Distribución de los macrolíquenes corticícolas y su relación con la vegetación en el Parque Natural de Los Alcornocales (Cádiz, S de España)

Distribución de los macrolíquenes corticícolas y su relación con la vegetación en el Parque Natural de Los Alcornocales (Cádiz, S de España).Se estudiaron los macrolíquenes corticícolas en distintas unidades de vegetación: alcornocal (Quercus suber L.), quejigal (Quercus canariensis Willd.) y acebuchal (Olea europaea L. var. oleaster DC.); la influencia de la orientación en la composición y número de especies; y como afectaba el perímetro del forófito a la diversidad de macrolíquenes corticícolas. Se observó una clara diferencia en la distribución de los macrolíquenes en el quejigal frente a la del acebuchal y el alcornocal. Sólo existían diferencias entre las orientaciones norte y sur en el acebuchal. También se observó una disminución en la diversidad de los macrolíquenes corticícolas al aumentar el perímetro del forófito en el acebuchal

Type-f thioredoxins have a role in the short-term activation of carbon metabolism and their loss affects growth under short-day conditions in Arabidopsis thaliana

14 páginas.-- 11 figuras.-- 57 referencias.-- Supplementary data can be found at JXB online http://jxb.oxfordjournals.org/content/early/2016/02/02/jxb.erw017/suppl/DC1Redox regulation plays a central role in the adaptation of chloroplast metabolism to light. Extensive biochemical analyses in vitro have identified f-type thioredoxins (Trxs) as the most important catalysts for light-dependent reduction and activation of the enzymes of the Calvin-Benson cycle. However, the precise function of type f Trxs in vivo and their impact on plant growth are still poorly known. To address this issue we have generated an Arabidopsis thaliana double knock-out mutant, termed trxf1f2, devoid of both f1 and f2 Trxs. Despite the essential function previously proposed for f-type Trxs, the visible phenotype of the trxf1f2 double mutant was virtually indistinguishable from the wild type when grown under a long-day photoperiod. However, the Trx f-deficient plants showed growth inhibition under a short-day photoperiod which was not rescued at high light intensity. The absence of f-type Trxs led to significantly lower photosynthetic electron transport rates and higher levels of non-photochemical energy quenching. Notably, the Trx f null mutant suffered from a shortage of photosystem I electron acceptors and delayed activation of carbon dioxide fixation following a dark-light transition. Two redox-regulated Calvin-Benson cycle enzymes, fructose 1,6-bisphosphatase (FBPase) and Rubisco activase, showed retarded and incomplete reduction in the double mutant upon illumination, compared with wild-type plants. These results show that the function of f-type Trxs in the rapid activation of carbon metabolism in response to light is not entirely compensated for by additional plastid redox systems, and suggest that these Trxs have an important role in the light adjustment of photosynthetic metabolism.This work was supported by grant number BIO2013-43556-P from the Ministerio de Economía y Competitividad, Spain. The anti-FBPase and anti-Rubisco activase antibodies were provided by Dr Sahrawy, Estación Experimental del Zaidín, Granada, Spain and by Dr Portis, USDA, Urbana, USA, respectively. BN was the recipient of an FPI pre-doctoral fellowship from the Ministerio de Economía y Competitividad, Spain.Peer reviewe

Influence of Partial Soil Wetting on Water Relation Parameters of the Olive Tree

A drip versus pond irrigation experiment was carried out with 30-year-old ‘Manzanilla’ olive trees planted at 7 m 5 m in an orchard in Southwest Spain. At the end of the dry season of 1998, we chose two dry-land trees, D1 and D2, and two drip-irrigated trees, I1 and I2. During the experiments, the D1 and I1 trees were pond-irrigated, increasing the soil water content to around field capacity in the whole rootzone. The D2 and I2 trees were drip-irrigated, remaining part of the rootzone in drying soil. The results showed that the ratio between the transpiration of the pond-irrigated D1 tree and that of the drip-irrigated D2 tree (D1/D2 Ep) increased from an average of 0.88 before irrigation to 1.22 fourteen days after the first water supply. For the I trees, I1/I2 Ep varied from 0.76 to 1.02 nine days after the I1 tree was pond-irrigated for the first time. Transpiration, therefore, was restricted when using a drip irrigation system which, despite supplying enough water to cover the calculated crop demand, affected a part of the rootzone only. During the drip versus pond irrigation experiment, the recovery of leaf water potential, stomatal conductance and photosynthesis rate was greater and quicker in the pond-irrigated than in the drip-irrigated trees.– Influence de l’irrigation partielle du sol sur les paramètres des relations hydriques de l’olivier. Une comparaison de l’irrigation goutte à goutte avec l’irrigation en cuvette a été conduite sur oliviers ‘Manzanilla’ âgés de 30 ans plantés à 7 m 5 m dans un verger du sud-ouest de l’Espagne. À la fin de la saison sèche de 1998, nous avons choisi deux arbres sur sol sec, D1 et D2, et deux arbres sur sol irrigué au goutte à goutte, I1 et I2. Durant les expériences, les arbres D1 et I1 ont été irrigués en cuvette, en augmentant la teneur en eau du sol jusqu’à la capacité au champ dans toute la zone racinaire. Les arbres D2 et I2 ont été irrigués au goutte à goutte, laissant une partie de la zone racinaire dans un sol se desséchant. Les résultats ont montré que le quotient entre la transpiration de l’arbre D1 irrigué en cuvette et celle de l’arbre D2 irrigué au goutte à goutte (D1/D2 Ep) a augmenté à partir d’une moyenne de 0,88 avant irrigation jusqu’à 1,22 quatorze jours après le premier apport d’eau. Pour les arbres I, I1/I2 Ep a varié entre 0,76 et 1,02 neuf jours après que l’arbre I1 ait été irrigué en cuvette pour la première fois. Par conséquent, la transpiration était réduite quand on utilisait un système d’irrigation au goutte à goutte qui, malgré l’apport d’eau suffisant pour couvrir les besoins potentiels des cultures, a affecté seulement une partie de la zone racinaire. Durant cette comparaison de l’irrigation goutte à goutte et de l’irrigation en cuvette, la récupération de la teneur en eau des feuilles, de la conductance stomatique et du taux de photosynthèse était supérieure et plus rapide pour les arbres irrigués en cuvette que pour ceux irrigués au goutte à goutte

Is stomatal conductance optimized over both time and space in plant crowns? A field test in grapevine (Vitis vinifera)

15 páginas.-- 13 figuras.-- 1 tabla.-- 64 referenciasCrown carbon gain is maximized for a given total water loss if stomatal conductance (gs) varies such that the marginal carbon product of water (∂A/∂E) remains invariant both over time and among leaves in a plant crown, provided the curvature of assimilation rate (A) versus transpiration rate (E) is negative. We tested this prediction across distinct crown positions in situ for the first time by parameterizing a biophysical model across 14 positions in four grapevine crowns (Vitis vinifera), computing optimal patterns of gs and E over a day and comparing these to the observed patterns. Observed water use was higher than optimal for leaves in the crown interior, but lower than optimal in most other positions. Crown carbon gain was 18% lower under measured gs than under optimal gs. Positive curvature occurred in 39.6% of cases due to low boundary layer conductance (gbw), and optimal gs was zero in 11% of cases because ∂A/∂E was below the target value at all gs. Some conclusions changed if we assumed infinite gbw, but optimal and measured E still diverged systematically in time and space. We conclude that the theory's spatial dimension and assumption of positive curvature require further experimental testingThis work was funded by the Spanish Ministry of Science and Innovation (research projects AGL2008-04525-C02-01, AGL2011-30408-C04-01 and AGL2009-11310/AGR). T.N.B. was supported by the US National Science Foundation (Award No. 1146514) and by the Grains Research and Development Corporation (GRDC). S.M. benefitted from a FPI grant BES-2009-016906 from the Spanish Ministry of Science and Innovation.Peer reviewe

Machine Learning-Based Analysis of a Wind Turbine Manufacturing Operation: A Case Study

This study analyzes the lead time of the bending operation in the wind turbine tower manufacturing process. Since the operation involves a significant amount of employee interaction and the parts processed are heavy and voluminous, there is considerable variability in the recorded lead times. Therefore, a machine learning regression analysis has been applied to the bending process. Two machine learning algorithms have been used: a multivariate Linear Regression and the M5P method. The goal of the analysis is to gain a better understanding of the effect of several factors (technical, organizational, and experience-related) on the bending process times, and to attempt to predict these operation times as a way to increase the planning and controlling capacity of the plant. The inclusion of the experience-related variables serves as a basis for analyzing the impact of age and experience on the time-wise efficiency of workers. The proposed approach has been applied to the case of a Spanish wind turbine tower manufacturer, using data from the operation of its plant gathered between 2018 and 2021. The results show that the trained models have a moderate predictive power. Additionally, as shown by the output of the regression analysis, there are variables that would presumably have a significant impact on lead times that have been found to be non-factors, as well as some variables that generate an unexpected degree of variability

Role of leaf hydraulic conductance in the regulation of stomatal conductance in almond and olive in response to water stress

11 páginas..-- 5 figuras.-- 1 tablas.-- 55 referencias.-- We thank A. Montero for field work assistance, J. Perez Hormaeche for helping us with the VD images analysis and T. Brodribb and J.M. Torres-Ruiz for discussion.The decrease of stomatal conductance (gs) is one of the prime responses to water shortage and the main determinant of yield limitation in fruit trees. Understanding the mechanisms related to stomatal closure in response to imposed water stress is crucial for correct irrigation management. The loss of leaf hydraulic functioning is considered as one of the major factors triggering stomatal closure. Thus, we conducted an experiment to quantify the dehydration response of leaf hydraulic conductance (Kleaf) and its impact on gs in two Mediterranean fruit tree species, one deciduous (almond) and one evergreen (olive). Our hypothesis was that a higher Kleaf would be associated with a higher gs and that the reduction in Kleaf would predict the reduction in gs in both species. We measured Kleaf in olive and almond during a cycle of irrigation withholding. We also compared the results of two methods to measure Kleaf: dynamic rehydration kinetics and evaporative flux methods. In addition, determined gs, leaf water potential (Ψleaf), vein density, photosynthetic capacity and turgor loss point. Results showed that gs was higher in almond than in olive and so was Kleaf (Kmax = 4.70 and 3.42 mmol s-1 MPa-1 m-2, in almond and olive, respectively) for Ψleaf > -1.2 MPa. At greater water stress levels than -1.2 MPa, however, Kleaf decreased exponentially, being similar for both species, while gs was still higher in almond than in olive. We conclude that although the Kleaf decrease with increasing water stress does not drive unequivocally the gs response to water stress, Kleaf is the variable most strongly related to the gs response to water stress, especially in olive. Other variables such as the increase in abscisic acid (ABA) may be playing an important role in gs regulation, although in our study the gs-ABA relationship did not show a clear pattern..This work was funded by the Spanish Ministry of Science and Innovation (research project AGL2009-11310/AGR). V.H.-S. benefited from a Juan de la Cierva research fellowship from the Spanish Ministry of Science and Innovation and C.M.R.-D. benefited from a FPDI research fellowship from the Junta de Andalucí

Canopy architecture and radiation interception measurements in olive

In this work we tested techniques suitable for a future validation of the RATP model to simulate transpiration and photosynthesis of mature olive trees under field conditions. Canopy architecture was characterised with an electromagnetic 3D digitiser and the software 3A. Although the capability of the software to deal with big data sets has to be improved, the system seems to meet the RATP requirements. An array of radiation sensors mounted in an aluminium bar and located at different positions within the canopy showed to be an useful tool for monitoring radiation distribution; these data can be used to validate the RATP predictions. Leaves intercepting more radiation showed greater values both of area based nitrogen content and photosynthetic capacity, and the increment of nitrogen was found to be related to the increment in leaf mass area. A method was tested for assessing plant leaf area, which could allow us to determine the leaf area of the biggest trees in the orchard, with reduced time and labour.Ministerio de Ciencia y Tecnología AGL2002- 04048-CO3-0

Coastal flooding risk associated to tropical cyclones in a changing climate. Application to Port of Spain (Trinidad and Tobago)

The aim of this paper is to provide a methodology to assess flooding risk associated to the combination of extreme flooding levels driven by Tropical Cyclone (TCs) and relative sea level rise (RSLR). The approach is based on the risk conceptual framework where the hazard, exposure, and vulnerability are defined and combined to address flooding socioeconomic consequences in Port of Spain for present and future climate (RCP8.5 in 2050). Hazard and flooding impact are assessed using a combination of statistical methods and dynamical simulations, together with a high resolution Digital Elevation Model (DEM). Combining flooding maps, exposure databases and vulnerability damage functions we have evaluated socioeconomic consequences in terms of affected population and economic damage. Besides, we have quantified the uncertainty in the results coming from the sea level rise projections and vulnerability information. The application of the methodology indicates increasing flooding threat for the future climate that could exacerbate economic losses in case of inaction. The expected annual damage (EAD) in present climate is 12.24 MUSD while in 2050 it will reach 15.22 [14.88- 15.67] MUSD.This paper comes out from the project “Port of Spain Probabilistic Hazard and Vulnerability Assessment based on Climate Change Projections” funded by the Inter-American Development Bank (IDB). We acknowledge the World Climate Research Programme's Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modelling groups for producing and making available their model output

Variabilidad radial y acimutal del flujo de savia en olivos plantados en seto

5 páginas.-- 4 figuras.-- Comunicación oral presentada en el XI Simposio Hispano-Portugués de Relaciones Hídricas en las Plantas, Sevilla 17-20 Sep. (2012)La heterogeneidad de densidad de flujo de savia tanto alrededor del tronco como en profundidad respecto al cambium es un hecho bien conocido que requiere ser analizado para un correcto uso e interpretación de las estimas de transpiración a partir de las medidas de flujo de savia. Por ello, se hizo un experimento en olivos ‘Arbequina’ de 5 años de edad en una plantación en seto (4 m x 1.5 m) donde se instalaron cuatro sondas por árbol, en tres árboles representativos de la plantación. Los resultados han mostradoque se puede reducir el número de sondas hasta una para estimar el flujo de savia en olivos plantados en seto de esta edad. La correlación obtenida para la densidad de flujo de savia relativa entre la sección más externa del xilema conductor y las interiores frente a la conductancia estomática relativa medida en hojas jóvenes y viejas aportó evidencias sobre la hipótesis de que los vasos exteriores están preferentemente conectados a las hojas jóvenes del año.N

Linking changes in radial profiles of sap flux density with the response of water vapour exchange to water deficit

8 páginas, 5 figuras, 1 tabla, 19 referencias.-- IX International Workshop on Sap Flow, celebrado del 4-7 de junio 2013, en Gante, Bélgica.Knowledge of temporal variations in radial profiles of sap flux density (Js) and its relation to canopy water vapour exchange would help to improve our understanding of plant water relations. In this study we aimed to test if there is a consistent radial profile of Js in olive trees under optimal soil water availability and severe water stress conditions. Furthermore, if the radial profile of Js is not consistent through time we aimed to assess whether this radial variability can be explained through differential water exchange response to evaporative demand (D) of sun-exposed, new foliage and shade, old foliage. We measured sap flux density in the trunk of 6-year-old olive trees under two different irrigation treatments: a full irrigation treatment and a treatment replacing 30% of the of irrigation needs. We related the hourly radial profiles characterized with the Beta probability distribution function with independent water vapour exchange measurements at different exposures in the tree canopy (sun-exposed, young foliage and shade, old foliage). Results showed that under well irrigated conditions the shape of the radial profile of Js hardly varied, but under water deficit situations most of the sap appears to be conducted deeper into the sapwood and Js is also more variable throughout the sapwood. Accordingly, results demonstrated that in shade, old foliage water vapour exchange varied less than in sun-exposed new foliage. As a result, in days under severe water deficit, the contribution of shade old foliage to the whole tree transpiration was greater. Radial profile changes and canopy measurements were found to respond in a similar way to D. During conditions of low D and soil water deficit it was observed a greater contribution of the inner xylem to total stem flow and shade, old leaves to canopy gas exchange.Peer reviewe