Effects of Quercus suber Decline on Woody Plant Regeneration: Potential Implications for Successional Dynamics in Mediterranean Forests

15 páginas.-- 2 figuras.-- 1 tabla.-- 82 referencias.--The online version of this article (doi:10.1007/s10021-016-0044-5) contains supplementary material, which is available to authorized usersIn the last two decades, widespread tree decline and mortality have been documented in forests worldwide. These mortality events usually show certain level of host-specificity, translating into rapid changes in the relative abundance of the adult community. Despite these short-term changes, it is poorly understood whether the decline and mortality of certain tree species are likely to result in long-term vegetation shifts. Trajectories of forest recovery and the probability of occurrence of permanent vegetation shifts are to a large extent determined by post-mortality regeneration dynamics. Using a spatially explicit neighborhood approach, we evaluated the spatial patterns of natural regeneration of the woody plant community in mixed Mediterranean forests affected by the decline of their dominant tree species, Quercus suber. We predicted the abundance, survival, and richness of the seedling and sapling bank as a function of the distribution and health status of the tree and shrub community. Results indicated that Q. suber decline had detectable effects on seedlings and saplings of coexistent woody species from very different functional groups (trees, shrubs, and lianas). The sign and magnitude of these effects varied substantially among coexistent species, which could imply shifts in the species ranking of seedling and sapling abundance, affecting successional trajectories and potentially leading to vegetation shifts. Because most of these changes pointed towards a loss of dominance of Q. suber, management strategies are urgently needed in order to attenuate adult mortality or promote its regeneration, counteracting the negative effects of global change drivers (exotic pathogens, climate change) on these valuable forests.This research was supported by the Ministerio de Ciencia e Innovación (MICIIN) projects INTERBOS (CGL2008-04503-C03-03), DIVERBOS (CGL2011-30285-C02-01), RETROBOS (CGL2011-26877), and RESTECO (CGL2014-52858-R), and the Junta de Andalucía project ANASINQUE (PGC2010-RNM-5782). BI was supported by a Formación de Personal Investigador (FPI)-MICINN Grant, J.M.A. by a Formación de Personal Universitario (FPU)-MEC Grant, and I.M.P.R. by a JAEdoc-Consejo Superior de Investigaciones Científicas (CSIC) contract.Peer reviewe

The Economics Spectrum Drives Root Trait Strategies in Mediterranean Vegetation

[EN] Extensive research efforts are devoted to understand fine root trait variation and to confirm the existence of a belowground root economics spectrum (RES) from acquisitive to conservative root strategies that is analogous to the leaf economics spectrum (LES). The economics spectrum implies a trade-off between maximizing resource acquisition and productivity or maximizing resource conservation and longevity; however, this theoretical framework still remains controversial for roots. We compiled a database of 320 Mediterranean woody and herbaceous species to critically assess if the classic economics spectrum theory can be broadly extended to roots. Fine roots displayed a wide diversity of forms and properties in Mediterranean vegetation, resulting in a multidimensional trait space. The main trend of variation in this multidimensional root space is analogous to the main axis of LES, while the second trend of variation is partially determined by an anatomical trade-off between tissue density and diameter. Specific root area (SRA) is the main trait explaining species distribution along the RES, regardless of the selected traits. We advocate for the need to unify and standardize the criteria and approaches used within the economics framework between leaves and roots, for the sake of theoretical consistency.S

A plant economics spectrum in Mediterranean forests along environmental gradients: Is there coordination among leaf, stem and root traits?

12 páginas..- 4 figuras.-- 70 referencias.--Supporting Information: Additional Supporting Information may be found in the online version of this article: Appendix S1. Species list.--Appendix S2. Functional traits list.--Appendix S3. Phylogenetic tree.-- Appendix S4. Pearson correlation coefficients between traits.-- Appendix S5. Relationships between morphologicaltraits, carbon isotope fraction and leaf chlorophyll.-- Appendix S6. Phylogenetic generalized least square analysis.-- Appendix S7. Non-metric multidimensional scaling analysis.-- Appendix S8. Illustration of the scale effects.Questions: Is there any evidence of coordination among leaf, stem and root traits, and thereby of the existence of a plant economics spectrum at the species and community level in Mediterranean forests? Are these traits related to plant size and seed mass? Location: Mediterranean forests and shrublands, Sierra Morena mountains, Córdoba, southern Spain. Methods: We selected nine woody plant communities along a natural local gradient of soil water and nutrient availability. We measured key leaf, stem, root and whole-plant traits for 38 dominant woody plant species. The variation across species of 15 functional traits (of the leaf, stem and root) was analysed and coordination among them was tested. We explored the relationships between these traits (hereafter 'resource-use traits' due to their close association with the acquisition-conservation trade-off) and plant height and seed mass. Finally, we compared results at species level with those calculated at community level, considering community-weighted means (CWMs). Results: We found a significant coordination between traits belonging to different plant organs, and propose the existence of a plant economics spectrum in Mediterranean forests along the environmental gradient. However, weaker relationships were found within groups of species under similar environmental conditions. We did not find the expected orthogonal relationships between plant height, seed mass and resource-use traits. Relationships among functional traits were stronger at the community level than at the species level. Conclusions: This study reveals a high degree of functional coordination between traits belonging to different plant organs at both species and community level, and suggests the existence of a plant economics spectrum across 38 Mediterranean woody plant species. However, this general trend of functional coordination between organs became weaker or disappeared when considering restricted groups of species belonging to environmentally similar sites (e.g. dry vs wet sites), suggesting that the diversification of strategies within communities is not related to the economics spectrum at a lower spatial scale. Interestingly, the high degree of coordination between resource-use traits and seed mass at the community level seems to support the tolerance-fecundity model, which predicts an inverse relationship between fecundity and stress tolerance. © 2015 International Association for Vegetation Science.We thank Miguel Verdú for help with the phylogenetic tree and analyses and Jose Rafael Vera for plant trait analyses. We also thank Jard ın Botánico de Córdoba (Francisca Herrera) and the Semillas Cantueso Company (José Angel Cantueso) for providing seedmass data. We are very grateful to Francesco de Bello for interesting comments on previous versions of the manuscript. This study was funded by the Spanish MEC coordinated project DIVERBOS (CGL2011-30285-C02-01 and C02-02), the Andalusian ANASINQUE project (PGC2010-RNM-5782), the Life + Biodehesa Project (11/BIO/ES/000726), ECO-MEDIT (CGL2014-53236-R) and European FEDER funds. Dr. DavidWalker revised the Englis

CRISPR-ERA for Switching Off (Onco) Genes

Genome-editing nucleases like the popular CRISPR/Cas9 enable the generation of knockout cell lines and null zygotes by inducing site-specific double-stranded breaks (DSBs) within a genome. In most cases, when a DNA template is not present, the DSB is repaired by nonhomologous end joining (NHEJ), resulting in small nucleotide insertions or deletions that can be used to construct knockout alleles. However, for several reasons, these mutations do not produce the desired null result in all cases, instead generating a similar protein with functional activity. This undesirable effect could limit the therapeutic efficiency of gene therapy strategies focused on abrogating oncogene expression by CRISPR/Cas9 and should be taken into account. This chapter reviews the irruption of CRISPR technology for gene silencing and its application in gene therapy

Climatic events inducing die-off in Mediterranean shrublands : are species' responses related to their functional traits ?

Altres ajuts: ICTS-RBD 38/2007Extreme climatic episodes, likely associated with climate change, often result in profound alterations of ecosystems and, particularly, in drastic events of vegetation die-off. Species attributes are expected to explain different biological responses to these environmental alterations. Here we explored how changes in plant cover and recruitment in response to an extreme climatic episode of drought and low temperatures were related to a set of functional traits (of leaves, roots and seeds) in Mediterranean shrubland species of south-west Spain. Remaining aerial green cover 2 years after the climatic event was positively related to specific leaf area (SLA), and negatively to leaf water potential, stable carbon isotope ratio and leaf proline content. However, plant cover resilience, i.e. the ability to attain pre-event values, was positively related to a syndrome of traits distinguished by a higher efficiency of water use and uptake. Thus, higher SLA and lower water-use efficiency characterized species that were able to maintain green biomass for a longer period of time but were less resilient in the medium term. There was a negative relationship between such syndromes and the number of emerging seedlings. Species with small seeds produced more seedlings per adult. Overall, recruitment was positively correlated with species die-off. This study demonstrates the relationship between plant traits and strong environmental pulses related to climate change, providing a functional interpretation of the recently reported episodes of climate-induced vegetation die-off. Our findings reveal the importance of selecting meaningful traits to interpret post-event resilience processes, particularly when combined with demographic attributes

DCBA: Simulating Population Dynamics P Systems with Proportional Object Distribution

Population Dynamics P systems refer to a formal framework for ecological modelling. The semantics of the model associates probabilities to rules, but at the same time, the model is based on P systems, so the rules are applied in a maximally parallel way. Since the success of the rst model using this framework [5], initially called multienvironment probabilistic P systems, several simulation algorithms have been de ned in order to better reproduce the behaviour of the ecosystems with the models. BBB and DNDP are previous attempts, which de ne blocks of rules having the same left-hand side, but do not de ne a deterministic behaviour when di erent rules are competing for the same resources. That is, di erent blocks of rules present in their lefthand side common objects, being applicable at the same time. In this paper, we introduce a new simulation algorithm, called DCBA, which performs a proportional distribution of resources.Junta de Andalucía P08-TIC04200Ministerio de Educación y Ciencia TIN2009-1319

The starburst-active galactic nucleus connection in the merger galaxy Mrk 938: An infrared and X-ray view

Mrk 938 is a luminous infrared (IR) galaxy in the local Universe believed to be the remnant of a galaxy merger. It shows a Seyfert 2 nucleus and intense star formation according to optical spectroscopic observations. We have studied this galaxy using new Herschel far-IR imaging data in addition to archival X-ray, UV, optical, near-IR and mid-IR data. Mid- and far-IR data are crucial to characterize the starburst contribution, allowing us to shed new light on its nature and to study the coexistence of active galactic nuclei (AGN) and starburst activity in the local Universe. The decomposition of the mid-IR Spitzer spectrum shows that the AGN bolometric contribution to the mid-IR and total IR luminosity is small [Lbol(AGN)/LIR ? 0.02], which agrees with previous estimations. We have characterized the physical nature of its strong IR emission and constrained it to a relatively compact emitting region of ?2 kpc. It is in this obscured region where most of the current star formation activity is taking place as expected for luminous IR galaxies. We have used Herschel imaging data for the first time to constrain the cold dust emission with unprecedented accuracy. We have fitted the integrated far-IR spectral energy distribution and derived the properties of the dust, obtaining a dust mass of 3 × 107 M . The far-IR is dominated by emission at 35 K, consistent with dust heated by the ongoing star formation activityThanks to F. Schweizer for kindly providing the optical image of Mrk 938, to J. Gallimore for providing the MIPS SED data, and to H. Krimm and W. Baumgartner for the analysis of the BAT ob- servations. PE, AA-H and MP-S acknowledge support from the Spanish Plan Nacional de Astronom ́ıa y Astrof ́ısica under grant AYA2009-05705-E. AA-H and MP-S acknowledge support under grant AYA2010-21161-C02-01. MP-S acknowledges support from the CSIC under grant JAE-Predoc-2007. AMP-G acknowledges support by the Spanish Plan Nacional de Astronom ́ıa y Astrof ́ısica under the grant AYA2008-06311-CO2-01. CRA acknowledges fi- nancial support from STFC (ST/G001758/1) and from the Span- ish Ministry of Science and Innovation (MICINN) through project Consolider-Ingenio 2010 Programme grant CSD2006-00070: First Science with the GTC. MP acknowledges Junta de Andaluc ́ıa and Spanish Ministry of Science and Innovation through projects PO8- TIC-03531 and AYA2010-15169. PACS has been developed by a consortium of institutes led by MPE (Germany) and including UVIE (Austria); KU Leuven, CSL, IMEC (Belgium); CEA, LAM (France); MPIA (Germany); INAF- IFSI/OAA/OAP/OAT, LENS, SISSA (Italy) and IAC (Spain). This development has been supported by the funding agencies BMVIT (Austria), ESA-PRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI/INAF (Italy) and CICYT/MCYT (Spain). SPIRE has been developed by a consortium of institutes led by Cardiff University (UK) and including University of Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, University of Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, University of Sus- sex (UK) and Caltech, JPL, NHSC, University of Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC (UK) and NASA (USA). This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Labo- ratory, California Institute of Technology, under NASA contract 1407

Self-assembled coumarin- and 5-fluorouracil-PEG micelles as multifunctional drug delivery systems

The copper(I)-catalyzed azide/alkyne cycloaddition is recognized as one of the most successful click reactions to access self-assembling amphiphilic polymer-drug conjugates (PDCs). In this way, poor water-soluble drugs can be linked covalently to hydrophilic poly(ethylene glycol) (PEG) to obtain PEGylated drug micelles that can be used as versatile carriers for the delivery of diverse therapeutic agents. In this work, two novel amphiphilic PDCs that combine PEG with privileged scaffolds well-known for their anticancer properties, such as coumarin and 5-fluorouracil, have been synthesized and characterized. These conjugates were able to self-assemble into micelles at relatively high critical micellar concentration, probably due to the large portion of hydrophilic PEG. The micelles allowed to load other anticancer drugs (paclitaxel, curcumin, and gemcitabine), providing a unique opportunity to develop promising co-delivery carriers for synergistic cancer therapy. The Korsmeyer-Peppas mathematical model was used for describing the in vitro kinetics of drug release from the micelles. Similar sustained and controlled drug release profiles were obtained for paclitaxel and curcumin in both conjugates, which was attributed to the excellent stability driven by the strong interaction between polymeric conjugates and drugs in the micelle core. In contrast, the high instability observed for the gemcitabine-loaded micelles provided an initial uncontrolled burst release of drug. A preliminary in vitro cytotoxicity study of the micelles against human pancreatic cancer cells PANC-1 and BxPC-3 was also carried out, demonstrating that both coumarin and 5-fluorouracil retain their anticancer properties after conjugation with PEG.La cicloadición de azida/alquino catalizada por cobre (I) se reconoce como una de las reacciones de clic más exitosas para acceder a conjugados de polímero-fármaco anfifílicos (PDC) autoensamblados. De esta manera, los fármacos poco solubles en agua se pueden unir covalentemente al poli(etilenglicol) (PEG) hidrofílico para obtener micelas de fármacos PEGilados que se pueden utilizar como vehículos versátiles para la administración de diversos agentes terapéuticos. En este trabajo, dos PDC anfifílicos novedosos que combinan PEG con andamios privilegiados conocidos por sus propiedades anticancerígenas, como la cumarina .y 5-fluorouracilo, han sido sintetizados y caracterizados. Estos conjugados pudieron autoensamblarse en micelas a una concentración micelar crítica relativamente alta, probablemente debido a la gran porción de PEG hidrofílico. Las micelas permitieron cargar otros medicamentos contra el cáncer (paclitaxel, curcumina y gemcitabina), lo que brinda una oportunidad única para desarrollar portadores de administración conjunta prometedores para la terapia sinérgica contra el cáncer. Se utilizó el modelo matemático de Korsmeyer-Peppas para describir la cinética in vitro de la liberación del fármaco desde las micelas. Se obtuvieron perfiles similares de liberación sostenida y controlada del fármaco para paclitaxel.y curcumina en ambos conjugados, lo que se atribuyó a la excelente estabilidad impulsada por la fuerte interacción entre los conjugados poliméricos y los fármacos en el núcleo de la micela. Por el contrario, la alta inestabilidad observada para las micelas cargadas con gemcitabina proporcionó una liberación inicial descontrolada del fármaco. También se llevó a cabo un estudio preliminar de citotoxicidad in vitro de las micelas contra las células de cáncer de páncreas humano PANC-1 y BxPC-3, demostrando que tanto la cumarina como el 5-fluorouracilo conservan sus propiedades anticancerígenas después de la conjugación con PEG

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

The morphometric acclimation to depth explains the long-term resilience of the seagrass Cymodocea nodosa in a shallow tidal lagoon

Cadiz Bay is a shallow mesotidal lagoon with extensive populations of the seagrass Cymodocea nodosa at intertidal and shallow subtidal elevations. This work aims to understand the mechanisms behind the resilience of this species to gradual sea level rise by studying its acclimation capacity to depth along the shallow littoral, and therefore, to gradual variations in the light environment. To address this objective, these populations have been monitored seasonally over a 10 year period, representing the longest seasonal database available in the literature for this species. The monitoring included populations at 0.4, -0.08 and -0.5 m LAT. The results show that C. nodosa has a strong seasonality for demographic and shoot dynamic properties - with longer shoots and larger growth in summer (high temperature) than in winter (low temperature), but also some losses. Moreover, shoots have different leaf morphometry depending on depth, with small and dense shoots in the intertidal areas (0.4 m) and sparse large shoots in the subtidal ones (-0.08 and 0.5 m). These differences in morphometry and shoot dynamic properties, combined with the differences in shoot density, explain the lack of differences in meadow production balance (i.e. meadow growth - meadow losses) between the intertidal (0.4 m) and the deepest population (-0.5 m), supporting the long term resilience of Cymodocea nodosa in Cadiz Bay. This study contributes to the understanding of the mechanisms behind seagrass stability and resilience, which is particularly important towards predicting the effects of climate change on these key coastal ecosystems, and also highlights the value of continuous long-term monitoring efforts to evaluate seagrass trajectories