4 resultados para Open landscapes

em CORA - Cork Open Research Archive - University College Cork - Ireland


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Ireland and Britain were once covered in natural forest, but extensive anthropogenic deforestation reduced forest cover to less than 1% and 5 %, respectively, by the beginning of the 20th century. Large-scale afforestation has since increased the level of forest cover to 11% in Ireland and 12% in Britain, with the majority of planted forests comprising small monoculture plantations, many of which are of non - native conifer tree species. At present the forest cover of Ireland and Britain generally consists of small areas of remnant semi-natural woodland and pockets of these plantation forests within a predominantly agricultural landscape. Invertebrates comprise a large proportion of the biodiversity found within forested habitats. In particular, spiders and carabid beetles play an important role in food webs as both predators and prey and respond to small-scale changes in habitat structure, meaning they are particularly sensitive to forest management. Hoverflies play an important role in control and pollination and have been successfully used as indicators of habitat disturbance and quality. This research addressed a number of topics pertinent to the forest types present in the contemporary Irish and British landscapes and aimed to investigate the invertebrate diversity of these forests. Spiders and carabid beetles were sampled using pitfall trapping and hoverflies were sampled using Malaise net trapping. Topics included the impacts of afforestation, the importance of open space, the choice of tree species, and the use of indicators for biodiversity assessment, as well as rare native woodlands and the effect of grazing on invertebrate diversity. The results are discussed and evidence-based recommendations are made for forest policy and management to protect and enhance invertebrate biodiversity in order to promote sustainable forest management in Ireland and Britain.

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This thesis explores the impact of Christianity on the landscape in Ireland from the conversion period to the coming of the Anglo-Normans. The premise is that ecclesiastical and secular settlement formed a cohesive whole which characterised the societal organisation of early medieval Ireland. The matter of the thesis is to isolate some of the agents of cohesion to see was this homogenous or did it vary in different areas. One of these agents was the ownership of land and the thesis undertakes to identify ecclesiastical landholding and examine the manner of settlement on it. A corollary is to explore the contribution of the genealogical link between kin-group, founding saint and territory to the construction of local identities. This necessitated a narrow focus; thus small study areas were chosen, which approximated to early medieval kingdoms in North Louth, Rathdown, Co Dublin and Ross, Co Cork. A multidisciplinary approach was taken using both archaeological and documentary evidence. The thesis found ecclesiastical sites were at the same density through the study areas, but there were considerable regional variations in related secular settlement. Ecclesiastical estates were identified in the three study areas and common settlement patterns were found in two of them. Settlement in all areas indicated the foundation of minor churches by local groups. Ecclesiastical sites were found to be integral to kin-group identity and status, but the manner in which each group negotiated this, was very different. Finally the thesis examined material evidence for a change from diffused to concentrated power in the political organisation of Irish society, a process entwined with developments of the Viking Age. This centralisation of power and associated re-formation of identity was still often mediated through the ecclesiastical sphere but the thesis demonstrates diversity in the materialising of the mediation.

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This thesis explores the evolution of kingship in early medieval Ireland (AD 400–1150) through a kingdom based and multi-scalar approach to royal landscapes. Through exploring the role of place and landscape in the construction of early medieval Irish kingship, this study will assess the relationship between the social, economic and ideological roles of the king in Irish society. Kingship in Ireland was vested in places, such that royal landscapes were the pre-eminent symbol of regality and authority. As such, an interdisciplinary study of kingship grounded in archaeological methodologies has a unique potential to contribute to our knowledge of the practice of kingship. Consequently, this research considers the material apparatus of different scales of kingships and explores the role of landscape in the construction of kingship and the evolution of kingdoms. It takes two major case studies; (i) Cashel, Munster and the Éoganachta federation; and (ii) the Uí Néill, Tara and the Síl nÁedo Sláine kingdom of Brega. Through interdisciplinary methodologies it charts the genesis and development of political federations, focusing specifically on the role that royal landscapes’ played in their evolution. Similarly, this thesis engages critically with the nature of assembly places and practices in Ireland, and focuses specifically on issues pertaining to the nature of assembly and the archaeological manifestation of such practices. It includes a list of 115 landscapes identified as assembly places, and through the analysis of this material, this thesis examines the ways in which different types of royal sites articulated together to create royal landscapes implicated in the exercise of kingship, and the construction and maintenance of authority. Moreover, through the analysis of assembly places within the context of the development of kingdoms, and structures of jurisdiction and administration, it also investigates the evolution of supra-regional scales of identity and community associated with the emergence of major political federations in early medieval Ireland.

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Open environments involve distributed entities interacting with each other in an open manner. Many distributed entities are unknown to each other but need to collaborate and share resources in a secure fashion. Usually resource owners alone decide who is trusted to access their resources. Since resource owners in open environments do not have a complete picture of all trusted entities, trust management frameworks are used to ensure that only authorized entities will access requested resources. Every trust management system has limitations, and the limitations can be exploited by malicious entities. One vulnerability is due to the lack of globally unique interpretation for permission specifications. This limitation means that a malicious entity which receives a permission in one domain may misuse the permission in another domain via some deceptive but apparently authorized route; this malicious behaviour is called subterfuge. This thesis develops a secure approach, Subterfuge Safe Trust Management (SSTM), that prevents subterfuge by malicious entities. SSTM employs the Subterfuge Safe Authorization Language (SSAL) which uses the idea of a local permission with a globally unique interpretation (localPermission) to resolve the misinterpretation of permissions. We model and implement SSAL with an ontology-based approach, SSALO, which provides a generic representation for knowledge related to the SSAL-based security policy. SSALO enables integration of heterogeneous security policies which is useful for secure cooperation among principals in open environments where each principal may have a different security policy with different implementation. The other advantage of an ontology-based approach is the Open World Assumption, whereby reasoning over an existing security policy is easily extended to include further security policies that might be discovered in an open distributed environment. We add two extra SSAL rules to support dynamic coalition formation and secure cooperation among coalitions. Secure federation of cloud computing platforms and secure federation of XMPP servers are presented as case studies of SSTM. The results show that SSTM provides robust accountability for the use of permissions in federation. It is also shown that SSAL is a suitable policy language to express the subterfuge-safe policy statements due to its well-defined semantics, ease of use, and integrability.