21 research outputs found

    Influencia de la densidad de la masa adulta y el tratamiento del suelo sobre la regeneración del pino laricio (Pinus nigra Arn. ssp. Salzmannii) en España

    Get PDF
    Satisfactory results relating to the natural regeneration of the Spanish black pine (Pinus nigra Arn ssp. salzmannii) is generally difficult to achieve. The natural regeneration of this pine was studied comparing two types of soil treatment and various overstory densities in six experimental forests. These studies were conducted from 1999 to 2002 and seed rain and germination, as well as seedling survival were observed in a number of specific plots: Brushing, scalping and control plots. In addition various overstory densities were used (measured as base area (square m/ha). Soil and air temperature together with soil moisture were continuously recorded throughout this summer period. The results showed that seed germination was higher in plots using the scalping technique, as opposed to the brushed or controlled plots. The best seedling survival percentage was found in scalped plots together with a larger basal area. It was also found that seedling survival was lower during the first year than during the second one. The results have practical implications for management of Spanish black pine forests as well as valuable information which could improve the conditions for regeneration.Generalmente es difícil conseguir una regeneración natural satisfactoria del pino laricio (Pinus nigra Arn ssp. salzmannii). Esta ha sido estudiada en dos tipos de tratamiento del suelo y bajo diferentes rangos de densidad de masa en seis montes de la Provincia de Cuenca. Entre 1999 y 2000 se ha seguido la lluvia de semillas, germinación y supervivencia de plántulas en las parcelas en las que se realizaron los tratamientos de suelo y bajo diferentes rangos de densidad de masa adulta, medida como área basimétrica (m cuadrados/ha). La temperatura del suelo y aire y la humedad del suelo han sido registradas durante el verano y para las dos primeras épocas de crecimiento de las plántulas. En las zonas decapadas la germinación fue superior a la encontrada en las zonas desbrozadas o testigo. El mejor porcentaje de supervivencia se calculó para las zonas decapadas en combinación con el mayor nivel de área basimétrica medido. La mortalidad de plántulas fue superior durante el primer periodo de crecimiento. Los resultados tienen implicaciones prácticas especialmente en lo relativo a una gestión forestal que mejore las condiciones para la regeneración natural de los bosques de pino laricio

    “Tourism, water, and gender”—An international review of an unexplored nexus

    Get PDF
    This international literature review of the tourism–water nexus identifies a gender gap. Tourism development can affect water supply both quantitatively and qualitatively. Many regions will face considerable problems of water availability and quality, affecting their tourism sector and increasing competition with local residents, and other industries especially agriculture. This international review of literature explores the tourism–water nexus, comparing and contrasting literature published in English, Chinese, and Spanish. Securing access to safe water for continued tourism development is a common theme and the vast majority of work has focused on hotels including water pricing, water-saving practices and innovative management methods. In all continents, struggles are apparent, and the unsustainability of tourism is having impacts on water quantity and quality. This article identifies significant gaps in the literature including climate change, the energy-water nexus, and the links with the Sustainable Development Goals. Furthermore, studies from a gendered perspective are minimal and the potential for areas of further gendered studies within the tourism–water nexus are highlighted including intersectionality, water insecurity and sanitation, tourism and gender based violence, and additional unpaid care work

    Trophic Ecology of Atlantic Bluefin Tuna (Thunnus thynnus) Larvae from the Gulf of Mexico and NW Mediterranean Spawning Grounds: A Comparative Stable Isotope Study

    Get PDF
    The present study uses stable isotopes of nitrogen and carbon (ή15Nandή13C) as trophic indicators for Atlantic bluefin tuna larvae (BFT) (6–10mm standard length) in the highly contrasting environmental conditions of the Gulf of Mexico (GOM) and the Balearic Sea (MED). These regions are differentiated by their temperature regime and relative productivity, with the GOM being significantly warmer and more productive. MED BFT larvae showed the highest ή15N signatures, implying an elevated trophic position above the underlyingmicrozooplankton baseline. Ontogenetic dietary shifts were observed in the BFT larvae from the GOM and MED which indicates early life trophodynamics differences between these spawning habitats. Significant trophic differences between the GOM and MED larvae were observed in relation to ή15N signatures in favour of the MED larvae, which may have important implications in their growth during their early life stages. These low ή15N levels in the zooplankton from the GOM may be an indication of a shifting isotopic baseline in pelagic food webs due to diatrophic inputs by cyanobacteria. Lack of enrichment for ή15N in BFT larvae compared to zooplankton implies an alternative grazing pathway from the traditional food chain of phytoplankton— zooplankton—larval fish. Results provide insight for a comparative characterization of the trophic pathways variability of the two main spawning grounds for BFT larvaeVersión del editor4,411

    Differentiated stable isotopes signatures between pre- and post-flexion larvae of Atlantic bluefin tuna (Thunnus thynnus) and of its associated tuna species of the Balearic Sea (NW Mediterranean)

    No full text
    The trophic ecology of bluefin tuna larvae (Thunnus thynnus) from the Balearic Sea, together with its co-existing tuna species such as albacore (T. alalunga), bullet (Auxis rochei) and little tunny (Euthynnus alletteratus) were examined by nitrogen and carbon stable isotope analyses. A total of 286 larvae were analyzed for this study, of which 72 larvae corresponded to bluefin, 57 to albacore, 81 to bullet tuna and 76 to little tunny. Tuna larvae were separated into the pre-flexion and post-flexion developmental stages. Within the size 3–9 mm standard length (SL), the stable isotope of nitrogen (ή15N) showed significant differences between species where bluefin tuna larvae ranked highest. Pre-flexion bluefin tuna and little tunny larvae showed significantly higher ή15N signatures than the post-flexion larvae. This effect is attributed to a biochemical trace of maternal ή15N signatures. However, neither albacore nor bullet tuna larvae showed this pattern in ή15N signatures, possibly owing to a compensation effect between lower maternal ή15N values transmitted to pre-flexion larvae and the early increase of ή15N values in post-flexion stages. One way ANOVA showed significant differences between species in the stable isotope ratio of carbon (ή13C) values, which suggests specific differences of carbon sources. Furthermore, a similar significant ontogenic effect between ή13C signatures of pre-flexion and post-flexion larvae is also evidenced in all four species. At pre-flexion stages, all species except bullet tuna larvae showed significant negative relationships between ή15N and larval standard length. At post-flexion stages, a significant linear relationship with larval size was only observed in albacore and bullet tuna larvae indicating a possible trophic shift towards early piscivory. With respect to ή13C values with larval size, all four species showed significant linear decreases. It may be explained by the metabolism of growth of somatic mass subject to modification of the relative carbon isotopic sources. In conclusion, the species' signatures of ή15N and ή13C indicate differentiated early life trophic niches. In addition, it is worth remarking the potential use of transgenerational isotopic transmission in future research applicationsVersión del edito

    Developing performance audit in Spanish local government: an empirical study of a way forward

    Get PDF
    Like many developed countries, public services in Spain are facing a prolonged period of financial austerity. Consequently, most parts of the Spanish public sector have to give consideration to various aspects of public services, including the means for improving existing performance. Performance audit is seen as a key means for improving performance in Spanish local government but the approach is not as well developed as in many other countries. This paper is an empirically based study of the current situation regarding performance audit in the Spanish local government sector and provides pointers as to how this approach might be strengthened
    corecore