995 resultados para Iberian massif
Resumo:
The study of the Upper Jurassic-Lower Cretaceous deposits (Higueruelas, Villar del Arzobispo and Aldea de Cortés Formations) of the South Iberian Basin (NW Valencia, Spain) reveals new stratigraphic and sedimentological data, which have significant implications on the stratigraphic framework, depositional environments and age of these units. Moreover, these new data encourage revising the previously proposed stratigraphic correlations between the studied units and those deposited in adjacent areas of the Iberian Basin. The Higueruelas Fm was deposited in a mid-inner carbonate platform where oncolitic bars migrated by the action of storms and where oncoid production progressively decreased towards the uppermost part of the unit. The overlying Villar del Arzobispo Fm has been traditionally interpreted as an inner platform-lagoon evolving into a tidal-flat. Here it is interpreted as an inner-carbonate platform affected by storms, where oolitic shoals protected a lagoon, which had siliciclastic inputs from the continent. The Aldea de Cortés Fm has been previously interpreted as a lagoon surrounded by tidal-flats and fluvial-deltaic plains. Here it is reinterpreted as a coastal wetland where siliciclastic muddy deposits interacted with shallow fresh to marine water bodies, aeolian dunes and continental siliciclastic inputs. The contact between the Higueruelas and Villar del Arzobispo Fms, classically defined as gradual, is interpreted here as gradual and rapid, because the transition between both units comprises few meters. More importantly, the contact between the Villar del Arzobispo and Aldea de Cortés Fms, previously considered as unconformable, is here interpreted as gradual. The presence of Alveosepta in the Villar del Arzobispo Fm suggests that at least part of this unit is Kimmeridgian, unlike the previously assigned Late Tithonian-Middle Berriasian age. Consequently, the underlying Higueruelas Fm, previously considered Tithonian, should not be younger than Kimmeridgian. Accordingly, sedimentation of the Aldea de Cortés Fm, previously considered Valanginian-Hauterivian, probably started during the Tithonian and it may be considered part of the regressive trend of the Late Jurassic-Early Cretaceous cycle. This is consistent with the dinosaur faunas, typically Jurassic, described in the Villar del Arzobispo and Aldea de Cortés Fms.
Resumo:
Saproxylic diversity assessment is a major goal for conservation strategies in woodlands and it should consider woodland composition and configuration at site and tree level as key modelling factors. However, in Mediterranean woodlands little is known about the relation with the environmental factors that structure their assemblages, especially those linked to tree hollow microhabitats. We assessed the diversity of Syrphidae (Diptera) and Coleoptera saproxylic guilds that co-occurred in tree hollows located in three different Iberian Mediterranean woodlands in the Cabañeros National Park (Spain). Furthermore, we evaluated how differences in tree hollow microenvironmental variables (understood as the physical and biotic characteristics of a hollow and tree individual) influenced saproxylic guild diversity both within and among woodland sites. We found that woodland sites that provided greater heterogeneity of trees and hollow microhabitats determined higher saproxylic guild diversity. Nevertheless, certain species or even complete guilds can be favoured in woodlands where some hollow microhabitats predominate as a consequence of historical tree management. In general, hollow volume was the main determining factor for saproxylic guild richness and abundance in woodland sites, and large hollow volume was usually related to higher diversity, which highlighted the importance of multi-habitat hollow trees. Moreover, saproxylic guilds also responded to other different microenvironmental variables, which indicated different ecological preferences among guilds. The conservation of saproxylic insects in Iberian Mediterranean areas must be addressed to protect woodland sites that provide high diversity and large numbers of tree hollow microhabitats, and practices to enhance microhabitat heterogeneity should even be encouraged.
Resumo:
The assessment of the relationship between species diversity, species interactions and environmental characteristics is indispensable for understanding network architecture and ecological distribution in complex networks. Saproxylic insect communities inhabiting tree hollow microhabitats within Mediterranean woodlands are highly dependent on woodland configuration and on microhabitat supply they harbor, so can be studied under the network analysis perspective. We assessed the differences in interacting patterns according to woodland site, and analysed the importance of functional species in modelling network architecture. We then evaluated their implications for saproxylic assemblages’ persistence, through simulations of three possible scenarios of loss of tree hollow microhabitat. Tree hollow-saproxylic insect networks per woodland site presented a significant nested pattern. Those woodlands with higher complexity of tree individuals and tree hollow microhabitats also housed higher species/interactions diversity and complexity of saproxylic networks, and exhibited a higher degree of nestedness, suggesting that a higher woodland complexity positively influences saproxylic diversity and interaction complexity, thus determining higher degree of nestedness. Moreover, the number of insects acting as key interconnectors (nodes falling into the core region, using core/periphery tests) was similar among woodland sites, but the species identity varied on each. Such differences in insect core composition among woodland sites suggest the functional role they depict at woodland scale. Tree hollows acting as core corresponded with large tree hollows near the ground and simultaneously housing various breeding microsites, whereas core insects were species mediating relevant ecological interactions within saproxylic communities, e.g. predation, competitive or facilitation interactions. Differences in network patterns and tree hollow characteristics among woodland sites clearly defined different sensitivity to microhabitat loss, and higher saproxylic diversity and woodland complexity showed positive relation with robustness. These results highlight that woodland complexity goes hand in hand with biotic and ecological complexity of saproxylic networks, and together exhibited positive effects on network robustness.
Resumo:
This paper is part of the research project HAR2012–34035 (Lectura arqueológica del uso social del espacio. Espacios domésticos y vida social entre la Antigüedad y el Medievo, funded by the Ministry of Economy and Competitiveness).
Resumo:
The last decades have been fruitful in reforms in public sector accounting across the world, namely moving from cash-based into accrual-based regimes. In this process of bringing public sector accounting close to business accounting, International Public Sector Accounting Standards (IPSASs) have been developed and adopted in several countries. In the EU context, public sector harmonization among member-States is currently being considered, namely via the development of European Public Sector Accounting Standards (EPSASs). Both IPSASs and EPSASs are understood as, among other things, important to contribute for a more informative and transparent financial reporting of public sector entities and governments. Moreover they are expected to approximate public sector accounting and the National Accounts, hence allowing for more reliable information to monitor fiscal discipline among EU countries. The Iberian countries, after using accrual accounting in the public sector for more than twenty years (Spain from middle 1980s and Portugal from 1990s), have acknowledged the need to embark in an international harmonization process adopting IPSASs, particularly after the adoption of IFRSs in the business sector, which was creating some difficulties for consolidated accounts. Spain has passed the Chart of Accounts for the Public Sector through the Order EHA/1037/2010, which is adapted to IPSASs; Portugal has just passed Law-decree 192/2015, September 11, and is expecting to start implementation in 2017. In both countries a central role in this reform has been assumed by the national standard-setters for public sector accounting. Based on the “Actor Network Theory” to help understanding how and why organizations interact and how this interaction could have an impact on their choice of accounting policies, this paper aims to analyse, from the Iberian public sector accounting standard-setters perspective, how the adoption/adaptation of IPSASs has been considered and developed in these countries. Research questions to be considered are the following, which will be asked in interviews to the members of the standard-setting committees in both Portugal and Spain: • What were the driving forces leading to the decision to adopt and implement IPSASs? • Which other governmental bodies’ experiences, if any, were considered in the adoption of IPSASs? • What specific steps were/are being undertaken to prepare for the conversion from the existing system to IPSASs? • What were/are the institutional challenges faced/expected to face? • What assistance have been received from IFAC and/or IPSASB, or from other sources, if any, throughout the adoption/implementation? • How can the success of the adoption/implementation be characterised? • What benefits can/have the government derive/derived from the adoption and implementation of IPSASs? The paper is expected to contribute to the understanding of the issues underlying the process of embarking in public sector accounting reforms towards IPSASs.
(Table 3) Sr and Nd isotope composition, and Sr and carbonate contents of Atlantis Massif IODP holes