Lecanora caledonica is described as new to science. Molecular analyses show that it belongs to the L. intumescens group. It is also rather similar in appearance to L. intumescens, but differs mainly chemically in containing only atranorin and an unknown UV+ ice blue substance. There are also anatomical and morphological differences to the other species of the group. The new species has a pronounced oceanic distribution and is so far known only from western Norway and Scotland.

This study examined epibionts on three species of sea turtles (loggerhead, green and hawksbill) obtained in Japanese waters as bycatch, strandings, or landings for breeding. Species diversity of barnacle epibionts on sea turtles appears to be affected by the behaviour and foraging habitat of the turtles. Green and hawksbill turtles are found in neritic areas all year round, while loggerhead turtles are found in inshore areas only during the breeding season in Japan. The turtle barnacle Cylindrolepas sinica is found on green and hawksbill turtles frequently, but occurrence on the loggerhead turtle is quite rare (1/190: a new host record). The present study recorded a single individual of loggerhead turtle (a large male) with C. sinica attached. This turtle was captured in August and December at the site of tagging on Okinawa. The recaptured records indicate that the loggerhead turtle wintered around Okinawa rather than migrating to the open sea as most Japanese loggerheads do and resulted in the attachment of C. sinica. Satellite tracking has been an important tool in investigating the sea turtles’ life histories; however, this method is costly and can elucidate migration routes only after the attachment of a transmitter. In contrast, studying the diversity of the epibionts can provide information on the foraging habitat (infection site) and behaviour of the turtles. Such a method can have benefits in getting large sample sizes at nesting beaches, from fishery bycatch and strandings.

Euphausiid life histories and distribution in the vicinity of South Georgia were studied from a series of samples taken in April 1980, November–December 1981, and July–August 1983. Size frequency data indicated a two-year life cycle for Euphausia frigida and the possibility of a three-year cycle for E. triacantha. The genus Thysanoessa was represented by a mixture of T. macrura and the dominant T. vicina. A one-year life cycle is proposed for the latter but that of the former is unknown. Spawning in E. frigida and to a lesser extent Thysanoessa spp. commenced as early as July and euphausiid calyptopes were a feature of the plankton for much of the year. E. superba eggs were found in low abundance over the shelf to the north of the island, but no hatched larvae were found. Behaviour patterns such as diurnal and seasonal migration partially confounded attempts to relate euphausiid distribution to environmental features. However calyptopes of most species, were generally more abundant in oceanic water deeper than 500 m and there was limited evidence that in August, E. frigida had commenced spawning in the colder part of the survey area.

Summary 257

I. DEFINING AND QUANTIFYING OCEANICITY 257

II. ECOLOGICAL CONSEQUENCES OF OCEANICITY 261

III. ECOLOGICAL HISTORY OF OCEANICITY IN WESTERN EUROPE 263

IV. POSITIVE AND NEGATIVE INFLUENCES OF OCEANICITY 267

1. Species versus communities 267

2. Case study – Primula scotica – climatic effects on reproduction 268

3. Case study – cranberry production and anoxia tolerance 268

V. MODIFYING EFFECTS OF OCEANICITY ON PLANT DISTRIBUTION 269

VI. PHYSIOLOGICAL IMPACT OF WARM WINTERS 271

1. Phenology 271

2. Metabolic consequences of warm winters 272

3. Warm winters and mountain-top vegetation 274

VII. TREELINES AND OCEANICITY 276

VIII. CONCLUSIONS 278

Acknowledgements 279

References 279

A cyclic behaviour in the intensity of maritime conditions which varies with the periodic behaviour of the North Atlantic oscillation has recently become apparent in the climatic record of northern Europe. Periodic increases in oceanicity are usually viewed as having a positive effect on plant survival, as milder winters, reduction of temperature extremes, low risk of exposure to frost, and freedom from drought reduce many aspects of environmental stress. However, warmer winters in maritime environments may also have a powerful influence in creating habitats that are unfavourable for many species. The dangers of long periods of soil saturation for overwintering plants, soaking injury to germinating seeds, premature bud burst in spring, depression of treelines by increased cloud cover and high lapse rates, as well as the constant leaching of soils, are all negative aspects of the maritime environment. Woody species in which root dormancy is delayed by mild winters are particularly vulnerable to the consequences of winter flooding. Subsequent re-exposure to oxygen as water tables fall in spring can aggravate flooding damage through post-anoxic injury, leading to severe dieback of anchoring roots. Soil leaching, particularly after human disturbance, can induce nutrient deficiencies and the establishment of oligotrophic communities with reduced productivity. Podzolization and iron pan formation have in the past facilitated the processes of paludification in oceanic regions. The resulting spread of bogs and acid moorlands can further reduce the potential for productivity in both agriculture and natural plant communities. Given the probability that current climatic trends may increase the degree of oceanicity in western and northern regions of Europe, the potentially negative consequences of such a climatic change need to be considered in relation to future ecological changes and their consequences for conservation and land use.