John Coll

Sensitivity of ferry services to the western isles of Scotland to changes in wave and wind climate

The roughness of the seas is rarely mentioned as a major factor in the economic or social welfare of a region. In this study, the relationship between the ocean wave climate and the economy of the Western Isles of Scotland is examined. This sparsely populated region has a high dependency on marine activities, and ferry services provide vital links between communities. The seas in the region are among the roughest in the world during autumn and winter, however, making maintenance of a reliable ferry service both difficult and expensive. A deterioration in wave and wind climate either in response to natural variability or as a regional response to anthropogenic climate change is possible. Satellite altimetry and gale-frequency data are used to analyze the contemporary response of wave and wind climate to the North Atlantic Oscillation (NAO). The sensitivity of wave climate to the NAO extends to ferry routes that are only partially sheltered and are exposed to ocean waves; thus, the reliability of ferry services is sensitive to NAO. Any deterioration of the wave climate will result in a disproportionately large increase in ferry-service disruption. The impacts associated with an unusually large storm event that affected the region in January 2005 are briefly explored to provide an insight into vulnerability to future storm events.

Developing a predictive modelling capacity for a climate change-vulnerable blanket bog habitat: Assessing 19611990 baseline relationships

Aim: Understanding the spatial distribution of high priority habitats and developing predictive models using climate and environmental variables to replicate these distributions are desirable conservation goals. The aim of this study was to model and elucidate the contributions of climate and topography to the distribution of a priority blanket bog habitat in Ireland, and to examine how this might inform the development of a climate change predictive capacity for peat-lands in Ireland. Methods: Ten climatic and two topographic variables were recorded for grid cells with a spatial resolution of 1010 km, covering � 87% of the mainland land surface of Ireland. Presence-absence data were matched to these variables and generalised linear models (GLMs) fitted to identify the main climatic and terrain predictor variables for occurrence of the habitat. Candidate predictor variables were screened for collinearity, and the accuracy of the final fitted GLM was evaluated using fourfold cross-validation based on the area under the curve (AUC) derived from a receiver operating characteristic (ROC) plot. The GLM predicted habitat occurrence probability maps were mapped against the actual distributions using GIS techniques. Results: Despite the apparent parsimony of the initial GLM using only climatic variables, further testing indicated collinearity among temperature and precipitation variables for example. Subsequent elimination of the collinear variables and inclusion of elevation data produced an excellent performance based on the AUC scores of the final GLM. Mean annual temperature and total mean annual precipitation in combination with elevation range were the most powerful explanatory variable group among those explored for the presence of blanket bog habitat. Main conclusions: The results confirm that this habitat distribution in general can be modelled well using the non-collinear climatic and terrain variables tested at the grid resolution used. Mapping the GLM-predicted distribution to the observed distribution produced useful results in replicating the projected occurrence of the habitat distribution over an extensive area. The methods developed will usefully inform future climate change predictive modelling for Ireland.

Minimal climate change impacts on natural organic matter forecasted for a potable water supply in Ireland

Natural organic matter poses an increasing challenge to water managers because of its potential adverse impacts on water treatment and distribution, and subsequently human health. Projections were made of impacts of climate change on dissolved organic carbon (DOC) in the primarily agricultural Boyne catchment which is used as a potable water supply in Ireland. The results indicated that excluding a potential rise in extreme precipitation, future projected loads are not dissimilar to those observed under current conditions. This is because projected increases in DOC concentrations are offset by corresponding decreases in precipitation and hence river flow. However, the results presented assume no changes in land use and highlight the predicted increase in DOC loads from abstracted waters at water treatment plants.

The diversity and composition of moth assemblages of protected and degraded raised bogs in Ireland

Peatlands are globally important habitats, which act as net carbon stores. As a result of drainage, peat extraction and agricultural intensification, raised bogs in the midlands of Ireland are a diminishing and increasingly fragmented peatland habitat. A network of protected sites has been established, which is intended to represent the best abiotic and plant community systems. Lepidoteran communities are an important component of raised bog biodiversity and may be useful as biodiversity indicators, yet they are a neglected area of research. We address this by surveying night‐flying macro‐moths on six protected and six degraded raised bogs to establish whether there is a distinct moth fauna associated with the wettest areas of protected sites by comparing them to assemblages found on degraded sites where this wet habitat has been lost. In general, differences between moth assemblages on protected and degraded raised bogs are rather subtle, with assemblages on both site types generally similar. But, a number of species were found to be associated with protected sites, three of which are bog‐associated species of conservation concern and may be particularly vulnerable due to the continuing loss of the wettest areas of raised bogs. Degraded sites were found to harbour a significant number of bog‐associated species of conservation concern and may have a role to play in peatland invertebrate conservation, hitherto undervalued. To determine this, further research is required to describe the invertebrate fauna of these sites and of marginal areas of protected sites.