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| Scheiner, Samuel M; National Science Foundation; sscheine@nsf.gov; Levassor, Catherine; ;. |
| We examined patterns of commonness and rarity among plant species in montane wet grasslands of Iberia. This examination is set within two contexts. First, we expanded on an earlier scheme for classifying species as common or rare by adding a fourth criterion, the ability of that species to occupy a larger or smaller fraction of its potential suitable habitats, i.e., habitat occupancy. Second, we explicated two theories, the superior organism theory and the generalist/specialist trade-off theory. The data consisted of 232 species distributed among 92 plots. The species were measured for mean local abundance, size of environmental volume occupied, percentage of volume occupied, range within Iberia, and range in Europe and the Mediterranean basin. In general,... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Commonness; Endangered species; Generalist/specialist trade-off; Geographic range; Habitat occupancy; Habitat specificity; Iberia; Local abundance; Montane grasslands; Rarity; Superior organism theory.. |
| Ano: 1999 |
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| Altaba, Cristian R.. |
| The allozyme data base of Arntzen & García-París (1995) on midwife toads (Alytes, Discoglossidae) is reanalysed considering each locus as a discrete character. The phylogeny thus inferred differs from the one obtained with genetic distances in the position of A. dickhilleni from the Betic region – it appears that its sister species is the widespread A. obstetricans, not the Mallorcan endemic A. muletensis. This phylogenetic hypothesis agrees with the taxonomic treatment of the genus based on morphology. A testable biogeographic hypothesis is proposed to account for the diversification of midwife toads in Iberia and the Balearics. The postulated underlying geological changes were the spread of inland saline lakes that divided Iberia (16 mY B.P.), the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Alytes; Midwife toads; Taxonomy; Phylogeny; Biogeography; Western Mediterranean; Iberia; Balearic Islands. |
| Ano: 1997 |
URL: http://www.repository.naturalis.nl/record/504192 |
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| Xavier, J.R.; Soest, R.W.M. van; Breeuwer, J.A.J.; Martins, A.M.F.; Menken, S.B.J.. |
| In this study we assessed the sequence variation in the I3-M11 partition of the mtDNA cytochrome c oxidase subunit I gene (COI) in ten populations of the Atlanto-Mediterranean demosponge Phorbas fictitius (Porifera: Poecilosclerida) at two spatial scales: a regional scale comparing mainland (Iberian) and insular (Macaronesian) populations, and a local (Archipelagic) scale focusing on different island populations of the Azores archipelago. A multiple approach combining diversity measures, FST estimates, phylogenetic inference and nested clade phylogeographic analysis was used to assess the genetic structure and elucidate the evolutionary history of this species. Genetic differentiation, based of FST estimates, was found among most populations at both scales... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Azores; Genetic diversity; Iberia; Macaronesia; Mitochondrial DNA; Porifera; 42.72. |
| Ano: 2010 |
URL: http://www.repository.naturalis.nl/record/355610 |
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| Amler, M.R.W.. |
| During a field trip to the Peña-Corada Unit of the southernmost Esla region of the Cantabrian Mountains in 1927, the German stratigrapher Wilhelm Kegel sampled brachiopods and bivalves from a section in the Laoz valley near La Ercina. The stratigraphic position is believed to be part of the Nocedo Formation of Frasnian age. This fauna includes poorly preserved steinkerns of a near-shore bivalve fauna that was prepared for publication including labels and proposed names, but never published. The fauna represents only a very small and random part of the former community. But as information on Frasnian bivalves is scarce, the few specimens add important information on the distribution and palaeogeographic occurrence of near-shore, that is, Rhenish Facies... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Bivalvia; Rhenish Facies; Nocedo Formation; Frasnian; Cantabrian Mountains; Iberia; Wilhelm Kegel; 38.22. |
| Ano: 2010 |
URL: http://www.repository.naturalis.nl/record/361952 |
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