Tuesday, October 21, 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 (59,354 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 131

1. Tanned or burned: The role of fire in shaping physical seed dormancy - Moreira, Bruno; Pausas, J. G.
Plant species with physical seed dormancy are common in mediterranean fire-prone ecosystems. Because fire breaks seed dormancy and enhances the recruitment of many species, this trait might be considered adaptive in fire-prone environments. However, to what extent the temperature thresholds that break physical seed dormancy have been shaped by fire (i.e., for post-fire recruitment) or by summer temperatures in the bare soil (i.e., for recruitment in fire-independent gaps) remains unknown. Our hypothesis is that the temperature thresholds that break physical seed dormancy have been shaped by fire and thus we predict higher dormancy lost in response to fire than in...

2. Leaf physiological traits in relation to resprouter ability in the Mediterranean Basin - Hernández Lledó, Encarni I.; Pausas, J. G.; Vilagrosa, Alberto
In Mediterranean ecosystems, fire is a strong selective agent among plants, and the different post-fire regeneration strategies (e.g. resprouting and non-resprouting) have implications for other plant traits. Because young plants of non-resprouters need to grow quickly and mature well before the next fire, we predict that they should possess leaf traits related to increased efficiency in growth and resource acquisition compared with resprouter species. To test this hypothesis, we measured specific leaf area, leaf nitrogen and carbon concentrations and leaf physiological traits, including gas exchange parameters and chlorophyll fluorescence, in 19 Mediterranean species cultivated in a common garden. Both cross-species...

3. Local versus regional intraspecific variability in regeneration traits - Moreira, Bruno; Tavsanoglu, Ç.; Pausas, J. G.
Intraspecific trait variability has a fundamental contribution to the overall trait variability. However, little is known concerning the relative role of local (e.g. disturbances and species interaction) and regional (biogeographical) processes in generating this intraspecific trait variability. While biogeographical processes enhance plant trait variability between distant populations, in fire-prone ecosystems, recurrent fires may have a preponderant role in generating variability at a local scale. We hypothesize that plants respond to the local spatio-temporal heterogeneity generated by fire by having a relatively large local variability in regeneration traits in such a way that overrides the variability at a broader biogeographical scale....

4. Fires enhance flammability in Ulex parviflorus - Pausas, J. G.; Alessio, Giorgio A.; Moreira, Bruno; Corcobado, Guadalupe
6 páginas, 2 figuras, 2 tablas.

5. Disentangling the role of heat and smoke as germination cues in Mediterranean Basin flora - Moreira, Bruno; Tormo, J.; Estrelles, E.; Pausas, J. G.
BACKGROUND AND AIMS: The role of fire as a germination cue for Mediterranean Basin (MB) plants is still unclear. The current idea is that heat stimulates germination mainly in Cistaceae and Fabaceae and that smoke has a limited role as a post-fire germination cue, in comparison with other Mediterranean-type ecosystems (MTEs), suggesting that fire-stimulated germination is less relevant in the MB than in other MTEs. However, recent studies showed that the assembly of Mediterranean plant communities is strongly driven by post-fire germination, suggesting an important role for fire as a germination cue. We hypothesize that both heat and smoke have...

6. Influence of plant morphology on splash erosion in a Mediterranean matorral - Bochet, E.; Poesen, Jean; Rubio, José Luis
[EN] The influence of plant morphology on splash erosion was investigated under natural conditions within a patchy Mediterranean matorral. The relative efficiency of different plant attributes (litter, canopy) in the control of soil detachment was studied among different morphological types of plants: a tussock grass, an evergreen and a summer-deciduous shrub. Splashed sediments were collected in splashcups below and outside the plants throughout approximatively two years in order to determine the spatial variability of the process in a patchy environment. The influence of total precipitation, rainfall intensity and initial water content on soil detachment were also tested. The results underlined...

7. Quinolone and fluoroquinolone residues in agricultural soils from Valencian Community (Spain) - Andreu Pérez, V.; Pascual, Juan Antonio; Picó, Yolanda
Fluoroquinolones (FQ) represent a major group of synthetic antibiotics, which have been widespread use during the last 15 years in human and in veterinary medicine for the treatment of bacterial diseases. Their use leads to an entry of these compounds into the environment through the excretion of unmetabolised quinolones and the disposal of unused drugs (Andreu et al. 2007). Quinolones are rather persistent with half-lives of 151 days. They interfere with bacterial DNA metabolism by inhibiting two enzymes, topoisomerase II and IV. These enzymes introduce negative super helical twists into the DNA strands. Inhibition of these reactions prevents DNA replication,...

8. Detection of Anthropogenic pressures on western Mediterranean irrigation systems (La Albufera de Valencia agriculture system, eastern Spain) - Pascual, Juan Antonio; Andreu Pérez, V.; Picó, Yolanda
Irrigation systems are considered as one of the major landscapes features in western Mediterranean environments. Both socio-economic and cultural elements are interrelated in their development and preservation. Generally, due to their location in flat lands and close to major urban-industrial zones, irrigation lands are suffering of intense pressures that can alter their agricultural values, environmental quality and, consequently, the sustainability of the systems. To understand the nature of anthropogenic pressures on large Mediterranean water agricultural systems a methodology based on environmental forensics criteria has been developed and applied to La Albufera Natural Park in Valencia (Eastern Spain), a protected area...

9. Plant phylodiversity enhances soil microbial productivity in facilitation-driven communities - Navarro-Cano, J. A.; Goberna, M.; Valiente-Banuet, Alfonso; Montesinos-Navarro, Alicia; García, Carlos; Verdú, M.
The classical relationship between biodiversity and ecosystem functioning can be better understood when the phylogenetic component of biodiversity is considered. We linked plant phylodiversity and ecosystem functioning in a water-limited gypsum ecosystem driven by plant facilitation. We tested whether (1) plant facilitation relaxes the abiotic filter imposed by gypsum, allowing the establishment of non-gypsophyte plant species, and consequently increasing plant phylodiversity, and (2) plant phylodiversity influences soil microbial productivity. Our data revealed that the gypsophyte Ononis tridentata spatially determines a macrophytic mosaic, ameliorates the microenvironment, and maximizes plant richness and phylodiversity through facilitating non-gypsophyte species. Beyond the direct effect of...

10. Physiological differences explain the co-existence of different regeneration strategies in Mediterranean ecosystems - Vilagrosa, Alberto; Hernández Lledó, Encarni I.; Luis, V.; Cochard, H.; Pausas, J. G.
Fire and drought are selective driving forces in Mediterranean plants, and thus their ability to resprout or recruit after these disturbances is of paramount importance. The contrast in regeneration niche between resprouters and seeders, and each group's different root characteristics, suggest that they are subjected to different degrees of environmental stress and, consequently, to different evolutionary forces. We compared leaf traits, xylem traits related to hydraulic efficiency and vulnerability to cavitation, and the physiological response to an imposed drought between seedlings of resprouters and seedlings of seeders. We used 12 species co-existing in Mediterranean basin ecosystems. Major differences were found...

11. Laboratory and field assessment of the capacitance sensors Decagon 10HS and 5TE for estimating the water content of irrigated soils - Visconti Reluy, Fernando; Paz Bécares, José Miguel de; Martínez, D.; Molina, M. J.
Capacitance sensors such as Decagon 10HS and 5TE are increasingly used for soil water content (θ) estimation. However, their reliability and limitations in clayey soils irrigated with saline waters have not been completely characterized under field conditions. Four levels of soil water content were combined with six levels of soil salinity in twenty-four pots to assess the performance of both sensors in a wide range of soil salinities. A simplified power-law dielectric mixing model was calibrated in the laboratory to estimate the θ of a clay loam soil from the measurements of apparent dielectric permittivity (e{open}b) performed with both sensors....

12. In situ genetic association for serotiny, a fire-related trait, in Mediterranean maritime pine (Pinus pinaster) - Budde, K. B.; Heuertz, Myriam; Hernández-Serrano, A.; Pausas, J. G.; Vendramin, Giovanni G.; Verdú, M.; González Martínez, Santiago C.
Wildfire is a major ecological driver of plant evolution. Understanding the genetic basis of plant adaptation to wildfire is crucial, because impending climate change will involve fire regime changes worldwide. We studied the molecular genetic basis of serotiny, a fire-related trait, in Mediterranean maritime pine using association genetics. A single nucleotide polymorphism (SNP) set was used to identify genotype : phenotype associations in situ in an unstructured natural population of maritime pine (eastern Iberian Peninsula) under a mixed-effects model framework. RR-BLUP was used to build predictive models for serotiny in this region. Model prediction power outside the focal region was...

13. Genetic structure of a phytophagous mite species affected by crop practices: The case of Tetranychus urticae in clementine mandarins - Pascual-Ruíz, S.; Gómez-Martinez, M. A.; Ansaloni, T.; Segarra-Moragues, José G.; Sabater-Muñoz, Beatriz; Jacas, J. A.; Hurtado-Ruíz, M. A.
Tetranychus urticae Koch is a cosmopolitan mite considered as the most polyphagous species among spider mites. This mite is a key pest of clementine mandarins in Eastern Spain, where Spanish clementine production concentrates. Crop management practices can affect the population dynamics of this mite and, consequently, its impact on the orchard. Microsatellite markers were used to study mite population genetics from two commercial orchards which had been managed differently following Integrated Pest Management (IPM) or Organic Pest Management (OPM) schemes during four consecutive years. A multiplex system including 20 microsatellite loci was designed specifically and allowed an efficient and inexpensive...

14. Genetic component of flammability variation in a Mediterranean shrub - Moreira, Bruno; Castellanos, María Clara; Pausas, J. G.
Recurrent fires impose a strong selection pressure in many ecosystems worldwide. In such ecosystems, plant flammability is of paramount importance because it enhances population persistence, particularly in non-resprouting species. Indeed, there is evidence of phenotypic divergence of flammability under different fire regimes. Our general hypothesis is that flammability-enhancing traits are adaptive; here, we test whether they have a genetic component. To test this hypothesis, we used the postfire obligate seeder Ulex parviflorus from sites historically exposed to different fire recurrence. We associated molecular variation in potentially adaptive loci detected with a genomic scan (using AFLP markers) with individual phenotypic variability...

15. Comparative analysis of policies to deal with wildfire risk - Carreiras, M.; Ferreira, A. J. D.; Valente, S.; Fleskens, Luuk; González-Pelayo, Óscar; Rubio, José Luis; Stoof, C. R.; Coelho, C. O. A.; Ferreira, C. S. S.; Ritsema, Coen
Fires are the main driver of land degradation in forest areas in Mediterranean sub-humid regions and are likely to increase as a result of climate and other global changes. To prevent deleterious processes induced by fire, several policies and strategies have been implemented at national and regional scales. We perform a comparative study of policies and strategies of Portuguese and Spanish (Comunitat Valenciana) cases in order to assess the differences between them and identify their roles in forest fire prevention and in combating and mitigating impacts. To this end, we analyse the sustainability objectives stated in the legislation of each...

16. The role of fire in structuring trait variability in Neotropical savannas - Dantas, V.D.L.; Pausas, J. G.; Batalha, M. A.; Paula Loiola, P. de; Cianciaruso, M.V.
Intraspecific trait variability plays a fundamental role in community structure and dynamics; however, few studies have evaluated its relative importance to the overall response of communities to environmental pressures. Since fire is considered a key factor in Neotropical savannas, we investigated to what extent the functional effects of fire in a Brazilian savanna occurs via intra- or interspecific trait variability. We sampled 12 traits in communities subjected to three fire regimes in the last 12 years: annual, biennial, and protected. To evaluate fire's relative effects, we fitted a general linear mixed models with species as random and fire as fixed...

17. The lanky and the corky: Fire-escape strategies in savanna woody species - Dantas, V.D.L.; Pausas, J. G.
Fire and herbivory are the main disturbances shaping the structure of savannas. In these ecosystems, the key strategies by which woody plants escape fire are either early height growth (the lanky strategy) or early bark growth (the corky strategy). We hypothesize that the dominance of each strategy in different savannas depends on the prevailing disturbance regimes. Given the importance of herbivory in afrotropical savanna, we expect woody plants in these savannas to be taller and have thinner barks (the lanky strategy) than plants in neotropical savanna where fire tends to be more intense (the corky strategy). We compiled data on...

18. The development of soil and water conservation policies and practices in five selected countries from 1960 to 2010 - Graff, J. de; Aklilu, A.; Ouessar, M.; Asins Velis, Sabina
Since the 1930s there has been worldwide concern about the effects and impacts of land degradation. After the problems experienced in the Dust Bowl in the USA, much attention was paid to soil and water conservation in both developed and developing countries. Initially Governments stimulated the establishment of physical control measures, such as terraces, check dams and reforestation. This was achieved through top-down regulations, and Forestry Departments were often in charge of the implementation. Subsequently the measures were implemented through more specialized agencies, and later with incentives, such as food aid in developing countries and subsidies in developed countries. In...

19. Syndrome-driven diversification in a mediterranean ecosystem - Verdú, M.; Pausas, J. G.
Phylogenetic methods to detect lineage diversification have been traditionally used within a particular taxonomic clade, but rarely applied to detect local diversification. For understanding in situ diversification triggered by novel conditions it is necessary to focus on the time slice where such conditions occur. These new conditions may differentially affect the diversification rate of lineages with different morpho-functional syndromes. A prominent example of these processes occurs in the Mediterranean Basin, where climate arising along the Tertiary/Quaternary transition acted as an environmental filter. In this context, lineages with different syndromes (sclerophyllous and nonsclerophyllous) are hypothesized to have different local diversification rates...

20. Soil geography and diversity of the European biogeographical regions - Ibáñez, J. J.; Zinck, J. A.; Dazzi, C.
For decades, soil geography has beenmainly a qualitative and descriptive discipline. There are nowtechnologies and mathematical tools available that allow formalizing soil geography in more quantitative terms. In this paper, the distribution and diversity of the soils of Europe are analyzed using GIS tools and pedodiversity algorithms. Soil data were taken from the European Soil Database (V2.0) and computed within the spatial framework of the Biogeographical Regions of Europe (BGRE) as defined by the European Environmental Agency (EEA) on the basis of climate and vegetation. The results obtained show the soil assemblages, including dominant soils and endemic and non-endemic soil...

Página de resultados:
 

Busque un recurso