We provide a map of the 15 biogeographic provinces of Argentina based on the ecoregions recognized for the country, combining climatic, geological and biotic criteria. Argentinean provinces belong to the Neotropical region (Yungas, Paraná Forest, Araucaria Forest, Chaco and Pampean provinces), the South American transition zone (Puna, Monte, Comechingones and Cuyan High Andean provinces) and the Andean region (Patagonian, Maule, Valdivian Forest, Magellanic Forest, Falkland Islands and Magellanic Moorland provinces). In order to facilitate future biogeographic analyses, we provide a file of this biogeographical regionalisation in vector format using the World Geodetic Survey 1984.

Evolutionary biogeography aims to provide a hierarchical system of biotic regionalisation for areas of the Earth that correspond to natural areas related by their common evolutionary history. In this context, the central Pampean Ranges of Argentina, formed by the mountain systems of Córdoba and San Luis, are immersed in the Chacoan dominion; however, higher-altitude environments of these mountains, namely highland grasslands and tabaquillo forests, have relationships with the Andean region and other Neotropical areas that are different from the Chacoan dominion, which would indicate that the current classification would not be natural. To clarify their biogeographic relationships, a track analysis of the distribution of the biota of vertebrates and vascular plants of the highland grasslands and tabaquillo forests of central Pampean Argentinian Ranges was conducted. The obtained distributional patterns suggest that the area under study has diverse geobiotic origins, both Andean and Neotropical, indicating that, in this area, an interaction of biota with different evolutionary origins occurs; so, its status as a biogeographic province is proposed, belonging to the South American transition zone.

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The colonial tunicate Clavelina lepadiformis is a recent invader to the northwest Atlantic and has the potential to cause ecological and economic harm. This paper provides a review of the biological and ecological characteristics of C. lepadiformis, and hypothesizes the likely mechanisms of introduction, establishment and future expansion. The intent of this paper is to provide a consolidated source of information for marine ecosystem managers and provide a starting point for developing a management strategy, should one be desired. Although C. lepadiformis is not currently a management challenge because of the limited range of the invasion in North America; the similarities between C. lepadiformis and other tunicate invaders, and the proximity of incipient populations to boating, shipping, aquaculture, and energy infrastructure suggest future economic burden of this new invader. Other regions such as the west coast of North America and New Zealand may be at risk for invasion by C. lepadiformis.Key words: invasive species; Long Island Sound; tunicate; ascidian; non-indigenous; management; marine invasion General backgroundBiological invasions, along with climate change, chemical pollution, and land use change, remain the most pressing threats to ecosystems (Millennium Ecosystem Assessment 2005). Invasive species were a contributing factor in more than 50% of animal extinctions included in the IUCN red list database. Only habitat destruction and direct harvesting contributed to more extinctions (Clavero and Garcia-Berthou 2005). Beyond extinctions, invasive species contribute to rapid changes in the character of ecosystems by causing lasting changes in food webs and ecosystem stability (Harris and Tyrell 2001;Dijkstra and Harris 2009). The economic costs of invasive species are just as dramatic. Some estimates put the cost of invasive species in the USA at over $120 billion per year (Pimentel et al. 2005). Canada's direct costs from invasive species are $187 million Canadian dollars with additional costs amounting to $13.3 to $34.5 billion Canadian dollars (Colautti et al. 2006). In Germany annual costs associated with 20 invasive species are between 100 and 265 million euro (Reinhardt et al. 2003). Although the USA federal government has enacted numerous laws and regulations to curb the onslaught of invasive species (USDA 2011), new species are still arriving.The recent discovery of the non-indigenous tunicate Clavelina lepadiformis Müller, 1776 in Long Island Sound (USA) (Reinhardt et al. 2010) gives us an opportunity to review and assess the current status of applied marine invasive species ecology and to make recommendations for the management of C. lepadiformis for Long Island Sound. Long Island Sound is a highly populated estuary along the eastern seaboard of the USA, surrounded by the states of New York and Connecticut. Currently C. lepadiformis has been discovered in two distinct harbors, New London and Stonington, in Connecticut, USA. relationship to its recent invasion of the northwest Atlantic...