-west of the Mfabeni swamp or in the southern parts of the study area. The techniques used in this study were developed into a water mapping protocol that uses image endmembers and spectral mixture analysis to measure water concentration.Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2006.
28
CHMEL, Kryštof. "Ekologie lesního společenstva ptáků na Papui Nové Guinei." Doctoral thesis, 2017. http://www.nusl.cz/ntk/nusl-371665.
Анотація:
The thesis addresses several aspects of ecology of lowland rainforest avifauna in Papua New Guinea. It describes spatial and temporal distributional patterns of abundance and diversity of bird community and different feeding guilds. More specifically, spatial patterns were explored in relation to topography, tree species composition, forest structure including vertical forest strata and inter-specific associations. The thesis also focuses on nest survival in continuous and fragmented forest, particularly in relation to nest predation.