ABSTRACT In regions with water shortages, detailed planning on water resource use is essential. The use of climate models for short- and medium-range forecasts is an important strategy for obtaining early information on the water requirements of crops and the water regime of a particular basin. This study aimed to assess the performance of seasonal climate forecasts and their applicability in estimating irrigation needs. To that end, the Simulation Model for Irrigation Strategies and climate forecast data derived from the Eta model were used. To analyze simulations, five members (days 13, 14, 15, 16 and 17) of the seasonal forecasts of rainfall and reference evapotranspiration for every month between 2001 and 2012 were used. The spread for reference evapotranspiration demonstrated that the model was unable to reproduce the behavior of this variable during the dry period. Comparison between forecasts months in advance showed no significant differences between the rainfall and the reference evapotranspiration forecasts. However, the results obtained for a one-month lead-time forecast exhibited superior performance. shortages essential short mediumrange medium range basin needs end used simulations days 13 14 15 1 17 200 201 period However onemonth one leadtime lead time 20 2

RESUMO Em regiões com baixa disponibilidade hídrica é de grande importância um planejamento mais detalhado sobre o uso de recursos hídricos. A utilização de modelos climáticos destinados às previsões de curto e médio prazo se apresenta como uma estratégia importante para se obter informações antecipadas acerca da demanda hídrica de culturas e do regime hídrico de determinada bacia. Objetivou-se, neste estudo, avaliar o desempenho das previsões climáticas sazonais e sua aplicabilidade na estimativa da demanda de irrigação. Para tanto, utilizou-se o Modelo de Simulação de Estratégias de Irrigação e dados de previsão climática derivados do modelo Eta. Para análise das simulações, foi utilizado um conjunto de cinco membros (dias 13, 14, 15, 16 e 17) de previsão sazonal de precipitação e evapotranspiração de referência para cada mês entre o período de 2001 a 2012. O espalhamento para a evapotranspiração de referência demonstrou que o modelo não foi capaz de reproduzir o comportamento desta variável durante o período seco. Comparação entre previsões com os meses de antecedência não demonstraram diferenças significativas entre previsões da precipitação e da evapotranspiração de referência. Contudo, os resultados obtidos para as previsões com um mês de antecedência apresentaram melhor desempenho. hídricos bacia Objetivouse, Objetivouse Objetivou se, Objetivou-se estudo irrigação tanto utilizouse utilizou Eta simulações dias 13 14 15 1 17 200 2012 seco Contudo 20 201 2

ABSTRACT Social technology is based around three axes: community, environmental protection and economic solidarity. The páramo itself is a vital ecosystem for water regulation as it is the source of water supplies for human consumption and performance of economic activities. This article intends to identify the limitations to apply social technology to the protection of the páramo in the central highlands of Ecuador, where processes of self-management, empowerment, participation, agreement-making, cooperation and pursuit for collective welfare have been observed. The methodology is quantitative within the framework of discourse analysis. The results show that, in order to reach a large agreement for the protection and recovery of the páramo, involving all of the communities settled in the area, it is necessary to overcome limitations mostly related to the lacking attention by the government in regards to basic utilities, management plans for conservation areas and studies for economic alternatives allowing communities to subsist in the lower zones, compromising not to extend their agricultural borders further into the highlands. This information helps strengthen natural resource management from a new perspective.

RESUMEN La tecnología social se fundamenta en tres ejes: la comunidad, el cuidado ambiental y la solidaridad económica. Por su parte, el páramo es un ecosistema vital en la regulación hídrica porque sustenta el suministro de agua para consumo humano y el desarrollo de actividades económicas. Este artículo se centra en identificar las limitaciones para aplicar los fundamentos de la tecnología social en la protección del páramo, ubicado en la Sierra central del Ecuador, lugar donde se observan procesos de autogestión, empoderamiento, participación, logro de acuerdos, cooperación y búsqueda del bienestar colectivo. La metodología es cualitativa, en el marco del análisis del discurso. Los resultados muestran que, para que exista un gran acuerdo de protección y recuperación del páramo, entre todas las comunidades asentadas en esta zona, es necesario vencer limitaciones relacionadas, principalmente, con la falta de atención por parte del gobierno en temas de servicios básicos, planes de manejo para áreas de conservación y estudio de alternativas económicas que permitan a las comunidades subsistir en las zonas bajas y comprometerse a no ampliar la frontera agrícola hacia zonas altas. Esta información contribuye a fortalecer la gestión de recursos naturales desde una nueva perspectiva.

RESUMO A tecnologia social baseia-se em três eixos: a comunidade, o cuidado ambiental e a solidariedade econômica. O páramo é um ecossistema vital para a regulação hídrica pois ele fornece agua para o consumo humano e a realização de atividades económicas. Esse artigo focou-se na identificação das limitações para aplicar os fundamentos da tecnologia social para a proteção do páramo, situado na Sierra central de Equador, sítio onde pode-se observar processos de autogestão, empoeiramento, participação, efetuação de acordos, cooperação e procuração de um bem-estar coletivo. A metodologia é qualitativa, dentro do contexto da análise do discurso. Os resultados mostram que, para ter um acordo grande para a proteção e recuperação do páramo, com todas as comunidades estabelecidas na zona, é necessário vencer limitações relacionadas principalmente à falta de atenção do governo em relação à serviços básicos, planes de gestão de áreas de conservação e estudo de alternativas económicas que permitam que as comunidades possam subsistir nas zonas baixas, e comprometer-se a não estender a fronteira agrícola em direção às zonas altas. Essa informação contribui a fortalecer a gestão de recursos naturais com uma nova perspectiva.

Resumen. La mojarra (Eucinostomus currani) es un recurso importante de subsistencia en mercados locales de Ecuador. Sin embargo, poco es sabido sobre la historia de vida temprana y la biología reproductiva de esta especie. En 2016 y 2017, se recolectaron larvas de E. currani en 3 playas arenosas en el Golfo de Guayaquil, Ecuador, y se identificaron usando códigos de barras de ADN. La longitud estándar de las larvas osciló entre 4.00 y 15.78 mm. También recolectamos otolitos para comprender mejor la historia de vida temprana de E. currani. Los otolitos se usaron para estimar la edad, la tasa de crecimiento de la población (±EE), las fechas de eclosión y la época reproductiva. En promedio, la edad de los peces fue de 16.5 ± 4.5 días, mientras que la tasa de crecimiento promedio fue de 0.70 ± 0.05 y 0.22 ± 0.16 mm por día en marzo y mayo, respectivamente. En el Golfo de Guayaquil, la mayoría de las fechas de eclosión y la actividad reproductiva presunta de E. currani ocurrió durante la época húmeda (diciembre-abril) cuando aguas más calidas prevalecieron. Hasta donde tenemos conocimiento, este es el primer estudio que estima las fechas de eclosión y la tasa de crecimiento larval para una especie de la familia Gerreidae en el Océano Pacífico.

Abstract. The flagfin mojarra (Eucinostomus currani) is an important subsistence fishery resource in local Ecuadorian markets; however, very little is known about the early life history and reproductive biology of this species. In 2016 and 2017, E. currani larvae were collected at 3 sandy beaches in the Gulf of Guayaquil, Ecuador, and identified using DNA barcoding. Standard lengths ranged from 4.00-15.78 mm. We also collected otoliths to better understand the early life history of E. currani. Otoliths were used to estimate the age, population growth rate (±SE), hatch dates, and reproductive period. On average, the fish were 16.5 ± 4.5 days old, while the average growth rate was 0.70 ± 0.05 and 0.22 ± 0.16 mm per day in March and May, respectively. In the Gulf of Guayaquil, most hatch dates and the presumed reproductive activity of E. currani occurred during the wet season (December-April) when warmer water prevailed. To our knowledge, this is the first study to estimate the hatch dates and larval growth rate for a species of the family Gerreidae in the Pacific Ocean.

The water resources within the lower section of the Upper Vaal catchment, where the Vaal Barrage is situated, are highly utilised and developed, and water quality regulation has become a contested space between resource users and the regulators. The credibility and scientific defensibility of discharge standards in water-use licences (WULs), the relationship between upstream and downstream waste loads, the relationship between flows and water quality standards in WUL, and the water quality components of the resource quality objectives (RQOs) are being contested. This study explores the perceptions and motivations underlying these contestations as a contribution to scientific understanding of water quality management in a highly developed system. Perceived unrealistic RQOs, perceived lack of scientific credibility of the methods for deriving water quality standards in WUL, data inadequacy, as well as poor institutional capacity were identified as the top motivations for contesting applicable regulatory instruments in the catchment. Punitive measures, incentives, and education and awareness-raising were identified as key to accelerating compliance. Overall, this paper contributes to our general understanding of the intricacies of water quality management within a contested space. SIGNIFICANCE: Water quality management in South Africa is increasingly becoming a contested space, particularly in catchments that are highly developed and utilised. The findings in this study imply that (1) there is a need for a multi-pronged approach to increase water quality compliance, (2) there is a need for trust within the regulatory system to foster confidence among actors and stakeholders, and (3) transparent, open processes and scientifically credible and defensible methods, and data are needed for deriving standards in water-use licences (WULs).

Abstract: Environmental pollution from transportation has been a fundamental challenge for humanity throughout history, with conventional fuels contributing significantly to environmental degradation. This project seeks to suppress pollution and reduce noise generated by motorcycle taxis, whether for personal and/or private use. The main objective of the research work was to implement an electrolyzer in the combustion system of a motorcycle taxi to suppress environmental pollution and reduce noise. Methods included vehicle preparation, electrolyzer installation, battery adjustment, hydrogen generation, emissions measurement, safety, and data collection. As a result, the electrolyzer was implemented in the single-cylinder motorcycle taxi; The noise limit allowed at work in Peru is 85 dB, which is equivalent to 100 % noise at most; When using gasoline, a value of 76.4 dB was obtained, equivalent to 89.88 % noise, and when using hydrogen, a value of 71.7 dB was obtained, equivalent to 84.35 % noise, therefore, the total noise reduction was 4.70 dB (5.53 %) than established. The discussion highlighted that hydrogen is a clean fuel, with zero emissions and only emitting water vapor instead of polluting gases (5). The conclusion highlights the critical importance of the research, supported by the total reduction of 5.53 % of noise with this new technology and in turn external sources support that using hydrogen produced a smoother and quieter combustion; Regarding the useful life of the engine, due to the cleaner and more efficient combustion, the accumulation of waste was reduced, which benefits reducing the wear of internal components and the need for costly maintenance.

Resumen: La contaminación ambiental derivada del transporte ha sido un desafío fundamental para la humanidad a lo largo de la historia, con los combustibles convencionales contribuyendo significativamente a la degradación ambiental. Este proyecto busca suprimir la contaminación y reducir el ruido generada por mototaxis, ya sean de uso personal y/o privado. El trabajo de investigación tuvo como objetivo principal implementar un electrolizador en el sistema de combustión de un mototaxi para suprimir la contaminación ambiental y reducir el ruido. Los métodos incluyeron la preparación del vehículo, instalación del electrolizador, ajuste de la batería, generación de hidrógeno, medición de emisiones, seguridad y recolección de datos. Como resultado, se logró implementar el electrolizador en el mototaxi monocilíndrico; el límite de ruido permitido en el trabajo en el Perú es de 85 dB, que equivalen el 100 % de ruido como máximo; al utilizar gasolina se obtuvo un valor de 76.4 dB equivalentes a 89.88 % de ruido y al usar hidrógeno se obtuvo un valor de 71.7 dB siendo el 84.35 % de ruido, por lo tanto, la reducción total de ruido fue de 4.70 dB (5.53%) de lo establecido. La discusión destacó que el hidrógeno es un combustible limpio, con nulas emisiones y solo emitiendo vapor de agua en vez de gases contaminantes (5). La conclusión subraya la importancia crítica de la investigación, respaldada por la reducción total del 5.53 % de ruido con esta nueva tecnología y a su vez fuentes externas apoyan, que el utilizar hidrógeno produjo una combustión más suave y silenciosa. En cuanto a la vida útil del motor, la combustión más limpia y eficiente reduce la acumulación de residuos, lo que disminuye el desgaste de los componentes internos y la necesidad de mantenimientos costosos.

Resumen: Antecedentes: La fenología del follaje, bioquímica, longevidad foliar y propiedades espectrales del tejido foliar deben variar dentro y entre especies. Sin embargo, la covariación interespecífica entre fenología del follaje y espectroscopía foliar rara vez se ha demostrado en ambientes áridos estacionales. Preguntas y / o Hipótesis: Probamos la hipótesis de covariación intra e interespecífica entre tasas de crecimiento y variabilidad en fenología del follaje e índices espectroscópicos. Especies de estudio / Descripción de datos / Modelo matemático: La variación intra e interespecífica en número relativo de hojas, características funcionales y espectroscopía foliar se cuantificó en nueve especies de arbustos perennes de chaparrales. Sitio y años de estudio: Rancho El Mogor, Valle de Guadalupe, Baja California, de 2017 a 2018. Métodos: La fenología del follaje se cuantificó con índices del número relativo de hojas, junto con el crecimiento de tallo y variables funcionales de hojas y la espectroscopía con tres índices de vegetación. Resultados: Las especies deciduas presentaron mayores tasas de crecimiento en tallo. Los tres índices de vegetación variaron interespecíficamente (ca. 20 % varianza explicada), e intraespecíficamente entre estaciones (ca. 55 % varianza explicada). Los tres índices de vegetación estuvieron correlacionados y solamente NDVI se asoció con la variabilidad del follaje y el crecimiento de tallo. Conclusiones: El número relativo de hojas y la espectroscopía foliar de especies de chaparral están asociados con características funcionales en un ambiente árido estacional.

Abstract Background: Canopy phenology, foliar biochemistry, and leaf lifespan vary according to season within and across species. Intrinsically, this variation should also determine changes in the spectral properties of foliar tissue. However, whether canopy phenology and leaf spectroscopy co-vary across species has seldom been tested in seasonal drylands. Questions and / or Hypotheses: We tested the covariation between growth rate, foliage phenology, and leaf spectral indices, expecting that species with high growth rates should have large variability in relative leaf number and foliar spectroscopy. Studied species / data description / Mathematical model: We partition the intra and interspecific variation in relative leaf number and spectroscopy within nine perennial chaparral shrub species. Study site and dates: Rancho El Mogor, Valle de Guadalupe, Baja California, during 2017 and 2018. Methods: Foliage phenology was quantified with an index of relative leaf number, foliar spectroscopy with three standard vegetation indices, and resource-use with stem growth and leaf functional traits. Results: Species with higher variability in foliage phenology (more deciduous species) had higher stem growth rates. The three vegetation indices varied significantly across species (ca. 20 % of explained variance), and across seasons within species (ca. 55 % of explained variance). The values of the three vegetation indices were correlated, and only NDVI was correlated with foliage phenology and stem growth. Conclusions: Our results show that variations in relative leaf number and spectroscopy in chaparral species are coupled with functional traits of species involved in resource exploitation strategies in a seasonally arid environment.

Globally, the demand for mineral products is ever increasing. Extraction of these mineral resources results in the continuous production of a huge volume of waste material, including tailing dumps. The mass of tailings usually exceeds the actual resource and often contains hazardous contaminants. This study investigated the effects of tailings disposal on soil, water, and air quality in the Nampundwe area. Water, soil, and dust samples were collected from different locations in the surrounding communities. The constituents analysed in the samples included copper, cobalt, iron, sulfate, and silica. According to the results obtained, some seepages occurred from the tailings impoundment to the shallow aquifer in the area. However, the general water quality meets the Zambia Environmental Management Agency (ZEMA) statutory limits. Recorded concentrations of sulfate (1500 mg/l), copper (1.5 mg/l), cobalt (1.0 mg/l), iron (2.0 mg/l), and silica were between 0.003 mg/l and 705 mg/l, which is far below ZEMA's statutory limit. Silica concentration was also evident in the air. The highest concentration recorded was 260 ppcc (particle per cubic centimeter) recorded in July 2019 from the northern direction of the tailings dam. The concentration was below the statutory limit of 350 ppcc. The topsoil from the northern part of the tailings recorded a silica dust concentration of 39.9 ppcc. Iron was evident in the underground soil with a concentration of 8.01 ppcc, cobalt 0.005 ppcc, copper 0.051 ppcc, while sulfate was recorded as 0.41 ppcc.

Abstract In areas with arid and semi-arid climates, the availability and quality of water are critical factors for the development of agronomy. To face the challenge, an alternative for the use of this resource is the implementation of efficient and sustainable techniques such as the use of drip irrigation. The objective of the work was to analyze the agronomic behavior of rye under unfavorable water and temperature conditions to determine the effectiveness of phenotypic stability on La Costa de Hermosillo, Sonora, Mexico. Two rye genotypes were planted under a split plot experimental design (large plot: three water levels and small plot: two genotypes of seeds obtained in different cycles). The agronomic characteristics of the plant, the physicochemical characteristics of the grain were evaluated; and the significance between the different variables was determined with a correlation analysis. The analysis of variance revealed effects on plant height, number of spikes and grains, grain size, thousand grain weight, yield and protein content of rye due to the different water regimes used. Between 219-314 spikes per linear meter were obtained, with a commercially acceptable grain size (7.45-7.95 mm long x 2.18-2.40 mm wide). High yield values (1.72-3.11 t ha-1) were also observed, as well as excellent protein content (20.3-22.8%). These results demonstrate that rye is a versatile cereal that adapts to adverse environmental conditions such as a decrease in the amount of irrigation water and extremely high temperatures.

Resumen En zonas de clima árido y semiárido, la disponibilidad y la calidad del agua son factores críticos para el desarrollo de la agronomía. Para enfrentar el desafío, una alternativa para el aprovechamiento de este recurso es la implementación de técnicas eficientes y sostenibles como el uso de riego por goteo. El objetivo del trabajo fue analizar el comportamiento agronómico del centeno en condiciones desfavorables de agua y temperatura para determinar la efectividad de la estabilidad fenotípica en la Costa de Hermosillo, Sonora, México. Se sembraron dos genotipos de centeno bajo un diseño experimental de parcelas divididas (parcela grande: tres niveles de agua y parcela chica: dos genotipos de semillas obtenidas en ciclos diferentes). Se evaluaron las características agronómicas de la planta, las características fisicoquímicas del grano; y se determinó la significancia entre las distintas variables con un análisis de correlación. El análisis de varianza reveló efectos sobre la altura de la planta, el número de espigas y de granos, tamaño de grano, el peso de mil granos, rendimiento y contenido de proteína del centeno debido a los diferentes regímenes hídricos utilizados. Se obtuvieron entre 219-314 espigas por metro lineal, con tamaño de grano comercialmente aceptable (7.45-7.95 mm largo x 2.18-2.40 mm ancho). También se observaron valores de rendimiento altos (1.72-3.11 t ha-1), así como un excelente contenido de proteína (20.3-22.8%). Estos resultados demuestran que el centeno es un cereal versátil que se adapta a condiciones ambientales adversas como disminución en la cantidad de agua de riego y temperaturas extremadamente altas.

In the context of South Africa's water scarcity, desalination has emerged as a possible solution for coastal areas. However, the quality of the intake water for desalination is often problematic, prompting the need for pre-treatment. The aim of this study was to conduct a comparative environmental life cycle assessment (LCA) on 4 seawater filtration systems intended for the pre-treatment of a reverse osmosis desalination project. These systems were implemented in a pilot trial and are based on modern water treatment technologies, namely, granular filtration (pressure driven and gravity driven), dissolved air flotation (DAF), and ultrafiltration (UF). For all 4 systems, data were collected for both the construction and operation phases, and LCAs were performed, resulting in environmental scores that allow for comparison based on the pre-treatment of 1 kL of seawater of the same quality. The SimaPro LCA tool and the ReCiPe midpoint method were used and environmental scores were calculated for 18 impact categories, including climate change, acidification, toxicity, eutrophication, resource depletion, etc. This methodology also allowed the identification of the highest environmental burdens/scores within each system. The most significant finding is that local electricity consumption is responsible for the greatest proportion of environmental impacts. Thus, the systems consuming more energy for operating equipment such as blowers, pumps, and mixers were found to have the highest environmental burdens. Hence, the DAF system has the highest environmental scores for most impacts, followed by the single-phase gravity filtration system, then the two-phase partial pressure filtration system and finally the UF system. Therefore, focus should shift towards energy optimisation of process units, especially the rotary ones, as well as energy mitigation and recovery strategies. The use of renewable energy for pre-treatment should also be considered locally.

Resumo O noroeste pacífico da Costa Rica é uma região com uma estacionalidade no regime de chuvas muito marcada. Somado a essa sazonalidade, esta área da Costa Rica é propensa a fenômenos hidroclimáticos extremos como secas e inundações, por exemplo. A distribuição limitada de pluviômetros ou a falta de disponibilidade de informações relevantes fazem com que os dados complementares obtidos de satélites e suas respectivas reanálises sejam fundamentais para obter informações cruciais e, assim, embasar as ações de gestão dos recursos hídricos e suas repercussões nos ecossistemas, tanto naturais quanto produtivos. Para analisar os padrões de precipitação, foram analisadas as séries temporais de precipitação do produto CHIRPS para cinco ecorregiões delimitadas na Área de Conservação Guanacaste, no Pacífico noroeste da Costa Rica. Estas curvas foram correlacionadas com as séries temporais das regiões de monitoramento da temperatura superficial do mar nas regiões Niño 1.2, Niño 3, Niño 3.4 e Niño 4. Todas as ecorregiões analisadas correlacionaram de forma negativa e forte com a região do Niño 1.2, com valores de R entre -0.72 e -0.74. Além disso, foi detectado um atraso na curva do Niño 4 de quatro a cinco meses, em relação à curva da região Niño 1.2. O estudo sugere que a anomalia do El Niño 4, com um desfasamento de aproximadamente 4 a 5 meses, pode ser utilizada como indicador de possíveis impactos nos padrões de precipitação nas diferentes ecorregiões estudadas. Este tempo é suficiente para planejar ações, especialmente no setor agroprodutivo. Neste trabalho, é demonstrado o potencial de previsibilidade dos efeitos do fenômeno ENOS sobre o padrão de precipitação em áreas extensas e com certa homogeneidade ecossistêmica, como as ecorregiões na Área de Conservação Guanacaste.

Abstract The Pacific Northwest of Costa Rica is a region with marked seasonality in rainfall patterns. This area of Costa Rica is prone to extreme hydroclimatic phenomena such as droughts and floods. Due to the limited distribution of rainfall gauges and the unavailability of relevant information, complementary data obtained from satellites and their respective reanalyzes become imperative for acquiring crucial information. This information can support water resource management actions and their impacts on both natural and productive ecosystems. To analyze the precipitation patterns, we utilized the CHIRPS product’s precipitation time series for five ecoregions within the Guanacaste Conservation Area, located in the northwestern Pacific region of Costa Rica. These curves were strongly and negatively correlated with time series from sea surface temperature monitoring regions, including Niño 1.2, Niño 3, Niño 3.4, and Niño 4. All analyzed ecoregions exhibited strong negative correlations with the Niño 1.2 region, with correlation coefficients (R values) ranging between -0.72 to -0.74. Additionally, a lag of four to five months was observed in the Niño 4 curve compared to the Niño 1.2 region. This study suggests that the Niño 4 anomaly, with a lag of approximately 4 to 5 months, can serve as an indicator of possible impacts on precipitation patterns in different ecoregions. This provides sufficient time to plan actions, particularly within the agricultural sector. This study demonstrates the potential predictability of the effects of ENSO phenomenon on precipitation patterns for large areas with a certain eco-systemic homogeneity, such as the ecoregions in the Guanacaste Conservation Area.

Resumen El pacífico noroeste de Costa Rica es una región con una estacionalidad en el régimen de lluvias muy marcada. Sumado a dicha estacionalidad, esta área de Costa Rica es propensa a fenómenos hidroclimáticos extremos como sequías e inundaciones, por ejemplo. La escasa distribución de pluviómetros o bien, la no disponibilidad de información pertinente, hacen que los datos complementarios obtenidos de satélites y sus respectivas reanálisis, sean fundamentales para disponer de información crucial y así poder fundamentar las acciones de gestión del recurso hídrico y sus repercusiones en los ecosistemas, tanto naturales como productivos. Para analizar los patrones de precipitación, se analizaron las series de tiempo de precipitación del producto CHIRPS para cinco ecorregiones delimitadas en el Área de Conservación Guanacaste, en el Pacífico noroeste de Costa Rica. Estas curvas se correlacionaron con las series de tiempo de las regiones de monitoreo de la temperatura superficial del mar en las regiones Niño 1.2, Niño 3, Niño 3.4 y Niño 4. Todas las ecorregiones analizadas correlacionaron de forma negativa y fuertemente con la región del Niño 1.2, con valores de R entre -0.72 y -0.74. Por otra parte, se detectó un rezago en la curva de Niño 4 de cuatro a cinco meses, con la curva de la región Niño 1.2. El estudio sugiere que la anomalía del Niño 4, con un desfase de aproximadamente 4 a 5 meses, puede ser utilizada como indicador de posibles impactos en los patrones de precipitación en las diferentes ecorregiones estudiadas. Este tiempo es suficiente para planear acciones, sobre todo en el sector agroproductivo. En este trabajo se muestra el potencial de predictibilidad de los efectos del fenómeno ENOS sobre el patrón de la precipitación para áreas extensas y con cierta homogeneidad ecosistémica, como son las ecorregiones en el Área de Conservación Guanacaste.

Abstract The study of the freshwater-saltwater interface zone (FWSWI) is fundamental for the characterization of coastal aquifers and the evolution of freshwater reserves. In this work we study the factors that condition the dynamics of the IADAS in the locality of Pinamar. To carry out this task, a monitoring borehole was drilled on the coastal front, electrical conductivity (EC) profiling was performed, and continuous pressure, temperature and salinity sensors were installed. Information was collected from the tide gauge located in the town of Santa Teresita, while hydrometeorological data were obtained from a station located in the town of Pinamar. A correlation between high tide events and salinity, water level and temperature values were verified. The response times between the rise of the tide and the increase of the salinity are less than 8 hours, while the interval required to reach equilibrium again takes at least 2 days. Temperature variations are influenced by the prevailing climatic conditions at the time of the rising tide. The analysis of the relationship between storage variation and high tide events allows inferring that, when recharge events occur, there is a greater stability due to the increase of the hydraulic load on the IADAS. The study of IADAS behavior is an effective indicator for resource management.

Resumen El estudio de la zona de interfase agua dulce-agua salada (IADAS) resulta fundamental para la caracterización de acuíferos costeros y la evolución de las reservas de agua dulce. En este trabajo se estudian los factores que condicionan la dinámica de la IADAS en la localidad de Pinamar. Para llevar a cabo esta tarea se realizó una perforación de monitoreo sobre el frente costero, se realizaron perfilajes de conductividad eléctrica (CE) y se instalaron sensores continuos presión, temperatura y salinidad. Se recopiló información proveniente del mareógrafo ubicado en la localidad de Santa Teresita mientras que los datos hidrometeorológicos se obtuvieron a partir de estación ubicada en la localidad de Pinamar. Se verifica una correlación entre los eventos de pleamar y los valores de conductividad eléctrica, nivel hidráulico y temperatura. Los tiempos de respuesta entre el ascenso de la marea y el aumento de la salinidad se reconocen menos de 8 horas, en tanto que el intervalo requerido para alcanza nuevamente el equilibrio demora al menos 2 días. Las variaciones de la temperatura se encuentran influenciadas por las condiciones climáticas dominantes al momento del ascenso de la marea. El análisis de la relación entre la variación del almacenamiento y los eventos de pleamar permiten inferir que, cuando se producen eventos de recarga, existe una mayor estabilidad debido al incremento de la carga hidráulica sobre la IADAS. El estudio del comportamiento de la IADAS resulta un indicador eficaz para la gestión de los recursos hídricos en sectores costeros.

Abstract The marketing of microbial pesticides has increased exponentially in recent years. Almost 70 % of the products marketed use as active ingredient conidia of biocontrol fungi, and One of the most frequently used criteria to evaluate the quality of these products is conidial germination test, Specifically, this methodology is used to select and assess the viability and vigor of elite strains with biological potential. Some of the factors that influence conidial germination over time, include the selection of culture medium, temperature, incubation time, and the addition of germination synchronizing agents. The optimization for each elite strain allows the characterization of a microorganism behavior over time, ensuring its biological activity and effective management as a biological resource for commercial purposes. The main objective of this study was to identify the optimal conditions (culture media, incubation time, and synchronizing agent concentration) for the germination of three elite strains: Trichoderma koningiopsis (Th003), Lecanicillium lecanii (Vl026), and Metarhizium robertsii (Mt004), which are active ingredients in biopesticides. As a result, the optimal conditions selected are as follows: agar-water medium with 0.0003 % benomyl for Th003 with an incubation period of 18 hours, agar-water medium with 0.0003 % benomyl for Vl026 with an incubation period of 24 hours, and PDA agar supplemented with 0.0003 % benomyl for Mt004 with an incubation period of 18 hours. These conditions will allow a precise evaluation of the germination of the biological control agents ensuring over time their viability and vigor as active ingredients in biopesticides.

Resumen La comercialización de plaguicidas microbianos ha aumentado de manera exponencial en los últimos años. Casi el 70 % de los productos que se comercializan utilizan como principio activo conidios de hongos biocontroladores y uno de los criterios más utilizados para evaluar la calidad de estos productos es la prueba de germinación de conidios. Específicamente, se utiliza para la selección y la evaluación de la viabilidad y vigor de cepas élite con potencial biológico. Algunos de los factores que influyen en la germinación de los conidios incluye la selección del medio del cultivo, la temperatura, el tiempo de incubación y la adición de sustancias sincronizadoras de germinación. La optimización para cada cepa élite permite estimar el comportamiento del microorganismo, lo que garantizará su actividad biológica y eficacia, al ser un recurso biológico con fines comerciales. El objetivo de este trabajo fue seleccionar las condiciones óptimas (medios de cultivo, tiempo de incubación y concentración de sustancia sincronizadora) para la germinación de tres cepas élite Trichoderma koningiopsis (Th003), Lecanicillium lecanii (Vl026) y Metarhizium robertsii (Mt004), las cuales son principios activos de bioplaguicidas en proceso de comercialización. Como resultado se seleccionó el medio de cultivo de agar agua con benomil al 0,0003 % con un tiempo de lectura de 18 h para Th003 y de 24 h para Vl026. Para la cepa Mt004, el medio de cultivo que favoreció la germinación sincrónica de los conidios fue agar PDA suplementado con benomil al 0,0003 % con un tiempo de lectura de 18 h. Estas condiciones permitirán a través del tiempo realizar una correcta evaluación de la germinación de los agentes de control biológico y garantizar su viabilidad y vigor como principio activo de bioplaguicidas.

Summary Background and aims: In the Atacama Desert certain plant species can be found in small and isolated areas, limited to regions with water availability. The degree of connectivity within and between these natural populations depends on their pollen and seed dispersal abilities, as well as on the barriers imposed by the landscape. Prosopis flexuosa is a species of high economic and ecological importance included in the algarrobo Conservation and Management program. The main objective of this work is to analyze the genetic variability and mating system of P. flexuosa in the Atacama Desert. M&M: Genetic diversity parameters as well as the mating system were evaluated in a natural population (Quillagua) based on microsatellite molecular markers. The hierarchical distribution of genetic variance and kinship coefficients were analyzed. Results: The results indicate high levels of genetic diversity (HE = 0.67-0.65; Ar = 3.83.7), high outcrossing rates (tm = 0.97, ts = 0.85), low biparental inbreeding (11.6%) and multiple paternity. The proportion of full sibs decreases when considering seeds from the same or different pods (89[PRESERVECIRC]16%). Only the variance between families is significant (p < 0.001) and mean kinships estimated show that progenies within families are not only constituted by half sibs. Conclusions: The results are discussed and related to the limited pollen and seed dispersal and their implication for the management of this resource. The study of the mating system parameters of this Chilean desert population suggests that the low population density and the environment fragmentation would not be influencing their mating capacity.

Resumen Introducción y Objetivos: En el desierto de Atacama ciertas plantas viven aisladas y acotadas a regiones con disponibilidad de agua. La conectividad dentro y entre poblaciones depende de las barreras impuestas por el paisaje y de su capacidad de dispersión. Prosopis flexuosa es una especie con alta importancia económica y ecológica incluida en el Programa de Conservación y Manejo del algarrobo. El objetivo de este trabajo es analizar la variabilidad genética y sistema de fecundación de P. flexuosa en el Desierto de Atacama. M&M: Se evaluó la diversidad genética y el sistema de fecundación sobre la base de marcadores moleculares microsatélites en una población natural (Quillagua). Se analizó la distribución jerárquica de la varianza genética y los niveles de las coancestrías. Resultados: Los resultados indican altos niveles de diversidad genética (HE = 0,67-0,65; Ar = 3,8-3,7), fecundación principalmente cruzada (tm = 0,97, ts = 0,85), baja endogamia biparental (11,6%) y paternidad múltiple. La proporción de hermanos completos disminuye cuando se consideran semillas del mismo o diferente fruto (89[PRESERVECIRC]16%). Solamente la varianza entre familias resulta significativa (p < 0,001) y las coancestrías promedio estimadas dan cuenta que las progenies familiares no están conformadas solamente por medios hermanos. Conclusiones: Los resultados son discutidos y relacionados con la dispersión limitada del polen y semillas y su implicancia para el manejo. El estudio del sistema de fecundación de esta población del desierto chileno sugiere que la baja densidad poblacional y la fragmentación del ambiente no influirían en su capacidad de apareamiento.

Resumen Este artículo tiene como objetivo visibilizar el proceso de institucionalización, participación y conflicto social en torno a la gestión y manejo del agua potable en Costa Rica y estima como punto de arranque la segunda década del siglo XX, la cual discurre hacia la construcción de un eficaz modelo centralizado-descentralizado a partir de la década de 1970. Dicho proceso es analizado mediante la identificación de tres periodos históricos diferenciados mediante los cuales se pretende explicar el continuun, cambios, vacíos y conflictos de intereses del modelo de gestión del agua y su marco jurídico. El principal hallazgo es mostrar o poner en evidencia que la participación comunitaria bajo el mencionado modelo de gestión centralizado-descentralizado, aún vigente, ha garantizado la protección del agua para el bien común y parece ser, hasta ahora, una coraza legal-institucionalizada que impide la privatización del líquido vital. Se concluye que los intentos de privatizar la disponibilidad del agua potable con fines comerciales, no ha conseguido distorsionar la función social del Estado, la cual es proteger y garantizar el agua como un bien público.

Résumé Cet article vise à rendre visible le processus d'institutionnalisation, de participation et de conflit social lié à la gestion et à la distribution de l'eau potable au Costa Rica. Il prend comme point de départ la deuxième décennie du XXe siècle qui mène à la construction d'un modèle efficace centralisé-décentralisé à partir des années 1970. Ce processus est analysé en identifiant trois périodes historiques distinctes pour expliquer la continuité, les changements, les lacunes et les conflits d'intérêts du modèle de gestion de l'eau et de son cadre juridique. La découverte principale consiste à mettre en évidence que la participation communautaire sous le modèle de gestion centralisé-décentralisé, toujours en vigueur, a garanti la protection de l'eau pour le bien commun. Jusqu'à présent, il semble être une protection légale-institutionnalisée empêchant la privatisation du liquide vital. On a conclu que les tentatives de privatisation de l'accès à l'eau potable à des fins commerciales n'ont pas réussi à déformer la fonction sociale de l'État, qui est de protéger et de garantir l'eau en tant que bien public.

Abstract This article aims to shed light on the process of institutionalization, participation, and social conflict regarding the management of drinking water in Costa Rica. It takes the second decade of the 20th century as its starting point, leading towards the construction of an effective centralized-decentralized model from the 1970s. This process is analyzed by identifying three distinct historical periods, through which the article seeks to explain the continuum, changes, gaps, and conflicting interests of the water management model and its legal framework. The main finding highlights that community participation under the mentioned centralized-decentralized management model, still in force, has ensured the protection of water for the common good. It appears to be, up to now, a legally institutionalized shield preventing the privatization of this vital resource. The conclusion is that attempts to privatize the availability of drinking water for commercial purposes have not succeeded in distorting the social function of the State, which is to protect and guarantee water as a public good.

Abstract: Water resource management is an important issue that involves several factors such as economics, social, politician, among others, for its adequate administration. Water can be classified according to its usage purposes since it is used for human consumption, industrial usage, agriculture, etc. Thus, correct strategies to manage this vital liquid are essential to effectively use it. This paper studies water management from a mathematical optimization approach by considering factors and constraints that may suit real-world conditions. The proposed mathematical model is based on the classical transportation problem, which is well-known in the literature. We perform an empirical evaluation of the proposed model using off-the-shelf optimization software over a set of proposed instances, and the results show the feasibility of the proposal. Finally, we discuss the faced challenges in the research and possible future research directions that may help the management of water resources from a computational approach.