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Monitoreo de la dinámica de sedimento para la gestión hídrica del Río Papaloapan (México) mediante aplicaciones geomáticas.
No full textSearching for manatees in the dark waters of a transboundary river between Mexico and Belize: a predictive distribution model.
No full textAntillean manatees in the Hondo River have been recorded from aerial and aquatic surveys, and interviews. However, these studies have been conducted only in the lower riverbed, leaving a gap of information about their presence and habitat characteristics in the rest of the river. We characterize and determine the ecohydrological variables influencing the presence and habitat use of manatees in the Hondo River. During 2017 and 2018, 30 based-boat field trips were conducted in five consecutive transects of 15 km each. A mixed methodology was used for manatee detection: side-scan sonar, direct sightings, and feces collection. Ecohydrological variables were measured in all transects and fixed points. The survey effort was 136.5 h. We recorded 123 manatees: 47% were observations during the boat-based surveys, 29% were at fixed points, and 24% were opportunistic. Additionally, 10 manatee feces were found. The first transect of the river showed the highest relative abundance for the two sampled seasons (windy = 0.27 manatees/km, dry = 0.55 manatees/km). According to the Poisson model, the estimated population was equal to 51 manatees. A random forest model suggested high probability of observing manatees in the first transects and decreasing at the upstream. The ecohydrological variables influencing the detection of manatees were conductivity, transparency, depth, and proximity to the Four Mile lagoon. The first two transects have ecohydrological characteristics that makes a benign environment for refuge, rest and feeding of manatees. We recommend carrying out conservation efforts in the first transects, such as protection and the regulation of boat transit
Making the post-2020 global biodiversity framework a successful tool for building biodiverse, inclusive, resilient and safe food systems for all
No full text
Unraveling the Complexity of Coffee Leaf Rust Behavior and Development in Different Coffea arabica Agroecosystems
No full textCrop health management systems can be designed according to practices that help to reduce crop losses by restricting pathogen development and promoting host plant growth. A good understanding of pathogen and host dynamics, which are interdependent, is therefore needed. In this article, we used a holistic approach to explain the behavior of coffee leaf rust (CLR), a major coffee disease. We monitored coffee plant and CLR dynamics simultaneously in plots under different disease management and agroforestry systems. Diseased leaves were also collected to characterize inoculum stock and rust life stages (latent rust area, area with uredospores, necrosis due to rust) through picture analysis. We used structural equation modeling to obtain an overview of CLR pathosystem functioning on a plant scale. This overview integrates processes such as disease dilution by host leaf renewal, direct and indirect effects of fruit load on CLR development, antagonistic effects of shading depending on rust life stages, the tonic effect of copper-based fungicides on leaf retention, and effects on rust life stages depending on fungicide types
Coffee agroforestry systems capable of reducing disease-induced yield and economic losses while providing multiple ecosystem services
No full textCrop losses caused by pests and diseases decrease the incomes and threaten the livelihoods of thousands of families worldwide.During two years, in a research network of 61 coffee plots under a wide variety of shade and management conditions in Turrialba, Costa Rica, we quantified primary and secondary coffee losses (yield and economic losses) and indicators of three other ecosystem services: provisioning of agroforestry products (bananas, plantains, other fruits, and timber), maintenance of soil fertility and carbon sequestration. We then performed an analysis of the relationships between losses and ecosystem service indicators. Our results suggest that the regulation of diseases and associated losses in agroforestry systems should be based on, and take advantage of, the positive effects of plant biodiversity, adequate shade cover, good soil fertility, and minimal use of fungicides
Cambios en la estructura productiva y emisiones de carbono en la economía salvadoreña para el período 2005-2014
No full textTesis (Mag.Sc.) - CATIE, Turrialba (Costa Rica), 2020El diseño de políticas de mitigación es determinante dadas sus implicaciones ambientales, sociales y económicas, así como los co-beneficios que se derivan de la puesta en marcha de acciones dirigidas a la disminución de emisiones. Esta tesis indaga, mediante la aplicación del análisis insumo-producto, cuáles son los sectores clave de la economía salvadoreña respecto a las emisiones de 2 para el año 2014, identificando los sectores que emiten CO2 directamente y también aquellas ramas que bajo dicho enfoque no figuran, pero que cuando se analizan las interacciones dentro de la estructura productiva se vuelven importantes por el arrastre que tienen hacia otros sectores. Los principales resultados exponen que las ramas transporte; electricidad, gas y agua; construcción y productos del petróleo, químicos y minerales no metálicos son los sectores clave para la mitigación. Asimismo, se aplica un análisis de descomposición estructural (ADE) a través del cual se identifican el efecto intensidad de las emisiones (EIE), cambio tecnológico (ET), estructura y nivel de la demanda final (EEDF y ENDF) como fuentes de cambio de las emisiones. Los resultados indican que los dos componentes que han determinados la tendencia de las emisiones en el período son EIE y ENDF. Asimismo, se incorpora un análisis de sensibilidad de los resultados, aplicando 24 técnicas de descomposición
Shade tree Chloroleucon eurycyclum promotes coffee leaf rust by reducing uredospore wash-off by rain
No full textaddition, may interact with environment. To better understand shade trees effects on coffee leaf rust (CLR), we
studied three disease stages separately: sporulation, uredospore wash-off by rain, and uredospore deposition on
leaves. The study was conducted during almost one year in the long-term trial on coffee-based agroforestry
systems established by CATIE in 2000, in Turrialba, a low altitude area of Costa Rica. We only used the Full Sun
and Shade provided by Chloroleucon eurycyclum treatments. For studying sporulation, we harvested diseased
leaves every three weeks and collected the uredospores present on the lesions. For assessments of uredospore
wash-off, we located containers at ground level below the coffee bushes and in the interval between rows of
coffee bushes, and removed them after rainfall events (43 rainfall events studied) to count the number of uredospores
collected. For uredospore deposition, we used varnish to capture deposited uredospores on apparently
healthy coffee bush leaves (55 dates). We also studied the raindrop kinetic energy by using splashcups, on 19
rainy days. The number of uredospores produced and preserved was 2.22 times higher below shade trees than in
full sun, whereas the number of uredospores lost by wash-off, below the coffee bush, was 1.62 times lower.
Reduced wash-off was probably due to raindrop interception by shade trees and stemflow and to the increased
kinetic energy of the raindrops in the understory of the Shade treatment (twice as high as that measured in full
sun), which reduced the capacity of coffee leaves to intercept raindrops. In addition, we found 1.43 times more
uredospores deposited on apparently healthy leaves below shade trees than in full sun, partly due to the higher
number of uredospores produced and preserved below shade trees. Increasing throughfall and reducing raindrop
kinetic energy below shade trees seem crucial to improved CLR regulation. This can be achieved by selecting
specific shade tree functional traits and by implementing shade pruning during the rainy season
Evaluación del estado de la vegetación ribereña en ríos con influencia de proyectos hidroeléctricos, provincia de Chiriquí, Panamá
No full textCATIE - Centro Agronómico Tropical de Investigación y Enseñanz
Modelación hidrológica del río Torres, San José, Costa Rica su variación con respecto al cambio climático.
No full textTesis (Mag. Sc.) en manejo y gestión de cuencas hidrográficas) -- CATIE. División de Educación y Escuela de Posgrado. Turrialba (Costa Rica), 2020.Los sistemas hidrológicos se ven directamente afectados por la magnitud y la probabilidad de ocurrencia de eventos extremos. Esta investigación se basó en evaluar la respuesta hidrológica de una microcuenca urbana ubicada en Costa Rica, y su variación con respecto al cambio climático. Para ello, se subdividió la microcuenca en tres áreas de drenaje (AD1, AD2 y AD3) para detallar el análisis a nivel de morfometría, relieve, red de drenaje, suelo y clima; los cuales fueron insumos para el análisis hidrológico. Se realizó un análisis hidrológico con datos máximos anuales históricos observados (1987-2019) y datos máximos anuales proyectados RCP8.5 (2006-2050), para la estimación de caudales extremos a 25, 50 y 100 años de período de retorno. Los valores de precipitación máxima anual observada se obtuvieron de seis estaciones meteorológicas del Instituto Meteorológico Nacional (IMN) y el Instituto Costarricense de Electricidad (ICE). El registro venía incompleto, por lo que, se realizó un rellenado de datos con el método de los promedios con verificación de curva de doble masa para obtener la serie de 33 años. Se trabajó únicamente con los hietogramas de la estación Sabana y San Luis, debido a la distribución espacial y temporal de las lluvias para la zona de estudio