The unique ecology of Ophelia bicornis, Savigny (Polychaeta)

Tephrochronology studies in the North Atlantic typically focus on large scale silicic volcanic eruptions such as the Askja 1875, Hekla 1104 and Öræfajokull 1362. However, smaller-scale Icelandic eruptions are becoming more important as regional time marker horizons and have the potential for application across widerdistances e.g. the Eyjafjallajökull eruption of 2010. The Grákolla tephra is one such layer, sourced within the Torfajökull volcanic system. On the basis of major element chemistry, the tephra layer exhibits an identical geochemical fingerprint to the Landnám tephra, which is also sourced from the Torfajökull system. However, distinct differences are discernible on the basis of trace element chemistry, although some data overlap remains. This realisation highlights the potential for introducing significant age discrepancies to a dating framework based on recent silicic Torfajökull tephra deposits in the Faroe Islands if tephra identification is based solely on major element chemistry. Six hundred years separate the eruptions, which although a relatively short time frame for geological events, represents a significant time frame for the dating of human events.

Government statistics illustrate that by 2050 there will be a shortage of meat and milk due to globalpopulationgrowth and the increaseddemand from the Far East. Ensuring food security in terms of availability and nutritionalsafety is, therefore, important for our future existence. Central to achieving milk and meat security are ruminants. Ruminants have a four chambered stomach composed of the reticulum, rumen, abomasum and omasum with microbial fermentation of forage occurring in the rumen. Rumen microbial fermentation is largely responsible for animal production, ruminant product quality and much of greenhouse gas emissions. Indeed, when forage reaches the rumen, the rumen microbes degrade the plant cell wall and subsequently metabolise plant cell content, including plant amino acids and proteins which they convert into proteins that they can utilise. In order to ensure availability of milk and meat of the best possible quality (with the least greenhouse gas emissions) for the future, we must increase our understanding of the plant-microbe interactome using the principles of systems biology and 'omic' technology.

Nitrogen (N) is the most important element that controls plant growth. During the past twenty years, our understanding of which N species are important for plant growth has developed significantly but it is still thought that large nitrogenous molecules need to be broken down into their constituent amino acids to be available for plant and microbial growth. This paper builds on our understanding of this process and suggests that small peptides are equally important for microbial nutrition and that soil microbes outcompete plants for low molecular weight N compounds in maritime Antarctic soil.