Environment Workshops 2013. Oak forests coping with global change: ecology and management

Congreso celebrado del 30 de septiembre-2 de octubre 2013, en Baeza (Jaén), España.The genus Quercus has about 500 species distributed throughout the Northern Hemisphere. Oak forests and woodlands are very abundant in the Mediterranean region and are vital providing a variety of ecosystem services. They provide with raw materials like cork, wood and fuel, and fodder for wild and domestic animals. The silvopastoral system known as “dehesa” provides habitats for wild animals and contributes to a higher biodiversity at the landscape scale. Oak trees provide a climate regulating service by their capacity to sequester carbon and therefore to mitigate the effects of climatic change. There is an increasing demand for cultural services provided by oak woodlands, mainly for recreation, ecotourism, and to enjoy their aesthetic and spiritual values. However, Global Change is affecting negatively oak forests and therefore diminishing their ecosystem services and in consequence human wellbeing. Main drivers are: land use change, introduction of exotic pathogens, air and soil pollution deteriorating oak health, and climatic change, in particular the reduction of rainfall. The aims of the workshop are to analyse the vulnerability and resilience of Quercus species coping with Global Change; to review the main ecological processes related with the regeneration of oaks and how they influence the recruitment and persistence of oak forests; to discuss the different management options for coping with the decline of oak forests and to assure their sustainability, showing case studies from Spain, Portugal and Mexico.Peer reviewe

Respuesta plástica a la luz y al agua en cuatro especies mediterráneas del género Quercus (Fagaceae)

La luz y el agua son dos de los principales factores que regulan el crecimiento y la supervivencia de las plantas leñosas mediterráneas. El objetivo de este estudio es conocer el nivel de respuesta plástica de plántulas de cuatro especies de Quercus a tratamientos de sombra y sequía. Además queremos evaluar qué variables son más plásticas a uno u otro factor, y probar la hipótesis de que los rasgos fisiológicos son más plásticos que los rasgos estructurales. Se cultivaron en condiciones controladas plántulas de Quercus ilex subsp. ballota, Q. súber, Q. pyrenaica y Q. canariensis en tres tratamientos de luz (100, 27 y 3 % de luz incidente) y con agua abundante. A partir de mediados de primavera, a la mitad de las plántulas se les suprimió el agua, de forma que recibieron dos tratamientos de agua (riego versus no riego) dentro de cada tratamiento de luz. Se analizaron distintos rasgos fisiológicos como la tasa de fotosíntesis y respiración, el punto de compensación y de saturación a la luz, la conductancia estomática, la eficiencia en el uso del agua y de nitrógeno y la eficiencia fotosintética a la luz. También se estudiaron distintos rasgos morfológicos o estructurales, como el área foliar, el área específica foliar, las concentraciones foliares de N y C, y un índice de clorofila. En general, la respuesta plástica de las variables estructurales al factor agua fue muy baja, mientras que la respuesta de las fisiológicas fue relativamente alta. Con la luz, no se detectaron diferencias significativas en la respuesta plástica entre las variables estructurales y fisiológicas. En estas especies de Quercus mediterráneos, la mayor respuesta plástica a la luz podría estar ligada con una estrategia de tolerancia a la sombra, mientras que la baja respuesta plástica al agua (i.e., canalización) respondería a una estrategia de tolerancia a la sequía, indicando que la tolerancia a bajos niveles de recursos puede ser alcanzada mediante diferentes estrategias.Light and water availability are two of the main factors that regulate growth and survival of Mediterranean woody plants. The objective of this study is to investigate the plastic response of seedlings of four Mediterranean Quercus species to these factors, as well as to determine what traits are more plastic to one or another factor. Our hypothesis was that physiological variables are more plastic than structural variables. We cultivated in controlled conditions seedlings of Quercus ilex ssp. ballota, Q. súber, Q. pyrenaica and Q. canariensis in three treatments of light (100, 27 and 3 % of incident light) and with abundant water. On late spring, watering was stopped for half of the seedlings, so there were two water treatments (irrigation versus no-irrigation) within each treatment of light. Several physiological traits were studied: photosynthetic and respiration rate, light compensation and saturation points, stomatal conductance, water use and nitrogen use efficiency. We also evaluated different structural traits were studied such as leaf area, specific leaf area, leaf nitrogen and carbon concentrations, and a chlorophyll index. Changes in water availability induced low plastic responses of structural traits, whereas responses of physiological traits were relatively higher. On the other hand, there were not significant differences in the plastic response of structural or physiological traits to changes in light availability. In these Mediterranean oak species, the higher response to light could be linked to a shade tolerance strategy and the low response to water (i.e., canalization) could be related to drought tolerant strategy, thus indicating that tolerance to low-resources may be attained through different strategies.Este trabajo ha sido financiado con los proyectos HETEROMED (REN2002-04041) y DINAMED (CGL2005-05830) del MEC de España. JLQ ha disfrutado de una beca FPI-MEC (BES-2003-1716)

Tasas de crecimiento en 21 especies de trigo silvestre y su relación con la tasa de fotosíntesis y la concentración de nitrógeno foliar

8 págimas, 3 figuras, 1 tabla y 5 referencias.-- Trabajo presentado en el VI Simposium Nacional - II Ibérico sobre nutrición mineral de las plantas, Sevilla, del 12 al 15 de Noviembre de 1996.-- Entidades colaboradoras Junta de Andalucía, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Sociedad Española de Fisiología Vegetal, El Monte, Caja de Huelva y Sevilla y Gat Fertilíquidos.[EN]: 21 species of wild wheat (Aegilops and Amblyopyrum genus) and one cultivar of Triticum aestivu (cv Yécora) were grown in field conditions. The aim of this study was to know the factors determining the relative growth rate and use efficiency of nitrogen and water in different species. The leaf N concentration is positively correlated with both the relative growth rate and the photosynthetic rate. The photosynthetic rate is also strongly correlated with stomatal conductance. The water use eficiency (WUE) is not related with any of the parameters studied. However, the photosynthetic nitrogen use efficiency (PNUE) is positively correlated with stomatal conductance, suggesting that the use of N was limited by the stomata closure. In an opposite way with the nomal trend found in other studies, there is no negative correlation between PNUE and WUE. Abreviaturas: PNUE, eficiencia en el uso del nitrógeno; RGR, tasa de crecimiento relativo; WUE, eficiencia en el uso del agua.[ES]: Se han estudiado 21 especies de trigo silvestre (género Aegilops y Amblyopyrum) y una variedad agrícola (Triticum aestivum cv Yécora) con la intención de conocer los factores determinantes de la tasa de crecimiento y la eficiencia en el uso del nitrógeno y del agua en condiciones de campo. La concentración de N foliar- esta correlacionada positivamente con la tasa de crecimiento relativo y la tasa de fotosíntesis. La tasa de fotosíntesis aparece correlacionada con la conductancia estomática. La eficiencia en el uso del agua (WUE) no se relaciona significativamente con ninguno de los parámetros estudiados. Sin embargo, la eficiencia en el uso del nitrógeno (PNUE) esta correlacionada positivamente con la conductancia estomática, sugiriendo que el uso del N esta limitado por el cierre estomático. En contra de lo esperado, no existe una relación negativa entre PNUE y WUE. Abreviaturas: PNUE, eficiencia en el uso del nitrógeno; RGR, tasa de crecimiento relativo; WUE, eficiencia en el uso del agua.Este trabajo fué posible gracias a una beca postdoctoral del MEC a Rafael Villar Montero y a la Beca predoctoral de la Junta de Andalucía-Monte de Piedad a Diego García.Peer reviewe

Importancia del peso de semilla en especies del género Quercus. Evidencias en condiciones controladas y experimentos de campo

Congreso celebrado del 21-25 de septiembre 2009, en Ávila, España.Peer reviewe

Effectiveness and safety of integrase strand transfer inhibitors in Spain: a prospective real-world study

IntroductionSecond-generation integrase strand transfer inhibitors (INSTIs) are preferred treatment options worldwide, and dolutegravir (DTG) is the treatment of choice in resource-limited settings. Nevertheless, in some resource-limited settings, these drugs are not always available. An analysis of the experience with the use of INSTIs in unselected adults living with HIV may be of help to make therapeutic decisions when second-generation INSTIs are not available. This study aimed to evaluate the real-life effectiveness and safety of dolutegravir (DTG), elvitegravir/cobicistat (EVG/c), and raltegravir (RAL) in a large Spanish cohort of HIV-1-infected patients. MethodsReal-world study of adults living with HIV who initiated integrase INSTIs DTG, EVG/c, and RAL-based regimens in three settings (ART-naive patients, ART-switching, and ART-salvage patients). The primary endpoint was the median time to treatment discontinuation after INSTI-based regimen initiation. Proportion of patients experiencing virological failure (VF) (defined as two consecutive viral loads (VL) & GE;200 copies/mL at 24 weeks or as a single determination of VL & GE;1,000 copies/mL while receiving DTG, EVG/c or RAL, and at least 3 months after INSTI initiation) and time to VF were also evaluated. ResultsVirological effectiveness of EVG/c- and RAL-based regimens was similar to that of DTG when given as first-line and salvage therapy. Treatment switching for reasons other than virological failure was more frequent in subjects receiving EVG/c and, in particular, RAL. Naive patients with CD4+ nadir <100 cells/& mu;L were more likely to develop VF, particularly if they initiated RAL or EVG/c. In the ART switching population, initiation of RAL and EVG/c was associated with both VF and INSTI discontinuation. There were no differences in the time to VF and INSTI discontinuation between DTG, EVG/c and RAL. Immunological parameters improved in the three groups and for the three drugs assessed. Safety and tolerability were consistent with expected safety profiles. DiscussionWhereas second-generation INSTIs are preferred treatment options worldwide, and DTG is one of the treatment of choices in resource-limited settings, first-generation INSTIs may still provide high virological and immunological effectiveness when DTG is not available

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation