Understanding the events and processes responsible for patterns of within species diversity, provides insight into major evolutionary themes like adaptation, species distributions, and ultimately speciation itself. Here, I combine ecological, genetic and spatial perspectives to evaluate the roles that both historical and contemporary factors have played in shaping the population structure and genetic variation of foxsnakes (Pantherophis gloydi). First, I determine the likely impact of habitat loss on population distribution, through radio-telemetry (32 individuals) at two locations varying in habitat patch size. As predicted, individuals had similar habitat use patterns, but restricted movements to patches of suitable habitat at the more disturbed site. Also, occurrence records spread across a fragmented region were non-randomly distributed and located close to patches of usable habitat, suggesting habitat distribution limits population distribution. Next, I combined habitat suitability modeling with population genetics (589 individuals, 12 microsatellite loci) to infer how foxsnakes disperse through a mosaic of natural and altered landscape features. Boundary regions between genetic clusters were comprised of low suitability habitat (e.g. agricultural fields). Island populations were grouped into a single genetic cluster suggesting open water presents less of a barrier than non-suitable terrestrial habitat. Isolation by distance models had a stronger correlation with genetic data when including resistance values derived from habitat suitability maps, suggesting habitat degradation limits dispersal for foxsnakes. At larger temporal and spatial scales I quantified patterns of genetic diversity and population structure using mitochondrial (101 cytochrome b sequences) and microsatellite (816 individuals, 12 loci) DNA and used Approximate Bayesian computation to test competing models of demographic history. Supporting my predictions, I found models with populations which have undergone population size drops and splitting events continually had more support than models with small founding populations expanding to stable populations. Based on timing, the most likely cause was the cooling of temperatures and infilling of deciduous forest since the Hypisthermal. On a smaller scale, evidence suggested anthropogenic habitat loss has caused further decline and fragmentation. Mitochondrial DNA structure did not correspond to fragmented populations and the majority of foxsnakes had an identical haplotype, suggesting a past bottleneck or selective sweep. / Thesis (Ph.D, Biology) -- Queen's University, 2011-01-11 10:40:52.476

Lake Okeechobee is the largest lake in the southeastern United States and is a central component of the hydrology and environment of the Everglades ecosystem in South Florida. The natural state of the lake has been degraded as wetlands and natural habitats in the Lake Okeechobee watershed have been replaced with farms, urban areas, and dairy operations. Excessive phosphorus loadings from these diverse sources have been identified as the leading causes of the lake’s impairment. For more than four decades, many resources have been allocated to regional and local restoration efforts to reduce phosphorus loadings into the lake. However, phosphorus loadings have not decreased and the recovery of the lake could take more time, particularly with today’s limited local budgets. Market-based instruments, such as water quality trading programs, have emerged over the past decades to cost-effectively achieve water quality objectives in impaired watersheds. The main objective of this dissertation was to assess the environmental and economic benefits of implementing a phosphorus trading program in Lake Okeechobee watershed, compared to a conventional command-and-control approach. A comprehensive literature overview of nationally and internationally implemented trading programs was conducted to highlight advantages and challenges of these programs towards achieving water quality goals, and to outline the essential elements of a successful program. Furthermore, a modeling framework, integrating a hydrologic-water quality model with an economic model, was developed to assess the potential cost savings that trading might offer over a command-and-control approach. The modeling framework was applied in three priority basins of the Lake Okeechobee watershed. In each case, while developing trading scenarios to achieve phosphorus load reduction targets, the trading program was less expensive than the conventional command-and-control approach. This research provided the foundation for stakeholders to better understand whether water quality trading has the potential to work in the Lake Okeechobee watershed and to facilitate the development of a pilot program. In addition, it offered some insights on the potential economic opportunities that pollution sources would have by participating in the trading program. The modeling framework developed in this dissertation could facilitate the assessment of future water quality trading programs in other watersheds.

[EN] Adaptation to the multiple facets of global change challenges the conventional means of sustainably planning and managing water resources at the river basin scale. Numerous demand or supply management options are available, from which adaptation measures need to be selected in a context of high uncertainty of future conditions. Given the interdependency of water users, agreements need to be found at the local level to implement the most effective adaptation measures. Therefore, this thesis develops an approach combining economics and water resources engineering to select a cost-effective programme of adaptation measures in the context of climate change uncertainty, and to define an equitable allocation of the cost of the adaptation plan between the stakeholders involved. A framework is developed to integrate inputs from the two main approaches commonly used to plan for adaptation. The first, referred to as "top-down", consists of a modelling chain going from global greenhouse gases emission scenarios to local hydrological models used to assess the impact of climate change on water resources. Conversely, the second approach, called "bottom-up", starts from assessing vulnerability at the local level to then identify adaptation measures used to face an uncertain future. Outcomes from these two approaches are integrated to select a cost-effective combination of adaptation measures through a least-cost optimization model developed at the river basin scale. The model is then used to investigate the trade-offs between different planning objectives defined in terms of environmental flow requirements, irrigated agriculture development, and the cost of the programme of measures. The performances of a programme of measures are finally assessed under different climate projections to identify robust and least-regret adaptation measures. The issue of allocating the cost of the adaptation plan is considered through two complementary perspectives. The outcome of a negotiation process between the stakeholders is modelled through the implementation of cooperative game theory to define cost allocation scenarios. These results are compared with cost allocation rules based on social justice principles to provide contrasted insights into a negotiation process. This innovative framework has been applied in a Mediterranean case study in the Orb River basin (France). Mid-term climate projections, downscaled from 9 General Climate Models, are used to assess the uncertainty associated with climate projections. Demand evolution scenarios have been developed to project agricultural and urban water demands on the 2030 time horizon. The least-cost river basin optimization model developed in GAMS allows the cost-effective selection of a programme of measures from a catalogue of 462 supply and demand management measures. Nine cost allocation scenarios based on different social justice principles have been discussed through face-to-face semi-structured interviews with 15 key informants and compared with solution concepts from cooperative game theory for a 3-player game defined at the river basin scale. The interdisciplinary framework developed in this thesis combines economics and water resources engineering methods, establishing a promising means of bridging the gap between bottom-up and top-down approaches and supporting the creation of cost-effective and equitable adaptation plans at the local level. / [ES] La adaptación a los múltiples aspectos del cambio global supone un reto para los enfoques convencionales de planificación y gestión sostenible de los recursos hídricos a escala de cuenca. Numerosas opciones de gestión de la demanda o de la oferta están disponibles, de entre las cuales es necesario seleccionar medidas de adaptación en un contexto de elevada incertidumbre sobre las condiciones futuras. Dadas las interdependencias existentes entre los usuarios del agua a nivel local, hace falta buscar acuerdos a escala de cuenca para implementar las medidas de adaptación más eficaces. Por este motivo, esta tesis desarrolla una metodología que, combinando economía e ingeniería de los recursos hídricos, busca seleccionar un programa de medidas coste-eficaz frente a las incertidumbres del cambio climático, y asimismo definir un reparto justo del coste de la adaptación entre los actores implicados. El marco metodológico ha sido desarrollado para integrar contribuciones de los dos principales enfoques utilizados para la planificación de la adaptación. El primero, denominado descendente ("top-down"), consiste en una cadena de modelación que va desde los escenarios de emisiones de gases efecto invernadero a nivel global hasta los modelos hidrológicos utilizados a nivel local para evaluar así el impacto del cambio climático sobre los recursos hídricos. Por el contrario, el segundo enfoque denominado ascendente ("bottom-up") empieza por evaluar la vulnerabilidad del sistema a nivel local para después identificar medidas de adaptación frente a un futuro incierto. Los resultados de los métodos mencionados previamente se han integrado con el fin de seleccionar una combinación coste-eficaz de medidas de adaptación a través de un modelo de optimización a menor coste a escala de cuenca. El modelo se utiliza para investigar las soluciones de compromiso ("trade-offs") entre diversos objetivos de planificación como son los caudales ecológicos necesarios, el desarrollo del regadío y el coste del programa de medidas. Seguidamente, se han evaluado los programas de adaptación frente a varias condiciones climáticas para definir así un programa de medidas robusto y de arrepentimiento mínimo frente al cambio climático. En la última parte se aborda el problema del reparto justo de los costes del plan de adaptación, entendiendo que esto es una manera de favorecer su implementación. Para ello, se han modelado los resultados de un proceso de negociación entre los diferentes actores mediante escenarios de reparto basados en la teoría de juegos cooperativos. Posteriormente, se han comparado estos resultados con otras reglas de reparto de costes basadas en principios de justicia social, proporcionando así un punto de vista diferente al proceso de negociación. Este novedoso enfoque ha sido aplicado a una cuenca mediterránea, la cuenca del rio Orb (Francia). Para ello, se han empleado proyecciones climáticas a medio-plazo de datos reescalados de 9 Modelos de Circulación Global. Además, se han desarrollado escenarios de evolución de la demanda en los sectores urbano y agrícola para el horizonte de planificación de 2030. El modelo de optimización a menor coste a escala de cuenca desarrollado en GAMS permite seleccionar un programa de medidas, de entre las 462 medidas de gestión de la oferta o de la demanda. Nueve escenarios de reparto de costes basados en diferentes principios de justicia social han sido debatidos con informantes clave mediante entrevistas y comparados con conceptos de solución de la teoría de juegos cooperativos, considerando un juego de 3 jugadores a escala de cuenca. El marco interdisciplinario desarrollado durante esta tesis combina métodos de economía y de ingeniería de los recursos hídricos de manera prometedora y permite integrar los enfoques "top-down" y "bottom-up", contribuyendo a definir un plan de adaptación coste-eficaz y justo a nivel local. / [CA] L'adaptació als múltiples aspectes del canvi global implica un repte per als enfocaments convencionals de planificació i gestió sostenible dels recursos hídrics a escala de conca. Existeixen nombroses opcions de gestió de la demanda y de la oferta. De entre elles, cal seleccionar mesures d'adaptació en un context d'incertesa elevada sobre les condicions futures. Donades les interaccions entre els usuaris de l'aigua a nivell local, és necessari buscar acords a escala de conca per tal d'implementar les mesures d'adaptació més eficaces. Per aquest motiu, la tesi desenvolupa una metodologia que, mitjançant la combinació d'economia i enginyeria dels recursos hídrics, siga adient per seleccionar un programa de mesures cost-eficaç per a fer front a les incerteses del canvi climàtic i, a més a més, definir un repartiment just del cost d'adaptació entre els actors implicats. El marc metodològic ha estat desenvolupat amb el fi de permetre integrar contribucions del principals enfocaments que s'utilitzen per a la planificació de l'adaptació. El primer, que es denomina descendent ("top-down"), consisteix a una cadena de modelació que va des dels escenaris d'emissions de gas d'efecte hivernacle a nivell global fins als models hidrològics a nivell local per avaluar l'impacte del canvi climàtic sobre els recursos hídrics. Per contra, el segon enfocament, que es denomina ascendent ("bottom-up"), comença per avaluar la vulnerabilitat del sistema a nivell local per a tot seguit identificar mesures d'adaptació de cara a un futur incert. Els resultats del mètodes esmentats prèviament, s'han integrat per a seleccionar una combinació de mesures d'adaptació cost-eficaç mitjançant un model d'optimització a menor cost a escala de conca. El model s'utilitza per investigar les solucions de compromís ("trade-offs") entre els diversos objectius de planificació, com són els cabals ecològics necessaris, el desenvolupament del regadiu i el cost del programa de mesures. A continuació, s'avaluen els programes d'adaptació per a varies condicions climàtiques amb el fi de definir un programa de mesures robust i de penediment mínim per a fer front al canvi climàtic. En la darrera part, s'escomet el problema del repartiment just dels costs del pla d'adaptació, considerant que això és una manera de facilitar la implementació del pla. En conseqüència, els resultats d'un procés de negociació entre els diferents actors han estat modelats mitjançant escenaris de repartiment basats en la teoria de jocs cooperatius. Tot seguit, els resultats s'han comparat amb altres regles de repartiment de costos basades en principis de justícia social. Això ha proporcionat un punt de vista diferent al procés de negociació. Aquest enfocament innovador s'ha aplicat a una conca mediterrània, la conca del riu Orb (França). Amb aquesta finalitat s'han utilitzat projeccions climàtiques a mig termini de dades reescalades de 9 Models de Circulació Global (MCG). A més a més, s'han desenvolupat escenaris d'evolució de la demanada en els sectors agrícola i urbà per a l'horitzó de planificació de 2030. El model d'optimització a menor cost a escala de conca desenvolupat en GAMS permet seleccionar un programa de mesures, de entre les 462 mesures de gestió de la oferta o de la demanda. Els nou escenaris de repartiment de costs han estat debatuts amb informants clau, mitjançant entrevistes, i comparats amb conceptes de solució de la teoria de jocs cooperatius, considerant un joc de 3 jugadors a escala de conca. El marc interdisciplinari desenvolupat al llarg de la tesi combina mètodes d'economia i d'enginyeria dels recursos hídrics de manera prometedora i permet la integració d'enfocaments "top-down" i "bottom-up", fet que contribueix a definir un pla d'adaptació cost-eficaç i just a escala local. / Girard, CDP. (2015). Integrating top-down and bottom-up approaches to design a cost-effective and equitable programme of measures for adaptation of a river basin to global change [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59461 / TESIS / Premios Extraordinarios de tesis doctorales

Planners who are involved in locational decision making often use raster-based geographic information systems (GIS) to quantify the value of land in terms of suitability or cost for a certain use. From a computational point of view, this process can be seen as a transformation of one or more sets of values associated with a grid of cells into another set of such values through a function reflecting one or more criteria. While it is generally anticipated that different transformations lead to different ‘best’ locations, little has been known on how such differences arise (or do not arise). Examples of such spatial decision problems can be easily found in the literature and many of them concern the selection of a set of cells (to which the land use under consideration is allocated) from a raster surface of suitability or cost depending on context. To facilitate GIS’s algorithmic approach, it is often assumed that the quality of the set of cells can be evaluated as a whole by the sum of their cell values. The validity of this assumption must be questioned, however, if those values are measured on a scale that does not permit arithmetic operations. Ordinal scale of measurement in Stevens’s typology is one such example. A question naturally arises: is there a more mathematically sound and consistent approach to evaluating the quality of a path when the quality of each cell of the given grid is measured on an ordinal scale? The thesis attempts to answer the questions highlighted above in the context of path planning through a series of computational experiments using a number of random landscape grids with a variety of spatial and non-spatial structures. In the first set of experiments, we generated least-cost paths on a number of cost grids transformed from the landscape grids using a variety of transformation parameters and analyzed the locations and (weighted) lengths of those paths. Results show that the same pair of terminal cells may well be connected by different least-cost paths on different cost grids though derived from the same landscape grid and that the variation among those paths is affected by how given values are distributed in the landscape grid as well as by how derived values are distributed in the cost grids. Most significantly, the variation tends to be smaller when the landscape grid contains more distinct patches of cells potentially attracting or distracting cost-saving passage or when the cost grid contains a smaller number of low-cost cells. The second set of experiments aims to compare two optimization models, minisum and minimax (or maximin) path models, which aggregate the values of the cells associated with a path using the sum function and the maximum (or minimum) function, respectively. Results suggest that the minisum path model is effective if the path search can be translated into the conventional least-cost path problem, which aims to find a path with the minimum cost-weighted length between two terminuses on a ratio-scaled raster cost surface, but the minimax (or maximin) path model is mathematically sounder if the cost values are measured on an ordinal scale and practically useful if the problem is concerned not with the minimization of cost but with the maximization of some desirable condition such as suitability. / Planerare som arbetar bland annat med att fatta beslut som hänsyftar till vissa lokaler använder ofta rasterbaserade geografiska informationssystem (GIS) för att sätta ett värde på marken med avseende på lämplighet eller kostnad för en viss användning. Ur en beräkningssynpunkt kan denna process ses som en transformation av en eller flera uppsättningar värden associerade med ett rutnät av celler till en annan uppsättning sådana värden genom en funktion som återspeglar ett eller flera kriterier. Medan det generellt förväntas att olika omvandlingar leder till olika "bästa" platser, har lite varit känt om hur sådana skillnader uppstår (eller inte uppstår). Exempel på sådana rumsliga beslutsproblem kan lätt hittas i litteraturen och många av dem handlar om valet av en uppsättning celler (som markanvändningen övervägs tilldelas) från en rasteryta av lämplighet eller kostnad beroende på kontext. För att underlätta GISs algoritmiska tillvägagångssätt antas det ofta att kvaliteten på uppsättningen av celler kan utvärderas som helhet genom summan av deras cellvärden. Giltigheten av detta antagande måste emellertid ifrågasättas om dessa värden mäts på en skala som inte tillåter aritmetiska transformationer. Användning av ordinal skala enligt Stevens typologi är ett exempel av detta. En fråga uppstår naturligt: Finns det ett mer matematiskt sunt och konsekvent tillvägagångssätt för att utvärdera kvaliteten på en rutt när kvaliteten på varje cell i det givna rutnätet mäts med ordinalskala? Avhandlingen försöker svara på ovanstående frågor i samband med ruttplanering genom en serie beräkningsexperiment med hjälp av ett antal slumpmässigt genererade landskapsnät med en rad olika rumsliga och icke-rumsliga strukturer. I den första uppsättningen experiment genererade vi minsta-kostnad rutter på ett antal kostnadsnät som transformerats från landskapsnätverket med hjälp av en mängd olika transformationsparametrar, och analyserade lägen och de (viktade) längderna för dessa rutter. Resultaten visar att samma par ändpunkter mycket väl kan vara sammanbundna med olika minsta-kostnad banor på olika kostnadsraster härledda från samma landskapsraster, och att variationen mellan dessa banor påverkas av hur givna värden fördelas i landskapsrastret såväl som av hur härledda värden fördelas i kostnadsrastret. Mest signifikant är att variationen tenderar att vara mindre när landskapsrastret innehåller mer distinkta grupper av celler som potentiellt lockar eller distraherar kostnadsbesparande passage, eller när kostnadsrastret innehåller ett mindre antal låg-kostnad celler. Den andra uppsättningen experiment syftar till att jämföra två optimeringsmodeller, minisum och minimax (eller maximin) sökmodeller, vilka sammanställer värdena för cellerna som är associerade med en sökväg med summanfunktionen respektive maximum (eller minimum) funktionen. Resultaten tyder på att minisumbanemodellen är effektiv om sökningen av sökvägen kan översättas till det konventionella minsta kostnadsproblemet, vilket syftar till att hitta en väg med den minsta kostnadsvägda längden mellan två terminaler på en ratio-skalad rasterkostyta, men minimax (eller maximin) banmodellen är matematiskt sundare om kostnadsvärdena mäts i ordinär skala och praktiskt användbar om problemet inte bara avser minimering av kostnad men samtidigt maximering av någon önskvärd egenskap såsom lämplighet. / <p>QC 20181002</p>

<p>Land use change constitutes a primary driving force in shaping social-ecological systems world wide, and its effects reach far beyond the directly impacted areas. Graph based landscape ecological tools have become established as a promising way to efficiently explore and analyze the complex, spatial systems dynamics of ecological networks in physical landscapes. However, little attention has been paid to making these approaches operational within ecological assessments, physical planning, and design. This thesis presents a network based, landscape-ecological tool that can be implemented for effective use by practitioners within physical planning and design, and ecological assessments related to these activities. The tool is based on an ecological profile system, a common generalized network model of the ecological infrastructure, graph theoretic metrics, and a spatially explicit, geographically defined representation, deployable in a GIS. Graph theoretic metrics and analysis techniques are able to capture the spatio-temporal dynamics of complex systems, and the generalized network model places the graph theoretic toolbox in a geographically defined landscape. This provides completely new insights for physical planning, and environmental assessment activities. The design of the model is based on the experience gained through seven real-world cases, commissioned by different governmental organizations within Stockholm County. A participatory approach was used in these case studies, involving stakeholders of different backgrounds, in which the tool proved to be flexible and effective in the communication and negotiation of indicators, targets, and impacts. In addition to successful impact predictions for alternative planning scenarios, the tool was able to highlight critical ecological structures within the landscape, both from a system-centric, and a site-centric perspective. In already being deployed and used in planning, assessments, inventories, and monitoring by several of the involved organizations, the tool has proved to effectively meet some of the challenges of application in a multidisciplinary landscape.</p>

Land use change constitutes a primary driving force in shaping social-ecological systems world wide, and its effects reach far beyond the directly impacted areas. Graph based landscape ecological tools have become established as a promising way to efficiently explore and analyze the complex, spatial systems dynamics of ecological networks in physical landscapes. However, little attention has been paid to making these approaches operational within ecological assessments, physical planning, and design. This thesis presents a network based, landscape-ecological tool that can be implemented for effective use by practitioners within physical planning and design, and ecological assessments related to these activities. The tool is based on an ecological profile system, a common generalized network model of the ecological infrastructure, graph theoretic metrics, and a spatially explicit, geographically defined representation, deployable in a GIS. Graph theoretic metrics and analysis techniques are able to capture the spatio-temporal dynamics of complex systems, and the generalized network model places the graph theoretic toolbox in a geographically defined landscape. This provides completely new insights for physical planning, and environmental assessment activities. The design of the model is based on the experience gained through seven real-world cases, commissioned by different governmental organizations within Stockholm County. A participatory approach was used in these case studies, involving stakeholders of different backgrounds, in which the tool proved to be flexible and effective in the communication and negotiation of indicators, targets, and impacts. In addition to successful impact predictions for alternative planning scenarios, the tool was able to highlight critical ecological structures within the landscape, both from a system-centric, and a site-centric perspective. In already being deployed and used in planning, assessments, inventories, and monitoring by several of the involved organizations, the tool has proved to effectively meet some of the challenges of application in a multidisciplinary landscape.