769 resultados para Rural and Regional Airports
Resumo:
It has been 10 years since the publication of the relative risk model (RRM) for regional scale ecological risk assessment. The approach has since been used successfully for a variety of freshwater, marine, and terrestrial environments in North America, South America, and Australia. During this period the types of stressors have been expanded to include more than contaminants. Invasive species, habitat loss, stream alteration and blockage, temperature, change in land use, and climate have been incorporated into the assessments. Major developments in the RRM have included the extensive use of geographical information systems, uncertainty analysis using Monte Carlo techniques, and its application to retrospective assessments to determine causation. The future uses of the RRM include assessments for forestry and conservation management, an increasing use in invasive species evaluation, and in sustainability. Developments in risk communication, the use of Bayesian approaches, and in uncertainty analyses are on the horizon.
Resumo:
Chinese Academy of Sciences [KZCX2-YW-315, KZCX2-YW-Q1-01]; National Natural Science Foundation of China [40625002, 90502009, 200905006]; Office of Science (BER), U. S. Department of Energy ; EU/FP7 [212250]
Resumo:
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.
Resumo:
Long-term regional changes in phytoplankton biomass in the Northeast Atlantic and North Sea are investigated using data from the Continuous Plankton Recorder survey. During the last decade there have been large changes in the long-term variation in phytoplankton biomass in the Northeast Atlantic and North Sea. Most regions, particularly in the North Sea, have shown a considerable increase in phytoplankton biomass while the opposite pattern was seen in the northern oceanic region of the Northeast Atlantic. These different spatial responses show similar patterns of change to the decadal variability in sea surface temperature influenced by the North Atlantic Oscillation index. Two rare oceanographic events and their relationship to the interannual changes in phytoplankton biomass are discussed. The results highlight the importance of maintaining long-term biological monitoring programmes to assess the biological responses to slow oceanic/atmospheric processes and to rare or episodic physical events.
Resumo:
Using an effective combination of multivariate testing and ordination analyses, this study compares the extents to which the diets of two co-occurring fish species (Pagrus auratus and Pseudocaranx georgianus) are related to body size (length class), season and region and the rank order importance of those effects. Thus, volumetric dietary compositions were determined for these species on the lower west coast of Australia, where both are abundant, and for P. auratus from the mid west coast and P. georgianus from the south coast. The diet of P. auratus on the lower west coast was strongly related to body size and slightly less to season. With increasing body size, its diet shifted from predominantly ophiuroids to larger prey, such as brachyuran crabs, teleosts, echinoids and ultimately asteroids, probably reflecting a shift from foraging over soft sediments to areas over and around reefs. Seasonal changes on the lower west coast were restricted mainly to small P. auratus, while larger fish underwent seasonal changes further north. Analyses using a common size range of medium to larger P. auratus demonstrated that dietary composition differed more between regions than seasons. The relationships between diet and length class of P. georgianus on both the lower west and south coasts were less pronounced than for P. auratus and seasonal changes were restricted to the south coast, where amphipod consumption increased markedly in summer. The diet of P. georgianus was related far more to region than length class and season, with more small teleosts, small crabs, carideans and littorinids and less amphipods, isopods and small bivalves being ingested on the lower west than south coasts. Although crabs and teleosts were important typifying prey of P. auratus and P. georgianus, when co-occurring, the former predator tended to ingest greater volumes of larger and often less mobile prey. This reflects differences in dentition, jaw morphology and feeding behaviour and reduces the potential for competition for food resources. The results imply that P. auratus and P. georgianus are opportunistic feeders and that the effects of length class, season and region on dietary composition and their rank orders can vary markedly between species and for length class and season between regions for the same species.