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Nathalie Van der Putten Cyriel Verbruggen Ryszard Ochyra Elie Verleyen Yves Frenot 《Journal of Biogeography》2010,37(3):582-592
Aim The aim here was to assess whether the present‐day assemblage of subantarctic flowering plants is the result of a rapid post‐Last Glacial Maximum (LGM) colonization or whether subantarctic flowering plants survived on the islands in glacial refugia throughout the LGM. Location The circumpolar subantarctic region, comprising six remote islands and island groups between latitudes 46° and 55° S, including South Georgia in the South Atlantic Ocean, the Prince Edward Islands, Îles Crozet, Îles Kerguelen, the Heard Island group in the South Indian Ocean and Macquarie Island in the South Pacific Ocean. Methods Floristic affinities between the subantarctic islands were assessed by cluster analysis applied to an up‐to‐date dataset of the phanerogamic flora in order to test for the existence of provincialism within the subantarctic. A review of the primary literature on the palaeobotany, geology and glacial history of the subantarctic islands was carried out and supplemented with additional palaeobotanical data and new field observations from South Georgia, Île de la Possession (Îles Crozet) and Îles Kerguelen. Results First, a strong regionalism was observed, with different floras characterizing the islands in each of the ocean basins, and endemic species being present in the South Indian Ocean and South Pacific Ocean provinces. Second, the majority of the plant species were present at the onset of accumulation of post‐glacial organic sediment and there is no evidence for the natural arrival of new immigrants during the subsequent period. Third, a review of geomorphological data suggested that the ice cover was incomplete during the LGM on the majority of the islands, and ice‐free biological refugia were probably present even on the most glaciated islands. Main conclusions Several independent lines of evidence favour the survival of a native subantarctic phanerogamic flora in local refugia during the LGM rather than a post‐LGM colonization from more distant temperate landmasses in the Southern Hemisphere. 相似文献
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Rasmus Christian Elling 《Ethnic and racial studies》2015,38(14):2534-2550
Ethnic politics is a serious domestic challenge in Iran. Non-Persian communities are mobilizing to claim their rights and to demand representation in a system that activists claim is biased against minorities and the peripheral regions. Yet the inner workings of contemporary Iranian ethnic politics are largely understudied. This article explores recent evolutions in the role that ethnicity, regionalism and tribalism plays in Iranian domestic politics. It focuses on how these interconnected factors figured in the 2013 presidential and local council elections in Iran in a particular province that has a history of ethnic tensions. Incidentally, these elections brought Hassan Rouhani, a moderate cleric, to power as president. Among his electoral promises was to end the securitization of the minority issue. This article illustrates some of the barriers to a transformative ethnic politics – barriers that political leaders will have to overcome to enact real change. 相似文献
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