The current pressure on water resources is such, that water scarcity is now an important issue in regions with abundant water resources like the Tropics. These regions are characterized by high precipitation rates almost all year long. This results in a relatively large availability of water resources. However, these water resources are not always equally distributed in time or space, which causes periods and puts areas under water stress in tropical regions. Added to this is the challenge related to the access to these water resources, resulting in a reduced availability in general terms. Costa Rica is a clear example of a country in the Tropical regions, where water scarcity is, actually, on the top of the water agenda. Costa Rica is in the torrid tropical region in Central America, yet it experiences periods of shortage in its available water resources at the end of the dry season. This affects all water sectors, specially agriculture and drinking water supply systems. This situation has been magnified by global change, with a greater demand of resources from population growth, impermeabilization of recharge areas due to urbanization, and reduction of resources due to climate change. To adapt to the situation, it is necessary to conduct an evaluation of suitable water management tools for the country’s environmental conditions in a systematic way. This work focuses on one of these tools: managed aquifer recharge (MAR) MAR techniques are a promising approach to address the defined problems, by storing the excess of available water resources during the rainy season in suitable aquifer systems for later use during the dry season. MAR techniques present certain advantages compared to surface storage: less losses through evaporation, less demand of superficial area, among others. In order to determine if MAR techniques are suitable for Costa Rica and will help overcome the temporary water scarcity challenge, three main topics at different scale are investigated. First, at a country scale, the search of suitable areas for specific MAR techniques within the country is carried out based on physical criteria. Second, at a research scale, it is reduced to a basin level. For this case, the assessment of a MAR project based on the first stage of the Australian MAR guidelines is done. This consists of a checklist of five critical elements, which constitutes the base for the assessment of a MAR project. Third, the research is taken into a laboratory scale, where the research focuses on an injection well in an unconfined aquifer system. For the first topic, suitable areas for the implementation of MAR technique spreading methods are identified in Costa Rica by conducting a geographical information science-multi-criteria decision analysis (GIS-MCDA) approach. This is based on four criteria: hydrogeological geoaptitude, terrain slope, top soil texture, and drainage network density. By carrying out a GIS-MCDA, the country is classified into suitable and unsuitable. Based on this method, 61 % of the country is suitable for spreading methods. Among the higher ranked suitable areas are the ones located in the northern and northwest regions. The ranking of the country based on spreading methods by means of a GIS-MCDA method is a first course of action to determine where further research is needed. In the second research level, the feasibility of a MAR project was assessed in the Machuca River basin. This river basin was chosen because: the drinking water supply systems (WSS) do not meet the actual demand, there is government interest to research new water supply alternatives and there is enough basic information on this water basin. To evaluate the feasibility of a MAR project in the basin, the first stage of the feasibility assessment proposed by the Australian MAR guidelines was performed. This consists of a checklist of five critical elements: 1) sufficient demand, 2) adequate recharge source, 3) suitable aquifer, 4) space to treat and, 5) human capability. For an easier analysis of the whole river basin, it was divided into five locations based on the superficial aquifer water levels. It was concluded that a MAR project seems viable in this river basin in the Coyolar and Orotina locations. Regarding the MAR technique to be applied in the MAR project at the Machuca River basin, two considerations were taken: the previously determined suitability and the local conditions. First, the entire Machuca River is ranked as suitable for surface infiltration (MAR spreading method) based on the results from the country scale analysis. The Coyolar and Orotina locations are ranked as having a moderate suitability (between 0.4-0.6). Second, the best material aquifer for recharge in these two locations are the fractured lavas and alluvium located under clay layers. For these two reasons (moderate spreading methods suitability and local conditions), it was decided that direct injection MAR techniques (aquifer storage and recovery – ASR) will be more appropriate for these two locations. At the laboratory research scale, the effect of the well screen length on the injection rate for an unconfined aquifer was corroborated under controlled laboratory conditions. This is one of the first experiments on the topic to the best of the author’s knowledge. One of the main findings of the laboratory research is the almost neglectful effect on the injection rate for screen lengths above 80 % of the saturated thickness in an unconfined aquifer. The effect on the screen length is notable in the injection rate for open screen length under 80 % of the total aquifer thickness (95 % of the maximum achievable injection rate) and it increases for open screen lengths under 40 % (90 % of the maximum achievable injection rate). Based on the experimental results, it is recommended to use a screen length of 40 % of the saturated aquifer thickness for ASR wells and of 80 % for injection wells. This assessment shows that MAR techniques are suitable for Costa Rica’s environmental conditions. Further on, the assessment at the basin level shows MAR techniques as a promising solution to overcome water scarcity issues. The laboratory scale aquifer-well interactions show promising results regarding the effect of the screen well in the injection rate. Still, more research is needed in this field regarding other aquifer types. Based on all these findings, MAR techniques are an appropriate tool for the integrated water management in the tropical regions. / Der gegenwärtige Druck auf die Wasserressourcen ist so groß, dass Wasserknappheit sogar in den Tropen zum Thema wird. Diese Regionen sind von hohen Niederschlagsraten geprägt, was zu einer relativ großen Verfügbarkeit von Wasserressourcen führt. Diese sind jedoch nicht immer zeitlich und räumlich gleich verteilt, was temporären und/oder regionalen Wasserstress verursacht. Darüber hinaus hängt die Herausforderung auch mit dem Zugang zu diesen Wasserressourcen zusammen, was zu einer allgemein reduzierten Verfügbarkeit führt. Costa Rica ist ein Beispiel für ein tropisches Land, in dem Wasserknappheit in den letzten Jahren zunehmend an Relevanz gewonnen hat. Costa Rica leidet gegen Ende der Trockenzeit fast jedes Jahr an einem temporären Wassermangel. Dies betrifft alle Wassersektoren, insbesondere die Landwirtschaft und die Trinkwasserversorgung. Diese Situation wird durch den globalen Wandel verstärkt, mit einer größeren Nachfrage nach Ressourcen aufgrund von Bevölkerungswachstum, der Verhinderung von Grundwasserneubildung durch Urbanisierung und Versiegelung und, nicht zuletzt, den Klimawandel. Um sich an diese Situation anzupassen, ist es notwendig, eine systematische Evaluierung geeigneter Wasserbewirtschaftungsinstrumente für die Umweltbedingungen des Landes durchzuführen. Die vorliegende Arbeit konzentriert sich auf eines dieser Werkzeuge: Managed Aquifer Recharge (MAR). MAR-Techniken stellen einen vielversprechenden Ansatz dar, um die zuvor definierten Probleme anzugehen, indem die überschüssigen Wasserressourcen während der Regenzeit in geeigneten Grundwasserleitersystemen zur späteren Nutzung in der Trockenzeit gespeichert werden. MAR-Techniken bieten im Vergleich zur Oberflächenspeicherung gewisse Vorteile, unter anderem geringere Verdunstungsverluste und geringeren Raumbedarf. Um zu bestimmen, ob MAR-Techniken für Costa Rica geeignet sind und dabei helfen können, die zeitlichen Wasserknappheitsherausforderungen zu überwinden, wurden drei Hauptthemen in unterschiedlichen Skalen untersucht. Die Suche nach geeigneten Gebieten für spezifische MAR-Techniken im Land erfolgte zunächst auf der Grundlage von physikalischen Kriterien. Als Zweites wurde die Forschungsskala auf ein Beckenniveau reduziert. Für diesen Fall wurde die Bewertung eines MAR-Projekts auf der Grundlage der ersten Stufe der australischen MAR-Richtlinien durchgeführt. Diese basiert auf einer Checkliste mit fünf kritischen Elementen, welche die Grundlage für die Bewertung eines MAR-Projektes bilden. Zuletzt wurde die Untersuchung im Labormaßstab durchgeführt, wobei sich die Experimente auf Injektionsbohrlöcher in einem ungespannten Grundwasserleitersystem konzentrierten. Für das erste Thema wurden in Costa Rica geeignete Bereiche für die Implementierung von MAR-Technik-Verteilungsmethoden mithilfe eines GIS-basierten Multikriterien- Entscheidungsanalysen-Ansatzes (GIS-MCDA) identifiziert. Dieser basierte auf vier Kriterien: Hydrogeologie, Geländegefälle, oberste Bodentextur und Drainagenetzdichte. Durch die Realisierung eines GIS-MCDA wurde das Land in geeignete und ungeeignete Gebiete eingeteilt. Mit dieser Methode wurden 61 % des Landes als geeignet für die Beckeninfiltration befunden. Gut eingestufte Gebiete liegen hierbei größtenteils im Norden und im Nordwesten. Das Ranking-Verfahren des Landes mit Hilfe einer GIS-MCDA-Methode ist eine erste Vorgehensweise zur Bestimmung weiterer Forschungsgebiete. In der zweiten Forschungsstufe wurde die Machbarkeit eines MAR-Projekts im Machuca-Einzugsgebiet untersucht. Dieses Flussgebiet wurde aus folgenden Gründen gewählt: Die Trinkwasserversorgungsanlagen erfüllen die tatsächliche Nachfrage nicht, weshalb es auch im Interesse der Regierung liegt, nach Alternativen für die Wasserversorgung zu forschen. Darüber hinaus ist die Region geologisch gut erschlossen und die Informationsdichte ist ausreichend hoch. Um die Realisierbarkeit eines MAR-Projektes im Einzugsgebiet zu bewerten, wurde die erste Stufe der Machbarkeitsbewertung anhand der Checkliste an fünf kritischen Elementen durchgeführt: 1) ausreichende Nachfrage, 2) angemessene Wiederaufladungsquelle, 3) geeigneter Grundwasserleiter, 4) Raum für Maßnahmen und 5) Humanressourcen. Um die Analyse des gesamten Flusseinzugsgebietes zu vereinfachen, wurde es in fünf Bereiche eingeteilt, die auf den oberflächennahen Grundwasserständen basieren. Es wurde der Schluss gezogen, dass ein MAR-Projekt in diesem Flussgebiet an den Standorten Coyolar und Orotina nachhaltig erscheint. In Bezug auf die MAR-Technik, die in einem MAR-Projekt am Machuca-Flussbecken angewendet werden soll, wurden Überlegungen angestellt hinsichtlich der zuvor ermittelten Eignung und der örtlichen Gegebenheiten. Zunächst wurde der gesamte Machuca-Fluss aufgrund der Ergebnisse der Länderanalyse als geeignet für die Oberflächeninfiltration eingestuft. Die Coyolar- und Orotina-Standorte wurden mit einer moderaten Eignung eingestuft. Weiterhin wurde festgestellt, dass die für die Grundwasseranreicherung geeignetste Formation die Kies- und Bruchlavenlagen darstellen, die sich unter einer Tonschicht befinden. Aus diesen beiden Gründen (moderate Eignung für Beckeninfiltration, und lokale Hydrogeologie) wurde entschieden, dass MAR-Techniken mit direkter Injektion (Aquifer Storage and Recovery - ASR) für diese beiden Standorte geeigneter sind. In der kleinsten Untersuchungsskala wurde der Einfluss der Filterlänge auf die Injektionsrate für einen freien Grundwasserleiter unter kontrollierten Laborbedingungen bestätigt. Dies ist eines der ersten Experimente zu diesem Thema nach bestem Wissen des Autors. Eines der Hauptergebnisse der Laborforschung ist der fast vernachlässigbare Effekt auf die Injektionsrate bei Filterlängen von über 80 % der gesättigten Mächtigkeit in einem freien Grundwasserleiter. Die Wirkung auf die Filterlänge ist bei der Injektionsrate für offene Filterlängen unter 80 % der gesamten Grundwasserleiterhöhe (95 % der maximal erreichbaren Injektionsrate) und bei offenen Filterlängen unter 40 % (90 % der maximal erreichbaren Injektionsrate). Basierend auf den experimentellen Ergebnissen wird empfohlen, eine Filterlänge von 40 % der gesättigten Grundwasserleiterhöhe für ASR-Brunnen und 80 % für Injektionsbohrungen zu verwenden. Die vorliegende Bewertung zeigt, dass MAR-Techniken für die Umweltbedingungen in Costa Rica gut geeignet sind. Darüber hinaus demonstriert die Bewertung auf der Einzugsgebietsebene MAR als eine Lösung zur Überwindung von Wasserknappheitsproblemen. Die Grundwasserleiter-Brunnen-Interaktionen im Labormaßstab zeigen vielversprechende Ergebnisse hinsichtlich der Wirkung der Filterlänge auf die Injektionsrate. Dennoch ist auf diesem Gebiet mehr Forschung in Bezug auf andere Aquifertypen erforderlich. Basierend auf all diesen Erkenntnissen sind MAR-Techniken ein geeignetes Werkzeug für das integrierte Wassermanagement in der tropischen Umwelt. / La presión actual sobre los recursos hídricos es tal, que la escasez de agua es ahora un problema importante en áreas con abundantes recursos hídricos como las regiones tropicales. Estas regiones se caracterizan por altas tasas de precipitación casi durante todo el año. Esto da como resultado una disponibilidad relativamente grande de recursos hídricos. Sin embargo, estos recursos hídricos no siempre se distribuyen equitativamente en el tiempo y el espacio, lo que causa períodos y pone áreas bajo estrés hídrico en las regiones tropicales. Además de esto, el desafío también está relacionado con el acceso a estos recursos hídricos, lo que crea una disponibilidad reducida en términos generales. Costa Rica es un claro ejemplo de un país en las regiones tropicales, donde la escasez de agua se encuentra en lo más alto de la agenda del agua. Costa Rica está situada en la región tropical tórrida de América Central, sin embargo, experimenta períodos de escasez en sus recursos hídricos disponibles al final de la estación seca. Esto afecta a todos los sectores de agua, especialmente a la agricultura y a los sistemas de suministro de agua potable. Esta situación ha sido magnificada por el cambio global, con una mayor demanda de recursos por el crecimiento de la población, la impermeabilización de las áreas de recarga por la urbanización y la reducción de recursos debido al cambio climático. Para adaptarse a esta situación, es necesario llevar a cabo una evaluación sistemática de las herramientas de gestión del agua adecuadas para las condiciones ambientales del país. Este trabajo se centra en una de estas herramientas: la gestión de la recarga acuíferos gestionados (MAR). Las técnicas de MAR son un enfoque prometedor para abordar los problemas previamente definidos, almacenando el exceso de recursos hídricos disponibles durante la estación lluviosa en sistemas acuíferos adecuados para su uso posterior en la estación seca. Las técnicas de MAR presentan ciertas ventajas en comparación con el almacenamiento en superficie: menos pérdidas por evaporación y menor demanda de área superficial, entre otras. Con el fin de determinar si las técnicas de MAR son adecuadas para Costa Rica y ayudarán a superar los desafíos temporales de escasez de agua, se investigaron tres temas principales a diferentes escalas. Primero, en una escala de país, la búsqueda de áreas adecuadas para técnicas específicas de MAR en el país se realizó con base en criterios físicos. En segundo lugar, la escala de investigación se reduce a un nivel de cuenca. Para este caso, se realizó la evaluación de un proyecto de MAR basado en la primera etapa de las directrices australianas de MAR. Esta consiste en una lista de verificación de cinco elementos críticos, que constituye la base para la evaluación de un proyecto MAR. En tercer lugar, la investigación se lleva a escala de laboratorio, donde la investigación se centra en los pozos de inyección en un sistema acuífero no confinado. Para el primer tema, las áreas adecuadas para la implementación de los métodos de infiltración de la MAR se identifican en Costa Rica mediante un enfoque de ciencia la información geográfica y análisis de decisión multicriterio (SIG-MCDA). Esto se basa en cuatro criterios: geoaptitud hidrogeológica, pendiente del terreno, textura del suelo superior y densidad de la red de drenaje. Al realizar un GIS-MCDA, el país se clasifica en áreas adecuadas e inadecuadas. Con base en este método, el 61 % del país se consideró adecuado para métodos de infiltración. Las áreas adecuadas mejor clasificadas se encuentran en las regiones del norte y noroeste del país. La clasificación del país según el potencial de los métodos de infiltración por medio de un método GIS-MCDA es un primer curso de acción para determinar otras áreas de investigación. En el segundo nivel de investigación, se evaluó la factibilidad de un proyecto MAR en la cuenca del río Machuca. Esta cuenca hidrográfica se eligió porque: los sistemas de suministro de agua potable no satisfacen la demanda real, existe un interés del gobierno en buscar nuevas alternativas de suministro de agua y hay suficiente información básica en esta cuenca hidrográfica. Para evaluar la factibilidad de un proyecto MAR en la cuenca, la primera etapa de la evaluación se realizó sobre la base de la lista de cinco elementos críticos: 1) demanda suficiente, 2) fuente de recarga adecuada, 3) acuífero adecuado, 4) espacio para tratar el agua y, 5) la capacidad humana. Para facilitar el análisis de toda la cuenca del río, se dividió en cinco localidades en función de los niveles de agua superficiales del acuífero. Se concluyó que un proyecto MAR parece viable en esta cuenca en las localidades Coyolar y Orotina. Con respecto a la técnica de MAR que se aplicará en un proyecto MAR en la cuenca del río Machuca, se tomaron dos consideraciones: la idoneidad previamente determinada y las condiciones locales. En primer lugar, todo el río Machuca se clasifica como adecuado para la infiltración superficial (método de infiltración MAR) en función de los resultados del análisis a escala de país. Las localidades Coyolar y Orotina se clasifican con una idoneidad moderada. En segundo lugar, el mejor material acuífero para la recarga en estos dos lugares son las fracturas lavas y aluviones ubicados bajo capas de arcilla. Se decidió que las técnicas de inyección directa MAR (almacenamiento y recuperación - ASR) serán más apropiadas para estas dos ubicaciones por estas dos razones (idoneidad de los métodos de propagación moderada y condiciones locales). En la escala de investigación más pequeña, el efecto de la longitud de la pantalla del pozo sobre la tasa de inyección para un acuífero no confinado se corroboró bajo condiciones de laboratorio controladas. Este es uno de los primeros experimentos sobre el tema según el mejor conocimiento del autor. Uno de los principales hallazgos de la investigación de laboratorio es el efecto casi nulo en la tasa de inyección para longitudes de pantalla superiores al 80 % del espesor saturado en un acuífero no confinado. El efecto en la longitud de la pantalla es apreciable en la velocidad de inyección para pantalla abierta inferior al 80 % del espesor total del acuífero (95 % de la máxima velocidad de inyección alcanzable) y aumenta para longitudes de pantalla abierta por debajo del 40 % (90 % de la máxima tasa de inyección alcanzable). En base a los resultados experimentales, se recomienda utilizar una longitud de malla del 40 % del espesor del acuífero saturado para los pozos ASR y del 80 % para los pozos de inyección. La presente evaluación muestra que las técnicas de MAR son adecuadas para las condiciones ambientales de Costa Rica. Más allá, la evaluación a nivel de cuenca muestra las técnicas de MAR como una solución para superar los problemas de escasez de agua. Las interacciones entre acuíferos y pozos a escala de laboratorio muestran resultados prometedores con respecto al efecto de la pantalla en la velocidad de inyección. Aun así, se necesita más investigación en este campo con respecto a otros tipos de acuíferos. Con base en todos estos hallazgos, las técnicas de MAR son una herramienta apropiada para la gestión integrada del agua en las regiones tropicales.

Cette étude cherche à contribuer à une meilleure compréhension du système de la Forêt modèle Reventazón (FMR), un sous-système du Réseau international des forêts modèles (RIFM), et son interaction potentielle avec d'autres forêts modèles du RIFM. Dans un tel contexte, l’approche systémique permettra d’étudier le sous-système de la FMR où diverses composantes sont organisées et interagissent entre elles. Cette étude analysera d’abord une des composantes de la FMR : les pratiques agroforestières avec cultures annuelles dans la partie nord du bassin versant de la rivière Reventazón. Une méthodologie qualitative sera ensuite développée afin d’ordonner par priorité les éléments échangeables ou transférables entre au moins deux forêts modèles du RIFM, puis appliquée à la FMR (Costa Rica) et à la Forêt modèle du Bas-Saint-Laurent (Canada). Cette étude démontrera le potentiel d'établir des liens plus rapprochés entre ces sites en développant des opportunités de collaboration horizontale et de partage des connaissances. / The purpose of this investigation is to develop a better understanding of the Reventazón Model Forest's (RMF) system, a subsystem of the International Model Forest Network (IMFN), and its potential interaction with other model forests of the IMFN. In this context, the system approach is used to examine the RMF subsystem, within which a variety of components are organized and interconnected. This study first carries out the analysis of one of the RMF components: the agroforestry practices with annual crops in the northern part of the Reventazón watershed. A qualitative methodology is then developed and applied to facilitate the priority ranking of elements potentially transferrable or exchangeable between at least two model forests through the comparison of the RMF (Costa Rica) and the Bas-Saint-Laurent Model Forest (Canada). This study demonstrates the prospect that exists for these sites to establish a closer relationship by engaging in horizontal collaboration and knowledge sharing opportunities.

En el proceso de selección para un puesto de trabajo en el Ministerio de Hacienda de Costa Rica se produjeron situaciones arbitrarias para la elección. Por ello, en este informe se analiza el Caso Guevara Díaz vs. Costa Rica, recaído en la sentencia de la Corte Interamericana de Derechos Humanos del 22 de junio del 2022. En este caso, la Corte colige que el Estado de Costa Rica es responsable por discriminación por razón de discapacidad, en perjuicio del señor Guevara Díaz durante el proceso de selección para el puesto de trabajador misceláneo en el Ministerio de Hacienda. En este sentido, el presente informe analiza y critica los principales puntos de cuestionamiento realizados por la Corte referidos al reconocimiento de responsabilidad estatal, la discapacidad como categoría protegida dentro del mandato de no discriminación, así como la obligación de reparación del Estado. La metodología utilizada en el presente informe se centra en el estudio jurídico de los derechos involucrados en la Convención Americana de Derechos Humanos, así como otros instrumentos internacionales pertinentes como la Convención Internacional sobre los Derechos de las Personas con Discapacidad, la jurisprudencia de la Corte Interamericana de Derechos Humanos, y otras fuentes de derecho relevantes como la doctrina. / In the selection process for a job position in the Ministry of Finance of Costa Rica, there were arbitrary situations for the election. Thus, this report analyzes the Case of Guevara Díaz vs. Costa Rica, which is the result of the judgment of the Inter-American Court of Human Rights of June 22, 2022. In this case, the Court concludes that the State of Costa Rica is responsible for discrimination on the basis of disability, to the detriment of Mr. Guevara Díaz during the selection process for the position of miscellaneous worker in the Ministry of Finance. In this sense, this report analyzes and criticizes the main points of questioning made by the Court regarding the recognition of State responsibility, disability as a protected category within the mandate of non-discrimination, as well as the State's obligation to provide reparations. The methodology used in this report focuses on the legal analysis of the rights involved in the American Convention on Human Rights, as well as other relevant international instruments such as the International Convention on the Rights of Persons with Disabilities, the jurisprudence of the Inter-American Court of Human Rights, and other relevant sources of law such as doctrine.

Leaf traits have long been used to classify and characterise species in natural ecosystems. In addition, leaf traits provide important information about plants’ strategies for the use of resources and can be used to improve our understanding of ecosystem level processes such as nutrient cycling and carbon allocation. To explore the linkages between leaf traits and productivity, we worked in two resource-limited ecosystems (a grassland and a forest), and used leaf traits to understand how species respond to changes in available resources and their relationship to ecosystem processes. We worked in a species rich limestone-grassland located in central England, which has been subjected to long-term climatic manipulation (winter warming, summer drought and extra summer rainfall). We characterised species composition in terms of their identity, abundance and leaf structural properties (nitrogen content and leaf mass per area (LMA)) in the main treatments and the control. We found that change in species abundance was the most important factor to understand the differences in productivity (above ground biomass and total foliar nitrogen). We then measured CO2 exchange at ecosystem level, using a chamber technique, and assessed the treatments’ effect on the gross primary productivity (GPP) and ecosystem respiration (Reco). GPP and Reco were controlled by soil moisture and above ground biomass but also influenced by the conditions experienced during the growing season prior to the measuring period. Our second location was a post-disturbance chronosequence in a seasonally dry tropical forest in Costa Rica and we used leaf level gas exchange measurements to explore the role of nitrogen (N) and phosphorus (P) on the temporal-spatial variation of photosynthesis of dominant species. We found that photosynthetic efficiency was strongly linked to leaf N and P content, but that there was an important seasonal pattern on this relationship likely associated to P remobilization. Additionally we found seasonal changes in resources (water, nutrients) had a larger impact on the photosynthetic parameters than changes along the chronosequence. The two ecosystems studied for this thesis are contrasting in their physiognomy, species composition and climate, but are also characterised by species whose structural traits (high LMA and high C:N ratio) are likely to have a significant impact on the nutrient cycling processes. We learned that leaf traits provide important information about species strategies and their usage of resources and they can also aid to address questions at ecosystem level in time and space, either through simple aggregation or as emergent properties. Additionally, the traits explored are important input information to up-scale processes from leaf to the ecosystem level, a step needed to address the effect changes in resources will have on the seasonally dry tropical forest and grasslands, which represent a significant fraction of the total global carbon storage.

Over the past ten years, the Costa Rican dance style known as swing criollo has gone from relative obscurity to acceptance as national heritage. In the 1970s and 1980s, it was considered a dance of the urban working-class chusma, or "riff-raff," because of its associations with the working-class music of cumbia and San José's seedy dance salons. Starting in the early 2000s, however, an active campaign of nationalization and folklorization by dance instructors brought the dance to the status of national patrimony. This was achieved through dance classes, festival performances, the creation of a short video documentary, and the work of the dance company La Cuna del Swing to canonize the dancers and stages of swing criollo. The folklorization of swing criollo at first seems to be a top-down phenomenon that suggests little agency among working-class dancers; they have been personified in the national imaginary as exotic Others, an urban folk from an earlier generation that now exists only to perform and embody that tradition. On further examination, the folklorization of swing criollo represents a new sort of folklore, one that is highly contested and engages in a different discourse of authenticity, some influenced by dancers themselves. Swing criollo as a "modern" and "urban" form has allowed for self-mythmaking among the dancers of the self-proclaimed "old guard" that invented the style. It also legitimizes the dance style in its popular form, as opposed to older projections of folklore that that place tradition in opposition to modernity. I examine discourses surrounding the nationalization of swing criollo as well as the negotiations of spaces of culture through which swing's legitimization unfolded. I conclude by suggesting that ethnomusicologists should continue to theorize folklore's changing nature as it is contested and re-defined to include popular, urban, and modern cultural expressions. / text

Despite the dramatic increase in ecotourism as a sustainable development strategy over the last two decades (Honey 2008; Yunis 2000), theoretical models to interpret and evaluate ecotourism—as well as the broader field of tourism—are lacking (Farrell and Twining-Ward 2003; Weaver and Lawton 2007). Farrell and Twining-Ward (2003) call for a reconceptualization of tourism study that incorporates social-ecological systems (SES) theory. This dissertation responds by assessing ecotourism as an SES in a dryland setting, addressing the question: "What key characteristics of ecotourism increase social-ecological resilience?" The study site is Santa Rosa National Park and surrounding communities in Guanacaste, Costa Rica. Higham and Lück (2008) cite sustainability as the "ultimate goal of ecotourism" (Higham and Lück 2008, p 124); however sustainability itself proves to be a difficult concept to measure and evaluate (Cater and Lowman 1994; Dernbach 2002; Weaver 2001a). SES theory recognizes sustainability as a process rather than an end goal and identifies resilience as a key attribute (Berkes, Colding, and Folke 2003). With ecotourism as an economic strategy of nearly every developing country since the early 1990s and an increasing economic strategy in rural areas worldwide (Valaoras, Pistolas, and Sotiropoulou 2002; Honey 2008), this study investigates ecotourism through the lens of social-ecological resilience for increased sustainability. Based on a 12-month survey conducted in Santa Rosa National Park and the surrounding area, this study identifies characteristics of ecotourism that can cause different levels of resilience using indicators of increasing biodiversity, economic diversity and social capital. These relationships are represented by linked and continually changing social and ecological systems, diagramed by Holling‘s adaptive renewal cycle (Berkes, Colding, and Folke 2003; Gunderson and Holling 2002). Three research papers are included as part of this dissertation: 1) Área de Conservación Guanacaste, Parque Nacional Santa Rosa Ecotourism Study: Final Survey Results, Analysis and Recommendations; 2) Ecotourism‘s Contribution to Social-ecological Resilience: A Case Study Analysis of Rural, Dryland Ecotourism in Guanacaste, Costa Rica; and 3) Barrier-free Ecotourism? The Costa Rican Approach. Findings of this study include recommendations for ecotourism programs to increase social-ecological resilience and contribute to the sustainability of linked SESs.

For decades LGBTQ rights have been approached purely by a legal strategy, in particular advocating for the legalization of same-sex marriage. However, discrimination and violence against the LGBTQ community continues to be a major issue in Latin America because of cultural values such as Catholicism and machismo that uphold a standard of and, in turn, have control over people’s sexuality. Using a human rights approach towards the politics of sexuality, LGBTI activists in Costa Rican and Nicaragua have been successful in transforming public opinion about sexuality and more importantly, sexual diversity. As a result of their egalitarian framework and efforts to educate people about sexual diversity, they have made great advancements toward achieving acceptance and equality for LGBTI people. This study focuses on how Costa Rican and Nicaraguan LGBTI activists have worked around traditional cultural values such as Catholicism and machismo that prevent people from accepting and tolerating LGBTI people. The examples of LGBTI activists in these two countries have important implications for other LGBTI activists and the strategies they use to try to achieve full equality (social and legal) for people whose sexual identity differs from the conventional.

This PhD thesis explores the migration dynamics between Nicaragua and Costa Rica. Rather than just describing the main characteristics of the contemporary migration relations between the two countries, however, it also evaluates the historical and regional contexts within which they have been produced. This has implied the incorporation of a historicised and multi-scale analytical perspective which has been adopted throughout the research. The research therefore explores both expelling and attracting factors in both the origin (with a particular focus upon rural communities in distinct regions of Nicaragua) and the destination. It has also been important to analyse in some detail the continuities and ruptures of the migration history between the two countries in order to understand the current migration dynamics more profoundly. The research stresses that the Nicaraguan Costa Rican migration dynamic should not be seen as as isolated bilateral relationship but as part of a wider dynamic that involves the whole Central American region and that, in general terms, migration should be seen not as an isolated pattern but as a wider process of social transformation.

1. A longstanding goal of ecology and conservation biology is to understand the environmental and biological controls of forest succession. However, the patterns and mechanisms that guide successional trajectories, especially within tropical forests, remain unclear. 2. We collected leaf functional trait and abiotic data across a 110-year chronosequence within a tropical dry forest in Costa Rica. Focusing on six key leaf functional traits related to resource acquisition and competition, along with measures of forest stand structure, we propose a mechanistic framework to link species composition, community trait distributions and forest structure. We quantified the community-weighted trait distributions for specific leaf area, leaf dry matter concentration, leaf phosphorus concentration, leaf carbon to nitrogen ratio and leaf stable isotopic carbon and nitrogen. We assessed several prominent hypotheses for how these functional measures shift in response to changing environmental variables (soil water content, bulk density and pH) across the chronosequence. 3. Increasingly, older forests differed significantly from younger forests in species composition, above-ground biomass and shifted trait distributions. Early stages of succession were uniformly characterized by lower values of community-weighted mean specific leaf area, leaf stable nitrogen isotope and leaf phosphorus concentration. Leaf dry matter concentration and leaf carbon to nitrogen ratio were lower during earlier stages of succession, and each trait reached an optimum during intermediate stages of succession. The leaf carbon isotope ratio was the only trait to decrease linearly with increasing stand age indicating reduced water use efficiency in older forests. However, in contrast with expectations, community-weighted trait variances did not generally change through succession, and when compared to null expectations were lower than expected. 4. The observed directional shift in community-weighted mean trait values is consistent with the 'productivity filtering' hypothesis where a directional shift in water and light availability shifts physiological strategies from 'slow' to 'fast'. In contrast with expectations arising from niche based ecology, none of the community trait distributions were over-dispersed. Instead, patterns of trait dispersion are consistent with the abiotic filtering and/or competitive hierarchy hypotheses.

This paper argues that a State can reconstruct it’s own politics in such a way that allows for more reliance on conflict resolving international organizations and institutions and can reduce the need for military force and/or power politics. Accordingly, the complexities of the security dilemma can be reduced or eliminated. I utilize a single case study approach that analyzes the 2010 territorial conflict known as the ‘Isla Calero’ dispute between Costa Rica and Nicaragua. Using both an inductive approach and semistructured interviews, this paper analyzes how the dispute was settled without the use of power politics. It is argued that Costa Rica was able to halt the cycle of the security dilemma through their decision to demilitarize. Moreover, I argue that Costa Rica’s approach is relevant and applicable to other states and could contribute to successful conflict resolution between States without the use of power politics.