66 research outputs found

    Flora y vegetación del Alto Oja (Sierra de La Demanda, La Rioja, España)

    Get PDF
    En el presente trabajo se han catalogado los "taxa" de plantas vasculares y se han descrito los tipos de comunidades vegetales y los procesos de sucesión y zonación de la cuenca alta del río Oja, una comarca montañosa de la Sierra de La Demanda (Sistema Ibérico Septentrional, Península Ibérica). En este territorio, que tiene 250 Km2, la cota máxima alcanza 2.270 m (pico San Lorenzo) y la mínima 712 m (Santurde de Rioja). En su curso hacia la Depresión del Ebro, el río Oja discurre por una cuenca en la que se distinguen dos unidades geomorfológicas: el núcleo meridional paleozoico y una orla septentrional mesozoica (cubierta en su piedemonte por materiales del Terciario), que se interpone entre el mencionado núcleo y la Depresión del Ebro. El macroclima es templado oceánico de tipo submediterráneo: se han reconocido tres termotipos (suprasub-, orosub- y criorosubmediterráneo) y dos ombrotipos (húmedo e hiperhúmedo). El Alto Oja forma parte del sector fitogeográfico denominado Oroibérico-Soriano.La flora se prospectó usando un muestreo basado en un análisis teselar previo. Se han elaborado un catálogo florístico y se han estudiado las áreas de distribución y las formas vitales de la flora. Se han identificado más de un millar de especies y subespecies, cifra que supone, aproximadamente, el 40% de la flora presente en la Comunidad Autónoma de La Rioja; esta riqueza es ligeramente superior a lo que cabría esperar en función del tamaño del área de estudio. Se trata de "taxa" europeos (en especial, atlánticos) y mediterráneos (en especial, orófitos occidentales), además de algunos boreo-alpinos y numerosas especies de amplia distribución. Existe, finalmente, un notable contenido en "taxa" ibéricos endémicos que son, en síntesis, especies y subespecies silicícolas ibéricas orófilas o basófilas pirenaico-cantábricas.El muestreo de las comunidades vegetales y el análisis de los datos se ha realizado empleando la aproximación de Braun-Blanquet; además, en algunos casos se han testado hipótesis parciales sobre clasificación usando técnicas estadísticas de análisis multivariante. Se han encontrado en el territorio más de setenta tipos de comunidades vegetales (del rango de asociación o interior), pertenecientes a 32 clases de vegetación. El espacio suprasubmediterráneo está mayoritariamente ocupado por tipos de vegetación europeo-atlánticos (bosques planocaducifolios, matorrales de rosáceas o genistelas, brezales, prados y pastizales), pero no faltan algunos tipos de vegetación mediterráneos (carrascales, tomillares y fenalares xéricos). En el espacio orosub- y criorosubmediterráneo existen tipos de vegetación típicamente orófilos mediterráneo-occidentales (enebrales, pastizales orófilos y cervunales). así como alguno de tipo eurosiberiano orófilo.La sucesión se estudió mediante la propuesta metodológica de Rivas-Martínez (1987). Se han encontrado series de vegetación de hayedos y acebales, quejigares, bosques de roble albar, melojares, bosques mixtos, encinares, saucedas, enebrales y pastizales psicorxerófilos, un complejo de vegetación de playas aluviales y tres "microgeosigmeta"

    Does functional soil microbial diversity contribute to explain within-site plant beta-diversity in an alpine grassland and a <i>dehesa</i> meadow in Spain?

    Get PDF
    Questions: Once that the effects of hydrological and chemical soil properties have been accounted for, does soil microbial diversity contribute to explain change in plant community structure (i.e. within-site beta-diversity)? If so, at which spatial scale does microbial diversity operate? Location: La Mina in Moscosa Farm, Salamanca, western Spain (dehesa community) and Laguna Larga in the Urbión Peaks, Soria, central-northern Spain (alpine grassland). Methods: The abundance of vascular plant species, soil gram-negative microbial functional types and soil chemical properties (pH, available phosphorus, and extractable cations) were sampled at both sites, for which hydrological models were available. Redundancy analysis (RDA) was used to partition variation in plant community structure into hydrological, chemical and microbial components. Spatial filters, arranged in scalograms, were used to test for the spatial scales at which plant community structure change. Results: In the case of the dehesa the diversity of soil gram-negative microbes, weakly driven by soil pH, contributed to a small extent (adj-R2 = 2%) and at a relative medium spatial scale to explain change in plant community structure. The abundance of a few dehesa species, both annual (Trifolium dubium, Vulpia bromoides) and perennial (Poa bulbosa, Festuca ampla), was associated with either increasing or decreasing soil microbial diversity. In the alpine meadow the contribution was negligible. Conclusions: Microbial diversity can drive community structure, though in the hierarchy of environmental factors structuring communities it appears to rank lower than other soil factors. Still, microbial diversity appears to promote or restrain individual plant species. This paper aims to encourage future studies to use more comprehensive and insightful techniques to assess microbial diversity and to combine this with statistical approaches such as the one used here

    Floristic Composition Mediates Change in Forage Nutritive Quality of Atlantic Mountain Grasslands after Experimental Grazing Exclusion

    Get PDF
    Simultaneous reduction of biodiversity and forage nutritive value after grazing abandonment represents a critical agroecological problem observed in temperate mountain grasslands. However, how both processes affect each other after the exclusion of large grazers is not well understood. To address this knowledge gap, we used four Atlantic grassland sites in the Aralar masif (northern Iberian Peninsula) to ask whether floristic composition mediates change in forage nutritive quality after grazing exclusion, and, if so, how much of the effect on forage quality is mediated. To examine the effects of grazing exclusion on forage quality and floristic composition a repeated-measures (2005–10) randomized complete block experiment was used. Then, the direct effects of grazing exclusion on forage quality were disentangled from the indirect effects mediated by concurrent change in floristic composition. Grazing exclusion deteriorated forage mineral content, phosphorus content, neutral detergent fiber and, especially, crude protein and enzymatic digestibility. Concurrent floristic change mediated change in crude protein (80%), enzymatic digestibility (55%) and forage content in calcium (31%). Our study shows that plant diversity and forage quality are intimately linked features of Atlantic mountain grasslands and highlights the importance of preserving leguminous and dicotyledonous species to maintain the nutritive value of these grasslands.This research was funded by the Basque Government—Eusko Jaurlaritza—(grant numbers: ETORTEK10/34, IT1022-16), by the UNESCO Cathedra of the University of the Basque Country—UPV/EHU—(grant number: UNESCO07/07), and by the Ministry of Economy and Competitiveness of the Spanish Government (grant number: AGL2013-48361-C2-1-R)

    New plant species presents in the Sierra de la Demanda (Sistema Ibérico, La Rioja, Spain)

    Get PDF
    Se citan y comentan una serie de taxones hallados en la Sierra de la Demanda (La Rioja, España), cuya presencia en la provincia era poco o nada conocida

    Risk-taking and fairness among cocaine-dependent patients in dual diagnoses: Schizophrenia and Anti-Social Personality Disorder

    Get PDF
    This study reports experimental results from a clinical sample of patients with a cocaine-related disorder and dual diagnosis: Schizophrenia and Anti-Social Personality Disorder. Both types of patients as well as a non-clinical group of students performed two incentivized decision-making tasks. In the first part of the experiment, they performed a lottery-choice task in order to elicit their degree of risk aversion. In the second part, they decided in two modified dictator games aimed at eliciting their aversion to advantageous and disadvantageous inequality. It is found that the Anti-Social Personality Disorder group exhibits no significant differences from the non-clinical sample in either task. However, compared with the students’ sample, subjects from the group with schizophrenia show more risk aversion and exhibit more aversion towards disadvantageous inequality

    The drawdown phase of dam decommissioning is a hot moment of gaseous carbon emissions from a temperate reservoir

    Get PDF
    Dam decommissioning (DD) is a viable management option for thousands of ageing dams. Reservoirs are large carbon sinks, and reservoir drawdown results in important carbon dioxide (CO2) and methane (CH4) emissions. We studied the effects of DD on CO2 and CH4 fluxes from impounded water, exposed sediment, and lotic water before, during, and 3-10 months after drawdown of the Enobieta Reservoir, north Iberian Peninsula. During the study period, impounded water covered 0-100%, exposed sediment 0-96%, and lotic water 0-4% of the total reservoir area (0.14 km(2)). Areal CO2 fluxes in exposed sediment (mean [SE]: 295.65 [74.90] mmol m(-2) d(-1)) and lotic water (188.11 [86.09] mmol m(-2) d(-1)) decreased over time but remained higher than in impounded water (-36.65 [83.40] mmol m(-2) d(-1)). Areal CH4 fluxes did not change over time and were noteworthy only in impounded water (1.82 [1.11] mmol m(-2) d(-1)). Total ecosystem carbon (CO2 + CH4) fluxes (kg CO2-eq d(-1)) were higher during and after than before reservoir drawdown because of higher CO2 fluxes from exposed sediment. The reservoir was a net sink of carbon before reservoir drawdown and became an important emitter of carbon during the first 10 months after reservoir drawdown. Future studies should examine mid- and long-term effects of DD on carbon fluxes, identify the drivers of areal CO2 fluxes from exposed sediment, and incorporate DD in the carbon footprint of reservoirs.This study was funded by the projects Alteration of carbon sinks and sources in shrinking inland waters (Alter-C), the Spanish Ministry of Science, Innovation and Universities (refs: PID2020-114024GB-C31 funded by MCIN/AEI/10.13039/501100011033/) and Effects of the drawdown of Enobieta Reservoir (Navarre) on the biodiversity and functioning of river ecosystems (DESEMBALSE), Foundation BBVA (ref: PI064-17). AM was supported by an FI grant from the Agencia de Gestio d'Ajuts Universitaris i de Recerca (AGAUR) of the Generalitat de Catalunya. DvS and BO acknowledge support through the Consolidated Research Group 2017SGR0976. RM acknowledges support by the Generalitat de Catalunya through the Consolidated Research Group 2017SGR1124, and by the CERCA program. AE and MA support of the Basque Government through the Consolidated Research Group IT951-16. AM got a predoctoral grant by the University of the Basque Country (UPV/EHU). DvS is a Serra Hunter Fellow

    Is Brief Exposure to Green Space in School the Best Option to Improve Attention in Children?

    Get PDF
    The positive effects of Green Spaces on health are thought to be achieved through the mechanisms of mitigation, instoration and restoration. One of the benefits of Green Spaces may be the restoration of attention and so the objective of this research is testing empirically whether exposure to a green environment improves attention in school children. For so doing, we first used a split-unit statistical design in each of four schools, then combined the primary results via meta-analysis. The Attention Network Test (ANT) was used to measure attention before and after exposure and a total of 167 seven-year-old students participated in the experiments. Overall, our experimental results do not support the hypothesis that students’ exposure to activities in green vs. grey spaces affected their performance in ANT. This was so despite the fact that neither age nor gender biases have been detected and despite that our experiments have been proved to be sufficiently statistically powerful. It would be advisable to consider air pollution and noise. We also recommend that participants attend the experiment with mental exhaustion to maximize the ability to detect significant changes.This research was funded by KUTXA FUNDAZIOA, grant number KUTXA18/001

    Residential green and blue spaces and working memory in children aged 6–12 years old. Results from the INMA cohort

    Get PDF
    Availability of green and blue spaces in the area of residence has been related to various health outcomes during childhood, including neurodevelopment. Some studies have shown that children living in greener and/or bluer areas score better on cognitive tasks although the evidence is inconsistent. These protective effects are hypothesized to occur in part through reductions in air pollution exposure and odds of attention-deficit/hyperactivity disorder (ADHD). This study analysed the effects of residential green and blue spaces on working memory of children in the Spanish INfancia y Medio Ambiente (INMA) birth cohort and the potential joint mediating role of air pollution and ADHD. The study samples were composed of 1738 six-to eight-year-olds (M = 7.53, SD = 0.68, 49% female) and 1449 ten-to twelve-year-olds (M = 11.18, SD = 0.69, 50% female) living in Asturias, Gipuzkoa, Sabadell or Valencia, Spain. Individual Normalized Difference Vegetation Index (NDVI) values in 100-, 300- and 500-m buffers and availability of green and blue spaces &gt;5000 m2 in 300-m buffers were calculated using Geographic Information Systems software. Individual NO2 values for the home environment were estimated using ESCAPE's land use regression models. ADHD diagnosis was reported by participants' parents via a questionnaire. Working memory was measured with numbers and colours (in the younger group only) N-back tests (2- and 3-back d’). Mixed-effects models informed of the beneficial effects of NDVI in a 300-m buffer on numerical working memory in the younger sample although the results were not consistent for all d’ scores considered and failed to detect significant effects through the candidate mediators. Availability of major blue spaces did not predict working memory performance. Provision of green spaces may play a role in children's working memory but further research is required.</p
    corecore