domingo 16 de febrero de 2014

 

 



Soy un nuevo usuario

Olvidé mi contraseña

Entrada usuarios

Lógica Matemáticas Astronomía y Astrofísica Física Química Ciencias de la Vida
Ciencias de la Tierra y Espacio Ciencias Agrarias Ciencias Médicas Ciencias Tecnológicas Antropología Demografía
Ciencias Económicas Geografía Historia Ciencias Jurídicas y Derecho Lingüística Pedagogía
Ciencia Política Psicología Artes y Letras Sociología Ética Filosofía
 

rss_1.0 Recursos de colección

Digital.CSIC (42.150 recursos)
Repositorio institucional del Consejo Superior de Investigaciones Científicas. Digital.CSIC es un depósito de documentos digitales, cuyo objetivo es organizar, archivar, preservar y difundir en modo de acceso abierto la producción intelectual resultante de la actividad investigadora del CSIC.

(CIDE) Artículos post-print

Mostrando recursos 1 - 20 de 39

1. Systematic Revision of the Epipetrum Group of Dioscorea (Dioscoreaceae) Endemic to Chile - Viruel, Juan; Segarra-Moragues, José G.; Pérez-Collazos, Ernesto; Villar Pérez, Luis; Catalán, Pilar
A systematic revision of the Epipetrum group of Dioscorea (Dioscoreaceae), which traditionally included three taxa endemic to Chile, is presented. We evaluated the taxonomic value of macro- and micromorphological traits to delimit generic boundaries with respect to other yams and to identify and separate its taxa. The comprehensive survey included 10 qualitative and 43 quantitative traits related to all plant organs and new microanatomical features of leaf, fruits, seeds, and pollen. Discriminant analyses were conducted with three accumulative morphological data sets to test seven taxonomic hypotheses of differentiation among taxa. Our results indicate that these taxa are characterized by the...

2. Morphometric and molecular variation in concert: Taxonomy and genetics of the reticulate Pyrenean and Iberian alpine spiny fescues (Festuca eskia complex, Poaceae) - Torrecillas, P.; Sancho, C.; Komac, Benjamin; Villar Pérez, Luis
The Iberian mountain spiny fescues are a reticulate group of five diploid grass taxa consisting of three parental species and two putative hybrids: F.×souliei (F.eskia×F.quadriflora) and F.×picoeuropeana (F.eskia×F.gautieri). Phenotypic and molecular studies were conducted with the aim of determining the taxonomic boundaries and genetic relationships of the five taxa and disentangling the origins of the two hybrids. Statistical analyses of 31 selected phenotypic traits were conducted on individuals from 159 populations and on nine type specimens. Molecular analyses of random amplified polymorphic DNA (RAPD) markers were performed on 29 populations. The phenotypic analyses detected significant differences between the five taxa...

3. Female biased sex ratios in Pistacia lentiscus L. (Anacardiaceae) - Verdú, M.; García-Fayos, P.
Sex ratios of populations of the dioecious shrub Pistacia lentiscus L. (Anacardiaceae) were studied. Several hypotheses concerning biased sex ratios were tested. The expected pattern of male preponderance in stressful habitats was not found. The populations located in a microclimatic gradient, such as a slope, did not display a male-biased sex ratio on the stressful middle slope. The populations located in a climatic gradient did not display a male-biased sex ratio in the more xeric habitats. Testing the hypothesis of female preponderance when pollen grain competition exists, we found a significant correlation in the direction opposite to that predicted by...

4. Phylogenetic relatedness as a tool in restoration ecology: a meta-analysis - Verdú, M.; Gómez Aparicio, Lorena; Valiente-Banuet, Alfonso
Biotic interactions assembling plant communities can be positive (facilitation) or negative (competition) and operate simultaneously. Facilitative interactions and posterior competition are among the mechanisms triggering succession, thus representing a good scenario for ecological restoration. As distantly related species tend to have different phenotypes, and therefore different ecological requirements, they can coexist, maximizing facilitation and minimizing competition. We suggest including phylogenetic relatedness together with phenotypic information as a predictor for the net effects of the balance between facilitation and competition in nurse-based restoration experiments. We quantify, by means of a Bayesian meta-analysis of nurse-based restoration experiments performed worldwide, the importance of...

5. CNES and ESA CAROLS Airborne Campaigns at the Valencia Anchor Station and Los Monegros Site in the Framework of SMOS Validation - Lopez-Baeza, E.; Antolín Tomás, Carmen; Bouzinac, C.; Castañeda del Álamo, Carmen; Davidson, M.; Drusch, M.; Herrero Isern, Juan; Juglea, S.; Kerr, Y. H.; Mecklenburg, S.; Millán-Scheiding, C.; Novello, N.; Parde, M.; Saleh, K.; Wigneron, J. P.; Zribi, M.
This communication will present the main results of a series of airborne campaigns conducted at the Valencia Anchor Station (VAS) and Los Monegros site using the CAROLS (Combined Airborne Radio-instruments for Ocean and Land Studies) radiometer on board the ATR 42 aircraft from M¶et¶eo-France. The main objective was to contribute to the implementation of the SMOS emission model L-MEB (L-band Microwave Emission model of the Biosphere) in the framework of the validation of SMOS land data and products. Speci¯cally, the objectives of the CAROLS campaigns were the following: Soil Moisture Validation Studies: Previous °ights at the VAS area took place in 2008 in the context of the ESA...

6. Determination of linear alkylbenzenesulfonates and their degradation products in solis by liquid chromatography-electrospray-ion trap multiple-stage mass spectrometry - Andreu Pérez, V.; Picó, Yolanda
Linear alkylbenzenesulfonates (LAS) (C-10-C-13) and their degradation products, sulfophenyl carboxylate compounds (SPCs) (C-2-C-6, C-8, C-11), have been extracted from soil samples with methanol, isolated, concentrated by solid-phase extraction, and determined by liquid chromatography/negative ion electrospray quadrupole ion-trap tandem mass spectrometry (MSn). The ion fragmentation processes and pathways were studied in detail by MS, MS2, and MS3. Upon collision-induced dissociation, the deprotonated molecules of LASs render the ethylene-substituted benzenesulfonate ion (m/z 183), the fragmentation of which gave the intense signal at m/z 119, corresponding to the ethylene-substituted phenoxide ion formed by the loss of sulfur dioxide. The fragmentation pattern of SPCs...

7. SEIS.net: Sistema español de información de suelos en Internet - De la Rosa, Diego; Prange, N.; Sánchez Díaz, Juan; Colomer Marco, Joan Carles; Añó Vidal, Carlos; Recatalá Boix, Luis
[ES] SEIS.net (Sistema Español de Información de Suelos en Internet) recoge los resultados conseguidos en la ejecución de tres proyectos de investigación (MIMAM-CSIC, FAO-CSIC y SIDASS), coordinados por el grupo MicroLEIS del IRNAS, en el período 1999-2001. Haciendo uso de las más avanzadas tecnologías de la información y las comunicaciones, se ha tratado de recopilar y poner en ‘formato útil’ la información disponible sobre el estado actual de calidad y degradación de los suelos en España. El sistema se estructura en tres niveles de información, de menor a mayor detalle, Nivel #1: Primera Aproximación a los Suelos, Nivel #2: Atlas Digital de Comarcas...

8. Anthropogenic fires increase alien and native annual species in the Chilean coastal matorral - Gómez-González, Susana; Torres-Diaz, Cristian; Valencia, Graciela; Torres-Morales, Patricio; Cavieres, Lohengrin A.; Pausas, J. G.
Aim we tested the hypothesis that anthropogenic fires favour the successful establishment of alien annual species to the detriment of natives in the Chilean coastal matorral.Location Valparaíso Region, central Chile.Methods We sampled seed rain, seedbank emergence and establishment of species in four paired burned and unburned areas and compared (using GLMM) fire resistance and propagule arrival of alien and native species. To assess the relative importance of seed dispersal and seedbank survival in explaining plant establishment after fire, we compared seed rain and seedbank structure with post-fire vegetation using ordination analyses.Results Fire did not change the proportion of alien species...

9. Successional trends in standing dead biomass in Mediterranean basin species - Baeza, M. J.; Santana, V. M.; Pausas, J. G.; Vallejo, Ramón
Question: Landscape models of fire occurrence in ecosystems assume that the time since the last fire determines vegetation flammability by enabling the accumulation of dead biomass. In this study we ask if Mediterranean basin shrublands respond to these models or, on the contrary, if initial successional stages in these ecosystems could be more flammable than later stages. Location:Mediterranean shrubland in the Valencia region, eastern Spain. Methods: Using different stages of vegetation development (5, 9, 14 and 26 years since the last fire), we first study the structural composition of the aboveground biomass in 375 individuals of nine woody species. Then, we measure...

10. Facilitation can increase the phylogenetic diversity of plant communities - Valiente-Banuet, Alfonso; Verdú, M.
With the advent of molecular phylogenies the assessment of community assembly processes has become a central topic in community ecology. These processes have focused almost exclusively on habitat filtering and competitive exclusion. Recent evidence, however, indicates that facilitation has been important in preserving biodiversity over evolutionary time, with recent lineages conserving the regeneration niches of older, distant lineages. Here we test whether, if facilitation among distant-related species has preserved the regeneration niche of plant lineages, this has increased the phylogenetic diversity of communities. By analyzing a large worldwide database of species, we showed that the regeneration niches were strongly conserved...

11. Temporal shifts from facilitation to competition occur between closely related taxa - Valiente-Banuet, Alfonso; Verdú, M.
1. The relative contribution of positive and negative interactions to the organization of ecological communities is an important area, though poorly understood because of the complexity inherent to long-term interactions. For example, positive interactions like plant facilitation turn into negative interactions (competition) along the ontogeny of a plant or in response to temporal fluctuations in the environment. Furthermore, when many plants grow together indirect effects are usually positive and alleviate direct competitive effects. 2. The large number of direct and indirect interactions potentially occurring in natural communities and the temporal scale necessary to account for the ontogenetic shifts in the...

12. Early to rise makes a plant healthy, wealthy, and wise - Luis, Martín de; Verdú, M.; Raventós, José
Seedling emergence time is a crucial event in the life cycle of a plant, determining its fitness via different components including survival, growth, and fecundity. Precocious emergents usually survive, grow, and/or reproduce earlier in the life cycle, but for perennials it is unknown whether these benefits are maintained throughout the life of the plant. Here, we examine for the first time whether fitness benefits due to the early emergence of perennial plants are perpetuated or vanish with time. For nine years, in a Mediterranean gorse community, we followed the fate of 2118 seedlings belonging to the four dominant woody species....

13. Meta-analysis of meta-analyses in plant evolutionary - Castellanos, María Clara; Verdú, M.
After two decades of meta-analyses on plant traits, we can now look for global emergent patterns in plant evolutionary ecology. Hundreds of meta-analyses have focused on the effects of specific selection pressures on plant fitness, and the buildup of such results allows us to ask general questions regarding selection pressures and plant responses, a major focus of evolutionary ecology. Plant traits are affected by both abiotic and biotic factors. For example, biotic pressures like herbivory may affect physiological (i.e. secondary defences) and reproductive (i.e. seed predation) traits. Similarly, abiotic pressures such as increased CO2 may affect both plant physiology and reproduction. We...

14. The role of seed traits in determining the phylogenetic structure of temperate plant communities - Vandelook, Filip; Verdú, M.; Honnay, Olivier
Phylogenetic clustering of species within plant communities can be expected to result from environmental filtering acting on an evolutionary-conserved plant trait. One such a candidate trait is the embryo to seed-size ratio (E:S). A high E:S may allow faster germination immediately after imbibition, and is therefore assumed to be advantageous in dry habitats. In this study the hypothesis was tested that habitat filtering driven by soil moisture conditions and acting on seed germination and seedling establishment is an important ecological mechanism in structuring temperate plant communities. Vegetation samplings were performed in three habitats located within 200 km of each other...

15. Genders in Juniperus thurifera have different functional responses to variations in nutrient availability - Montesinos, D.; Villar Salvador, Pedro; García-Fayos, P.; Verdú, M.
Differences in reproductive investment can trigger asymmetric, context-dependent, functional strategies between genders in dioecious species. However, little is known about the gender responses of dioecious species to nutrient availability. We experimentally fertirrigated a set of male and female Juniperus thurifera trees monthly for 2 yr. Water potential, photosynthesis rate and stomatal conductance were measured monthly for 2 yr, while shoot nitrogen (N) concentration, carbon isotopic composition (d13C), branch growth, trunk radial growth and reproductive investment per branch were measured yearly. Control males had lower gas exchange rates and radial growth but greater reproductive investment and higher water use efficiency (WUE;...

16. Disrupted phylogeographical microsatellite and chloroplast DNA patterns indicate a vicariance rather than long-distance dispersal origin for the disjunct distribution of the Chilean endemic Dioscorea biloba (Dioscoreaceae) around the Atacama Desert - Viruel, Juan; Catalán, Pilar; Segarra-Moragues, José G.
Aim The Chilean endemic Dioscorea biloba (Dioscoreaceae) is a dioecious geophyte that shows a remarkable 600 km northsouth disjunction in the peripheral arid area of the Atacama Desert. Its restricted present-day distribution and probable Neogene origin indicate that its populations have a history linked to that of the Atacama Desert, making this an ideal model species with which to investigate the biogeography of the region. Location Chile, Atacama Desert and peripheral arid area. Methods Two hundred and seventy-five individuals from nine populations were genotyped for seven nuclear microsatellite loci, and plastid trnLF and trnTL sequences were obtained for a representative...

17. The network structure of plant-arbuscular mycorrhizal fungi - Montesinos-Navarro, Alicia; Segarra-Moragues, José G.; Valiente-Banuet, Alfonso; Verdú, M.
Ecological network theory predicts that in mutualistic systems specialists tend to interact with a subset of species with which generalists interact (i.e. nestedness). Approaching plant-arbuscular mycorrhizal fungi (AMF) association using network analyses will allow the generality of this pattern to be expanded to the ubiquitous plant-AMF mutualism. • Based on certain plant-AMF specificity recently suggested, networks are expected to be nested as a result of their mutualistic nature, and modular, with certain species interacting more tightly than others. Network analyses were used to test for nestedness and modularity and to compare the different contribution of plant and AMF to the...

18. Influence of organic matter transformations on the bioavailability of heavy metals - Ingelmo Sánchez, Florencio; Molina, M. J.; Soriano, María Desamparados; Gallardo, Antonio
The agricultural use of anaerobically digested sewage sludge (ADSS) as stable, mature compost implies knowing its total content in heavy metals and their bioavailability. This depends not only on the initial characteristics of the composted substrates but also on the organic matter transformations during composting which may influence the chemical form of the metals and their bioavailability. The objective of this work was to examine the relationships between the changes in the organic matter content and humus fractions, and the bioavailability of heavy metals. A detailed sampling at 0, 14, 84, and 140 days of the composting process was performed to measure...

19. Soil saturated hydraulic conductivity assessment from expert evaluation of field characteristics using an ordered logistic regression model - Ingelmo Sánchez, Florencio; Molina, M. J.; Paz Bécares, José Miguel de; Visconti Reluy, Fernando
The knowledge of the soil saturated hydraulic conductivity (Ks) is essential for irrigation management purposes and for hydrological modelling. Several attempts have been done to estimate Ks in base of a number of soil parameters. However, a reliable enough model for qualitative Ks estimation based on the expert assessment of field characteristics had not been developed up to date. Five field characteristics, namely macroporosity (M), stoniness (S), texture (T), compaction (C) and sealing (L), in addition to tillage (G) were carefully assessed according to three classes each, in 202 sites in an agricultural irrigated area in Eastern Mediterranean Spain. After the evaluation...

20. Mediterranean cork oak savannas require human use to sustain biodiversity and ecosystem services - Bugalho, Miguel N.; Caldeira, María C.; Pereira, João Santos; Aronson, James; Pausas, J.G.
Mediterranean cork oak savannas, which are found only in southwestern Europe and northwestern Africa, are ecosystems of high socioeconomic and conservation value. Characterized by sparse tree cover and a diversity of understory vegetation - ranging from shrub formations to grasslands - that support high levels of biodiversity, these ecosystems require active management and use by humans to ensure their continued existence. The most important product of these savannas is cork, a non-timber forest product that is periodically harvested without requiring tree felling. Market devaluation of, and lower demand for, cork are causing a decline in management, or even abandonment, of...

Página de resultados:
 

Busque un recurso