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The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.
The introduction of the Manila clam into British coastal waters in the 1980s was contested by conservation agencies. While recognizing the value of the clam for aquaculture, the government decided that it posed no invasive risk, as British sea temperatures would prevent naturalization. This proved incorrect. Here we establish the pattern of introduction and spread of the species over the first 30 years of its presence in Britain. We report archival research on the sequence of licensed introductions and examine their relationship in time and space to the appearance of wild populations as revealed in the literature and by field surveys. By 2010 the species had naturalized in at least 11 estuaries in southern England. These included estuaries with no history of licensed introduction. In these cases activities such as storage of catch before market or deliberate unlicensed introduction represent the probable mechanisms of dispersal. In any event naturalization is not an inevitable consequence of introduction and the chances of establishment over the period in question were finely balanced. Consequently in Britain the species is not currently aggressively invasive and appears not to present significant risk to indigenous diversity or ecosystem function. However it is likely to gradually continue its spread should sea surface temperatures rise as predicted.
The name Bos caffer was attributed by Sparrman in 1779. Since then, 92 species names have been given to the African buffalo. Taxonomists initially thought that each buffalo form represented a distinct species. Brooke (1873, 1875), who established the first classification of the African buffalo, reduced the number to three. Later, Blancou (1935) described up to 12 subspecies of buffalo.
Haltenorth (1963), Ansell (1972) and Grubb (1972) summarized the first classifications of Christy (1929), Schouteden (1945) and Blancou (1935, 1954), concluding that all forms should be considered as monospecific. Although there are considerable morphological variations in body size, fur colour, horn shape and size throughout the range of distribution, the African buffalo is currently considered as a single species by various authorities (IUCN 2013; Prins & Sinclair 2013), with a subdivision into four subspecies: Cape buffalo (S. c. caffer), forest buffalo (S. c. nanus), West African savanna buffalo (S. c. brachyceros), and Central African savanna buffalo (S. c. aequinoctialis). Additionally to those four subspecies, a mountain form(S. c. mathewsi) was also described in East Africa and may be distinct (Kingdon 1982).
This volume of the Haskins Society Journal furthers the Society's commitment to historical and interdisciplinary research on the early and central Middle Ages, especially in the Anglo-Saxon, Anglo-Norman, and Angevin worlds but also on the continent. The topics of the essays it contains range from the curious place of Francia in the historiography of medieval Europe to strategies of royal land distribution in tenth-century Anglo-Saxon England to the representation of men and masculinity in the works of Anglo-Norman historians. Essays on the place of polemical literature in Frutolf of Michelsberg's Chronicle, exploration of the relationship between chivalry and crusading in Baudry of Bourgeuil's History, and Cosmas of Prague's manipulation of historical memory in the service of ecclesiastical privilege and priority each extend the volume's engagement with medieval historiography, employing rich continental examples to do so. Investigations of comital personnel in Anjou and Henry II's management of royal forests and his foresters shed new light on the evolving nature of secular governance in the twelfth centuries and challenge and refine important aspects of our view of medieval rule in this period. The volume ends with a wide-ranging reflection on the continuing importance of the art object itself in medieval history and visual studies. Contributors: H.F. Doherty, Kathryn Dutton, Kirsten Fenton, Paul Fouracre, Herbert Kessler, Ryan Lavelle, Thomas J.H. McCarthy, Lisa Wolverton, Simon Yarrow.
Just as the proof of the pudding is in the eating, so it is in science that the testing of hypotheses is at the core of the development of theory. As set out in this book’s Introduction (Chapter 1), most ecological theory has been developed outside Australasia; this biogeographical region thus provides an excellent case study for investigating whether the generally accepted hypotheses from ecological theory really are applicable in a different context. Furthermore, many excellent observational studies have been carried out in Australasia; the history of invasions in that region can be viewed as a series of experimental tests of ecological theory. Indeed, the Australian native flora and fauna was so different from that of the rest of the world, that Darwin (before he became an atheist) asked himself in his diaries whether there had been two Creators instead of one (see Chapter 1).
In Chapter 1, we explained the reasoning behind the selection of the hypotheses that are reviewed in the main chapters in this book. At the beginning of this project all the authors were asked to formulate hypotheses, to give their feedback on the hypotheses, the way they were formulated and whether the hypotheses could be assessed by them; as a result of this collective effort authors could agree on assessing this present set of hypotheses. The hypotheses are derived from general ecological theory (see Chapter 1) but the material at hand cannot be viewed simply as ‘data’ such that the hypotheses can be tested as a part of statistical inference. This type of inference is familiar and easy for most scientists to address, and that is where most authors of this book clearly felt more secure than when they had to arrive at judgements from observations or from historical reconstructions. The overall conclusions, based on a meta-analysis of the assessment/testing of the 11 hypotheses by the authors of the chapters on species that moved into or out of Australasia as presented in the following tables, are clear: after weighing up the evidence many of the authors of chapters in this book concluded that there was no support for the individual hypothesis, or that they had to reject the hypothesis.
Some of today’s most pressing issues deal with invasions by alien species into natural or man-made ecosystems such as agricultural landscapes. Invasions are not a new phenomenon having been a part of the relationship between man and the environment ever since humans moved out into the savannas; however, they became part of the ecological agenda in the middle of the last century. The foundations of invasion ecology stem from Charles Elton, who, in his book, The Ecology of Invasions by Animals and Plants (published in 1958) attempted to draw together three stands of ecology – faunal history, ecology, particularly population ecology, and conservation. Elton’s book had some traction at the time (e.g. Baker and Stebbins 1965), however, few ecologists paid much attention to invasions during the 1960s even though island biogeography theory (MacArthur and Wilson 1967) did provide theoretical frameworks for how new species fitted into the resident species communities on islands. It was not until the 1970s that invasion ecology began to gain traction in the literature (e.g. Baker 1974; Embree 1979) and continues to this day (Richardson 2011). There have been recent attempts to create unified theoretical frameworks for understanding the invasion process (Blackburn et al. 2011) and the traits that determine the degree to which a species can invade a new ecosystem or the degree to which an ecosystem can be invaded by a new species (Richardson and Pysek 2006). These developments provide a foundation upon which to assess the degree to which hypotheses concerning biological invasions relate to real-world case studies that are proliferating in the literature.