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Sample records for ireland glacial refugia

  1. Glacial refugia and modern genetic diversity of 22 western North American tree species.

    PubMed

    Roberts, David R; Hamann, Andreas

    2015-04-01

    North American tree species, subspecies and genetic varieties have primarily evolved in a landscape of extensive continental ice and restricted temperate climate environments. Here, we reconstruct the refugial history of western North American trees since the last glacial maximum using species distribution models, validated against 3571 palaeoecological records. We investigate how modern subspecies structure and genetic diversity corresponds to modelled glacial refugia, based on a meta-analysis of allelic richness and expected heterozygosity for 473 populations of 22 tree species. We find that species with strong genetic differentiation into subspecies had widespread and large glacial refugia, whereas species with restricted refugia show no differentiation among populations and little genetic diversity, despite being common over a wide range of environments today. In addition, a strong relationship between allelic richness and the size of modelled glacial refugia (r(2) = 0.55) suggest that population bottlenecks during glacial periods had a pronounced effect on the presence of rare alleles. PMID:25761711

  2. Glacial refugia and modern genetic diversity of 22 western North American tree species

    PubMed Central

    Roberts, David R.; Hamann, Andreas

    2015-01-01

    North American tree species, subspecies and genetic varieties have primarily evolved in a landscape of extensive continental ice and restricted temperate climate environments. Here, we reconstruct the refugial history of western North American trees since the last glacial maximum using species distribution models, validated against 3571 palaeoecological records. We investigate how modern subspecies structure and genetic diversity corresponds to modelled glacial refugia, based on a meta-analysis of allelic richness and expected heterozygosity for 473 populations of 22 tree species. We find that species with strong genetic differentiation into subspecies had widespread and large glacial refugia, whereas species with restricted refugia show no differentiation among populations and little genetic diversity, despite being common over a wide range of environments today. In addition, a strong relationship between allelic richness and the size of modelled glacial refugia (r2 = 0.55) suggest that population bottlenecks during glacial periods had a pronounced effect on the presence of rare alleles. PMID:25761711

  3. Direct evidence of central European forest refugia during the last glacial period based on mollusc fossils

    NASA Astrophysics Data System (ADS)

    Juřičková, Lucie; Horáčková, Jitka; Ložek, Vojen

    2014-07-01

    Although there is evidence from molecular studies for the existence of central European last glacial refugia for temperate species, there is still a great lack of direct fossil records to confirm this theory. Here we bring such evidence in the form of fossil shells from twenty strictly forest land snail species, which were recorded in radiocarbon-dated late glacial or older mollusc assemblages of nine non-interrupted mollusc successions situated in the Western Carpathians, and one in the Bohemian Massif. We proposed that molluscs survived the last glacial period in central Europe in isolated small patches of broadleaf forest, which we unequivocally demonstrate for two sites of last glacial maximum age.

  4. Glacial refugia, recolonization patterns and diversification forces in Alpine-endemic Megabunus harvestmen.

    PubMed

    Wachter, Gregor A; Papadopoulou, Anna; Muster, Christoph; Arthofer, Wolfgang; Knowles, L Lacey; Steiner, Florian M; Schlick-Steiner, Birgit C

    2016-06-01

    The Pleistocene climatic fluctuations had a huge impact on all life forms, and various hypotheses regarding the survival of organisms during glacial periods have been postulated. In the European Alps, evidence has been found in support of refugia outside the ice shield (massifs de refuge) acting as sources for postglacial recolonization of inner-Alpine areas. In contrast, evidence for survival on nunataks, ice-free areas above the glacier, remains scarce. Here, we combine multivariate genetic analyses with ecological niche models (ENMs) through multiple timescales to elucidate the history of Alpine Megabunus harvestmen throughout the ice ages, a genus that comprises eight high-altitude endemics. ENMs suggest two types of refugia throughout the last glacial maximum, inner-Alpine survival on nunataks for four species and peripheral refugia for further four species. In some geographic regions, the patterns of genetic variation are consistent with long-distance dispersal out of massifs de refuge, repeatedly coupled with geographic parthenogenesis. In other regions, long-term persistence in nunataks may dominate the patterns of genetic divergence. Overall, our results suggest that glacial cycles contributed to allopatric diversification in Alpine Megabunus, both within and at the margins of the ice shield. These findings exemplify the power of ENM projections coupled with genetic analyses to identify hypotheses about the position and the number of glacial refugia and thus to evaluate the role of Pleistocene glaciations in driving species-specific responses of recolonization or persistence that may have contributed to observed patterns of biodiversity. PMID:27037513

  5. Refugia of Marine Fish in the Northeast Atlantic During the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Kettle, Anthony; Morales, Arturo; Rosello, Eufrasia; Heinrich, Dirk; Vollestad, Asbjorn

    2010-05-01

    Archaeozoological finds of the remains of marine and amphihaline fish from the Last Glacial Maximum (LGM) ca. 21 ka ago show evidence of very different species ranges compared to the present. Recent genetic results of some marine species also indicate the presence of a local population structure that further suggests a dramatic southward displacement of species ranges during the LGM. There are very few studies that have attempted to delimit the glacial refugia of marine fish from our present understanding of LGM climate conditions. The few studies that exist make predictions that may not agree with the data from archaeozoology and genetics. In this contribution, we show how an ecological niche model based on sea surface temperature and bathymetry can be used to effectively predict the spatial range of marine fish during the LGM. The results are startling especially for the northern species because the glacial refugia are almost completely displaced from the modern distribution. The results are important for understanding the present spatial genetic structure of marine populations that arose during the Pleistocene glaciations, and they present a challenge for future archaeozoological work to test the model predictions and delimit the glacial refugia.

  6. Phylogeography of a widespread species: pre-glacial vicariance, refugia, occasional blocking straits and long-distance migrations

    PubMed Central

    Santiso, Xabier; Lopez, Lúa; Retuerto, Rubén; Barreiro, Rodolfo

    2016-01-01

    Phylogeographic studies give us the opportunity to reconstruct the historical migrations of species and link them with climatic and geographic variation. They are, therefore, a key tool to understanding the relationships among biology, geology and history. One of the most interesting biogeographical areas of the world is the Mediterranean region. However, in this area, the description of concordant phylogeographic patterns is quite scarce, which limits the understanding of evolutionary patterns related to climate. Species with one-dimensional distribution ranges, such as the strawberry tree (Arbutus unedo), are particularly useful to unravel these patterns. Here, we describe its phylogeographic structure and check for concordance with patterns seen in other Mediterranean plants: longitudinal/latitudinal clines of diversity, evidence for glacial refugia and the role of sea straits in dispersal. We also identify the most likely source for the disjunct Irish population. With this aim, we sequenced four chloroplast non-coding fragments of A. unedo from 23 populations covering its whole distribution. We determined the genetic diversity, population structure, haplotype genealogy and time to the most recent common ancestor. The genealogy revealed two clades that separated during the last 700 ky but before the last glacial maximum. One clade occupies Atlantic Iberia and North Africa, while the other occurs in the Western Mediterranean. The Eastern Mediterranean is inhabited by newer haplotypes derived from both clades, while the Irish population is closely related to Iberian demes. The straits of Sicily and Gibraltar partially restricted the gene flow. We concluded that a vicariance event during the Late Quaternary in the western end of the species' range followed by eastward migration seems a likely explanation for the observed phylogeographic pattern. The role of straits indicates an occasional communication between Europe and North Africa, suggesting that the latter was

  7. Phylogeography of a widespread species: pre-glacial vicariance, refugia, occasional blocking straits and long-distance migrations.

    PubMed

    Santiso, Xabier; Lopez, Lúa; Retuerto, Rubén; Barreiro, Rodolfo

    2016-01-01

    Phylogeographic studies give us the opportunity to reconstruct the historical migrations of species and link them with climatic and geographic variation. They are, therefore, a key tool to understanding the relationships among biology, geology and history. One of the most interesting biogeographical areas of the world is the Mediterranean region. However, in this area, the description of concordant phylogeographic patterns is quite scarce, which limits the understanding of evolutionary patterns related to climate. Species with one-dimensional distribution ranges, such as the strawberry tree (Arbutus unedo), are particularly useful to unravel these patterns. Here, we describe its phylogeographic structure and check for concordance with patterns seen in other Mediterranean plants: longitudinal/latitudinal clines of diversity, evidence for glacial refugia and the role of sea straits in dispersal. We also identify the most likely source for the disjunct Irish population. With this aim, we sequenced four chloroplast non-coding fragments of A. unedo from 23 populations covering its whole distribution. We determined the genetic diversity, population structure, haplotype genealogy and time to the most recent common ancestor. The genealogy revealed two clades that separated during the last 700 ky but before the last glacial maximum. One clade occupies Atlantic Iberia and North Africa, while the other occurs in the Western Mediterranean. The Eastern Mediterranean is inhabited by newer haplotypes derived from both clades, while the Irish population is closely related to Iberian demes. The straits of Sicily and Gibraltar partially restricted the gene flow. We concluded that a vicariance event during the Late Quaternary in the western end of the species' range followed by eastward migration seems a likely explanation for the observed phylogeographic pattern. The role of straits indicates an occasional communication between Europe and North Africa, suggesting that the latter was

  8. Could brown bears (Ursus arctos) have survived in Ireland during the Last Glacial Maximum?

    PubMed

    Leonard, Saoirse A; Risley, Claire L; Turvey, Samuel T

    2013-08-23

    Brown bears are recorded from Ireland during both the Late Pleistocene and early-mid Holocene. Although most of the Irish landmass was covered by an ice sheet during the Last Glacial Maximum (LGM), Irish brown bears are known to have hybridized with polar bears during the Late Pleistocene, and it is suggested that the Irish brown bear population did not become extinct but instead persisted in situ through the LGM in a southwestern ice-free refugium. We use historical population modelling to demonstrate that brown bears are highly unlikely to have survived through the LGM in Ireland under any combination of life-history parameters shown by living bear populations, but instead would have rapidly become extinct following advance of the British-Irish ice sheet, and probably recolonized Ireland during the end-Pleistocene Woodgrange Interstadial from a closely related nearby source population. The time available for brown bear-polar bear hybridization was therefore restricted to narrow periods at the beginning or end of the LGM. Brown bears would have been extremely vulnerable to extinction in Quaternary habitat refugia and required areas substantially larger than southwestern Ireland to survive adverse glacial conditions. PMID:23676655

  9. Cryptic or mystic? Glacial tree refugia in northern Europe.

    PubMed

    Tzedakis, P C; Emerson, B C; Hewitt, G M

    2013-12-01

    Here, we examine the evidence for tree refugia in northern Europe during the Late Pleniglacial (LPG) interval of maximum tree-range contraction. Our review highlights the often equivocal nature of genetic data and a tendency to overestimate potential tree distributions due to warm climate-model bias, and also reveals a convergence of macrofossil and pollen evidence. What emerges is the absence of temperate trees north of 45°N and a west-east (W-E) asymmetry in boreal tree distribution, with a treeless Western Europe north of 46°N, while restricted boreal populations persisted in Eastern Europe up to 49°N, and higher latitudes east of the Fennoscandian ice-sheet. These results have implications for current thinking on European genetic diversity patterns, species migration capacity, and conservation strategies. PMID:24091207

  10. A Complex System of Glacial Sub-Refugia Drives Endemic Freshwater Biodiversity on the Tibetan Plateau

    PubMed Central

    Clewing, Catharina; Albrecht, Christian

    2016-01-01

    Although only relatively few freshwater invertebrate families are reported from the Tibetan Plateau, the degree of endemism may be high. Many endemic lineages occur within permafrost areas, raising questions about the existence of isolated intra-plateau glacial refugia. Moreover, if such refugia existed, it might be instructive to learn whether they were associated with lakes or with more dynamic ecosystems such as ponds, wetlands, or springs. To study these hypotheses, we used pulmonate snails of the plateau-wide distributed genus Radix as model group and the Lake Donggi Cona drainage system, located in the north-eastern part of the plateau, as model site. First, we performed plateau-wide phylogenetic analyses using mtDNA data to assess the overall relationships of Radix populations inhabiting the Lake Donggi Cona system for revealing refugial lineages. We then conducted regional phylogeographical analyses applying a combination of mtDNA and nuclear AFLP markers to infer the local structure and demographic history of the most abundant endemic Radix clade for identifying location and type of (sub-)refugia within the drainage system. Our phylogenetic analysis showed a high diversity of Radix lineages in the Lake Donggi Cona system. Subsequent phylogeographical analyses of the most abundant endemic clade indicated a habitat-related clustering of genotypes and several Late Pleistocene spatial/demographic expansion events. The most parsimonious explanation for these patterns would be a scenario of an intra-plateau glacial refugium in the Lake Donggi Cona drainage system, which might have consisted of isolated sub-refugia. Though the underlying processes remain unknown, an initial separation of lake and watershed populations could have been triggered by lake-level fluctuations before and during the Last Glacial Maximum. This study inferred the first intra-plateau refugium for freshwater animals on the Tibetan Plateau. It thus sheds new light on the evolutionary history

  11. A Complex System of Glacial Sub-Refugia Drives Endemic Freshwater Biodiversity on the Tibetan Plateau.

    PubMed

    Clewing, Catharina; Albrecht, Christian; Wilke, Thomas

    2016-01-01

    Although only relatively few freshwater invertebrate families are reported from the Tibetan Plateau, the degree of endemism may be high. Many endemic lineages occur within permafrost areas, raising questions about the existence of isolated intra-plateau glacial refugia. Moreover, if such refugia existed, it might be instructive to learn whether they were associated with lakes or with more dynamic ecosystems such as ponds, wetlands, or springs. To study these hypotheses, we used pulmonate snails of the plateau-wide distributed genus Radix as model group and the Lake Donggi Cona drainage system, located in the north-eastern part of the plateau, as model site. First, we performed plateau-wide phylogenetic analyses using mtDNA data to assess the overall relationships of Radix populations inhabiting the Lake Donggi Cona system for revealing refugial lineages. We then conducted regional phylogeographical analyses applying a combination of mtDNA and nuclear AFLP markers to infer the local structure and demographic history of the most abundant endemic Radix clade for identifying location and type of (sub-)refugia within the drainage system. Our phylogenetic analysis showed a high diversity of Radix lineages in the Lake Donggi Cona system. Subsequent phylogeographical analyses of the most abundant endemic clade indicated a habitat-related clustering of genotypes and several Late Pleistocene spatial/demographic expansion events. The most parsimonious explanation for these patterns would be a scenario of an intra-plateau glacial refugium in the Lake Donggi Cona drainage system, which might have consisted of isolated sub-refugia. Though the underlying processes remain unknown, an initial separation of lake and watershed populations could have been triggered by lake-level fluctuations before and during the Last Glacial Maximum. This study inferred the first intra-plateau refugium for freshwater animals on the Tibetan Plateau. It thus sheds new light on the evolutionary history

  12. Adaptive phylogeography: functional divergence between haemoglobins derived from different glacial refugia in the bank vole

    PubMed Central

    Kotlík, Petr; Marková, Silvia; Vojtek, Libor; Stratil, Antonín; Šlechta, Vlastimil; Hyršl, Pavel; Searle, Jeremy B.

    2014-01-01

    Over the years, researchers have used presumptively neutral molecular variation to infer the origins of current species' distributions in northern latitudes (especially Europe). However, several reported examples of genic and chromosomal replacements suggest that end-glacial colonizations of particular northern areas may have involved genetic input from different source populations at different times, coupled with competition and selection. We investigate the functional consequences of differences between two bank vole (Clethrionomys glareolus) haemoglobins deriving from different glacial refugia, one of which partially replaced the other in Britain during end-glacial climate warming. This allows us to examine their adaptive divergence and hence a possible role of selection in the replacement. We determine the amino acid substitution Ser52Cys in the major expressed β-globin gene as the allelic difference. We use structural modelling to reveal that the protein environment renders the 52Cys thiol a highly reactive functional group and we show its reactivity in vitro. We demonstrate that possessing the reactive thiol in haemoglobin increases the resistance of bank vole erythrocytes to oxidative stress. Our study thus provides striking evidence for physiological differences between products of genic variants that spread at the expense of one another during colonization of an area from different glacial refugia. PMID:24827438

  13. Evidence for cryptic northern refugia in the last glacial period in Cryptomeria japonica

    PubMed Central

    Kimura, Megumi K.; Uchiyama, Kentaro; Nakao, Katsuhiro; Moriguchi, Yoshinari; San Jose-Maldia, Lerma; Tsumura, Yoshihiko

    2014-01-01

    Background and Aims Distribution shifts and natural selection during past climatic changes are important factors in determining the genetic structure of forest species. In particular, climatic fluctuations during the Quaternary appear to have caused changes in the distribution ranges of plants, and thus strongly affected their genetic structure. This study was undertaken to identify the responses of the conifer Cryptomeria japonica, endemic to the Japanese Archipelago, to past climatic changes using a combination of phylogeography and species distribution modelling (SDM) methods. Specifically, this study focused on the locations of refugia during the last glacial maximum (LGM). Methods Genetic diversity and structure were examined using 20 microsatellite markers in 37 populations of C. japonica. The locations of glacial refugia were assessed using STRUCTURE analysis, and potential habitats under current and past climate conditions were predicted using SDM. The process of genetic divergence was also examined using the approximate Bayesian computation procedure (ABC) in DIY ABC to test the divergence time between the gene pools detected by the STRUCTURE analysis. Key Results STRUCTURE analysis identified four gene pools: northern Tohoku district; from Chubu to Chugoku district; from Tohoku to Shikoku district on the Pacific Ocean side of the Archipelago; and Yakushima Island. DIY ABC analysis indicated that the four gene pools diverged at the same time before the LGM. SDM also indicated potential northern cryptic refugia. Conclusions The combined evidence from microsatellites and SDM clearly indicates that climatic changes have shaped the genetic structure of C. japonica. The gene pool detected in northern Tohoku district is likely to have been established by cryptic northern refugia on the coast of the Japan Sea to the west of the Archipelago. The gene pool in Yakushima Island can probably be explained simply by long-term isolation from the other gene pools since

  14. Mitochondrial DNA Signals of Late Glacial Recolonization of Europe from Near Eastern Refugia

    PubMed Central

    Pala, Maria; Olivieri, Anna; Achilli, Alessandro; Accetturo, Matteo; Metspalu, Ene; Reidla, Maere; Tamm, Erika; Karmin, Monika; Reisberg, Tuuli; Kashani, Baharak Hooshiar; Perego, Ugo A.; Carossa, Valeria; Gandini, Francesca; Pereira, Joana B.; Soares, Pedro; Angerhofer, Norman; Rychkov, Sergei; Al-Zahery, Nadia; Carelli, Valerio; Sanati, Mohammad Hossein; Houshmand, Massoud; Hatina, Jiři; Macaulay, Vincent; Pereira, Luísa; Woodward, Scott R.; Davies, William; Gamble, Clive; Baird, Douglas; Semino, Ornella; Villems, Richard; Torroni, Antonio; Richards, Martin B.

    2012-01-01

    Human populations, along with those of many other species, are thought to have contracted into a number of refuge areas at the height of the last Ice Age. European populations are believed to be, to a large extent, the descendants of the inhabitants of these refugia, and some extant mtDNA lineages can be traced to refugia in Franco-Cantabria (haplogroups H1, H3, V, and U5b1), the Italian Peninsula (U5b3), and the East European Plain (U4 and U5a). Parts of the Near East, such as the Levant, were also continuously inhabited throughout the Last Glacial Maximum, but unlike western and eastern Europe, no archaeological or genetic evidence for Late Glacial expansions into Europe from the Near East has hitherto been discovered. Here we report, on the basis of an enlarged whole-genome mitochondrial database, that a substantial, perhaps predominant, signal from mitochondrial haplogroups J and T, previously thought to have spread primarily from the Near East into Europe with the Neolithic population, may in fact reflect dispersals during the Late Glacial period, ∼19–12 thousand years (ka) ago. PMID:22560092

  15. Unravelling the evolutionary history and future prospects of endemic species restricted to former glacial refugia.

    PubMed

    Razgour, Orly; Salicini, Irene; Ibáñez, Carlos; Randi, Ettore; Juste, Javier

    2015-10-01

    The contemporary distribution and genetic composition of biodiversity bear a signature of species' evolutionary histories and the effects of past climatic oscillations. For many European species, the Mediterranean peninsulas of Iberia, Italy and the Balkans acted as glacial refugia and the source of range recolonization, and as a result, they contain disproportionately high levels of diversity. As these areas are particularly threatened by future climate change, it is important to understand how past climatic changes affected their biodiversity. We use an integrated approach, combining markers with different evolutionary rates and combining phylogenetic analysis with approximate Bayesian computation and species distribution modelling across temporal scales. We relate phylogeographic processes to patterns of genetic variation in Myotis escalerai, a bat species endemic to the Iberian Peninsula. We found a distinct population structure at the mitochondrial level with a strong geographic signature, indicating lineage divergence into separate glacial refugia within the Iberian refugium. However, microsatellite markers suggest higher levels of gene flow resulting in more limited structure at recent time frames. The evolutionary history of M. escalerai was shaped by the effects of climatic oscillations and changes in forest cover and composition, while its future is threatened by climatically induced range contractions and the role of ecological barriers due to competition interactions in restricting its distribution. This study warns that Mediterranean peninsulas, which provided refuge for European biodiversity during past glaciation events, may become a trap for limited dispersal and ecologically limited endemic species under future climate change, resulting in loss of entire lineages. PMID:26346923

  16. Phylogeographical Analysis of mtDNA Data Indicates Postglacial Expansion from Multiple Glacial Refugia in Woodland Caribou (Rangifer tarandus caribou)

    PubMed Central

    Klütsch, Cornelya F. C.; Manseau, Micheline; Wilson, Paul J.

    2012-01-01

    Glacial refugia considerably shaped the phylogeographical structure of species and may influence intra-specific morphological, genetic, and adaptive differentiation. However, the impact of the Quaternary ice ages on the phylogeographical structure of North American temperate mammalian species is not well-studied. Here, we surveyed ∼1600 individuals of the widely distributed woodland caribou (Rangifer tarandus caribou) using mtDNA control region sequences to investigate if glacial refugia contributed to the phylogeographical structure in this subspecies. Phylogenetic tree reconstruction, a median-joining network, and mismatch distributions supported postglacial expansions of woodland caribou from three glacial refugia dating back to 13544–22005 years. These three lineages consisted almost exclusively of woodland caribou mtDNA haplotypes, indicating that phylogeographical structure was mainly shaped by postglacial expansions. The putative centres of these lineages are geographically separated; indicating disconnected glacial refugia in the Rocky Mountains, east of the Mississippi, and the Appalachian Mountains. This is in congruence with the fossil record that caribou were distributed in these areas during the Pleistocene. Our results suggest that the last glacial maximum substantially shaped the phylogeographical structure of this large mammalian North American species that will be affected by climatic change. Therefore, the presented results will be essential for future conservation planning in woodland caribou. PMID:23285137

  17. Multiple Glacial Refugia of the Low-Dispersal Ground Beetle Carabus irregularis: Molecular Data Support Predictions of Species Distribution Models

    PubMed Central

    Homburg, Katharina; Drees, Claudia; Gossner, Martin M.; Rakosy, László; Vrezec, Al; Assmann, Thorsten

    2013-01-01

    Classical glacial refugia such as the southern European peninsulas were important for species survival during glacial periods and acted as sources of post-glacial colonisation processes. Only recently, some studies have provided evidence for glacial refugia north of the southern European peninsulas. In the present study, we combined species distribution models (SDMs) with phylogeographic analyses (using mitochondrial DNA = mtDNA) to investigate if the cold-adapted, stenotopic and flightless ground beetle species, Carabus irregularis, survived the Last Glacial Maximum (LGM) in classical and/or other refugia. SDMs (for both a western European and for a Carpathian subgroup) were calculated with MAXENT on the basis of 645 species records to predict current and past distribution patterns. Two mtDNA loci (CO1 and ND5, concatenated sequence length: 1785 bp) were analyzed from 91 C. irregularis specimens to reconstruct the phylogeography of Central and eastern European populations and to estimate divergence times of the given lineages. Strong intra-specific genetic differentiation (inter-clade ΦST values ranged from 0.92 to 0.99) implied long-term isolation of major clades and subsclades. The high divergence between the nominate subspecies and the Carpathian subspecies C. i. montandoni points to two independent species rather than subspecies (K-2P distance 0.042 ± 0.004; supposed divergence of the maternal lineages dated back 1.6 to 2.5 million years BP) differing not only morphologically but also genetically and ecologically from each other. The SDMs also inferred classical as well as other refugia for C. irregularis, especially north of the Alps, in southeastern Europe and in the Carpathians. The coincidences between the results of both methods confirm the assumption of multiple glacial refugia for the studied species and the usefulness of combining methodological approaches for the understanding of the history of low-dispersal insect species. PMID:23593425

  18. Tracing glacial refugia of Triturus newts based on mitochondrial DNA phylogeography and species distribution modeling

    PubMed Central

    2013-01-01

    Introduction The major climatic oscillations during the Quaternary Ice Age heavily influenced the distribution of species and left their mark on intraspecific genetic diversity. Past range shifts can be reconstructed with the aid of species distribution modeling and phylogeographical analyses. We test the responses of the different members of the genus Triturus (i.e. the marbled and crested newts) as the climate shifted from the previous glacial period (the Last Glacial Maximum, ~21 Ka) to the current interglacial. Results We present the results of a dense mitochondrial DNA phylogeography (visualizing genetic diversity within and divergence among populations) and species distribution modeling (using two different climate simulations) for the nine Triturus species on composite maps. Conclusions The combined use of species distribution modeling and mitochondrial phylogeography provides insight in the glacial contraction and postglacial expansion of Triturus. The combined use of the two independent techniques yields a more complete understanding of the historical biogeography of Triturus than both approaches would on their own. Triturus newts generally conform to the ‘southern richness and northern purity’ paradigm, but we also find more intricate patterns, such as the absence of genetic variation and suitable area at the Last Glacial Maximum (T. dobrogicus), an ‘extra-Mediterranean’ refugium in the Carpathian Basin (T. cristatus), and areas where species displaced one another postglacially (e.g. T. macedonicus and western T. karelinii). We provide a biogeographical scenario for Triturus, showing the positions of glacial refugia, the regions that were postglacially colonized and the areas where species displaced one another as they shifted their ranges. PMID:23514662

  19. Refugia of marine fish in the northeast Atlantic during the last glacial maximum: concordant assessment from archaeozoology and palaeotemperature reconstructions

    NASA Astrophysics Data System (ADS)

    Kettle, A. J.; Morales-Muñiz, A.; Roselló-Izquierdo, E.; Heinrich, D.; Vøllestad, L. A.

    2011-03-01

    Archaeozoological finds of the remains of marine and amphihaline fish from the Last Glacial Maximum (LGM) ca. 21 ka ago show evidence of very different species ranges compared to the present. We have shown how an ecological niche model (ENM) based on palaeoclimatic reconstructions of sea surface temperature and bathymetry can be used to effectively predict the spatial range of marine fish during the LGM. The results indicate that the ranges of marine fish species now in northwestern Europe were displaced significantly southwards from the modern distribution, challenging an existing paradigm of marine glacial refugia. The model presents strong evidence that there was an invasion of important fish through the Straits of Gibraltar in glacial times, where they were exploited by Palaeolithic human populations around the western Mediterranean Sea. The ENM results are important for ongoing studies of molecular ecology that aim to assess marine glacial refugia from the genetic structure of living populations, and they pose questions about the genetic identity of vanished marine populations during the LGM. Economically, the approach may be used to understand how the ranges of exploited fish species may be displaced with the future climate warming. The research presents a challenge for future archaeozoological work to delimit the glacial refugia and to verify palaeoclimatic reconstructions based on deep-sea core records.

  20. Hidden levels of phylodiversity in Antarctic green algae: further evidence for the existence of glacial refugia

    PubMed Central

    De Wever, Aaike; Leliaert, Frederik; Verleyen, Elie; Vanormelingen, Pieter; Van der Gucht, Katleen; Hodgson, Dominic A.; Sabbe, Koen; Vyverman, Wim

    2009-01-01

    Recent data revealed that metazoans such as mites and springtails have persisted in Antarctica throughout several glacial–interglacial cycles, which contradicts the existing paradigm that terrestrial life was wiped out by successive glacial events and that the current inhabitants are recent colonizers. We used molecular phylogenetic techniques to study Antarctic microchlorophyte strains isolated from lacustrine habitats from maritime and continental Antarctica. The 14 distinct chlorophycean and trebouxiophycean lineages observed point to a wide phylogenetic diversity of apparently endemic Antarctic lineages at different taxonomic levels. This supports the hypothesis that long-term survival took place in glacial refugia, resulting in a specific Antarctic flora. The majority of the lineages have estimated ages between 17 and 84 Ma and probably diverged from their closest relatives around the time of the opening of Drake Passage (30–45 Ma), while some lineages with longer branch lengths have estimated ages that precede the break-up of Gondwana. The variation in branch length and estimated age points to several independent but rare colonization events. PMID:19625320

  1. Refugia of marine fish in the Northeast Atlantic during the Last Glacial Maximum: concordant assessment from archaeozoology and palaeotemperature reconstructions

    NASA Astrophysics Data System (ADS)

    Kettle, A. J.; Morales-Muñiz, A.; Roselló-Izquierdo, E.; Heinrich, D.; Vøllestad, L. A.

    2010-07-01

    Archaeozoological finds of the remains of marine and amphihaline fish from the Last Glacial Maximum (LGM) ca. 21 ka ago show evidence of very different species ranges compared to the present. We show how an ecological niche model (ENM) based on palaeoclimatic reconstructions of sea surface temperature and bathymetry can be used to effectively predict the spatial range of marine fish during the LGM. The results indicate that the ranges of marine fish species that are now in Northwestern Europe were almost completely displaced southward from the modern distribution. Significantly, there is strong evidence that there was an invasion of fish of current economic importance into the Western Mediterranean through the Straits of Gibraltar, where they were exploited by Palaeolithic human populations. There has been much recent interest in the marine glacial refugia to understand how the ranges of the economically important fish species will be displaced with the future climate warming. Recent ENM studies have suggested that species ranges may not have been displaced far southward during the coldest conditions of the LGM. However, archaeozoological evidence and LGM ocean temperature reconstructions indicate that there were large range changes, and certain marine species were able invade the Western Mediterranean. These findings are important for ongoing studies of molecular ecology that aim to assess marine glacial refugia from the genetic structure of living populations, and they pose questions about the genetic identity of vanished marine populations during the LGM. The research presents a challenge for future archaeozoological work to verify palaeoclimatic reconstructions and delimit the glacial refugia.

  2. Glacial Refugia and Future Habitat Coverage of Selected Dactylorhiza Representatives (Orchidaceae)

    PubMed Central

    2015-01-01

    The intensively discussed taxonomic complexity of the Dactylorhiza genus is probably correlated with its migration history during glaciations and interglacial periods. Previous studies on past processes affecting the current distribution of Dactylorhiza species as well as the history of the polyploid complex formation were based only on molecular data. In the present study the ecological niche modeling (ENM) technique was applied in order to describe the distribution of potential refugia for the selected Dactylorhiza representatives during the Last Glacial Maximum. Additionally, future changes in their potential habitat coverage were measured with regard to three various climatic change scenarios. The maximum entropy method was used to create models of suitable niche distribution. A database of Dactylorhiza localities was prepared on the grounds of information collected from literature and data gathered during field works. Our research indicated that the habitats of majority of the studied taxa will decrease by 2080, except for D. incarnata var. incarnata, for which suitable habitats will increase almost two-fold in the global scale. Moreover, the potential habitats of some taxa are located outside their currently known geographical ranges, e.g. the Aleutian Islands, the western slopes of the Rocky Mountains, Newfoundland, southern Greenland and Iceland. ENM analysis did not confirm that the Balkans, central Europe or central Russia served as the most important refugia for individual representatives of the Dactylorhiza incarnata/maculata complex. Our study rather indicated that the Black Sea coast, southern Apennines and Corsica were the main areas characterized by habitats suitable for most of the taxa. PMID:26599630

  3. Multiple glacial refugia for cool-temperate deciduous trees in northern East Asia: the Mongolian oak as a case study.

    PubMed

    Zeng, Yan-Fei; Wang, Wen-Ting; Liao, Wan-Jin; Wang, Hong-Fang; Zhang, Da-Yong

    2015-11-01

    In East Asia, temperate forests are predicted to have retracted southward to c. 30° N during the last glacial maximum (LGM) based on fossil pollen data, whereas phylogeographic studies have often suggested glacial in situ survival of cool-temperate deciduous trees in their modern northern ranges. Here we report a study of the genetic diversity and structure of 29 natural Mongolian oak (Quercus mongolica) populations using 19 nuclear simple sequence repeat (nSSR) loci and four chloroplast DNA fragments. Bayesian clustering analysis with nSSRs revealed five groups, which were inferred by approximate Bayesian computation (ABC) to have diverged in multiple refugia through multiple glacial-interglacial cycles. Analysis of chloroplast DNA variation revealed four lineages that were largely but incompletely geographically disjunct. Ecological niche modelling (ENMs) indicated a southward range shift of the oak's distribution at the LGM, although high suitability scores were also evident in the Changbai Mts. (Northeast China), the Korean Peninsula, areas surrounding the Bohai Sea, and along the coast of the Russian Far East. In addition, endemic chloroplast DNA haplotypes and nuclear lineages occurred in high-latitude northern areas where the ENM predicted no suitable habitat. The combined evidence from nuclear and chloroplast DNA, and the results of the ENM clearly demonstrate that multiple northern refugia, including cryptic ones, were maintained across the current distributional range of the Mongolian oak during the LGM or earlier glacial periods. Though spatially limited, postglacial expansions from these refugia have led to a pattern of decreased genetic diversity with increasing latitude. PMID:26439083

  4. Across the southern Andes on fin: glacial refugia, drainage reversals and a secondary contact zone revealed by the phylogeographical signal of Galaxias platei in Patagonia.

    PubMed

    Zemlak, Tyler S; Habit, Evelyn M; Walde, Sandra J; Battini, Miguel A; Adams, Emily D M; Ruzzante, Daniel E

    2008-12-01

    We employed DNA sequence variation at two mitochondrial (control region, COI) regions from 212 individuals of Galaxias platei (Pisces, Galaxiidae) collected throughout Patagonia (25 lakes/rivers) to examine how Andean orogeny and the climatic cycles throughout the Quaternary affected the genetic diversity and phylogeography of this species. Phylogenetic analyses revealed four deep genealogical lineages which likely represent the initial division of G. platei into eastern and western lineages by Andean uplift, followed by further subdivision of each lineage into separate glacial refugia by repeated Pleistocene glacial cycles. West of the Andes, refugia were likely restricted to the northern region of Patagonia with small relicts in the south, whereas eastern refugia appear to have been much larger and widespread, consisting of separate northern and southern regions that collectively spanned most of Argentinean Patagonia. The retreat of glacial ice following the last glacial maximum allowed re-colonization of central Chile from nonlocal refugia from the north and east, representing a region of secondary contact between all four glacial lineages. Northwestern glacial relicts likely followed pro-glacial lakes into central Chilean Patagonia, whereas catastrophic changes in drainage direction (Atlantic --> Pacific) for several eastern palaeolakes were the likely avenues for invasions from the east. These mechanisms, combined with evidence for recent, rapid and widespread population growth could explain the extensive contemporary distribution of G. platei throughout Patagonia. PMID:19017262

  5. Imprints of multiple glacial refugia in the Pyrenees revealed by phylogeography and palaeodistribution modelling of an endemic spider.

    PubMed

    Bidegaray-Batista, Leticia; Sánchez-Gracia, Alejandro; Santulli, Giulia; Maiorano, Luigi; Guisan, Antoine; Vogler, Alfried P; Arnedo, Miquel A

    2016-05-01

    Mediterranean mountain ranges harbour highly endemic biota in islandlike habitats. Their topographic diversity offered the opportunity for mountain species to persist in refugial areas during episodes of major climatic change. We investigate the role of Quaternary climatic oscillations in shaping the demographic history and distribution ranges in the spider Harpactocrates ravastellus, endemic to the Pyrenees. Gene trees and multispecies coalescent analyses on mitochondrial and nuclear DNA sequences unveiled two distinct lineages with a hybrid zone around the northwestern area of the Catalan Pyrenees. The lineages were further supported by morphological differences. Climatic niche-based species distribution models (SDMs) identified two lowland refugia at the western and eastern extremes of the mountain range, which would suggest secondary contact following postglacial expansion of populations from both refugia. Neutrality test and approximate Bayesian computation (ABC) analyses indicated that several local populations underwent severe bottlenecks followed by population expansions, which in combination with the deep population differentiation provided evidence for population survival during glacial periods in microrefugia across the mountain range, in addition to the main Atlantic and Mediterranean (western and eastern) refugia. This study sheds light on the complexities of Quaternary climatic oscillations in building up genetic diversity and local endemicity in the southern Europe mountain ranges. PMID:26878195

  6. Glacial Refugia in Pathogens: European Genetic Structure of Anther Smut Pathogens on Silene latifolia and Silene dioica

    PubMed Central

    Vercken, Elodie; Fontaine, Michael C.; Gladieux, Pierre; Hood, Michael E.; Jonot, Odile; Giraud, Tatiana

    2010-01-01

    Climate warming is predicted to increase the frequency of invasions by pathogens and to cause the large-scale redistribution of native host species, with dramatic consequences on the health of domesticated and wild populations of plants and animals. The study of historic range shifts in response to climate change, such as during interglacial cycles, can help in the prediction of the routes and dynamics of infectious diseases during the impending ecosystem changes. Here we studied the population structure in Europe of two Microbotryum species causing anther smut disease on the plants Silene latifolia and Silene dioica. Clustering analyses revealed the existence of genetically distinct groups for the pathogen on S. latifolia, providing a clear-cut example of European phylogeography reflecting recolonization from southern refugia after glaciation. The pathogen genetic structure was congruent with the genetic structure of its host species S. latifolia, suggesting dependence of the migration pathway of the anther smut fungus on its host. The fungus, however, appeared to have persisted in more numerous and smaller refugia than its host and to have experienced fewer events of large-scale dispersal. The anther smut pathogen on S. dioica also showed a strong phylogeographic structure that might be related to more northern glacial refugia. Differences in host ecology probably played a role in these differences in the pathogen population structure. Very high selfing rates were inferred in both fungal species, explaining the low levels of admixture between the genetic clusters. The systems studied here indicate that migration patterns caused by climate change can be expected to include pathogen invasions that follow the redistribution of their host species at continental scales, but also that the recolonization by pathogens is not simply a mirror of their hosts, even for obligate biotrophs, and that the ecology of hosts and pathogen mating systems likely affects recolonization

  7. Contributions of multiple refugia during the last glacial period to current mainland populations of Korean pine (Pinus koraiensis).

    PubMed

    Bao, Lei; Kudureti, Ayijiamali; Bai, Weining; Chen, Rongzhang; Wang, Tianming; Wang, Hongfang; Ge, Jianping

    2015-01-01

    The northern microrefugia that existed during the Last Glacial Maximum (LGM) are a key factor in the demographic history of species. Pinus koraiensis has a unique distribution in northeast Asia. The Changbai Mountains and the Korean peninsula (CM/KP) are usually considered to be the LGM refugia for P. koraiensis. However, the Xiaoxingan Range (XR), at the northern part of this species' distribution, is another possible refugium. We used chloroplast sequencing and ten nuclear single-copy gene loci to calculate the genetic diversity pattern of P. koraiensis. The probabilities of a single LGM refugium and of multiple LGM refugia were calculated based on approximate Bayesian computation. The effect of the latitudinal gradient on genetic diversity was not significant. However, unique alleles occurred at low frequencies in CM/KP and XR. A conservative estimate of the coalescence time between CM/KP and XR is 0.4 million years ago, a time prior to the LGM. Gene flow between CM/KP and XR was estimated to be more than one in per generation, an amount that may be sufficient to limit genetic divergence between the regions. Our study strongly supports the hypothesis that XR was another LGM refugium in addition to CM/KP. PMID:26691230

  8. Contributions of multiple refugia during the last glacial period to current mainland populations of Korean pine (Pinus koraiensis)

    PubMed Central

    Bao, Lei; Kudureti, Ayijiamali; Bai, Weining; Chen, Rongzhang; Wang, Tianming; Wang, Hongfang; Ge, Jianping

    2015-01-01

    The northern microrefugia that existed during the Last Glacial Maximum (LGM) are a key factor in the demographic history of species. Pinus koraiensis has a unique distribution in northeast Asia. The Changbai Mountains and the Korean peninsula (CM/KP) are usually considered to be the LGM refugia for P. koraiensis. However, the Xiaoxingan Range (XR), at the northern part of this species’ distribution, is another possible refugium. We used chloroplast sequencing and ten nuclear single-copy gene loci to calculate the genetic diversity pattern of P. koraiensis. The probabilities of a single LGM refugium and of multiple LGM refugia were calculated based on approximate Bayesian computation. The effect of the latitudinal gradient on genetic diversity was not significant. However, unique alleles occurred at low frequencies in CM/KP and XR. A conservative estimate of the coalescence time between CM/KP and XR is 0.4 million years ago, a time prior to the LGM. Gene flow between CM/KP and XR was estimated to be more than one in per generation, an amount that may be sufficient to limit genetic divergence between the regions. Our study strongly supports the hypothesis that XR was another LGM refugium in addition to CM/KP. PMID:26691230

  9. Phylogeography of the Patagonian otter Lontra provocax: adaptive divergence to marine habitat or signature of southern glacial refugia?

    PubMed Central

    2011-01-01

    Background A number of studies have described the extension of ice cover in western Patagonia during the Last Glacial Maximum, providing evidence of a complete cover of terrestrial habitat from 41°S to 56°S and two main refugia, one in south-eastern Tierra del Fuego and the other north of the Chiloé Island. However, recent evidence of high genetic diversity in Patagonian river species suggests the existence of aquatic refugia in this region. Here, we further test this hypothesis based on phylogeographic inferences from a semi-aquatic species that is a top predator of river and marine fauna, the huillín or Southern river otter (Lontra provocax). Results We examined mtDNA sequences of the control region, ND5 and Cytochrome-b (2151 bp in total) in 75 samples of L. provocax from 21 locations in river and marine habitats. Phylogenetic analysis illustrates two main divergent clades for L. provocax in continental freshwater habitat. A highly diverse clade was represented by haplotypes from the marine habitat of the Southern Fjords and Channels (SFC) region (43°38' to 53°08'S), whereas only one of these haplotypes was paraphyletic and associated with northern river haplotypes. Conclusions Our data support the hypothesis of the persistence of L. provocax in western Patagonia, south of the ice sheet limit, during last glacial maximum (41°S latitude). This limit also corresponds to a strong environmental change, which might have spurred L. provocax differentiation between the two environments. PMID:21356052

  10. Genome-wide set of SNPs reveals evidence for two glacial refugia and admixture from postglacial recolonization in an alpine ungulate.

    PubMed

    Sim, Zijian; Hall, Jocelyn C; Jex, Bill; Hegel, Troy M; Coltman, David W

    2016-08-01

    Past glaciation events have played a major role in shaping the genetic diversity and distribution of wild sheep in North America. The advancement of glaciers can isolate populations in ice-free refugia, where they can survive until the recession of ice sheets. The major Beringian refugium is thought to have held thinhorn sheep (Ovis dalli) populations during times of glacial advance. While isolation in the major refugium can account for much of the genetic and morphological diversity seen in extant thinhorn sheep populations, mounting evidence suggests the persistence of populations in smaller minor refugia. We investigated the refugial origins of thinhorn sheep using ~10 000 SNPs obtained via a cross-species application of the domestic sheep ovine HD BeadChip to genotype 52 thinhorn sheep and five bighorn sheep (O. canadensis) samples. Phylogenetic inference revealed a distinct lineage of thinhorn sheep inhabiting British Columbia, which is consistent with the survival of a group of thinhorn sheep in a minor refugium separate from the Beringian refugium. Isolation in separate glacial refugia probably mediated the evolution of the two thinhorn sheep subspecies, the white Dall's sheep (O. d. dalli), which persisted in Beringia, and the dark Stone's sheep (O. d. stonei), which utilized the minor refugium. We also found the first genetic evidence for admixture between sheep from different glacial refugia in south-central Yukon as a consequence of post glacial expansion and recolonization. These results show that glaciation events can have a major role in the evolution of species inhabiting previously glaciated habitats and the need to look beyond established refugia when examining the evolutionary history of such species. PMID:27272944

  11. Pleistocene glacial refugia across the Appalachian Mountains and coastal plain in the millipede genus Narceus: Evidence from population genetic, phylogeographic, and paleoclimatic data

    PubMed Central

    Walker, Matt J; Stockman, Amy K; Marek, Paul E; Bond, Jason E

    2009-01-01

    Background Species that are widespread throughout historically glaciated and currently non-glaciated areas provide excellent opportunities to investigate the role of Pleistocene climatic change on the distribution of North American biodiversity. Many studies indicate that northern animal populations exhibit low levels of genetic diversity over geographically widespread areas whereas southern populations exhibit relatively high levels. Recently, paleoclimatic data have been combined with niche-based distribution modeling to locate possible refugia during the Last Glacial Maximum. Using phylogeographic, population, and paleoclimatic data, we show that the distribution and mitochondrial data for the millipede genus Narceus are consistent with classical examples of Pleistocene refugia and subsequent post-glacial population expansion seen in other organismal groups. Results The phylogeographic structure of Narceus reveals a complex evolutionary history with signatures of multiple refugia in southeastern North America followed by two major northern expansions. Evidence for refugial populations were found in the southern Appalachian Mountains and in the coastal plain. The northern expansions appear to have radiated from two separate refugia, one from the Gulf Coastal Plain area and the other from the mid-Atlantic coastal region. Distributional models of Narceus during the Last Glacial Maximum show a dramatic reduction from the current distribution, with suitable ecological zones concentrated along the Gulf and Atlantic coastal plain. We found a strong correlation between these zones of ecological suitability inferred from our paleo-model with levels of genetic diversity derived from phylogenetic and population estimates of genetic structuring. Conclusion The signature of climatic change, during and after the Pleistocene, on the distribution of the millipede genus Narceus is evident in the genetic data presented. Niche-based historical distribution modeling strengthens the

  12. Phylogeographic Analyses of American Black Bears (Ursus americanus) Suggest Four Glacial Refugia and Complex Patterns of Postglacial Admixture.

    PubMed

    Puckett, Emily E; Etter, Paul D; Johnson, Eric A; Eggert, Lori S

    2015-09-01

    Studies of species with continental distributions continue to identify intraspecific lineages despite continuous habitat. Lineages may form due to isolation by distance, adaptation, divergence across barriers, or genetic drift following range expansion. We investigated lineage diversification and admixture within American black bears (Ursus americanus) across their range using 22 k single nucleotide polymorphisms and mitochondrial DNA sequences. We identified three subcontinental nuclear clusters which we further divided into nine geographic regions: Alaskan (Alaska-East), eastern (Central Interior Highlands, Great Lakes, Northeast, Southeast), and western (Alaska-West, West, Pacific Coast, Southwest). We estimated that the western cluster diverged 67 ka, before eastern and Alaskan divergence 31 ka; these divergence dates contrasted with those from the mitochondrial genome where clades A and B diverged 1.07 Ma, and clades A-east and A-west diverged 169 ka. We combined estimates of divergence timing with hindcast species distribution models to infer glacial refugia for the species in Beringia, Pacific Northwest, Southwest, and Southeast. Our results show a complex arrangement of admixture due to expansion out of multiple refugia. The delineation of the genomic population clusters was inconsistent with the ranges for 16 previously described subspecies. Ranges for U. a. pugnax and U. a. cinnamomum were concordant with admixed clusters, calling into question how to order taxa below the species level. Additionally, our finding that U. a. floridanus has not diverged from U. a. americanus also suggests that morphology and genetics should be reanalyzed to assess taxonomic designations relevant to the conservation management of the species. PMID:25989983

  13. Northern glacial refugia and altitudinal niche divergence shape genome-wide differentiation in the emerging plant model Arabidopsis arenosa.

    PubMed

    Kolář, Filip; Fuxová, Gabriela; Záveská, Eliška; Nagano, Atsushi J; Hyklová, Lucie; Lučanová, Magdalena; Kudoh, Hiroshi; Marhold, Karol

    2016-08-01

    Quaternary climatic oscillations profoundly impacted temperate biodiversity. For many diverse yet undersampled areas, however, the consequences of this impact are still poorly known. In Europe, particular uncertainty surrounds the role of Balkans, a major hotspot of European diversity, in postglacial recolonization of more northerly areas, and the Carpathians, a debatable candidate for a northern 'cryptic' glacial refugium. Using genome-wide SNPs and microsatellites, we examined how the interplay of historical processes and niche shifts structured genetic diversity of diploid Arabidopsis arenosa, a little-known member of the plant model genus that occupies a wide niche range from sea level to alpine peaks across eastern temperate Europe. While the northern Balkans hosted one isolated endemic lineage, most of the genetic diversity was concentrated further north in the Pannonian Basin and the Carpathians, where it likely survived the last glaciation in northern refugia. Finally, a distinct postglacial environment in northern Europe was colonized by populations of admixed origin from the two Carpathian lineages. Niche differentiation along altitude-related bioclimatic gradients was the main trend in the phylogeny of A. arenosa. The most prominent niche shifts, however, characterized genetically only slightly divergent populations that expanded into narrowly defined alpine and northern coastal postglacial environments. Our study highlights the role of eastern central European mountains not only as refugia for unique temperate diversity but also sources for postglacial expansion into novel high-altitude and high-latitude niches. Knowledge of distinct genetic substructure of diploid A. arenosa also opens new opportunities for follow-up studies of this emerging model of evolutionary biology. PMID:27288974

  14. Fine Dissection of Human Mitochondrial DNA Haplogroup HV Lineages Reveals Paleolithic Signatures from European Glacial Refugia

    PubMed Central

    Sarno, Stefania; Sevini, Federica; Vianello, Dario; Tamm, Erika; Metspalu, Ene; van Oven, Mannis; Hübner, Alexander; Sazzini, Marco; Franceschi, Claudio; Pettener, Davide; Luiselli, Donata

    2015-01-01

    Genetic signatures from the Paleolithic inhabitants of Eurasia can be traced from the early divergent mitochondrial DNA lineages still present in contemporary human populations. Previous studies already suggested a pre-Neolithic diffusion of mitochondrial haplogroup HV*(xH,V) lineages, a relatively rare class of mtDNA types that includes parallel branches mainly distributed across Europe and West Asia with a certain degree of structure. Up till now, variation within haplogroup HV was addressed mainly by analyzing sequence data from the mtDNA control region, except for specific sub-branches, such as HV4 or the widely distributed haplogroups H and V. In this study, we present a revised HV topology based on full mtDNA genome data, and we include a comprehensive dataset consisting of 316 complete mtDNA sequences including 60 new samples from the Italian peninsula, a previously underrepresented geographic area. We highlight points of instability in the particular topology of this haplogroup, reconstructed with BEAST-generated trees and networks. We also confirm a major lineage expansion that probably followed the Late Glacial Maximum and preceded Neolithic population movements. We finally observe that Italy harbors a reservoir of mtDNA diversity, with deep-rooting HV lineages often related to sequences present in the Caucasus and the Middle East. The resulting hypothesis of a glacial refugium in Southern Italy has implications for the understanding of late Paleolithic population movements and is discussed within the archaeological cultural shifts occurred over the entire continent. PMID:26640946

  15. Paleoclimatic implications of glacial and postglacial refugia for Pinus pumila in western Beringia

    SciTech Connect

    Anderson, P M; Lozhkin, A V; Solomatkina, T B; Brown, T A

    2010-02-05

    Palynological results from Julietta Lake currently provide the most direct evidence to support the existence of a glacial refugium for Pinus pumila in mountains of southwestern Beringia. Both percentages and accumulation rates indicate the evergreen shrub survived until at least {approx}19,000 14C yr B.P. in the Upper Kolyma region. Percentage data suggest numbers dwindled into the late glaciation, whereas pollen accumulation rates point towards a more rapid demise shortly after {approx}19,000 14C yr B.P. Pinus pumila did not re-establish in any great numbers until {approx}8100 14C yr B.P., despite the local presence {approx}9800 14C yr B.P. of Larix dahurica, which shares similar summer temperature requirements. The postglacial thermal maximum (in Beringia {approx}11,000-9000 14C yr B.P.) provided Pinus pumila shrubs with equally harsh albeit different conditions for survival than those present during the LGM. Regional records indicate that in this time of maximum warmth Pinus pumila likely sheltered in a second, lower-elevation refugium. Paleoclimatic models and modern ecology suggest that shifts in the nature of seasonal transitions and not only seasonal extremes have played important roles in the history of Pinus pumila over the last {approx}21,000 14C yr B.P.

  16. The Connemara Fan: a major glacial grounding line fan west of Ireland

    NASA Astrophysics Data System (ADS)

    McCarron, Stephen; Praeg, Daniel; Monteys, Xavier; Scott, Gill

    2014-05-01

    Glacigenic topography on the mid-shelf (~130-350 m water depth) west of Galway, Ireland appears to have the morphological form, internal architecture and sediments associated with a large glacial grounding-line fan. Seismic data collected in 2009 and 2012 (during the GLAMAR and GATEWAYS 1 campaigns) reveal that the broad, arcuate ridges of the 'Olex moraine' form the landward part of a fan system which prograded beyond the mid-shelf break (defining the outer margin of the 'Clare Platform') westwards into the Porcupine Seabight. The topography is comparable to larger shelf-edge trough-mouth fans found further north along the same margin, however no discernible 'trough' has been identified on the Clare Platform. The ridge and fan topographic assemblage is renamed the 'Connemara Fan' in its entirety, based on its genetic relations and geographic location due west of Connemara, western Ireland. A macrofossil recovered from within a debris flow on the outer fan slope comprised of remobilised plumites dates to ~ 20 ka Cal B.P., indicating sediment reworking downslope following deglacial sediment input to at least that time. The Connemara Fan is the most southerly glacigenic fan identified along the north-east Atlantic margin. Its identification also adds to our knowledge of possibly multiple generations of ice sheets feeding onto the Irish shelf from west-central Ireland and the occurrence of ice sheet geometries and dynamics that evacuated ice, melt-water and sediment (ice streams?) westwards across the Clare Platform during past glaciations.

  17. Phylogeography of a widespread terrestrial vertebrate in a barely-studied Palearctic region: green toads (Bufo viridis subgroup) indicate glacial refugia in Eastern Central Asia.

    PubMed

    Zhang, Yi-Jun; Stöck, Matthias; Zhang, Peng; Wang, Xiu-Ling; Zhou, Hui; Qu, Liang-Hu

    2008-11-01

    The phylogeography of western Palearctic species is relatively well studied, but data on Eastern Central Asia are scarce. We present one of the first data sets from a widespread terrestrial vertebrate (Bufo pewzowi) inhabiting Eastern Central Asian mountains and deserts to gain knowledge on its phylogeography in this region. We applied combined phylogenetic and demographic analyses to understand the evolutionary history using mitochondrial DNA D-loop variation of toads from 37 locations. Genetic structure of Bufo pewzowi is strongly affected by landscape: we found three haplotype groups in eastern Kazakhstan, Dzungaria and Tarim Basin, divided by the Tian Shan and Dzungarian Alatau ranges. A vicariant hypothesis may explain divergence among groups. The divergence time of the three major clades was estimated about 0.9 million years ago (confidence interval 0.5-1.4), and is discussed with respect to Quaternary uplifting and glaciation in the Tian Shan. Demographic analyses provided evidence for both historical bottlenecks and population expansions and suggested Pleistocene signatures. Glacial refugia were inferred in the Tarim Basin (around the Turpan depression), in southern Dzungaria (Urumqui region), at the northern foot of the Tian Shan (Gongnaisi) and perhaps at the Altai range (Terekti). Regional Post-Last Glacial Maximum dispersal patterns are proposed. A taxonomic hypothesis is presented. This study provides a detailed history of how a widespread terrestrial vertebrate responded to geological change and Quaternary glacial events in Eastern Central Asia and may have significance for future phylogeographic research in this understudied region. PMID:18301990

  18. Genetic divergence and phylogeographic relationships among european perch (Perca fluviatilis) populations reflect glacial refugia and postglacial colonization.

    PubMed

    Nesbø, C L; Fossheim, T; Vollestad, L A; Jakobsen, K S

    1999-09-01

    We used the widely distributed freshwater fish, perch (Perca fluviatilis), to investigate the postglacial colonization routes of freshwater fishes in Europe. Genetic variability within and among drainages was assessed using mitochondrial DNA (mtDNA) D-loop sequencing and RAPD markers from 55 populations all over Europe as well as one Siberian population. High level of structuring for both markers was observed among drainages and regions, while little differentiation was seen within drainages and regions. Phylogeographic relationships among European perch were determined from the distribution of 35 mtDNA haplotypes detected in the samples. In addition to a distinct southern European group, which includes a Greek and a southern Danubian population, three major groups of perch are observed: the western European drainages, the eastern European drainages including the Siberian population, and Norwegian populations from northern Norway, and western side of Oslofjord. Our data suggest that present perch populations in western and northern Europe were colonized from three main refugia, located in southeastern, northeastern and western Europe. In support of this, nested cladistic analysis of mtDNA clade and nested clade distances suggested historical range expansion as the main factor determining geographical distribution of haplotypes. The Baltic Sea has been colonized from all three refugia, and northeastern Europe harbours descendants from both eastern European refugia. In the upper part of the Danube lineages from the western European and the southern European refugia meet. The southern European refugium probably did not contribute to the recolonization of other western and northern European drainages after the last glaciation. However, phylogenetic analyses suggest that the southern European mtDNA lineage is the most ancient, and therefore likely to be the founder of all present perch lineages. The colonization routes used by perch probably also apply to other

  19. Potential glacial origin of the seabed geomorphology of the Porcupine Bank, west of Ireland

    NASA Astrophysics Data System (ADS)

    Thébaudeau, Benjamin; McCarron, Stephen; Monteys, Xavier

    2015-04-01

    The Porcupine Bank lies west of Ireland between 51-54N and 11-15 W, located approximately between 150 km and 250 km from the Irish western coastline. The topography of the bank is gently sloping from the Porcupine Ridge contained within the 200m depth contour to the edge at the 500m depth contour. From then on, sharp escarpments occur to the north and west while the slope is gentler toward the Porcupine Seabight to the southeast. The Bank is linked to the Irish western shelf through a low ridge roughly 100km wide to the northeast. This region's geomorphology and shallow stratigraphy is still widely unexplored although it is located critically for our understanding of the last glaciation inception and termination of the British Irish Ice Sheet. The north-eastern Atlantic shelf region West of Ireland contains a relatively pristine record of glacial ice extension from Ireland and Scotland onto the shelf, probably during the last cold period (Late Midlandian glaciation in Ireland). Furthermore, national economic interest in the region is rising with long term investment being put forward for the Irish Marine Economy. Using multibeam and subbottom data collected more than a decade ago, the seabed surface of the region has been interpreted and mapped. Bedrock outcrop, sand ridges, erosional channels, iceberg scours and ridges of various forms have been recognised. These features show some clear influence of the proximal ice sheets as illustrated by the extensive coverage of iceberg scours. Similarly, the northern edge of the Porcupine Bank and the Porcupine Ridge in particular is characterised by large elongated ridges for which the origin is obscure. These appear roughly parallel to a W-E direction with some displaying a levelling effect on one of their sides. This paper will introduce the results of the mapping effort and argue for the interpretation of the above mentioned ridges as glacial in origin. Various scenarios of the consequences of that statement will then be

  20. Beyond the Mediterranean peninsulas: evidence of central European glacial refugia for a temperate forest mammal species, the bank vole (Clethrionomys glareolus).

    PubMed

    Deffontaine, V; Libois, R; Kotlík, P; Sommer, R; Nieberding, C; Paradis, E; Searle, J B; Michaux, J R

    2005-05-01

    This study details the phylogeographic pattern of the bank vole, Clethrionomys glareolus, a European rodent species strongly associated with forest habitat. We used sequences of 1011 base pairs of the mitochondrial DNA cytochrome b gene from 207 bank voles collected in 62 localities spread throughout its distribution area. Our results reveal the presence of three Mediterranean (Spanish, Italian and Balkan) and three continental (western, eastern and 'Ural') phylogroups. The endemic Mediterranean phylogroups did not contribute to the post-glacial recolonization of much of the Palaearctic range of species. Instead, the major part of this region was apparently recolonized by bank voles that survived in glacial refugia in central Europe. Moreover, our phylogeographic analyses also reveal differentiated populations of bank voles in the Ural mountains and elsewhere, which carry the mitochondrial DNA of another related vole species, the ruddy vole (Clethrionomys rutilus). In conclusion, this study demonstrates a complex phylogeographic history for a forest species in Europe which is sufficiently adaptable that, facing climate change, survives in relict southern and northern habitats. The high level of genetic diversity characterizing vole populations from parts of central Europe also highlights the importance of such regions as a source of intraspecific genetic biodiversity. PMID:15836645

  1. Too much of a good thing: sea ice extent may have forced emperor penguins into refugia during the last glacial maximum.

    PubMed

    Younger, Jane L; Clucas, Gemma V; Kooyman, Gerald; Wienecke, Barbara; Rogers, Alex D; Trathan, Philip N; Hart, Tom; Miller, Karen J

    2015-06-01

    The relationship between population structure and demographic history is critical to understanding microevolution and for predicting the resilience of species to environmental change. Using mitochondrial DNA from extant colonies and radiocarbon-dated subfossils, we present the first microevolutionary analysis of emperor penguins (Aptenodytes forsteri) and show their population trends throughout the last glacial maximum (LGM, 19.5-16 kya) and during the subsequent period of warming and sea ice retreat. We found evidence for three mitochondrial clades within emperor penguins, suggesting that they were isolated within three glacial refugia during the LGM. One of these clades has remained largely isolated within the Ross Sea, while the two other clades have intermixed around the coast of Antarctica from Adélie Land to the Weddell Sea. The differentiation of the Ross Sea population has been preserved despite rapid population growth and opportunities for migration. Low effective population sizes during the LGM, followed by a rapid expansion around the beginning of the Holocene, suggest that an optimum set of sea ice conditions exist for emperor penguins, corresponding to available foraging area. PMID:25728986

  2. Displaced phylogeographic signals from Gyrodactylus arcuatus, a parasite of the three-spined stickleback Gasterosteus aculeatus, suggest freshwater glacial refugia in Europe.

    PubMed

    Lumme, Jaakko; Mäkinen, Hannu; Ermolenko, Alexey V; Gregg, Jacob L; Ziętara, Marek S

    2016-08-01

    We examined the global mitochondrial phylogeography of Gyrodactylus arcuatus, a flatworm ectoparasite of three-spined stickleback Gasterosteus aculeatus. In accordance with the suggested high divergence rate of 13%/million years, the genetic variation of the parasite was high: haplotype diversity h=0.985 and nucleotide diversity π=0.0161. The differentiation among the parasite populations was substantial (Φst=0.759), with two main allopatric clades (here termed Euro and North) accounting for 54% of the total genetic variation. The diversity center of the Euro clade was in the Baltic Sea, while the North clade was spread across the Barents and White Seas. A single haplotype within the North clade was found in the western and eastern Pacific Ocean. Divergence of main clades was estimated to be circa 200 thousand years ago. Each main clade was further divided into six distinct subclades, estimated to have diverged in isolation since 135 thousand years ago. This second division corresponds approximately to the Eemian interglacial predating the last glacial maximum. A demographic expansion of the subclades is associated with colonisation of northern Europe since the last glacial maximum, circa 15-40 thousand years ago. The parasite phylogeny is most likely explained by sequential isolated bottlenecks and expansions in numerous allopatric refugia. The postglacial intermingling and high variation in the marine parasite populations, separately in the Baltic and Barents Seas, suggest low competition of divergent parasite matrilines, coupled with a large population size and high rate of dispersal of hosts. The genetic contribution of the assumed refugial fish populations maintaining the parasite during the last glacial maximum was not detected among the marine sticklebacks, which perhaps were infected after range expansion. PMID:27155331

  3. A multi-technique study of the glacial stratigraphy of Co. Clare and Co. Kerry, southwest Ireland

    NASA Astrophysics Data System (ADS)

    Richards, Andrew E.

    2002-03-01

    A multi-technique approach has been adopted in a study of the lithostratigraphy of glacial deposits in southwestern Ireland, including clast lithological analysis, fine sand geochemistry, low frequency mass specific susceptibility and fine sand calcium carbonate (equivalent) content. A revised lithostratigraphical scheme is suggested for the Quaternary glacial deposits of the region, together with a simple strategy that may be adopted for stratigraphical studies in other regions of southern Ireland. It appears that geochemical determinations via inductively coupled plasma-atomic absorption spectrometry are particularly useful in characterising and discriminating between till units within local stratigraphical studies and may be used to inform the applicability of other utilitarian techniques for use on a regional scale.

  4. Phylogeography of Quercus variabilis Based on Chloroplast DNA Sequence in East Asia: Multiple Glacial Refugia and Mainland-Migrated Island Populations

    PubMed Central

    Kang, Hongzhang; Sun, Xiao; Yin, Shan; Du, Hongmei; Yamanaka, Norikazu; Gapare, Washington; Wu, Harry X.; Liu, Chunjiang

    2012-01-01

    The biogeographical relationships between far-separated populations, in particular, those in the mainland and islands, remain unclear for widespread species in eastern Asia where the current distribution of plants was greatly influenced by the Quaternary climate. Deciduous Oriental oak (Quercus variabilis) is one of the most widely distributed species in eastern Asia. In this study, leaf material of 528 Q. variabilis trees from 50 populations across the whole distribution (Mainland China, Korea Peninsular as well as Japan, Zhoushan and Taiwan Islands) was collected, and three cpDNA intergenic spacer fragments were sequenced using universal primers. A total of 26 haplotypes were detected, and it showed a weak phylogeographical structure in eastern Asia populations at species level, however, in the central-eastern region of Mainland China, the populations had more haplotypes than those in other regions, with a significant phylogeographical structure (NST = 0.751> GST = 0.690, P<0.05). Q. variabilis displayed high interpopulation and low intrapopulation genetic diversity across the distribution range. Both unimodal mismatch distribution and significant negative Fu’s FS indicated a demographic expansion of Q. variabilis populations in East Asia. A fossil calibrated phylogenetic tree showed a rapid speciation during Pleistocene, with a population augment occurred in Middle Pleistocene. Both diversity patterns and ecological niche modelling indicated there could be multiple glacial refugia and possible bottleneck or founder effects occurred in the southern Japan. We dated major spatial expansion of Q. variabilis population in eastern Asia to the last glacial cycle(s), a period with sea-level fluctuations and land bridges in East China Sea as possible dispersal corridors. This study showed that geographical heterogeneity combined with climate and sea-level changes have shaped the genetic structure of this wide-ranging tree species in East Asia. PMID:23115642

  5. Paleodistribution modeling suggests glacial refugia in Scandinavia and out-of-Tibet range expansion of the Arctic fox.

    PubMed

    Fuentes-Hurtado, Marcelo; Hof, Anouschka R; Jansson, Roland

    2016-01-01

    Quaternary glacial cycles have shaped the geographic distributions and evolution of numerous species in the Arctic. Ancient DNA suggests that the Arctic fox went extinct in Europe at the end of the Pleistocene and that Scandinavia was subsequently recolonized from Siberia, indicating inability to track its habitat through space as climate changed. Using ecological niche modeling, we found that climatically suitable conditions for Arctic fox were found in Scandinavia both during the last glacial maximum (LGM) and the mid-Holocene. Our results are supported by fossil occurrences from the last glacial. Furthermore, the model projection for the LGM, validated with fossil records, suggested an approximate distance of 2000 km between suitable Arctic conditions and the Tibetan Plateau well within the dispersal distance of the species, supporting the recently proposed hypothesis of range expansion from an origin on the Tibetan Plateau to the rest of Eurasia. The fact that the Arctic fox disappeared from Scandinavia despite suitable conditions suggests that extant populations may be more sensitive to climate change than previously thought. PMID:26811782

  6. Last Glacial Maximum cirque glaciation in Ireland and implications for reconstructions of the Irish Ice Sheet

    NASA Astrophysics Data System (ADS)

    Barth, Aaron M.; Clark, Peter U.; Clark, Jorie; McCabe, A. Marshall; Caffee, Marc

    2016-06-01

    Reconstructions of the extent and height of the Irish Ice Sheet (IIS) during the Last Glacial Maximum (LGM, ∼19-26 ka) are widely debated, in large part due to limited age constraints on former ice margins and due to uncertainties in the origin of the trimlines. A key area is southwestern Ireland, where various LGM reconstructions range from complete coverage by a contiguous IIS that extends to the continental shelf edge to a separate, more restricted southern-sourced Kerry-Cork Ice Cap (KCIC). We present new 10Be surface exposure ages from two moraines in a cirque basin in the Macgillycuddy's Reeks that provide a unique and unequivocal constraint on ice thickness for this region. Nine 10Be ages from an outer moraine yield a mean age of 24.5 ± 1.4 ka while six ages from an inner moraine yield a mean age of 20.4 ± 1.2 ka. These ages show that the northern flanks of the Macgillycuddy's Reeks were not covered by the IIS or a KCIC since at least 24.5 ± 1.4 ka. If there was more extensive ice coverage over the Macgillycuddy's Reeks during the LGM, it occurred prior to our oldest ages.

  7. Last Glacial Maximum cirque glaciation in Ireland and implications for reconstructions of the Irish Ice Sheet

    NASA Astrophysics Data System (ADS)

    Barth, Aaron M.; Clark, Peter U.; Clark, Jorie; McCabe, A. Marshall; Caffee, Marc

    2016-06-01

    Reconstructions of the extent and height of the Irish Ice Sheet (IIS) during the Last Glacial Maximum (LGM, ∼19-26 ka) are widely debated, in large part due to limited age constraints on former ice margins and due to uncertainties in the origin of the trimlines. A key area is southwestern Ireland, where various LGM reconstructions range from complete coverage by a contiguous IIS that extends to the continental shelf edge to a separate, more restricted southern-sourced Kerry-Cork Ice Cap (KCIC). We present new 10Be surface exposure ages from two moraines in a cirque basin in the Macgillycuddy's Reeks that provide a unique and unequivocal constraint on ice thickness for this region. Nine 10Be ages from an outer moraine yield a mean age of 24.5 ± 1.4 ka while six ages from an inner moraine yield a mean age of 20.4 ± 1.2 ka. These ages show that the northern flanks of the Macgillycuddy's Reeks were not covered by the IIS or a KCIC since at least 24.5 ± 1.4 ka. If there was more extensive ice coverage over the Macgillycuddy's Reeks during the LGM, it occurred prior to our oldest ages.

  8. Map of glacial limits and possible refugia in the southern Alexander Archipelago, Alaska, during the late Wisconsin glaciation

    USGS Publications Warehouse

    Carrara, Paul E.; Ager, Thomas A.; Baichtal, James F.; VanSistine, D. Paco

    2003-01-01

    During the late Wisconsin glaciation (circa 26,000-13,000 carbon-14 yr BP) the Cordilleran glacier complex formed vast ice fields and large glaciers along the crest of the Coast Mountains. As these glaciers flowed west to the Pacific Ocean, they were joined by local glaciers originating on the higher reaches of the Alexander Archipelago (Mann and Hamiltion, 1995). This extensive volume of ice was channeled into deep troughs (present-day fiords) that formed major outlet glaciers, such as the glaciers that occupied Chatham Strait and Dixon Entrance. In several places along the coast, deep glacially scoured submarine troughs indicate that glaciers reached to the edge of the continental shelf. For instance, the glacier that extended into the Dixon Entrance trough is known to have extended to the edge of the continental shelf. Its retreat began sometime after 16,000-15,000 carbon-14 yr BP (Barrie and Conway, 1999).

  9. Post-glacial sea-level history for NE Ireland (Belfast Lough) based on offshore evidence

    NASA Astrophysics Data System (ADS)

    Quinn, R.; Plets, R. M.; Callard, L.; Cooper, A.; Long, A. J.; Belknap, D. F.; Edwards, R.; Jackson, D.; Kelley, J. T.; Long, D.; Milne, G. A.; Monteys, X.

    2013-12-01

    Glacio-isostatic adjustment (GIA) models suggest a complex relative sea-level (RSL) pattern around the Irish Sea Basin after the Last Glacial Maximum (LGM), with modelled sea-level lowstands ranging from -12 m in the north to greater than -60 m in the south of the Basin. However, these GIA models are poorly constrained by observational data offshore. Belfast Lough, on the NE coast of Ireland, is one of seven sites chosen to investigate this complex RSL history as part of the project ';Late Glacial Sea level minima in the Western British Isles' (NERC NE/H024301/1). Belfast Lough was chosen as one of the candidate sites on the basis of location (at the northern end of the Irish Sea Basin), sedimentary environment (grossly depositional) and the fact that the lowstand predicted for the Belfast Lough area by a recent version of the GIA model (-16.5 m) differs significantly from the (limited) extant observational data, which interprets the lowstand at -30 m. In 2011 and 2012 we gathered new multi-beam echo-sounder data, >200 km trackline pinger- and boomer- seismic reflection data and 46 vibrocores in Belfast Lough. Radiocarbon dating and palaeoenvironmental analysis are used to constrain the interpretation of the seismic and sediment data. Five seismo-stratigraphic units are interpreted, with a distinct erosional surface between U3 and U4 interpreted as a transgressive surface associated with sea level rise post-dating a RSL lowstand. Foraminiferal evidence indicates an increase in marine species (from lagoonal/estuarine to fully marine) from U4 to U5. Integration of the seismic and core data indicate an erosional event prior to 12.7 cal yr BP resulting in a planated surface in the inner Lough and wave-eroded drumlins at the mouth of the Lough between -15 and -22 m, interpreted as a possible slowstand. On the basis of seismic evidence in the outer Lough, an as yet undated lowstand at -42 m is tentatively interpreted to pre-date this stillstand. These results will be

  10. Post-glacial sea-level history for NE Ireland (Belfast Lough) based on offshore evidence

    NASA Astrophysics Data System (ADS)

    Quinn, Rory; Plets, Ruth; Callard, Louise; Cooper, Andrew; Antony, Long; Daniel, Belknap; Robin, Edwards; Derek, Jackson; Joseph, Kelley; David, Long; Glenn, Milne; Xavier, Monteys

    2014-05-01

    Glacio-isostatic adjustment (GIA) models suggest a complex relative sea-level (RSL) pattern around the Irish Sea Basin after the Last Glacial Maximum (LGM), with modelled sea-level lowstands ranging from -12 m in the north to greater than -60 m in the south of the Basin. However, these GIA models are poorly constrained by observational data offshore. Belfast Lough, on the NE coast of Ireland, is one of seven sites chosen to investigate this complex RSL history as part of the project 'Late Glacial Sea level minima in the Western British Isles' (NERC NE/H024301/1). Belfast Lough was chosen as one of the candidate sites on the basis of location (at the northern end of the Irish Sea Basin), sedimentary environment (grossly depositional) and the fact that the lowstand predicted for the Belfast Lough area by a recent version of the GIA model (-16.5 m) differs significantly from the (limited) extant observational data, which interprets the lowstand at -30 m. In 2011 and 2012 we gathered new multi-beam echo-sounder data, >200 km trackline pinger- and boomer- seismic reflection data and 46 vibrocores in Belfast Lough. Radiocarbon dating and palaeoenvironmental analysis are used to constrain the interpretation of the seismic and sediment data. Five seismo-stratigraphic units are interpreted, with a distinct erosional surface between U3 and U4 interpreted as a transgressive surface associated with sea level rise post-dating a RSL lowstand. Foraminiferal evidence indicates an increase in marine species (from lagoonal/estuarine to fully marine) from U4 to U5. Integration of the seismic and core data indicate an erosional event prior to 12.7 cal yr BP resulting in a planated surface in the inner Lough and wave-eroded drumlins at the mouth of the Lough between -15 and -22 m, interpreted as a possible slowstand. On the basis of seismic evidence in the outer Lough, an as yet undated lowstand at -42 m is tentatively interpreted to pre-date this stillstand. These results will be used

  11. Phylogeography of the South China Field Mouse (Apodemus draco) on the Southeastern Tibetan Plateau Reveals High Genetic Diversity and Glacial Refugia

    PubMed Central

    Liu, Yang; Liao, Lihuan; Zhang, Xiuyue; Yue, Bisong

    2012-01-01

    The southeastern margin of the Tibetan Plateau (SEMTP) is a particularly interesting region due to its topographic complexity and unique geologic history, but phylogeographic studies that focus on this region are rare. In this study, we investigated the phylogeography of the South China field mouse, Apodemus draco, in order to assess the role of geologic and climatic events on the Tibetan Plateau in shaping its genetic structure. We sequenced mitochondrial cytochrome b (cyt b) sequences in 103 individuals from 47 sampling sites. In addition, 23 cyt b sequences were collected from GenBank for analyses. Phylogenetic, demographic and landscape genetic methods were conducted. Seventy-six cyt b haplotypes were found and the genetic diversity was extremely high (π = 0.0368; h = 0.989). Five major evolutionary clades, based on geographic locations, were identified. Demographic analyses implied subclade 1A and subclade 1B experienced population expansions at about 0.052-0.013 Mya and 0.014-0.004 Mya, respectively. The divergence time analysis showed that the split between clade 1 and clade 2 occurred 0.26 Mya, which fell into the extensive glacial period (EGP, 0.5-0.17 Mya). The divergence times of other main clades (2.20-0.55 Mya) were congruent with the periods of the Qingzang Movement (3.6-1.7 Mya) and the Kun-Huang Movement (1.2-0.6 Mya), which were known as the most intense uplift events in the Tibetan Plateau. Our study supported the hypothesis that the SEMTP was a large late Pleistocene refugium, and further inferred that the Gongga Mountain Region and Hongya County were glacial refugia for A. draco in clade 1. We hypothesize that the evolutionary history of A. draco in the SEMTP primarily occurred in two stages. First, an initial divergence would have been shaped by uplift events of the Tibetan Plateau. Then, major glaciations in the Pleistocene added complexity to its demographic history and genetic structure. PMID:22666478

  12. Ireland

    ERIC Educational Resources Information Center

    Kail, Candice

    2010-01-01

    Ireland has a rich and long history. It is a land of fable and of strife, from the legendary warrior Fionn Mac Cumhaill (anglicized as Finn McCool) and the god-like Tuatha De Danann to the potato famine and the more recent Troubles. In the last decade, Ireland has experienced an economic boom and assumed a new place in the political landscape via…

  13. Post-glacial sea-level history for SW Ireland (Bantry Bay) based on offshore evidence

    NASA Astrophysics Data System (ADS)

    Plets, R. M.; Callard, L.; Cooper, A.; Long, A. J.; Belknap, D. F.; Edwards, R.; Jackson, D.; Kelley, J. T.; Long, D.; Milne, G. A.; Monteys, X.; Quinn, R.

    2013-12-01

    In recent years, progress in remote sensing techniques has helped to constrain the advance and retreat phases of the British-Irish Ice Sheet during and after the Last Glacial Maximum (LGM), both on- and offshore. However, little evidence has been collected to study the pattern of relative sea-level (RSL) change immediately after ice sheet retreat. Glacio-isostatic adjustment (GIA) models suggest a complex RSL pattern around Ireland, influenced by local and regional isostatic movements. Unfortunately, such models are poorly constrained for periods during which RSL was significantly lower than present, particularly the Late Pleistocene and Early Holocene, owing to the paucity of accurate observational data offshore. This poster presents post-LGM stratigraphic evidence from Bantry Bay (SW Ireland), one of seven areas targeted around the Irish Sea as part of a larger NERC funded project which aims to provide the first field data on the depth and age of the RSL minimum since deglaciation in the Irish Sea Basin. Data examined consists of: multibeam bathymetry and backscatter, pinger sub-bottom and vibrocores (25 sites). Notable features on the multibeam are a bluff line in the outer bay with a maximum height of 10 m in water depths of c. -80 m which forms the western edge of a large sediment lobe. The south-western boundary of this lobe is marked by a series of long (up to 22 km), parallel ridges at depths between -96 m and -131 m, with iceberg scouring evident on the offshore margin. Six seismo-stratigraphic units are interpreted from the pinger data, the most prominent of which can be traced from the inner part of the Bay to the inshore edge of the ridges. This unit sits on an erosional surface, is characterised by a turbid acoustic signature and is identified as alternating sand and clay layers with some traces of organic material and gas. Equal amounts of marine and estuarine foraminifera are present within this unit, whilst the underlying unit has a higher

  14. Less Pollen-Mediated Gene Flow for More Signatures of Glacial Lineages: Congruent Evidence from Balsam Fir cpDNA and mtDNA for Multiple Refugia in Eastern and Central North America

    PubMed Central

    Cinget, Benjamin; Gérardi, Sébastien; Beaulieu, Jean; Bousquet, Jean

    2015-01-01

    The phylogeographic structure and postglacial history of balsam fir (Abies balsamea), a transcontinental North American boreal conifer, was inferred using mitochondrial DNA (mtDNA) and chloroplast DNA (cpDNA) markers. Genetic structure among 107 populations (mtDNA data) and 75 populations (cpDNA data) was analyzed using Bayesian and genetic distance approaches. Population differentiation was high for mtDNA (dispersed by seeds only), but also for cpDNA (dispersed by seeds and pollen), indicating that pollen gene flow is more restricted in balsam fir than in other boreal conifers. Low cpDNA gene flow in balsam fir may relate to low pollen production due to the inherent biology of the species and populations being decimated by recurrent spruce budworm epidemics, and/or to low dispersal of pollen grains due to their peculiar structural properties. Accordingly, a phylogeographic structure was detected using both mtDNA and cpDNA markers and population structure analyses supported the existence of at least five genetically distinct glacial lineages in central and eastern North America. Four of these would originate from glacial refugia located south of the Laurentide ice sheet, while the last one would have persisted in the northern Labrador region. As expected due to reduced pollen-mediated gene flow, congruence between the geographic distribution of mtDNA and cpDNA lineages was higher than in other North American conifers. However, concordance was not complete, reflecting that restricted but nonetheless detectable cpDNA gene flow among glacial lineages occurred during the Holocene. As a result, new cpDNA and mtDNA genome combinations indicative of cytoplasmic genome capture were observed. PMID:25849816

  15. Phylogenetic analysis of the Australian trans-Bass Strait millipede genus Pogonosternum (Carl, 1912) (Diplopoda, Polydesmida, Paradoxosomatidae) indicates multiple glacial refugia in southeastern Australia

    PubMed Central

    Decker, Peter

    2016-01-01

    Abstract This study documents the first detailed phylogenetic analysis of an Australian paradoxosomatid millipede genus. Two mitochondrial genes (partial COI and 16S) as well as partial nuclear 28S rDNA were amplified and sequenced for 41 individuals of the southeastern Australian genus Pogonosternum Jeekel, 1965. The analysis indicates that five species groups of Pogonosternum occur across New South Wales, Victoria and Tasmania: Pogonosternum nigrovirgatum (Carl, 1912), Pogonosternum adrianae Jeekel, 1982, Pogonosternum laetificum Jeekel, 1982 and two undescribed species. Pogonosternum coniferum (Jeekel, 1965) specimens cluster within Pogonosternum nigrovirgatum. Most of these five species groups exhibit a pattern of high intraspecific genetic variability and highly localized haplotypes, suggesting that they were confined to multiple Pleistocene refugia on the southeastern Australian mainland. The phylogenetic data also show that northwestern Tasmania was colonized by Pogonosternum nigrovirgatum, probably from central Victoria, and northeastern Tasmania by an as yet undescribed species from eastern Victoria. PMID:27110194

  16. A new depositional model for glacial sediments in Killiney Bay during the Late Devensian deglaciation - East Central Ireland

    NASA Astrophysics Data System (ADS)

    Clerc, S.; Portier, E.; Buoncristiani, J. F.

    2009-04-01

    During the last glaciation in northwestern Europe, major studies are consistent with the hypothesis of an ice-stream flowing southward in the Irish Sea Basin, in connection with tributary flows on the eastern of the Irish Cap. During deglaciation, sediment deposition processes are predominant, leaving a record of glacially influenced environments. Evidence of such deposits still remains on the coast of the UK and Ireland today. Although these deposits have been studied for many decades, their depositional environment is still under debate and interpretations are evolving, together with new concepts. The present work focuses on the study of the Killiney Bay section, South Dublin, located in a topographic depression, expected to be a former subglacial tunnel valley in connection with an offshore canyon in the Irish Sea. Geometry and architecture have been approached by using panoramic photographs. In addition, fifteen detailed logs describe the stratigraphic succession, erosive surfaces and variations of small-scale sedimentary features. Seven Facies Associations were defined and used to reconstruct depositional environments. Although the section is affected by glaciotectonic deformation, primary sedimentological figures are well preserved. Within the section, a 600m long depression has been observed, in which a Gilbert-type delta has developed. Laterally, this delta evolves into prograding sheet-like structures interpreted as subaqueous fans. The corresponding facies association is composed of four main facies: -Matrix-supported coarse-grained facies (granules to cobbles) arranged in prograding sheet-like structures (dip angle 5-9° N160). -Massive sand to diffusely graded sand. -Coarse-to-medium sand facies with long wavelength ripples (1-2m), oriented N160. -Medium-to-coarse sand with climbing ripples and current ripples. These facies associations are characteristic of subaqueous (probably glaciolacustrine) environments. The transition from delta to fan delta has

  17. Deglacial and post-glacial sea-level history for Bantry Bay (SW Ireland) based on offshore evidence

    NASA Astrophysics Data System (ADS)

    Plets, Ruth; Callard, Louise; Cooper, Andrew; Long, Antony; Belknap, Daniel; Edwards, Robin; Jackson, Derek; Kelley, Joseph; Long, David; Milne, Glenn; Monteys, Xavier; Quinn, Rory

    2014-05-01

    As part of a large NERC funded project, seven areas around the Irish Sea were investigated in order to provide offshore field data on the depth and age of the relative sea-level (RSL) minimum since the post-Last Glacial Maximum (LGM). Such evidence is currently sparse, resulting in poorly constrained glacio-isostatic adjustment (GIA) models, particularly for areas where RSL was significantly lower than present during the Late Pleistocene and Early Holocene. We present offshore geomorphological and stratigraphic evidence for a lower than present sea level from SW Ireland (Bantry Bay), and compare our findings with the current GIA model. Data examined consists of: multibeam bathymetry and backscatter, pinger sub-bottom and vibrocores (25 sites). A bluff line in the outer bay detected on the multibeam in water depths of c. 80 m forms the western edge of a large sediment lobe. The south-western boundary of this lobe is marked by a series of long (up to 22 km), parallel ridges at depths between -96 m and -131 m, with iceberg scouring evident on the offshore margin. This sediment lobe is interpreted as the top of a lowstand delta with the ridges representing ice-marginal submarine morainic or deltaic sediments, reworked by stronger-than-present tidal currents during the lowstand (c. -80 m pre- 14.6 ka cal BP). The bluff line could then represent the eroded northern edge of this lowstand delta. The seismic data show a prominent unit, which can be traced throughout the basin, sitting on an erosional surface and characterised by a turbid acoustic signature. In the cores, this unit is identified as alternating sand and clay layers with some traces of organic material and gas. The micro-palaeontological data shows an increase in marine and estuarine foraminifera in this unit, becoming predominantly marine in the overlying sediments. Based on the integration of all data, we interpret the erosional surface as the transgressive surface, underlying intertidal-estuarine sediments

  18. Ice-sheet retreat from the continental shelf offshore of Northwest Ireland following the last glacial maximum: sedimentary facies and initial chronology

    NASA Astrophysics Data System (ADS)

    Weilbach, Kasper; O'Cofaigh, Colm; Lloyd, Jerry; Benetti, Sara; Dunlop, Paul; Howe, John; Purcell, Catriona

    2015-04-01

    The glacial history of North-West Ireland and the adjoining continental shelf have been debated for over a century. The traditional reconstruction of a British-Irish Ice Sheet (BIIS) in this region was based predominantly on terrestrial evidence and showed an ice sheet that did not extend beyond the present coastline of Britain and Ireland. This traditional reconstruction of a relatively restricted ice sheet has been replaced in the last decade by the reconstruction of a more dynamic ice sheet that, during the Last Glacial Maximum (LGM), flowed onto the continental shelf and extended to the NW-Irish shelf edge. High resolution swath bathymetry and sub bottom profiler data along with sedimentological, micropalaeontological and geochronological investigations of sediment cores from the shelf offshore of NW Ireland are being used to reconstruct the timing, extent and the nature of retreat of the BIIS from the shelf following the LGM. A total of twenty seven vibro-cores were collected during two research cruises on the NW-Irish shelf in 2008 and 2014 on board the Irish and UK research vessels the Celtic Explorer and RRS James Cook The cores were collected in two east-west orientated transects across a series of arcuate recessional moraines from the shelf edge to Donegal Bay. These moraines record progressive stillstands of a lobate ice sheet margin during its retreat from the shelf edge, although to date, there has been a lack of direct dating control to constrain the timing and rate of ice retreat across the shelf. Sedimentary descriptions of core facies and physical properties, combined with taxonomic analysis of foraminifera will be presented along with radiocarbon dates. This forms the first detailed reconstruction of glacigenic sedimentation, depositional environments and the timing of ice sheet retreat across the shelf offshore of NW Ireland. The project is part of a larger EU funded research programme GLANAM ('Glaciated North Atlantic Margins') which is

  19. Extending glacial refugia for a European tree: genetic markers show that Iberian populations of white elm are native relicts and not introductions

    PubMed Central

    Fuentes-Utrilla, P; Venturas, M; Hollingsworth, P M; Squirrell, J; Collada, C; Stone, G N; Gil, L

    2014-01-01

    Conservation policies usually focus on in situ protection of native populations, a priority that requires accurate assessment of population status. Distinction between native and introduced status can be particularly difficult (and at the same time, is most important) for species whose natural habitat has become both rare and highly fragmented. Here, we address the status of the white elm (Ulmus laevis Pallas), a European riparian tree species whose populations have been fragmented by human activity and is protected wherever it is considered native. Small populations of this species are located in Iberia, where they are unprotected because they are considered introductions due to their rarity. However, Iberia and neighbouring regions in southwestern France have been shown to support discrete glacial refuge populations of many European trees, and the possibility remains that Iberian white elms are native relicts. We used chloroplast RFLPs and nuclear microsatellites to establish the relationship between populations in Iberia and the Central European core distribution. Bayesian approaches revealed significant spatial structure across populations. Those in Iberia and southwestern France shared alleles absent from Central Europe, and showed spatial population structure within Iberia common in recognized native taxa. Iberian populations show a demographic signature of ancient population bottlenecks, while those in Central European show a signature of recent population bottlenecks. These patterns are not consistent with historical introduction of white elm to Iberia, and instead strongly support native status, arguing for immediate implementation of conservation measures for white elm populations in Spain and contiguous areas of southern France. PMID:24022495

  20. Lizards on Ice: Evidence for Multiple Refugia in Liolaemus pictus (Liolaemidae) during the Last Glacial Maximum in the Southern Andean Beech Forests

    PubMed Central

    Vera-Escalona, Iván; D'Elía, Guillermo; Gouin, Nicolás; Fontanella, Frank M.; Muñoz-Mendoza, Carla; Sites, Jack W.; Victoriano, Pedro F.

    2012-01-01

    Historical climate changes and orogenesis are two important factors that have shaped intraspecific biodiversity patterns worldwide. Although southern South America has experienced such complex events, there is a paucity of studies examining the effects on intraspecific diversification in this part of the world. Liolaemus pictus is the southernmost distributed lizard in the Chilean temperate forest, whose genetic structure has likely been influenced by Pleistocene glaciations. We conducted a phylogeographic study of L. pictus in Chile and Argentina based on one mitochondrial and two nuclear genes recovering two strongly divergent groups, Northern and Southern clades. The first group is distributed from the northernmost limit of the species to the Araucanía region while the second group is distributed throughout the Andes and the Chiloé archipelago in Southern Chile. Our results suggest that L. pictus originated 751 Kya, with divergence between the two clades occurring in the late Pleistocene. Demographic reconstructions for the Northern and Southern clades indicate a decrease in effective population sizes likely associated with Pleistocene glaciations. Surprisingly, patterns of genetic variation, clades age and historical gene flow in populations distributed within the limits of the Last Glacial Maximum (LGM) are not explained by recent colonization. We propose an “intra-Andean multiple refuge” hypothesis, along with the classical refuge hypothesis previously proposed for the biota of the Chilean Coastal range and Eastern Andean Cordillera. Our hypothesis is supported by niche modelling analysis suggesting the persistence of fragments of suitable habitat for the species within the limits of the LGM ice shield. This type of refuge hypothesis is proposed for the first time for an ectothermic species. PMID:23209552

  1. From glacial refugia to modern populations: new assemblages of organelle genomes generated by differential cytoplasmic gene flow in transcontinental black spruce.

    PubMed

    Gérardi, Sébastien; Jaramillo-Correa, Juan P; Beaulieu, Jean; Bousquet, Jean

    2010-12-01

    Assessing species' range-wide cytoplasmic diversity provides valuable insights regarding their dispersal and adaptive potential in a changing environment. Transcontinental chloroplast (cpDNA) and mitochondrial DNA (mtDNA) population structures were compared to identify putative ancestral and new cytoplasmic genome assemblages in black spruce (Picea mariana), a North American boreal conifer. Mean within-population diversity and allelic richness for cpSSR markers were 0.80 and 4.21, respectively, and diminished westward. Population differentiation based on G(ST) was lower for cpDNA than for mtDNA (G(ST) =0.104 and 0.645, respectively) but appeared comparable when estimated using Jost differentiation index (D=0.459 and 0.537, respectively). Further analyses resulted in the delineation of at least three genetically distinct cpDNA lineages partially congruent with those inferred from mtDNA data, which roughly corresponded to western, central and eastern Canada. Additionally, the patterns of variation in Alaska for both cpDNA and mtDNA markers suggested that black spruce survived the last glacial maximum in this northern region. The range-wide comparison of the geographic extent of cytoplasmic DNA lineages revealed that extensive pollen gene flow between ancestral lineages occurred preferentially from west to east during the postglacial expansion of the species, while seed-mediated gene flow remained geographically restricted. This differential gene flow promoted intraspecific cytoplasmic capture that generated new assemblages of cpDNA and mtDNA genomes during the Holocene. Hence, black spruce postglacial colonization unexpectedly resulted in an increase in genetic diversity with possible adaptive consequences. PMID:21044193

  2. Extra-Mediterranean refugia: The rule and not the exception?

    PubMed Central

    2012-01-01

    Some decades ago, biogeographers distinguished three major faunal types of high importance for Europe: (i) Mediterranean elements with exclusive glacial survival in the Mediterranean refugia, (ii) Siberian elements with glacial refugia in the eastern Palearctic and only postglacial expansion to Europe and (iii) arctic and/or alpine elements with large zonal distributions in the periglacial areas and postglacial retreat to the North and/or into the high mountain systems. Genetic analyses have unravelled numerous additional refugia both of continental and Mediterranean species, thus strongly modifying the biogeographical view of Europe. This modified notion is particularly true for the so-called Siberian species, which in many cases have not immigrated into Europe during the postglacial period, but most likely have survived the last, or even several glacial phases, in extra-Mediterranean refugia in some climatically favourable but geographically limited areas of southern Central and Eastern Europe. Recently, genetic analyses revealed that typical Mediterranean species have also survived the Last Glacial Maximum in cryptic northern refugia (e.g. in the Carpathians or even north of the Alps) in addition to their Mediterranean refuge areas. PMID:22953783

  3. Geomorphology of the Southwest Coast of County Cork, Ireland: A Look into the Rocks, Folds, and Glacial Scours

    NASA Astrophysics Data System (ADS)

    Bowden, S.; Wireman, R.; Sautter, L.; Beutel, E. K.

    2015-12-01

    Bathymetric data were collected off the southwest coast of County Cork, Ireland by the joint INFOMAR project between the Marine Institute of Ireland and the Geologic Survey of Ireland. Data were collected using a Kongsberg EM2040 multibeam sonar on the R/V Celtic Voyager, in August and September 2014, and were post-processed with CARIS HIPS and SIPS 8.1 and 9.0 software to create 2D and 3D bathymetric surfaces. From the computer generated images, some of the lithologic formations were relatively aged and observed. The studied regions range in depth from 20 to 118 m, with shallower areas to the northeast. Several large rock outcrops occur, the larger of which shows a vertical rise of nearly 20 m. These outcrops are oriented in a northeast-southwest direction, and exhibit significant bed folding, regional folding, tilted beds, and cross joints. The folds studied are plunging chevron folds. These folds have a northeast-southwest fold axis orthogonal to the cross joints and are older relative to the jointing systems. The NE-SW joints are older than the NW-SE joints due to their correlation with drainage and erosion patterns. Regional folding is the youngest feature due to its superposition on the chevron folding and jointing systems. The interaction of cross jointing and folding is consistent with the geologic history of the area, and creates a unique bathymetry worthy of further study.

  4. European quaternary refugia: a factor in large carnivore extinction?

    NASA Astrophysics Data System (ADS)

    O'Regan, Hannah J.; Turner, Alan; Wilkinson, David M.

    2002-12-01

    The extinction of large carnivores in Europe during the Quaternary is reviewed and the potential role of glacial refugia in these extinctions is investigated using the VORTEX model for population viability analysis. A model was built for a medium sized big cat similar to the extinct Panthera gombaszoegensis utilising life history data from the modern jaguar Panthera onca. This approach highlighted the potential importance of glacial refugia in the extinction process. Even model refugia the size of the Italian peninsula did not guarantee persistence of a population over a 1000 yr time span, illustrating the role of chance in survival in such a refugium. An area the size of the largest Mediterranean island was unable to support a big cat population for a period of 1000 yr. The models also demonstrated the importance of inbreeding as a mechanism for extinction in refugia. It is suggested that repeated genetic bottlenecks during successive glaciations would tend to remove lethal recessive alleles from the population, increasing the probability of survival in refugia in subsequent glaciations. The history of extinction of large carnivores in the European Quaternary is interpreted in the light of these results.

  5. Persistence across Pleistocene ice ages in Mediterranean and extra-Mediterranean refugia: phylogeographic insights from the common wall lizard

    PubMed Central

    2013-01-01

    Background Pleistocene climatic oscillations have played a major role in structuring present-day biodiversity. The southern Mediterranean peninsulas have long been recognized as major glacial refugia, from where Northern Europe was post-glacially colonized. However, recent studies have unravelled numerous additional refugia also in northern regions. We investigated the phylogeographic pattern of the widespread Western Palaearctic lizard Podarcis muralis, using a range-wide multilocus approach, to evaluate whether it is concordant with a recent expansion from southern glacial refugia or alternatively from a combination of Mediterranean and northern refugia. Results We analyzed DNA sequences of two mitochondrial (cytb and nd4) and three nuclear (acm4, mc1r, and pdc) gene fragments in individuals from 52 localities across the species range, using phylogenetic and phylogeographic methods. The complex phylogeographic pattern observed, with 23 reciprocally monophyletic allo- parapatric lineages having a Pleistocene divergence, suggests a scenario of long-term isolation in multiple ice-age refugia across the species distribution range. Multiple lineages were identified within the three Mediterranean peninsulas – Iberia, Italy and the Balkans - where the highest genetic diversity was observed. Such an unprecedented phylogeographic pattern - here called “refugia within all refugia” – compasses the classical scenario of multiple southern refugia. However, unlike the southern refugia model, various distinct lineages were also found in northern regions, suggesting that additional refugia in France, Northern Italy, Eastern Alps and Central Balkans allowed the long-term persistence of this species throughout Pleistocene glaciations. Conclusions The phylogeography of Podarcis muralis provides a paradigm of temperate species survival in Mediterranean and extra-Mediterranean glacial refugia. Such refugia acted as independent biogeographic compartments for the long

  6. Continuity of brown bear maternal lineages in northern England through the Last-glacial period

    NASA Astrophysics Data System (ADS)

    Edwards, Ceiridwen J.; Ho, Simon Y. W.; Barnett, Ross; Coxon, Peter; Bradley, Daniel G.; Lord, Tom C.; O'Connor, Terry

    2014-07-01

    Brown bears recolonised Europe rapidly after the Last Glacial Maximum (LGM), but there has been debate about whether bear populations were confined to separate glacial refugia in southern Europe, or if there was continuous gene flow among groups. To look in more detail at recolonisation routes into the British Isles after the LGM, 16 brown bear (Ursus arctos) samples from Lateglacial Yorkshire were analysed for mitochondrial DNA survival. The resulting data were compared with earlier work on Late Pleistocene and Holocene bears from Ireland (Edwards et al., 2011), as well as with both modern and ancient bears from across continental Europe. The results highlight the temporal and spatial continuity of brown bear maternal lineages through the Lateglacial period in northern England. While this region was not a refugial area in the LGM for the Irish Clade 2 brown bears, our data suggest that populations of brown bear in England did act as refugial sources for the later colonisation of Ireland, by Clade 1-i bears, during the Holocene. Our results contribute to a wider understanding of the phylogenetic relationships of brown bears through the Late Quaternary, and lend a valuable perspective on bear migration into peripheral Europe.

  7. Response to Edwards' comments on Origin of British and Irish mammals: disparate post-glacial colonisation and species introductions

    NASA Astrophysics Data System (ADS)

    Montgomery, W. I.; Provan, J.

    2014-12-01

    We are most grateful to Dr Edwards for her lucid summary of recent, calibrated dates for giant Irish deer, red deer, reindeer and brown bear in Irish deposits during the period before and after the Last Glacial Maximum (LGM). Montgomery et al. (2014) dealt largely with the period after the LGM because the physical evidence suggests Ireland was completely covered by ice for at least part of the period between 28 ka and 23 ka (Clark et al., 2012; O'Cofaigh et al., 2012) when Ireland would not have supported any terrestrial mammals. The earliest it was possible for re-colonisation of these species to occur after LGM was probably during the rapid retreat of ice after 23 ka and before 15 ka when the Irish Sea became a complete barrier to terrestrial mammals between Britain and Ireland. There are no dates for any of the four species during the LGM and only one for giant Irish deer (BM-1794, date 18,761-18,034 cal. BP) which is from a site close to the present coast just south of Dublin, between LGM and completion of the Irish Sea, suggesting that conditions generally remained unsuitable for even cold-adapted mammals for many millennia after LGM. Edwards (2014) indicates clearly that all four species are well represented after Ireland became an island although giant Irish deer struggle to make it into the Holocene and the red deer record is broken and perhaps influenced by people (Carden et al., 2012). The sudden reappearance of large mammals around 13-15 ka is consistent with re-colonisation from cryptic refugia lying to the south and west of present day Ireland. The relatively short periods of warming and cooling during the Older and Younger Dryas respectively, followed by warming in the Holocene and the arrival of Mesolithic and Neolithic people remain the major events in the history of Irish mammals until the late 19th Century to the present during which many mammals species have been introduced (Montgomery et al., 2014). Whilst events prior to the LGM are important

  8. Managing Climate Change Refugia for Climate Adaptation

    PubMed Central

    Daly, Christopher; Dobrowski, Solomon Z.; Dulen, Deanna M.; Ebersole, Joseph L.; Jackson, Stephen T.; Lundquist, Jessica D.; Millar, Constance I.; Maher, Sean P.; Monahan, William B.; Nydick, Koren R.; Redmond, Kelly T.; Sawyer, Sarah C.; Stock, Sarah; Beissinger, Steven R.

    2016-01-01

    Refugia have long been studied from paleontological and biogeographical perspectives to understand how populations persisted during past periods of unfavorable climate. Recently, researchers have applied the idea to contemporary landscapes to identify climate change refugia, here defined as areas relatively buffered from contemporary climate change over time that enable persistence of valued physical, ecological, and socio-cultural resources. We differentiate historical and contemporary views, and characterize physical and ecological processes that create and maintain climate change refugia. We then delineate how refugia can fit into existing decision support frameworks for climate adaptation and describe seven steps for managing them. Finally, we identify challenges and opportunities for operationalizing the concept of climate change refugia. Managing climate change refugia can be an important option for conservation in the face of ongoing climate change. PMID:27509088

  9. Managing Climate Change Refugia for Climate Adaptation.

    PubMed

    Morelli, Toni Lyn; Daly, Christopher; Dobrowski, Solomon Z; Dulen, Deanna M; Ebersole, Joseph L; Jackson, Stephen T; Lundquist, Jessica D; Millar, Constance I; Maher, Sean P; Monahan, William B; Nydick, Koren R; Redmond, Kelly T; Sawyer, Sarah C; Stock, Sarah; Beissinger, Steven R

    2016-01-01

    Refugia have long been studied from paleontological and biogeographical perspectives to understand how populations persisted during past periods of unfavorable climate. Recently, researchers have applied the idea to contemporary landscapes to identify climate change refugia, here defined as areas relatively buffered from contemporary climate change over time that enable persistence of valued physical, ecological, and socio-cultural resources. We differentiate historical and contemporary views, and characterize physical and ecological processes that create and maintain climate change refugia. We then delineate how refugia can fit into existing decision support frameworks for climate adaptation and describe seven steps for managing them. Finally, we identify challenges and opportunities for operationalizing the concept of climate change refugia. Managing climate change refugia can be an important option for conservation in the face of ongoing climate change. PMID:27509088

  10. Origin of British and Irish mammals: disparate post-glacial colonisation and species introductions

    NASA Astrophysics Data System (ADS)

    Montgomery, W. Ian; Provan, Jim; McCabe, A. Marshal; Yalden, Derek W.

    2014-08-01

    Global climate changes during the Quaternary reveal much about broader evolutionary effects of environmental change. Detailed regional studies reveal how evolutionary lineages and novel communities and ecosystems, emerge through glacial bottlenecks or from refugia. There have been significant advances in benthic imaging and dating, particularly with respect to the movements of the British (Scottish) and Irish ice sheets and associated changes in sea level during and after the Last Glacial Maximum (LGM). Ireland has been isolated as an island for approximately twice as long as Britain with no evidence of any substantial, enduring land bridge between these islands after ca 15 kya. Recent biogeographical studies show that Britain's mammal community is akin to those of southern parts of Scandinavia, The Netherlands and Belgium, but the much lower mammal species richness of Ireland is unique and needs explanation. Here, we consider physiographic, archaeological, phylogeographical i.e. molecular genetic, and biological evidence comprising ecological, behavioural and morphological data, to review how mammal species recolonized western Europe after the LGM with emphasis on Britain and, in particular, Ireland. We focus on why these close neighbours had such different mammal fauna in the early Holocene, the stability of ecosystems after LGM subject to climate change and later species introductions. There is general concordance of archaeological and molecular genetic evidence where data allow some insight into history after the LGM. Phylogeography reveals the process of recolonization, e.g. with respect to source of colonizers and anthropogenic influence, whilst archaeological data reveal timing more precisely through carbon dating and stratigraphy. More representative samples and improved calibration of the ‘molecular clock' will lead to further insights with regards to the influence of successive glaciations. Species showing greatest morphological, behavioural and

  11. Climate Change During the Late Glacial and Early Holocene From Lough Monreagh, Western Ireland: Evidence From Carbon and Oxygen Isotope Values of Lacustrine Marl

    NASA Astrophysics Data System (ADS)

    Manchester, C. W.; Patterson, W. P.

    2008-12-01

    Lake sediment is an archive of climate variability reconstructed using proxy data such as stable isotope values and trace element chemistry. These proxy data permit reconstruction of temperature, precipitation, and terrestrial vegetation variability through time. Stable oxygen isotope values conflate temperature and water oxygen isotope variability, while carbon isotope values of marl provide a record of variability in dissolved inorganic carbon (DIC). An 8.67m core, obtained from Lough Monreagh, Western Ireland, contains marl ranging in age from about 17,300-7,894 cal yr B.P. Marl was analyzed at 1mm resolution for stable oxygen and carbon isotope values. Variation in sedimentation rate results in samples that represent up to five years at minimum resolution and as little as four months at highest resolution. Oxygen isotope values decrease at 13,500 yr B.P. from -3.5 to -5 per mil VPDB inferring a decrease in temperature followed by a warming period consistent with previous interpretations of the Older Dryas. Another decrease in oxygen isotope values (-3.9 to -7.0 per mil VPDB) occurs from 12,800-11,500 yr B.P. indicating a significant decrease in temperature consistent with the Younger Dryas. Carbon isotope values increase between 17,200-14,000 yr B.P. from 3.6 to 6.0 per mil VPDB suggesting high productivity is forcing the carbon isotope values of DIC higher than bedrock values, contrary to ostracod population data that suggest low productivity. Carbon isotope values decrease between 12,800-11,500 from 4.0 to 3.0 per mil VPDB coincident with the Younger Dryas clay layer, a time where marl was not produced in the lake. A 6 per mil decrease in carbon isotope values between 11,262-10860 yr B.P. from 4 to -2 per mil VPDB indicates a significant increase in terrestrial vegetation. Sample to sample variability nearing the top of the core is higher due to increased sedimentation rate and concomitantly the sample resolution increases. This study represents the highest

  12. Extensive range persistence in peripheral and interior refugia characterizes Pleistocene range dynamics in a widespread Alpine plant species (Senecio carniolicus, Asteraceae)

    PubMed Central

    Escobar García, Pedro; Winkler, Manuela; Flatscher, Ruth; Sonnleitner, Michaela; KrejčíKová, Jana; Suda, Jan; HüLber, Karl; Schneeweiss, Gerald M; SchöNswetter, Peter

    2012-01-01

    Recent evidence suggests that survival of arctic-alpine organisms in peripheral or interior glacial refugia are not mutually exclusive and may both be involved in shaping an organism’s Pleistocene history, yet potentially at different time levels. Here, we test this hypothesis in a high-mountain plant (diploid lineage of Senecio carniolicus, Asteraceae) from the Eastern European Alps, in which patterns of morphological variation and current habitat requirements suggest survival in both types of refugia. To this end, we used AFLPs, nuclear and plastid DNA sequences and analysed them, among others, within a graph theoretic framework and using novel Bayesian methods of phylogeographic inference. On the basis of patterns of genetic diversity, occurrence of rare markers, distribution of distinct genetic lineages and patterns of range connectivity both interior refugia in the formerly strongly glaciated central Alps and peripheral refugia along the southern margin of the Alps were identified. The presence of refugia congruently inferred by markers resolving at different time levels suggests that these refugia acted as such throughout several glacial cycles. The high degree of range persistence together with gradual range expansion, which contrasts with the extent of range shifts implied for other Alpine species, is likely responsible for incipient lineage differentiation evident from the genetic data. Replacing a simplistic peripheral vs. interior refugia dualism by more complex models involving both types of refugia and considering different time levels will help identifying common phylogeographic patterns with respect to, for instance, location of refugia and colonization routes and elucidating their underlying genetic and/or ecological causes. PMID:22276934

  13. Extensive range persistence in peripheral and interior refugia characterizes Pleistocene range dynamics in a widespread Alpine plant species (Senecio carniolicus, Asteraceae).

    PubMed

    Escobar García, Pedro; Winkler, Manuela; Flatscher, Ruth; Sonnleitner, Michaela; Krejčíková, Jana; Suda, Jan; Hülber, Karl; Schneeweiss, Gerald M; Schönswetter, Peter

    2012-03-01

    Recent evidence suggests that survival of arctic-alpine organisms in peripheral or interior glacial refugia are not mutually exclusive and may both be involved in shaping an organism's Pleistocene history, yet potentially at different time levels. Here, we test this hypothesis in a high-mountain plant (diploid lineage of Senecio carniolicus, Asteraceae) from the Eastern European Alps, in which patterns of morphological variation and current habitat requirements suggest survival in both types of refugia. To this end, we used AFLPs, nuclear and plastid DNA sequences and analysed them, among others, within a graph theoretic framework and using novel Bayesian methods of phylogeographic inference. On the basis of patterns of genetic diversity, occurrence of rare markers, distribution of distinct genetic lineages and patterns of range connectivity both interior refugia in the formerly strongly glaciated central Alps and peripheral refugia along the southern margin of the Alps were identified. The presence of refugia congruently inferred by markers resolving at different time levels suggests that these refugia acted as such throughout several glacial cycles. The high degree of range persistence together with gradual range expansion, which contrasts with the extent of range shifts implied for other Alpine species, is likely responsible for incipient lineage differentiation evident from the genetic data. Replacing a simplistic peripheral vs. interior refugia dualism by more complex models involving both types of refugia and considering different time levels will help identifying common phylogeographic patterns with respect to, for instance, location of refugia and colonization routes and elucidating their underlying genetic and/or ecological causes. DNA sequences have been deposited in GenBank under accession nos. FR796701–FR797793 and nos. HE614296–HE614583. PMID:22276934

  14. Locating Pleistocene Refugia: Comparing Phylogeographic and Ecological Niche Model Predictions

    PubMed Central

    Waltari, Eric; Hijmans, Robert J.; Peterson, A. Townsend; Nyári, Árpád S.; Perkins, Susan L.; Guralnick, Robert P.

    2007-01-01

    Ecological niche models (ENMs) provide a means of characterizing the spatial distribution of suitable conditions for species, and have recently been applied to the challenge of locating potential distributional areas at the Last Glacial Maximum (LGM) when unfavorable climate conditions led to range contractions and fragmentation. Here, we compare and contrast ENM-based reconstructions of LGM refugial locations with those resulting from the more traditional molecular genetic and phylogeographic predictions. We examined 20 North American terrestrial vertebrate species from different regions and with different range sizes for which refugia have been identified based on phylogeographic analyses, using ENM tools to make parallel predictions. We then assessed the correspondence between the two approaches based on spatial overlap and areal extent of the predicted refugia. In 14 of the 20 species, the predictions from ENM and predictions based on phylogeographic studies were significantly spatially correlated, suggesting that the two approaches to development of refugial maps are converging on a similar result. Our results confirm that ENM scenario exploration can provide a useful complement to molecular studies, offering a less subjective, spatially explicit hypothesis of past geographic patterns of distribution. PMID:17622339

  15. Subglacial refugia in Iceland enabled groundwater amphipods to survive glaciations.

    PubMed

    Kristjánsson, Bjarni K; Svavarsson, Jörundur

    2007-08-01

    An endemic family of subterranean amphipods (Crustacea) has recently been discovered in Iceland, in addition to a new species of a previously known amphipod family. These findings are remarkable because Iceland was covered by glaciers from about 2.6 million BP to about 10,000 BP and is isolated on the mid-Atlantic Ridge, far from the North American and European continents. We argue that there were subglacial refugia in Iceland during the Quaternary glacial period. The presence of subterranean amphipods, belonging to an old group with its present distribution mainly in North America and the Eurasian continent, indicates past contact of subterranean fresh waters of Iceland and the North Atlantic continent. The amphipods currently found in Iceland may have been present in Greenland at 40 Ma, when the precursor of Iceland drifted together with the hot spot (Iceland plume) from Greenland. PMID:17874379

  16. What happened to the coal forests during Pennsylvanian glacial phases?

    SciTech Connect

    Falcon-Lang, H.J.; Dimichele, W.A.

    2010-09-15

    Sequence stratigraphic analysis of Pennsylvanian coal-bearing strata suggests that glacial-interglacial fluctuations at high latitudes drove cyclic changes in tropical biomes. A literature review of plant assemblages in this paleoclimatic context suggests that coal forests dominated during humid interglacial phases, but were replaced by seasonally dry vegetation during glacial phases. After each glacial event, coal forests reassembled with largely the same species composition. This remarkable stasis implies that coal-forest refugia existed across the equatorial landscape during glacial phases, expanding to repopulate lowlands during and following deglaciation. One possibility is that refugia comprised small pockets of wetland forest strung out along valleys at some sites, but data are currently insufficient to test this hypothesis. The model presented here, if accepted, dramatically alters our understanding of the coal forests and helps explain aspects of their dynamics.

  17. Coalescent-based hypothesis testing supports multiple Pleistocene refugia in the Pacific Northwest for the Pacific giant salamander (Dicamptodon tenebrosus).

    PubMed

    Steele, Craig A; Storfer, Andrew

    2006-08-01

    Phylogeographic patterns of many taxa are explained by Pleistocene glaciation. The temperate rainforests within the Pacific Northwest of North America provide an excellent example of this phenomenon, and competing phylogenetic hypotheses exist regarding the number of Pleistocene refugia influencing genetic variation of endemic organisms. One such endemic is the Pacific giant salamander, Dicamptodon tenebrosus. In this study, we estimate this species' phylogeny and use a coalescent modeling approach to test five hypotheses concerning the number, location and divergence times of purported Pleistocene refugia. Single refugium hypotheses include: a northern refugium in the Columbia River Valley and a southern refugium in the Klamath-Siskiyou Mountains. Dual refugia hypotheses include these same refugia but separated at varying times: last glacial maximum (20,000 years ago), mid-Pleistocene (800,000 years ago) and early Pleistocene (1.7 million years ago). Phylogenetic analyses and inferences from nested clade analysis reveal distinct northern and southern lineages expanding from the Columbia River Valley and the Klamath-Siskiyou Mountains, respectively. Results of coalescent simulations reject both single refugium hypotheses and the hypothesis of dual refugia with a separation date in the late Pleistocene but not hypotheses predicting dual refugia with separation in early or mid-Pleistocene. Estimates of time since divergence between northern and southern lineages also indicate separation since early to mid-Pleistocene. Tests for expanding populations using mismatch distributions and 'g' distributions reveal demographic growth in the northern and southern lineages. The combination of these results provides strong evidence that this species was restricted into, and subsequently expanded from, at least two Pleistocene refugia in the Pacific Northwest. PMID:16842421

  18. Postglacial recolonization at a snail's pace (Trochulus villosus): confronting competing refugia hypotheses using model selection.

    PubMed

    Dépraz, A; Cordellier, M; Hausser, J; Pfenninger, M

    2008-05-01

    The localization of Last Glacial Maximum (LGM) refugia is crucial information to understand a species' history and predict its reaction to future climate changes. However, many phylogeographical studies often lack sampling designs intensive enough to precisely localize these refugia. The hairy land snail Trochulus villosus has a small range centred on Switzerland, which could be intensively covered by sampling 455 individuals from 52 populations. Based on mitochondrial DNA sequences (COI and 16S), we identified two divergent lineages with distinct geographical distributions. Bayesian skyline plots suggested that both lineages expanded at the end of the LGM. To find where the origin populations were located, we applied the principles of ancestral character reconstruction and identified a candidate refugium for each mtDNA lineage: the French Jura and Central Switzerland, both ice-free during the LGM. Additional refugia, however, could not be excluded, as suggested by the microsatellite analysis of a population subset. Modelling the LGM niche of T. villosus, we showed that suitable climatic conditions were expected in the inferred refugia, but potentially also in the nunataks of the alpine ice shield. In a model selection approach, we compared several alternative recolonization scenarios by estimating the Akaike information criterion for their respective maximum-likelihood migration rates. The 'two refugia' scenario received by far the best support given the distribution of genetic diversity in T. villosus populations. Provided that fine-scale sampling designs and various analytical approaches are combined, it is possible to refine our necessary understanding of species responses to environmental changes. PMID:18422928

  19. Geothermal activity helps life survive glacial cycles.

    PubMed

    Fraser, Ceridwen I; Terauds, Aleks; Smellie, John; Convey, Peter; Chown, Steven L

    2014-04-15

    Climate change has played a critical role in the evolution and structure of Earth's biodiversity. Geothermal activity, which can maintain ice-free terrain in glaciated regions, provides a tantalizing solution to the question of how diverse life can survive glaciations. No comprehensive assessment of this "geothermal glacial refugia" hypothesis has yet been undertaken, but Antarctica provides a unique setting for doing so. The continent has experienced repeated glaciations that most models indicate blanketed the continent in ice, yet many Antarctic species appear to have evolved in almost total isolation for millions of years, and hence must have persisted in situ throughout. How could terrestrial species have survived extreme glaciation events on the continent? Under a hypothesis of geothermal glacial refugia and subsequent recolonization of nongeothermal regions, we would expect to find greater contemporary diversity close to geothermal sites than in nongeothermal regions, and significant nestedness by distance of this diversity. We used spatial modeling approaches and the most comprehensive, validated terrestrial biodiversity dataset yet created for Antarctica to assess spatial patterns of diversity on the continent. Models clearly support our hypothesis, indicating that geothermally active regions have played a key role in structuring biodiversity patterns in Antarctica. These results provide critical insights into the evolutionary importance of geothermal refugia and the history of Antarctic species. PMID:24616489

  20. The role of Pleistocene refugia and rivers in shaping gorilla genetic diversity in central Africa

    PubMed Central

    Anthony, Nicola M.; Johnson-Bawe, Mireille; Jeffery, Kathryn; Clifford, Stephen L.; Abernethy, Kate A.; Tutin, Caroline E.; Lahm, Sally A.; White, Lee J. T.; Utley, John F.; Wickings, E. Jean; Bruford, Michael W.

    2007-01-01

    The role of Pleistocene forest refugia and rivers in the evolutionary diversification of tropical biota has been the subject of considerable debate. A range-wide analysis of gorilla mitochondrial and nuclear variation was used to test the potential role of both refugia and rivers in shaping genetic diversity in current populations. Results reveal strong patterns of regional differentiation that are consistent with refugial hypotheses for central Africa. Four major mitochondrial haplogroups are evident with the greatest divergence between eastern (A, B) and western (C, D) gorillas. Coalescent simulations reject a model of recent east–west separation during the last glacial maximum but are consistent with a divergence time within the Pleistocene. Microsatellite data also support a similar regional pattern of population genetic structure. Signatures of demographic expansion were detected in eastern lowland (B) and Gabon/Congo (D3) mitochondrial haplogroups and are consistent with a history of postglacial expansion from formerly isolated refugia. Although most mitochondrial haplogroups are regionally defined, limited admixture is evident between neighboring haplogroups. Mantel tests reveal a significant isolation-by-distance effect among western lowland gorilla populations. However, mitochondrial genetic distances also correlate with the distance required to circumnavigate intervening rivers, indicating a possible role for rivers in partitioning gorilla genetic diversity. Comparative data are needed to evaluate the importance of both mechanisms of vicariance in other African rainforest taxa. PMID:18077351

  1. Ireland (2007)

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Between 51.5 and 55.5 degrees north latitude, Ireland could easily find itself buried in snow during the winter, but the island's average temperature in January is 7 degrees Celsius (45 degrees Fahrenheit). Ireland's mild climate results from the influence of the ocean current known as the North Atlantic Drift, which extends the warm waters of the Gulf Stream northward. The island enjoys mild temperatures in the summertime as well; extreme heat and cold are virtually unknown. Precipitation ranges from 78.5 centimeters (31 inches) around Dublin to 300 centimeters (118 inches) along the west coast. The mild, rainy climate is good for vegetation. In this image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite on May 2, 2007, Ireland overwhelms the viewer with hues of green, particularly in the interior, where the vegetation overlies lowlands of limestone--the remains of marine animals from an ancient sea. Little of the island's famous greenness results from trees, however. Seventeenth-century clearing removed most of the country's forests, and despite replanting efforts, Ireland is Europe's least forested country, after Iceland. The island's mild temperatures and humidity have instead blanketed the landscape in abundant grasses. Along Ireland's west coast, bare brown rocks emerge from the plant cover. In the north, the rocks are primarily ancient, crystalline rocks deposited well over a billion years ago. In the south, the rocks are primarily sandstone deposited roughly 350 million years ago. Evidence of urbanization dots the landscape, especially along the east coast. The metropolitan area of Dublin appears as an uneven patch of gray, mingled with dots of green. Human habitation is also evident around Londonderry, Belfast, and Cork.

  2. Thriving in the Cold: Glacial Expansion and Post-Glacial Contraction of a Temperate Terrestrial Salamander (Plethodon serratus)

    PubMed Central

    Newman, Catherine E.; Austin, Christopher C.

    2015-01-01

    The dynamic geologic history of the southeastern United States has played a major role in shaping the geographic distributions of amphibians in the region. In the phylogeographic literature, the predominant pattern of distribution shifts through time of temperate species is one of contraction during glacial maxima and persistence in refugia. However, the diverse biology and ecology of amphibian species suggest that a “one-size-fits-all” model may be inappropriate. Nearly 10% of amphibian species in the region have a current distribution comprised of multiple disjunct, restricted areas that resemble the shape of Pleistocene refugia identified for other temperate taxa in the literature. Here, we apply genetics and spatially explicit climate analyses to test the hypothesis that the disjunct regions of these species ranges are climatic refugia for species that were more broadly distributed during glacial maxima. We use the salamander Plethodon serratus as a model, as its range consists of four disjunct regions in the Southeast. Phylogenetic results show that P. serratus is comprised of multiple genetic lineages, and the four regions are not reciprocally monophyletic. The Appalachian salamanders form a clade sister to all other P. serratus. Niche and paleodistribution modeling results suggest that P. serratus expanded from the Appalachians during the cooler Last Glacial Maximum and has since been restricted to its current disjunct distribution by a warming climate. These data reject the universal applicability of the glacial contraction model to temperate taxa and reiterate the importance of considering the natural history of individual species. PMID:26132077

  3. Multiple ice-age refugia in Pacific cod, Gadus macrocephalus.

    PubMed

    Canino, Michael F; Spies, Ingrid B; Cunningham, Kathryn M; Hauser, Lorenz; Grant, W Stewart

    2010-10-01

    Pleistocene ice-ages greatly influenced the historical abundances of Pacific cod, Gadus macrocephalus, in the North Pacific and its marginal seas. We surveyed genetic variation at 11 microsatellite loci and mitochondrial (mt) DNA in samples from twelve locations from the Sea of Japan to Washington State. Both microsatellite (mean H = 0.868) and mtDNA haplotype (mean h = 0.958) diversities were large and did not show any geographical trends. Genetic differentiation between samples was significantly correlated with geographical distance between samples for both microsatellites (FST = 0.028, r(2) = 0.33) and mtDNA (FST = 0.027, r(2) = 0.18). Both marker classes showed a strong genetic discontinuity between northwestern and northeastern Pacific populations that likely represents groups previously isolated during glaciations that are now in secondary contact. Significant differences appeared between samples from the Sea of Japan and Okhotsk Sea that may reflect ice-age isolations in the northwest Pacific. In the northeast Pacific, a microsatellite and mtDNA partition was detected between coastal and Georgia Basin populations. The presence of two major coastal mtDNA lineages on either side of the Pacific Ocean basin implies at least two ice-age refugia and separate postglacial population expansions facilitated by different glacial histories. Northward expansions into the Gulf of Alaska were possible 14-15 kyr ago, but deglaciation and colonization of the Georgia Basin probably occurred somewhat later. Population expansions were evident in mtDNA mismatch distributions and in Bayesian skyline plots of the three major lineages, but the start of expansions appeared to pre-date the last glacial maximum. PMID:20819160

  4. Origin of British and Irish mammals: disparate post-glacial colonisation and species introductions

    NASA Astrophysics Data System (ADS)

    Montgomery, W. Ian; Provan, Jim; McCabe, A. Marshal; Yalden, Derek W.

    2014-08-01

    Global climate changes during the Quaternary reveal much about broader evolutionary effects of environmental change. Detailed regional studies reveal how evolutionary lineages and novel communities and ecosystems, emerge through glacial bottlenecks or from refugia. There have been significant advances in benthic imaging and dating, particularly with respect to the movements of the British (Scottish) and Irish ice sheets and associated changes in sea level during and after the Last Glacial Maximum (LGM). Ireland has been isolated as an island for approximately twice as long as Britain with no evidence of any substantial, enduring land bridge between these islands after ca 15 kya. Recent biogeographical studies show that Britain's mammal community is akin to those of southern parts of Scandinavia, The Netherlands and Belgium, but the much lower mammal species richness of Ireland is unique and needs explanation. Here, we consider physiographic, archaeological, phylogeographical i.e. molecular genetic, and biological evidence comprising ecological, behavioural and morphological data, to review how mammal species recolonized western Europe after the LGM with emphasis on Britain and, in particular, Ireland. We focus on why these close neighbours had such different mammal fauna in the early Holocene, the stability of ecosystems after LGM subject to climate change and later species introductions. There is general concordance of archaeological and molecular genetic evidence where data allow some insight into history after the LGM. Phylogeography reveals the process of recolonization, e.g. with respect to source of colonizers and anthropogenic influence, whilst archaeological data reveal timing more precisely through carbon dating and stratigraphy. More representative samples and improved calibration of the ‘molecular clock' will lead to further insights with regards to the influence of successive glaciations. Species showing greatest morphological, behavioural and

  5. Phylogeography of the montane caddisfly Drusus discolor: evidence for multiple refugia and periglacial survival.

    PubMed

    Pauls, Steffen U; Lumbsch, H Thorsten; Haase, Peter

    2006-07-01

    We studied the genetic population structure and phylogeography of the montane caddisfly Drusus discolor across its entire range in central and southern Europe. The species is restricted to mountain regions and exhibits an insular distribution across the major mountain ranges. Mitochondrial sequence data (COI) of 254 individuals from the entire species range is analysed to reveal population genetic structure. The data show little molecular variation within populations and regions, but distinct genetic differentiation between mountain ranges. Most populations are significantly differentiated based on F(ST) and exact tests of population differentiation and most haplotypes are unique to a single mountain range. Phylogenetic analyses reveal deep divergence between geographically isolated lineages. Combined, these results suggest that past fragmentation is the prominent process structuring the populations across Europe. We use tests of selective neutrality and mismatch distributions, to study the demographic population history of regions with haplotype overlap. The high level of genetic differentiation between mountain ranges and estimates of demographic history provide evidence for the existence of multiple glacial refugia, including several in central Europe. The study shows that these aquatic organisms reacted differently to Pleistocene cooling than many terrestrial species. They persisted in numerous refugia over multiple glacial cycles, allowing many local endemic clades to form. PMID:16780432

  6. Phylogeography of the Russian flying squirrel (Pteromys volans): implication of refugia theory in arboreal small mammal of Eurasia.

    PubMed

    Oshida, Tatsuo; Abramov, Alexei; Yanagawa, Hisashi; Masuda, Ryuichi

    2005-04-01

    A phylogeographical study of the Russian (Siberian) flying squirrel (Pteromys volans) was carried out using the complete mitochondrial (mt) cytochrome b gene sequences with special reference to the refugia theory for the arboreal traits of this species. We examined 31 specimens from 24 localities, resulting in 28 haplotypes. One breeding specimen with a unique haplotype from Hokkaido, Japan was included in the phylogenetic analysis. There were three mtDNA lineages: Hokkaido, Far Eastern, and northern Eurasia. Divergence data among lineages demonstrated that the Hokkaido group separated from the other groups during the Holsteinian interglacial. The phylogeographical pattern of P. volans is different from that previously reported for terrestrial rodents associated with treeless habitats. Unlike grasslands, forests decreased during glaciation and moved southward because of the cold and arid environmental conditions. The glacial refugia of P. volans would have been associated with forest dynamics in the Pleistocene. PMID:15773945

  7. Geothermal activity helps life survive glacial cycles

    PubMed Central

    Fraser, Ceridwen I.; Terauds, Aleks; Smellie, John; Convey, Peter; Chown, Steven L.

    2014-01-01

    Climate change has played a critical role in the evolution and structure of Earth’s biodiversity. Geothermal activity, which can maintain ice-free terrain in glaciated regions, provides a tantalizing solution to the question of how diverse life can survive glaciations. No comprehensive assessment of this “geothermal glacial refugia” hypothesis has yet been undertaken, but Antarctica provides a unique setting for doing so. The continent has experienced repeated glaciations that most models indicate blanketed the continent in ice, yet many Antarctic species appear to have evolved in almost total isolation for millions of years, and hence must have persisted in situ throughout. How could terrestrial species have survived extreme glaciation events on the continent? Under a hypothesis of geothermal glacial refugia and subsequent recolonization of nongeothermal regions, we would expect to find greater contemporary diversity close to geothermal sites than in nongeothermal regions, and significant nestedness by distance of this diversity. We used spatial modeling approaches and the most comprehensive, validated terrestrial biodiversity dataset yet created for Antarctica to assess spatial patterns of diversity on the continent. Models clearly support our hypothesis, indicating that geothermally active regions have played a key role in structuring biodiversity patterns in Antarctica. These results provide critical insights into the evolutionary importance of geothermal refugia and the history of Antarctic species. PMID:24616489

  8. Mapping human dispersals into the Horn of Africa from Arabian Ice Age refugia using mitogenomes

    PubMed Central

    Gandini, Francesca; Achilli, Alessandro; Pala, Maria; Bodner, Martin; Brandini, Stefania; Huber, Gabriela; Egyed, Balazs; Ferretti, Luca; Gómez-Carballa, Alberto; Salas, Antonio; Scozzari, Rosaria; Cruciani, Fulvio; Coppa, Alfredo; Parson, Walther; Semino, Ornella; Soares, Pedro; Torroni, Antonio; Richards, Martin B.; Olivieri, Anna

    2016-01-01

    Rare mitochondrial lineages with relict distributions can sometimes be disproportionately informative about deep events in human prehistory. We have studied one such lineage, haplogroup R0a, which uniquely is most frequent in Arabia and the Horn of Africa, but is distributed much more widely, from Europe to India. We conclude that: (1) the lineage ancestral to R0a is more ancient than previously thought, with a relict distribution across the Mediterranean/Southwest Asia; (2) R0a has a much deeper presence in Arabia than previously thought, highlighting the role of at least one Pleistocene glacial refugium, perhaps on the Red Sea plains; (3) the main episode of dispersal into Eastern Africa, at least concerning maternal lineages, was at the end of the Late Glacial, due to major expansions from one or more refugia in Arabia; (4) there was likely a minor Late Glacial/early postglacial dispersal from Arabia through the Levant and into Europe, possibly alongside other lineages from a Levantine refugium; and (5) the presence of R0a in Southwest Arabia in the Holocene at the nexus of a trading network that developed after ~3 ka between Africa and the Indian Ocean led to some gene flow even further afield, into Iran, Pakistan and India. PMID:27146119

  9. Mapping human dispersals into the Horn of Africa from Arabian Ice Age refugia using mitogenomes.

    PubMed

    Gandini, Francesca; Achilli, Alessandro; Pala, Maria; Bodner, Martin; Brandini, Stefania; Huber, Gabriela; Egyed, Balazs; Ferretti, Luca; Gómez-Carballa, Alberto; Salas, Antonio; Scozzari, Rosaria; Cruciani, Fulvio; Coppa, Alfredo; Parson, Walther; Semino, Ornella; Soares, Pedro; Torroni, Antonio; Richards, Martin B; Olivieri, Anna

    2016-01-01

    Rare mitochondrial lineages with relict distributions can sometimes be disproportionately informative about deep events in human prehistory. We have studied one such lineage, haplogroup R0a, which uniquely is most frequent in Arabia and the Horn of Africa, but is distributed much more widely, from Europe to India. We conclude that: (1) the lineage ancestral to R0a is more ancient than previously thought, with a relict distribution across the Mediterranean/Southwest Asia; (2) R0a has a much deeper presence in Arabia than previously thought, highlighting the role of at least one Pleistocene glacial refugium, perhaps on the Red Sea plains; (3) the main episode of dispersal into Eastern Africa, at least concerning maternal lineages, was at the end of the Late Glacial, due to major expansions from one or more refugia in Arabia; (4) there was likely a minor Late Glacial/early postglacial dispersal from Arabia through the Levant and into Europe, possibly alongside other lineages from a Levantine refugium; and (5) the presence of R0a in Southwest Arabia in the Holocene at the nexus of a trading network that developed after ~3 ka between Africa and the Indian Ocean led to some gene flow even further afield, into Iran, Pakistan and India. PMID:27146119

  10. Managing for Climate Change in Western Forest Ecosystems; The Role of Refugia in Adaptation Strategies (Invited)

    NASA Astrophysics Data System (ADS)

    Millar, C. I.; Morelli, T.

    2009-12-01

    Managing forested ecosystems in western North America for adaptation to climate change involves options that depend on resource objectives, landscape conditions, sensitivity to change, and social desires. Strategies range from preserving species and ecosystems in the face of change (resisting change); managing for resilience to change; realigning ecosystems that have been severely altered so that they can adapt successfully; and enabling species to respond to climate changes. We are exploring one extreme in this range of strategies, that is, to manage locations, species, communities, or ecosystems as refugia. This concept is familiar from the Quaternary literature as isolated locations where climates remained warm during cold glacial intervals and wherein species contracted and persisted in small populations. References to refugia have been made in the climate-adaptation literature but little elaborated, and applications have not been described. We are addressing this gap conceptually and in case-studies from national forest and national park environments in California. Using a classification of refugium categories, we extend the concept beyond the original use to include diverse locations and conditions where plant or animal species, or ecosystems of concern, would persist during future changing climatic backgrounds. These locations may be determined as refugial for reasons of local microclimate, substrate, elevation, topographic context, paleohistory, species ecology, or management capacity. Recognizing that species and ecosystems respond to climate change differently, refugium strategies are appropriate in some situations and not others. We describe favorable conditions for using refugium strategies and elaborate specific approaches in Sierra Nevada case studies.

  11. Hot spots of genetic diversity descended from multiple Pleistocene refugia in an alpine ungulate.

    PubMed

    Shafer, Aaron B A; Côté, Steeve D; Coltman, David W

    2011-01-01

    Species that inhabit naturally fragmented environments are expected to be spatially structured and exhibit reduced genetic diversity at the periphery of their range. Patterns of differentiation may also reflect historical processes such as recolonization from glacial refugia. We examined the relative importance of these factors in shaping the spatial patterns of genetic differentiation across the range of an alpine specialist, the North American mountain goat (Oreamnos americanus). Contrary to fossil evidence that suggests a single southern refugium, we detected evidence for additional refugia in northern British Columbia and the Alaskan coast using both mitochondrial and microsatellite DNA. A core area of elevated genetic diversity characterized both regions, and molecular dating suggested a recent Pleistocene split was followed by demographic expansion. Across their range, mountain goats were highly genetically structured and displayed the expected pattern of declining diversity toward the periphery. Gene flow was high within contiguous mountain ranges, but cross-assignments paradoxically suggest that long-distance contemporary dispersal movements are not uncommon. These results improve our understanding of how historical vicariance and contemporary fragmentation influence population differentiation, and have implications for conserving the adaptive potential of alpine populations and habitat. PMID:20731714

  12. A long pollen record from lowland Amazonia: Forest and cooling in glacial times

    SciTech Connect

    Colinvaux, P.A.; Moreno, J.E.; Bush, M.B.

    1996-10-04

    A continuous pollen history of more than 40,000 years was obtained from a lake in the lowland Amazon rain forest. Pollen spectra demonstrate that tropical rain forest occupied the region continuously and that savannas or grasslands were not present during the last glacial maximum. The data suggest that the western Amazon forest was not fragmented into refugia in glacial times and that the lowlands were not a source of dust. Glacial age forests were comparable to modern forests but also included species now restricted to higher evaluations by temperature, suggesting a cooling of the order of 5{degrees} to 6{degrees}C. 23 refs., 22 tabs.

  13. Shallow phylogeographic structuring of Vimba vimba across Europe suggests two distinct refugia during the last glaciation.

    PubMed

    Hänfling, B; Dümpelmann, C; Bogutskaya, N G; Brandl, R; Brändle, M

    2009-12-01

    Genetic variation and geographical structuring of vimba Vimba vimba were analysed across 26 sites (80 individuals) by means of mtDNA sequences (cyt b gene, mitochondrial control region) to localize hypothesized glacial refugia and to reconstruct postglacial recoloniation routes. Although genetic diversity among sequenced individuals was low, a combined analysis of the two sequenced fragments revealed a western (central and northern Europe: Danube, Elbe and lakes of Sweden) and an eastern clade (eastern Europe: Dnieper-South Bug, Don, Neman). Furthermore, a number of divergent ancestral haplotypes distributed around the Black and Caspian Seas became apparent. Mismatch analyses supported a sudden expansion model for the populations of the western clade between 50 and 10 000 bp. Overall, the study provides strong evidence for a northward and westward expansion of V. vimba from two refugial regions located in the Danubian drainage and the northern Pontic regions respectively. PMID:20738686

  14. Climate change refugia as a tool for climate adaptation

    EPA Science Inventory

    Climate change refugia, areas relatively buffered from contemporary climate change so as to increase persistence of valued physical, ecological, and cultural resources, are considered as potential adaptation options in the face of anthropogenic climate change. In a collaboration ...

  15. Modeling vertical coral connectivity and mesophotic refugia

    NASA Astrophysics Data System (ADS)

    Holstein, Daniel M.; Paris, Claire B.; Vaz, Ana C.; Smith, Tyler B.

    2016-03-01

    Whether mesophotic reefs will behave as refugia for corals threatened by global climate change and coastal development depends on vertical exchange of larvae between diverse habitats. Here we use a biophysical model of larval dispersal to estimate vertical connectivity of a broadcasting ( Orbicella faveolata) and a brooding ( Porites astreoides) species of coral in the US Virgin Islands. Modeling predicts subsidy to shallow areas by mesophotic larvae of both species based on local hydrology, adult reproductive characteristics, larval traits, and a wide range of scenarios developed to test depth-sensitive factors, such as fertilization rates and post-settlement survivorship. In extreme model scenarios of reduced fertilization and post-settlement survivorship of mesophotic larvae, 1-10 % local mesophotic subsidy to shallow recruitment is predicted for both species, which are demographically significant. Although direct vertical connectivity is higher for the broadcaster, the brooder demonstrates higher local multigenerational vertical connectivity, which suggests that local P. astreoides populations are more resilient than those of O. faveolata, and corroborates field studies. As shallow habitat degrades, mesophotic-shallow subsidy is predicted to increase for both species. This study is the first of its kind to simulate larval dispersal and settlement between habitats of different depths, and these findings have local, regional, and global implications for predicting and managing coral reef persistence in a changing climate.

  16. Middle Stone Age (MSA) site distributions in eastern Africa and their relationship to Quaternary environmental change, refugia and the evolution of Homo sapiens

    NASA Astrophysics Data System (ADS)

    Basell, Laura S.

    2008-12-01

    This paper considers the evolution of Homo sapiens in eastern Africa in relation to refugia and bottlenecks around ˜200 ka BP, at a macro scale. Middle Stone Age (MSA) lithics, site distributions and locations are analysed in relation to palaeovegetation maps of the last glacial/interglacial cycle, which are used as a proxy for earlier climate cycles. A "push and pull" model is then postulated for the spread of Homo sapiens out of refugia in eastern Africa, involving both volcanism (push) and habitat availability (pull). A date within OIS 5 is suggested for this expansion to other parts of the continent, and potentially further afield, contrary to a frequently proposed expansion within OIS 3.

  17. A Test of Climate Change Refugia in Montane Meadow Systems

    NASA Astrophysics Data System (ADS)

    Morelli, T.; Maher, S. P.; Moritz, C.; Beissinger, S. R.

    2013-12-01

    Climate change refugia, areas on the landscape buffered from recent shifts in temperature and precipitation patterns, are potentially important to understand population responses to anthropogenic climate change. With funding from the California Landscape Conservation Cooperative and the National Science Foundation, we used occupancy and genetic data to test the climate change refugia concept. Specifically, we estimated connectivity between Sierra Nevada meadows based on features such as topography and hydrology and determined the amount of change that meadows experienced during the 20th century. We then examined fine-scale population genetic structure across the California range of a montane meadow specialist, the Belding's ground squirrel (Urocitellus beldingi). We found distinctive genetic structure across the state as well as within the smaller geographic area of the central Sierra Nevada. Genetic diversity between survey sites predicted climate change refugia and population persistence supported hypothetical landscape connectivity. Our results highlight an important tool in climate change adaptation, given the limited resources available to land managers.

  18. Refugia preferences by the spiders Loxosceles reclusa and Loxosceles laeta (Araneae: Sicariidae).

    PubMed

    Vetter, Richard S; Rust, Michael K

    2008-01-01

    A variety of refugia were offered to different instars of brown recluse spiders, Loxosceles reclusa Gertsch and Mulaik, and a South American recluse spider, L. laeta (Nicolet), to determine whether they preferred certain types of refugia spaces. Variables included (1) crevice widths ranging from 3.2 to 21 mm, (2) horizontal and vertical orientations, and (3) new refugia or refugia that had silk deposited by a previous conspecific resident. An additional 30-d assay with similar-sized refugia studied each species' propensity for site fidelity or movement among refugia. L. reclusa preferred crevice widths > or = 9 mm with no correlation of body size to crevice width, whereas L. laeta preferred crevice sizes > or = 6.4 mm with a marginally significant correlation between crevice width and body size. Both species preferred (1) vertical instead of horizontal-oriented refugia and (2) refugia with conspecific silk compared with previously uninhabited refugia. There was no significant difference between the species in their propensity to move among refugia in the 30-d trial; however, both species had individuals that were always found in the same refugium for the entire assay and individuals changing refugia every 2-3 d. The propensity to switch refugia was not affected by the degree of starvation for the period tested as was initially hypothesized. The possible implications of this research toward developing novel control measures for Loxosceles spiders are discussed. PMID:18283940

  19. Spotlight on VET: Ireland

    ERIC Educational Resources Information Center

    Cedefop - European Centre for the Development of Vocational Training, 2013

    2013-01-01

    This paper provides an overview of VET (vocational education and training) in Ireland. In Ireland, the main providers of VET are the national Training and Employment Authority (FAS--a non-commercial semi-State body, part of the public sector) and vocational education committees (VECs--public sector bodies at county level responsible for vocational…

  20. Gifted Education in Ireland

    ERIC Educational Resources Information Center

    O'Reilly, Colm

    2013-01-01

    This article will outline the current status of gifted education in Ireland. To fully understand the picture, one needs to look at the history of the Irish education system and how educational decisions are made in the country. Political climate is often an important factor in how people view special education programs and Ireland is no different…

  1. Education in Ireland.

    ERIC Educational Resources Information Center

    Harden, Harold D.

    This study provides a profile of the educational system of Ireland. It is intended as background reading for University of West Florida officials involved with evaluating applications for admission of students from Ireland. The Irish educational system can be divided into primary (elementary), post primary (secondary), and tertiary education…

  2. Coalescent Simulation and Paleodistribution Modeling for Tabebuia rosealba Do Not Support South American Dry Forest Refugia Hypothesis.

    PubMed

    de Melo, Warita Alves; Lima-Ribeiro, Matheus S; Terribile, Levi Carina; Collevatti, Rosane G

    2016-01-01

    Studies based on contemporary plant occurrences and pollen fossil records have proposed that the current disjunct distribution of seasonally dry tropical forests (SDTFs) across South America is the result of fragmentation of a formerly widespread and continuously distributed dry forest during the arid climatic conditions associated with the Last Glacial Maximum (LGM), which is known as the modern-day dry forest refugia hypothesis. We studied the demographic history of Tabebuia rosealba (Bignoniaceae) to understand the disjunct geographic distribution of South American SDTFs based on statistical phylogeography and ecological niche modeling (ENM). We specifically tested the dry forest refugia hypothesis; i.e., if the multiple and isolated patches of SDTFs are current climatic relicts of a widespread and continuously distributed dry forest during the LGM. We sampled 235 individuals across 18 populations in Central Brazil and analyzed the polymorphisms at chloroplast (trnS-trnG, psbA-trnH and ycf6-trnC intergenic spacers) and nuclear (ITS nrDNA) genomes. We performed coalescence simulations of alternative hypotheses under demographic expectations from two a priori biogeographic hypotheses (1. the Pleistocene Arc hypothesis and, 2. a range shift to Amazon Basin) and other two demographic expectances predicted by ENMs (3. expansion throughout the Neotropical South America, including Amazon Basin, and 4. retraction during the LGM). Phylogenetic analyses based on median-joining network showed haplotype sharing among populations with evidence of incomplete lineage sorting. Coalescent analyses showed smaller effective population sizes for T. roseoalba during the LGM compared to the present-day. Simulations and ENM also showed that its current spatial pattern of genetic diversity is most likely due to a scenario of range retraction during the LGM instead of the fragmentation from a once extensive and largely contiguous SDTF across South America, not supporting the South

  3. Coalescent Simulation and Paleodistribution Modeling for Tabebuia rosealba Do Not Support South American Dry Forest Refugia Hypothesis

    PubMed Central

    de Melo, Warita Alves; Lima-Ribeiro, Matheus S.; Terribile, Levi Carina

    2016-01-01

    Studies based on contemporary plant occurrences and pollen fossil records have proposed that the current disjunct distribution of seasonally dry tropical forests (SDTFs) across South America is the result of fragmentation of a formerly widespread and continuously distributed dry forest during the arid climatic conditions associated with the Last Glacial Maximum (LGM), which is known as the modern-day dry forest refugia hypothesis. We studied the demographic history of Tabebuia rosealba (Bignoniaceae) to understand the disjunct geographic distribution of South American SDTFs based on statistical phylogeography and ecological niche modeling (ENM). We specifically tested the dry forest refugia hypothesis; i.e., if the multiple and isolated patches of SDTFs are current climatic relicts of a widespread and continuously distributed dry forest during the LGM. We sampled 235 individuals across 18 populations in Central Brazil and analyzed the polymorphisms at chloroplast (trnS-trnG, psbA-trnH and ycf6-trnC intergenic spacers) and nuclear (ITS nrDNA) genomes. We performed coalescence simulations of alternative hypotheses under demographic expectations from two a priori biogeographic hypotheses (1. the Pleistocene Arc hypothesis and, 2. a range shift to Amazon Basin) and other two demographic expectances predicted by ENMs (3. expansion throughout the Neotropical South America, including Amazon Basin, and 4. retraction during the LGM). Phylogenetic analyses based on median-joining network showed haplotype sharing among populations with evidence of incomplete lineage sorting. Coalescent analyses showed smaller effective population sizes for T. roseoalba during the LGM compared to the present-day. Simulations and ENM also showed that its current spatial pattern of genetic diversity is most likely due to a scenario of range retraction during the LGM instead of the fragmentation from a once extensive and largely contiguous SDTF across South America, not supporting the South

  4. Reef-coral refugia in a rapidly changing ocean.

    PubMed

    Cacciapaglia, Chris; van Woesik, Robert

    2015-06-01

    This study sought to identify climate-change thermal-stress refugia for reef corals in the Indian and Pacific Oceans. A species distribution modeling approach was used to identify refugia for 12 coral species that differed considerably in their local response to thermal stress. We hypothesized that the local response of coral species to thermal stress might be similarly reflected as a regional response to climate change. We assessed the contemporary geographic range of each species and determined their temperature and irradiance preferences using a k-fold algorithm to randomly select training and evaluation sites. That information was applied to downscaled outputs of global climate models to predict where each species is likely to exist by the year 2100. Our model was run with and without a 1°C capacity to adapt to the rising ocean temperature. The results show a positive exponential relationship between the current area of habitat that coral species occupy and the predicted area of habitat that they will occupy by 2100. There was considerable decoupling between scales of response, however, and with further ocean warming some 'winners' at local scales will likely become 'losers' at regional scales. We predicted that nine of the 12 species examined will lose 24-50% of their current habitat. Most reductions are predicted to occur between the latitudes 5-15°, in both hemispheres. Yet when we modeled a 1°C capacity to adapt, two ubiquitous species, Acropora hyacinthus and Acropora digitifera, were predicted to retain much of their current habitat. By contrast, the thermally tolerant Porites lobata is expected to increase its current distribution by 14%, particularly southward along the east and west coasts of Australia. Five areas were identified as Indian Ocean refugia, and seven areas were identified as Pacific Ocean refugia for reef corals under climate change. All 12 of these reef-coral refugia deserve high-conservation status. PMID:25646684

  5. Surviving in Mountain Climate Refugia: New Insights from the Genetic Diversity and Structure of the Relict Shrub Myrtus nivellei (Myrtaceae) in the Sahara Desert

    PubMed Central

    Migliore, Jérémy; Baumel, Alex; Juin, Marianick; Fady, Bruno; Roig, Anne; Duong, Nathalie; Médail, Frédéric

    2013-01-01

    The identification of past glacial refugia has become a key topic for conservation under environmental change, since they contribute importantly to shaping current patterns of biodiversity. However, little attention has been paid so far to interglacial refugia despite their key role for the survival of relict species currently occurring in climate refugia. Here, we focus on the genetic consequences of range contraction on the relict populations of the evergreen shrub Myrtus nivellei, endemic in the Saharan mountains since at least the end of the last Green Sahara period, around 5.5 ka B.P. Multilocus genotypes (nuclear microsatellites and AFLP) were obtained from 215 individuals collected from 23 wadis (temporary rivers) in the three main mountain ranges in southern Algeria (the Hoggar, Tassili n’Ajjer and Tassili n’Immidir ranges). Identical genotypes were found in several plants growing far apart within the same wadis, a pattern taken as evidence of clonality. Multivariate analyses and Bayesian clustering revealed that genetic diversity was mainly structured among the mountain ranges, while low isolation by distance was observed within each mountain range. The range contraction induced by the last episode of aridification has likely increased the genetic isolation of the populations of M. nivellei, without greatly affecting the genetic diversity of the species as a whole. The pattern of genetic diversity observed here suggests that high connectivity may have prevailed during humid periods, which is consistent with recent paleoenvironmental reconstructions. PMID:24058489

  6. Future distribution of tundra refugia in northern Alaska

    USGS Publications Warehouse

    Hope, Andrew G.; Waltari, Eric; Payer, David C.; Cook, Joseph A.; Talbot, Sandra L.

    2013-01-01

    Climate change in the Arctic is a growing concern for natural resource conservation and management as a result of accelerated warming and associated shifts in the distribution and abundance of northern species. We introduce a predictive framework for assessing the future extent of Arctic tundra and boreal biomes in northern Alaska. We use geo-referenced museum specimens to predict the velocity of distributional change into the next century and compare predicted tundra refugial areas with current land-use. The reliability of predicted distributions, including differences between fundamental and realized niches, for two groups of species is strengthened by fossils and genetic signatures of demographic shifts. Evolutionary responses to environmental change through the late Quaternary are generally consistent with past distribution models. Predicted future refugia overlap managed areas and indicate potential hotspots for tundra diversity. To effectively assess future refugia, variable responses among closely related species to climate change warrants careful consideration of both evolutionary and ecological histories.

  7. Phylogeographic evidence for two mesic refugia in a biodiversity hotspot.

    PubMed

    Nistelberger, H; Gibson, N; Macdonald, B; Tapper, S-L; Byrne, M

    2014-11-01

    Phylogeographic studies of flora in species-rich south-western Australia point to complex evolutionary histories, reflecting patterns of persistence and resilience to climatic changes during the Pleistocene. We asked whether coastal areas of the mid-west and south, as well as granite outcrops and inland ranges, have acted as major refugia within this region during Pleistocene climatic fluctuations by analysing phylogeographic patterns in the shrub Calothamnus quadrifidus R.Br. (Myrtaceae). We determined variation in chloroplast DNA data for 41 populations across the geographic range. Relationships and major clades were resolved using parsimony and Bayesian analyses. We tested for demographic and spatial expansion of the major clades and estimated clade divergence dates using an uncorrelated, lognormal relaxed clock based on two conservative chloroplast mutation rates. Two distinct phylogeographic clades were identified showing divergence during the Pleistocene, consistent with other phylogeographic studies of south-west Australian flora, emphasising the impact of climatic oscillations in driving divergence in this landscape. The southern clade was more diverse, having higher haplotype diversity and greater genetic structure, while the northern clade showed evidence of fluctuation in population size. Regions of high haplotype diversity with adjacent areas of low diversity observed in each clade indicated the locations of two coastal refugia: one on the south coast and another along the mid-west coast. This is the first evidence for major Pleistocene refugia using chloroplast genetic data in a common, widespread species from this region. PMID:24984607

  8. Phylogeographic evidence for two mesic refugia in a biodiversity hotspot

    PubMed Central

    Nistelberger, H; Gibson, N; Macdonald, B; Tapper, S-L; Byrne, M

    2014-01-01

    Phylogeographic studies of flora in species-rich south-western Australia point to complex evolutionary histories, reflecting patterns of persistence and resilience to climatic changes during the Pleistocene. We asked whether coastal areas of the mid-west and south, as well as granite outcrops and inland ranges, have acted as major refugia within this region during Pleistocene climatic fluctuations by analysing phylogeographic patterns in the shrub Calothamnus quadrifidus R.Br. (Myrtaceae). We determined variation in chloroplast DNA data for 41 populations across the geographic range. Relationships and major clades were resolved using parsimony and Bayesian analyses. We tested for demographic and spatial expansion of the major clades and estimated clade divergence dates using an uncorrelated, lognormal relaxed clock based on two conservative chloroplast mutation rates. Two distinct phylogeographic clades were identified showing divergence during the Pleistocene, consistent with other phylogeographic studies of south-west Australian flora, emphasising the impact of climatic oscillations in driving divergence in this landscape. The southern clade was more diverse, having higher haplotype diversity and greater genetic structure, while the northern clade showed evidence of fluctuation in population size. Regions of high haplotype diversity with adjacent areas of low diversity observed in each clade indicated the locations of two coastal refugia: one on the south coast and another along the mid-west coast. This is the first evidence for major Pleistocene refugia using chloroplast genetic data in a common, widespread species from this region. PMID:24984607

  9. Caribbean mesophotic coral ecosystems are unlikely climate change refugia.

    PubMed

    Smith, Tyler B; Gyory, Joanna; Brandt, Marilyn E; Miller, William J; Jossart, Jonathan; Nemeth, Richard S

    2016-08-01

    Deeper coral reefs experience reduced temperatures and light and are often shielded from localized anthropogenic stressors such as pollution and fishing. The deep reef refugia hypothesis posits that light-dependent stony coral species at deeper depths are buffered from thermal stress and will avoid bleaching-related mass mortalities caused by increasing sea surface temperatures under climate change. This hypothesis has not been tested because data collection on deeper coral reefs is difficult. Here we show that deeper (mesophotic) reefs, 30-75 m depth, in the Caribbean are not refugia because they have lower bleaching threshold temperatures than shallow reefs. Over two thermal stress events, mesophotic reef bleaching was driven by a bleaching threshold that declines 0.26 °C every +10 m depth. Thus, the main premise of the deep reef refugia hypothesis that cooler environments are protective is incorrect; any increase in temperatures above the local mean warmest conditions can lead to thermal stress and bleaching. Thus, relatively cooler temperatures can no longer be considered a de facto refugium for corals and it is likely that many deeper coral reefs are as vulnerable to climate change as shallow water reefs. PMID:26648385

  10. Using biological data to test climate change refugia

    NASA Astrophysics Data System (ADS)

    Morelli, T. L.; Maher, S. P.

    2015-12-01

    The concept of refugia has been discussed from theoretical and paleontological perspectives to address how populations persisted during periods of unfavorable climate. Recently, several studies have applied the idea to contemporary landscapes to identify locations that are buffered from climate change effects so as to favor greater persistence of valued resources relative to other areas. Refugia are now being discussed among natural resource agencies as a potential adaptation option in the face of anthropogenic climate change. Using downscaled climate data, we identified hypothetical refugial meadows in the Sierra Nevada and then tested them using survey and genetic data from Belding's ground squirrel (Urocitellus beldingi) populations. We predicted that refugial meadows would show higher genetic diversity, higher rates of occupancy and lower rates of extirpation over time. At each step of the research, we worked with managers to ensure the largest impact. Although no panacea, identifying climate change refugia could be an important strategy for prioritizing habitats for management intervention in order to conserve populations. This research was supported by the California LCC, the Northeast Climate Science Center, and NSF.

  11. Community Development in Ireland.

    ERIC Educational Resources Information Center

    Lee, Anna

    2003-01-01

    In the last decade, community development in Ireland has emphasized social and economic inclusion, regeneration, and civic participation. Continuing challenges include designation of diverse community representatives, demand for increased administrative efficiency, and management of mandates and accountability. There are more community development…

  12. Vocational Training in Ireland.

    ERIC Educational Resources Information Center

    Dooney, Roy; Dunne, Paul

    This monograph, one of a series of studies of vocational education in the countries of the European Communities, describes the vocational training system in Ireland. The study was compiled from existing statistics and descriptions, and most figures cited refer to 1984. The report is organized in eight chapters. Chapter 1 covers population,…

  13. Literacy Policy in Ireland

    ERIC Educational Resources Information Center

    Kennedy, Eithne

    2013-01-01

    Over the past 15 years or so, individual governments worldwide have put an unprecedented focus on educational policy in an effort to ensure the acquisition of literacy skills for all children, recognising underachievement in literacy as a universal social justice issue preventing many individuals from reaching their promise. In Ireland, literacy…

  14. Abortion in Ireland.

    PubMed

    Francome, C

    1992-08-22

    Substantial legal barriers to abortion persist in both the Irish Republic and Northern Ireland, despite growing popular support for abortion under certain conditions. A 1983 amendment to the republic's constitution guarantees the fetus the same right to life s the mother and bans the provision of information on abortion. Although a recent well publicized case of a pregnant, suicidal 14-year-old who travelled to England for an abortion resulted in an Irish Supreme Court ruling that abortion was acceptable in cases of "real and substantial risk" to a woman's life, uncertainty still surrounds the right to travel to England for the procedure. In Northern Ireland, the 1967 Abortion Act does not apply and abortions are denied even in cases of rape and incest. A total of 1766 women from Northern Ireland and 4158 from the republic travelled to England for abortions in 1991. Public opinion seems to have shifted toward support for less restrictive abortion laws, however. Whereas 80% of those surveyed in a 1980 Irish poll supported to ban on abortion in all cases, this statistic had dropped to 30% by 1990. Similarly, a 1991 poll taken in Northern Ireland found 80% of respondents to be a favor of abortion in cases where the procedure is necessary to maintain a woman's physical or mental health. PMID:1392954

  15. Counseling in Ireland

    ERIC Educational Resources Information Center

    O'Morain, Padraig; McAuliffe, Garrett J.; Conroy, Kayte; Johnson, Jennifer M.; Michel, Rebecca E.

    2012-01-01

    Counseling in Ireland has experienced rapid growth in the past 30 years. Public attitudes toward counseling have become more positive, especially with the increasing secularization of a once strongly religious Catholic society. Licensure is nonexistent but there are certification bodies that attempt to ensure qualified practice. There is no…

  16. Uncovering the glacial history of the Irish continental shelf (Invited)

    NASA Astrophysics Data System (ADS)

    Dunlop, P.; Benetti, S.; OCofaigh, C.

    2013-12-01

    In 1999 the Irish Government initiated a €32 million survey of its territorial waters known as the Irish National Seabed Survey (INSS). The INSS is amongst the largest marine mapping programmes ever undertaken anywhere in the world and provides high-resolution multibeam, backscatter and seismic data of the seabed around Ireland. These data have been used to provide the first clear evidence for extensive glaciation of the continental shelf west and northwest of Ireland. Streamlined drumlins on the mid to outer shelf record former offshore-directed ice flow towards the shelf edge and show that the ice sheet was grounded in a zone of confluence where ice flowing onto the shelf from northwest Ireland merged with ice flowing across the Malin Shelf from southwest Scotland. The major glacial features on the shelf are well developed nested arcuate moraine systems that mark the position of the ice sheet margin and confirm that the former British Irish Ice Sheet was grounded as far as the shelf edge around 100 km offshore of west Donegal at the last glacial maximum. Distal to the moraines, on the outermost shelf, prominent zones of iceberg plough marks give way to the Barra/Donegal fan and a well developed system of gullies and canyons which incise the continental slope. Since 2008 several scientific cruises have retrieved cores from the shelf and slope to help build a more detailed understanding of glacial events in this region. This presentation will provide an overview of the glacial history of the Irish shelf and will discuss ongoing research programmes that are building on the initial research findings to produce a better understanding of the nature and timing of ice sheet events in this region.

  17. Science questions for implementing climate refugia for salmon as a conservation strategy

    EPA Science Inventory

    The recognition and protection of climate refugia has been proposed as a potential adaptation strategy that may be useful for protecting the biotic integrity of watersheds under a changing climate. Climate refugia are areas that are buffered from climate change effects relative t...

  18. Use of on-site refugia to protect unionid populations from zebra mussel-induced mortality

    USGS Publications Warehouse

    Nichols, S. Jerrine; Black, M. Glen; Allen, Jeffrey D.

    2000-01-01

    Protecting unionid populations as zebra mussels spread into inland waterways has relied mainly on relocating at-risk animals into aquaculture facilities. While such relocations are the only viable management technique for some populations, facility availability is limited, leaving many unionids facing extirpation. Another management strategy is in-situ protection either by enhancing natural refugia or by creating managed refugia. We have reviewed all reports of natural refugia and found that refugia for unionids can be found in many areas. There are many habitats where zebra mussel colonization has been limited, or of a temporary nature. Within zebra mussel infested areas, unionid communities continue to survive in some shallow water sites such as estuaries, deltas, and lake-connected wetlands. Managed refugia can be created in areas where natural refugia do not exist. We present a case study on recent efforts to create refugia in an area with rapidly expanding zebra mussel populations. Preliminary analysis of unionid body condition indicates that removal of encrusted zebra mussels only once a year can improve unionid condition factors and decrease mortality. Natural and managed refugia can provide an additional conservation management option in some areas.

  19. Science questions for implementing climate refugia for cold-water fish as an adaptation strateby

    EPA Science Inventory

    Managing climate refugia has been proposed as a potential adaptation strategy that may be useful for protecting the biotic integrity of watersheds under a changing climate. Paleo-ecological evidence suggests that refugia allowed species to persist through prior periods of climate...

  20. Interglacial refugia preserved high genetic diversity of the Chinese mole shrew in the mountains of southwest China.

    PubMed

    He, K; Hu, N-Q; Chen, X; Li, J-T; Jiang, X-L

    2016-01-01

    The mountains of southwest China (MSC) harbor extremely high species diversity; however, the mechanism behind this diversity is unknown. We investigated to what degree the topography and climate change shaped the genetic diversity and diversification in these mountains, and we also sought to identify the locations of microrefugia areas in these mountains. For these purposes, we sampled extensively to estimate the intraspecific phylogenetic pattern of the Chinese mole shrew (Anourosorex squamipes) in southwest China throughout its range of distribution. Two mitochondrial genes, namely, cytochrome b (CYT B) and NADH dehydrogenase subunit 2 (ND2), from 383 archived specimens from 43 localities were determined for phylogeographic and demographic analyses. We used the continuous-diffusion phylogeographic model, extensive Bayesian skyline plot species distribution modeling (SDM) and approximate Bayesian computation (ABC) to explore the changes in population size and distribution through time of the species. Two phylogenetic clades were identified, and significantly higher genetic diversity was preserved in the southern subregion of the mountains. The results of the SDM, continuous-diffusion phylogeographic model, extensive Bayesian skyline plot and ABC analyses were congruent and supported that the Last Interglacial Maximum (LIG) was an unfavorable period for the mole shrews because of a high degree of seasonality; A. squamipes survived in isolated interglacial refugia mainly located in the southern subregion during the LIG and rapidly expanded during the last glacial period. These results furnished the first evidence for major Pleistocene interglacial refugia and a latitudinal effect in southwest China, and the results shedding light on the higher level of species richness in the southern subregion. PMID:26286667

  1. Population structure and genome-wide patterns of variation in Ireland and Britain

    PubMed Central

    O'Dushlaine, Colm T; Morris, Derek; Moskvina, Valentina; Kirov, George; Consortium, International Schizophrenia; Gill, Michael; Corvin, Aiden; Wilson, James F; Cavalleri, Gianpiero L

    2010-01-01

    Located off the northwestern coast of the European mainland, Britain and Ireland were among the last regions of Europe to be colonized by modern humans after the last glacial maximum. Further, the geographical location of Britain, and in particular of Ireland, is such that the impact of historical migration has been minimal. Genetic diversity studies applying the Y chromosome and mitochondrial systems have indicated reduced diversity and an increased population structure across Britain and Ireland relative to the European mainland. Such characteristics would have implications for genetic mapping studies of complex disease. We set out to further our understanding of the genetic architecture of the region from the perspective of (i) population structure, (ii) linkage disequilibrium (LD), (iii) homozygosity and (iv) haplotype diversity (HD). Analysis was conducted on 3654 individuals from Ireland, Britain (with regional sampling in Scotland), Bulgaria, Portugal, Sweden and the Utah HapMap collection. Our results indicate a subtle but clear genetic structure across Britain and Ireland, although levels of structure were reduced in comparison with average cross-European structure. We observed slightly elevated levels of LD and homozygosity in the Irish population compared with neighbouring European populations. We also report on a cline of HD across Europe with greatest levels in southern populations and lowest levels in Ireland and Scotland. These results are consistent with our understanding of the population history of Europe and promote Ireland and Scotland as relatively homogenous resources for genetic mapping of rare variants. PMID:20571510

  2. Pennsylvanian tropical rain forests responded to glacial-interglacial rhythms

    NASA Astrophysics Data System (ADS)

    Falcon-Lang, Howard J.

    2004-08-01

    Pennsylvanian tropical rain forests flourished during an icehouse climate mode. Although it is well established that Milankovitch-band glacial-interglacial rhythms caused marked synchronous changes in Pennsylvanian tropical climate and sea level, little is known of vegetation response to orbital forcing. This knowledge gap has now been addressed through sequence- stratigraphic analysis of megafloral and palynofloral assemblages within the Westphalian D Cantabrian Sydney Mines Formation of eastern Canada. This succession was deposited in a low- accommodation setting where sequences can be attributed confidently to glacio-eustasy. Results show that long-lived, low-diversity peat mires dominated by lycopsids were initiated during deglaciation events, but were mostly drowned by rising sea level at maximum interglacial conditions. Only upland coniferopsid forests survived flooding without significant disturbance. Mid- to late interglacial phases witnessed delta-plain progradation and establishment of high-diversity, mineral-substrate rain forests containing lycopsids, sphenopsids, pteridosperms, cordaites, and tree ferns. Renewed glaciation resulted in sea-level fall, paleovalley incision, and the onset of climatic aridity. Glacial vegetation was dominated by cordaites, pteridosperms, and tree ferns; hydrophilic lycopsids and sphenopsids survived in paleovalley refugia. Findings clearly demonstrate the dynamic nature of Pennsylvanian tropical ecosystems and are timely given current debates about the impact of Quaternary glacial-interglacial rhythms on the biogeography of tropical rain forest.

  3. Liver transplantation in Ireland.

    PubMed

    Iqbal, Masood; Elrayah, Elgaily A; Traynor, Oscar; McCormick, P Aiden

    2016-07-01

    The Irish National Liver Transplant program commenced in 1993 in St. Vincent's University Hospital in Dublin. It is an adult-only program and is the only liver transplant program in Ireland. Pediatric recipients are referred to King's College Hospital in the United Kingdom. To date, almost 1000 adult liver transplants have been performed. Current 1-year patient survival is 93%, and 5-year survival is 79%. The program is fully funded by the government health service. There is a close collaboration with the United Kingdom Organ Donation and Transplant Directorate, and there is an arrangement for organ sharing for super-urgent transplants. Traditionally, organ donation rates have been high in Ireland. However, demand for liver transplant has increased over the past 20 years, and waiting lists are now lengthening. Deceased cardiac death donation is now being considered, but there are no plans for living related donor liver transplant. Donor coordinators have recently been appointed to the major hospitals in Ireland, and it is hoped that this initiative will lead to an increase in organ donation rates. Liver Transplantation 22 1014-1018 2016 AASLD. PMID:27065358

  4. Extreme Glacial Legacies: A Synthesis of the Antarctic Springtail Phylogeographic Record

    PubMed Central

    McGaughran, Angela; Stevens, Mark I.; Hogg, Ian D.; Carapelli, Antonio

    2011-01-01

    We review current phylogeographic knowledge from across the Antarctic terrestrial landscape with a focus on springtail taxa. We describe consistent patterns of high genetic diversity and structure among populations which have persisted in glacial refugia across Antarctica over both short (<2 Mya) and long (>10 Mya) timescales. Despite a general concordance of results among species, we explain why location is important in determining population genetic patterns within bioregions. We complete our review by drawing attention to the main limitations in the field of Antarctic phylogeography, namely that the scope of geographic focus is often lacking within studies, and that large gaps remain in our phylogeographic knowledge for most terrestrial groups. PMID:26467614

  5. Did debris-covered glaciers serve as pleistocene refugia for plants? A new hypothesis derived from observations of recent plant growth on glacier surfaces

    USGS Publications Warehouse

    Fickert, T.; Friend, D.; Gruninger, F.; Molnia, B.; Richter, M.

    2007-01-01

    This study proposes a new hypothesis: Debris-covered glaciers served as Pleistocene biological refugia. This is based on detailed studies of vascular plant growth on six debris-mantled glaciers, literally around the world, as well as many casual observations also across the globe. We find that such glaciers are quite common and are distributed globally. Using Carbon Glacier, Mount Rainier, U.S.A., as a type locality and case study, we show aspects of the floristic and structural diversity as well as spatial patterns of plant growth on the glacier surface. Migration strategies, root characteristics, and origin and dispersal strategies for vascular plant species are documented. Also reported are special microclimatic conditions in these areas allowing for this remarkable plant ecology. We find that alpine taxa can grow considerably below their usual altitudinal niche due to the cooler subsurface soil temperatures found on glacial debris with ice underneath, and that may have significantly altered the spatial distribution of such flora during full glacial conditions. This in turn creates previously undocumented areas from which alpine, and perhaps arctic, plant species reestablished in post-glacial time. This hypothesis is complementary to both the nunatak hypothesis and tabula rasa theory and possibly helps solve the ongoing controversy between them. ?? 2007 Regents of the University of Colorado.

  6. Effective Climate Refugia for Cold-water Fishes

    NASA Astrophysics Data System (ADS)

    Ebersole, J. L.; Morelli, T. L.; Torgersen, C.; Isaak, D.; Keenan, D.; Labiosa, R.; Fullerton, A.; Massie, J.

    2015-12-01

    Climate change threatens to create fundamental shifts in in the distributions and abundances of endothermic organisms such as cold-water salmon and trout species (salmonids). Recently published projected declines in mid-latitude salmonid distributions under future climates range from modest to severe, depending on modeling approaches, assumptions, and spatial context of analyses. Given these projected losses, increased emphasis on management for ecosystem resilience to help buffer cold-water fish populations and their habitats against climate change is emerging. Using terms such as "climate-proofing", "climate-ready", and "climate refugia", such efforts stake a claim for an adaptive, anticipatory planning response to the climate change threat. To be effective, such approaches will need to address critical uncertainties in both the physical basis for projected landscape changes in water temperature and streamflow, as well as the biological responses of organisms. Recent efforts define future potential climate refugia based on projected streamflows, air temperatures, and associated water temperature changes. These efforts reflect the relatively strong conceptual foundation for linkages between regional climate change and local hydrological responses and thermal dynamics. Yet important questions remain. Drawing on case studies throughout the Pacific Northwest, we illustrate some key uncertainties in the responses of salmonids and their habitats to altered hydro-climatic regimes currently not well addressed by physical or ecological models. Key uncertainties include biotic interactions, organismal adaptive capacity, local climate decoupling due to groundwater-surface water interactions, the influence of human engineering responses, and synergies between climatic and other stressors. These uncertainties need not delay anticipatory planning, but rather highlight the need for identification and communication of actions with high probabilities of success, and targeted

  7. Evaluation of relocation of unionid mussels to in situ refugia

    USGS Publications Warehouse

    Cope, W.G.; Hove, M.C.; Waller, D.L.; Hornbach, D.J.; Bartsch, M.R.; Cunningham, L.A.; Dunn, H.L.; Kapuscinski, A.R.

    2003-01-01

    The aim of this study was to evaluate the recovery and survival of four species of unionid mussles [pimpleback, Quadrula pustulosa pustulosa (I. Lea, 1831); spike, Elliptio dilatata (Rafinesque, 1820); Higgins eye, Lampsilis higginsii (I. Lea, 1857); and pocketbook, Lampsilis cardium (Rafinesque, 1820)] that were experimentally relocated to in situ refugia in the St Croix River of Minnesota and Wisconsin, USA. In 1996, 150 mussels of each of the first three species (450 total) were relocated to three 5 x 5 m study grids (Site A), one near Lakeland, Minnesota, which served as a source-site control, and two in the experimental refuge 48 km upstream, near Franconia, Minnesota. In a second relocation in 1997, L. Cardium was substituted for L. Higginsii and 150 mussels of this and each of the other two species (450 total), were relocated to two study grids (Site B). The source site control was near Sunrise, Minnesota and the experimental refuge was 14 km downstream near Almelund, Minnesota. Mussel recovery, survival and substratum characteristics were evaluated annually at Site A for 2 years and for 3 years at Site B. Mean annual recovery of all three species ranged from 90 to 100% at Site A, and from 34 to 70% at site B. The mean annual survival of recaptured mussels ranged from 85 to 100% at Site A, and from 88 to 100% at Site B. The textural characteristics of the substratum differed significantly between the control and the two refuge locations at the beginning of the study, but did not differ from this initial status among subsequent years at Site A. At Site B, there was a significant shift in textural characteristics from large to smaller fractions over the four years. The relatively high survival of mussels during this study demonstrates the importance of proper handling and transport protocols when relocating mussels and the selection of suitable relocation habitat with stable substratum. When established correctly, in situ refugia may be a viable tool for

  8. Evaluation of relocation of unionid mussels to in situ refugia

    USGS Publications Warehouse

    Cope, W.G.; Hove, M.C.; Waller, D.L.; Hornbach, D.J.; Bartsch, M.R.; Cunningham, L.A.; Dunn, H.L.; Kapuscinski, A.R.

    2003-01-01

    The aim of this study was to evaluate the recovery and survival of four species of unionid mussles [pimpleback, Quadrula pustulosa pustulosa (I. Lea, 1831); spike, Elliptio dilatata (Rafinesque, 1820); Higgins eye, Lampsilis higginsii (I. Lea, 1857); and pocketbook, Lampsilis cardium (Rafinesque, 1820)] that were experimentally relocated to in situ refugia in the St Croix River of Minnesota and Wisconsin, USA. In 1996, 150 mussels of each of the first three species (450 total) were relocated to three 5 ?? 5 m study grids (Site A), one near Lakeland, Minnesota, which served as a source-site control, and two in the experimental refuge 48 km upstream, near Franconia, Minnesota. In a second relocation in 1997, L. cardium was substituted for L. higginsii and 150 mussels of this and each of the other two species (450 total), were relocated to two study grids (Site B). The source site control was near Sunrise, Minnesota and the experimental refuge was 14 km downstream near Almelund, Minnesota. Mussel recovery, survival and substratum characteristics were evaluated annually at Site A for 2 years and for 3 years at Site B. Mean annual recovery of all three species ranged from 90 to 100% at Site A, and from 34 to 70% at site B. The mean annual survival of recaptured mussels ranged from 85 to 100% at Site A, and from 88 to 100% at Site B. The textural characteristics of the substratum differed significantly between the control and the two refuge locations at the beginning of the study, but did not differ from this initial status among subsequent years at Site A. At Site B, there was a significant shift in textural characteristics from large to smaller fractions over the four years. The relatively high survival of mussels during this study demonstrates the importance of proper handling and transport protocols when relocating mussels and the selection of suitable relocation habitat with stable substratum. When established correctly, in situ refugia may be a viable tool for

  9. Glacial integrative modelling.

    PubMed

    Ganopolski, Andrey

    2003-09-15

    Understanding the mechanisms of past climate changes requires modelling of the complex interaction between all major components of the Earth system: atmosphere, ocean, cryosphere, lithosphere and biosphere. This paper reviews attempts at such an integrative approach to modelling climate changes during the glacial age. In particular, the roles of different factors in shaping glacial climate are compared based on the results of simulations with an Earth-system model of intermediate complexity, CLIMBER-2. It is shown that ice sheets, changes in atmospheric compositions, vegetation cover, and reorganization of the ocean thermohaline circulation play important roles in glacial climate changes. Another example of this approach is the modelling of two major types of abrupt glacial climate changes: Dansgaard-Oeschger and Heinrich events. Our results corroborate some of the early proposed mechanisms, which relate abrupt climate changes to the internal instability of the ocean thermohaline circulation and ice sheets. At the same time, it is shown that realistic representation of the temporal evolution of the palaeoclimatic background is crucial to simulate observed features of the glacial abrupt climate changes. PMID:14558899

  10. The ancient tropical rainforest tree Symphonia globulifera L. f. (Clusiaceae) was not restricted to postulated Pleistocene refugia in Atlantic Equatorial Africa.

    PubMed

    Budde, K B; González-Martínez, S C; Hardy, O J; Heuertz, M

    2013-07-01

    Understanding the history of forests and their species' demographic responses to past disturbances is important for predicting impacts of future environmental changes. Tropical rainforests of the Guineo-Congolian region in Central Africa are believed to have survived the Pleistocene glacial periods in a few major refugia, essentially centred on mountainous regions close to the Atlantic Ocean. We tested this hypothesis by investigating the phylogeographic structure of a widespread, ancient rainforest tree species, Symphonia globulifera L. f. (Clusiaceae), using plastid DNA sequences (chloroplast DNA [cpDNA], psbA-trnH intergenic spacer) and nuclear microsatellites (simple sequence repeats, SSRs). SSRs identified four gene pools located in Benin, West Cameroon, South Cameroon and Gabon, and São Tomé. This structure was also apparent at cpDNA. Approximate Bayesian Computation detected recent bottlenecks approximately dated to the last glacial maximum in Benin, West Cameroon and São Tomé, and an older bottleneck in South Cameroon and Gabon, suggesting a genetic effect of Pleistocene cycles of forest contraction. CpDNA haplotype distribution indicated wide-ranging long-term persistence of S. globulifera both inside and outside of postulated forest refugia. Pollen flow was four times greater than that of seed in South Cameroon and Gabon, which probably enabled rapid population recovery after bottlenecks. Furthermore, our study suggested ecotypic differentiation-coastal or swamp vs terra firme-in S. globulifera. Comparison with other tree phylogeographic studies in Central Africa highlighted the relevance of species-specific responses to environmental change in forest trees. PMID:23572126

  11. The ancient tropical rainforest tree Symphonia globulifera L. f. (Clusiaceae) was not restricted to postulated Pleistocene refugia in Atlantic Equatorial Africa

    PubMed Central

    Budde, K B; González-Martínez, S C; Hardy, O J; Heuertz, M

    2013-01-01

    Understanding the history of forests and their species' demographic responses to past disturbances is important for predicting impacts of future environmental changes. Tropical rainforests of the Guineo-Congolian region in Central Africa are believed to have survived the Pleistocene glacial periods in a few major refugia, essentially centred on mountainous regions close to the Atlantic Ocean. We tested this hypothesis by investigating the phylogeographic structure of a widespread, ancient rainforest tree species, Symphonia globulifera L. f. (Clusiaceae), using plastid DNA sequences (chloroplast DNA [cpDNA], psbA-trnH intergenic spacer) and nuclear microsatellites (simple sequence repeats, SSRs). SSRs identified four gene pools located in Benin, West Cameroon, South Cameroon and Gabon, and São Tomé. This structure was also apparent at cpDNA. Approximate Bayesian Computation detected recent bottlenecks approximately dated to the last glacial maximum in Benin, West Cameroon and São Tomé, and an older bottleneck in South Cameroon and Gabon, suggesting a genetic effect of Pleistocene cycles of forest contraction. CpDNA haplotype distribution indicated wide-ranging long-term persistence of S. globulifera both inside and outside of postulated forest refugia. Pollen flow was four times greater than that of seed in South Cameroon and Gabon, which probably enabled rapid population recovery after bottlenecks. Furthermore, our study suggested ecotypic differentiation—coastal or swamp vs terra firme—in S. globulifera. Comparison with other tree phylogeographic studies in Central Africa highlighted the relevance of species-specific responses to environmental change in forest trees. PMID:23572126

  12. Millenial-scale lag times in vegetation response to glacial climate in Siberia

    NASA Astrophysics Data System (ADS)

    Herzschuh, Ulrike; Birks, John H.; Andreev, Andrei; Melles, Martin; Brigham-Grette, Julie

    2016-04-01

    Vegetation change on all relevant temporal scales is assumed to be primarily driven by contemporary climate change, which would imply that vegetation-climate feedbacks become effective without long-term delay. However, our results from multivariate analyses of pollen assemblages from Lake Eĺgygytgyn (NE Siberia) and other data covering the Mid-Pliocene-Warm-Period and the Plio-Pleistocene-Transition challenge this concept of broad-scale vegetation-climate equilibrium. Our results indicate that interglacial vegetation during the Plio-Pleistocene transition mainly reflects the condition of the preceding glacial instead of contemporary interglacial climate. We assume that the observed vegetation-climate disequilibrium, in particular the absence of pine and spruce in interglacials following strong glacial stages, originates from the combined effects of permafrost persistence, distant glacial refugia, and fire plus possible interactions. Our results imply that today's widespread larch ecosystem on permafrost is not in climate-equilibrium but rather represents a transient vegetation type which is still responding to the extreme glacial condition of the last glacial. This also implies that feedback between vegetation and climate and between permafrost and climate in northern mid- and high latitudes becomes active with long-term delay, which is of relevance for global climate change.

  13. A review of pipe and bamboo artificial refugia as sampling tools in anuran studies

    USGS Publications Warehouse

    Glorioso, Brad M.; Waddle, J. Hardin

    2014-01-01

    Artificial pipe-like refugia have been used for more than 40 years in anuran studies, and have captured 28 species, primarily (82%) hylid treefrogs. Early pipe-like refugia were made using cut pieces of bamboo in the tropical forests of Puerto Rico, but most recent studies have used synthetic pipes and have occurred primarily in the southeastern United States. Characteristics of artificial refugia (e.g., color, length, and diameter), and their placement in the environment have varied greatly among studies, making comparisons difficult. Here, we summarize and evaluate different pipe designs and placement, address potential concerns when using artificial pipe-like refugia, and suggest studies necessary to better interpret the data gained from this technique in anuran studies.

  14. PREFACE: Kelvin and Ireland

    NASA Astrophysics Data System (ADS)

    Flood, Raymond; McCartney, Mark; Whitaker, Andrew

    2009-07-01

    Sir Joseph Larmor unveiling the Kelvin memorial in the Botanic Gardens, Belfast on a rainy day in 1913 Sir Joseph Larmor unveiling the Kelvin memorial in the Botanic Gardens, Belfast on a rainy day in 1913 © The Ulster Museum: Hogg collection William Thomson, later Lord Kelvin, was born in Belfast in 1824, and his family had lived near Ballynahinch in the north of Ireland, quite close to Belfast, from the seventeenth century. At the time of Kelvin's birth, James Thomson, his father, was Professor of Mathematics at the Belfast Royal Academical Institution (Inst). However, following the death of his wife in 1830, James took up a new position as Professor at the University of Glasgow, and he and his children moved there in 1832. Apart from three years studying at Cambridge, and a very brief period immediately afterwards travelling and teaching in Cambridge, Kelvin was to spend the rest of his life in Glasgow, where he occupied the Chair of Natural Philosophy (or Physics) for 53 years. The natural assumption might be that his birth in Ireland was irrelevant to Kelvin's life and work, and that the fine monument erected in his honour in Belfast's Botanic Gardens, which is pictured on the front cover of this volume, was more a demonstration of civic pride than a recognition of an aspect of Kelvin's life which was important to him. The purpose of the meeting was to demon strate that this was not the case, that, great Glaswegian as he undoubtedly became, Kelvin always delighted in the title of Irishman. The influence of his father, very much an Ulsterman, was immense, and Kelvin and his siblings were to follow his non-sectarian and reforming approach. Also important for Kelvin was his Christian upbringing, which began in Belfast, and his beliefs were to play a role of importance in his life and indeed in much of his most important work, in particular that on thermodynamics. Two of his siblings returned to Belfast and spent much of their lives there, and Kelvin was a

  15. Ireland's newest import.

    PubMed

    Kissling, F

    1999-01-01

    This editorial reports that leaders of the antiabortion movement have visited Northern and Southern Ireland to share their protest tactics with colleagues. This paper also comments on the irony of the issue of violent actions of antiabortion activists. Joe Scheidler and Patrick Mahoney, both militant American antiabortion leaders, may have spoken of saving lives in the island but they will sow the same divisiveness and a climate of hate they have helped create in the US. These leaders, particularly Scheidler, have ties with the most violent member of the movement, Michael Bray. Bray has served in prison for the bombing of ten abortion clinics in Washington, DC. He believes that any action undertaken in opposition to abortion is justified and condones the murder of doctors and nurses who provide abortions. A most realistic evidence of abortion violence in America is the one committed against Emily Lyons. She was maimed and blinded in one eye by a bomb blast that shattered an Alabama abortion clinic in 1998. These examples should serve as warning to the citizens of Ireland about the presence of the leaders in their country. Political and religious leaders should provide condemnation of their violent ways in the strongest possible terms. PMID:12178908

  16. PREFACE: Kelvin and Ireland

    NASA Astrophysics Data System (ADS)

    Flood, Raymond; McCartney, Mark; Whitaker, Andrew

    2009-07-01

    Sir Joseph Larmor unveiling the Kelvin memorial in the Botanic Gardens, Belfast on a rainy day in 1913 Sir Joseph Larmor unveiling the Kelvin memorial in the Botanic Gardens, Belfast on a rainy day in 1913 © The Ulster Museum: Hogg collection William Thomson, later Lord Kelvin, was born in Belfast in 1824, and his family had lived near Ballynahinch in the north of Ireland, quite close to Belfast, from the seventeenth century. At the time of Kelvin's birth, James Thomson, his father, was Professor of Mathematics at the Belfast Royal Academical Institution (Inst). However, following the death of his wife in 1830, James took up a new position as Professor at the University of Glasgow, and he and his children moved there in 1832. Apart from three years studying at Cambridge, and a very brief period immediately afterwards travelling and teaching in Cambridge, Kelvin was to spend the rest of his life in Glasgow, where he occupied the Chair of Natural Philosophy (or Physics) for 53 years. The natural assumption might be that his birth in Ireland was irrelevant to Kelvin's life and work, and that the fine monument erected in his honour in Belfast's Botanic Gardens, which is pictured on the front cover of this volume, was more a demonstration of civic pride than a recognition of an aspect of Kelvin's life which was important to him. The purpose of the meeting was to demon strate that this was not the case, that, great Glaswegian as he undoubtedly became, Kelvin always delighted in the title of Irishman. The influence of his father, very much an Ulsterman, was immense, and Kelvin and his siblings were to follow his non-sectarian and reforming approach. Also important for Kelvin was his Christian upbringing, which began in Belfast, and his beliefs were to play a role of importance in his life and indeed in much of his most important work, in particular that on thermodynamics. Two of his siblings returned to Belfast and spent much of their lives there, and Kelvin was a

  17. Three divergent lineages within an Australian marsupial (Petrogale penicillata) suggest multiple major refugia for mesic taxa in southeast Australia

    PubMed Central

    Hazlitt, Stephanie L; Goldizen, Anne W; Nicholls, James A; Eldridge, Mark D B

    2014-01-01

    Mesic southeastern Australia represents the continent's ancestral biome and is highly biodiverse, yet its phylogeographic history remains poorly understood. Here, we examine mitochondrial DNA (mtDNA) control region and microsatellite diversity in the brush-tailed rock-wallaby (Petrogale penicillata;n = 279 from 31 sites), to assess historic evolutionary and biogeographic processes in southeastern Australia. Our results (mtDNA, microsatellites) confirmed three geographically discrete and genetically divergent lineages within brush-tailed rock-wallabies, whose divergence appears to date to the mid-Pleistocene. These three lineages had been hypothesized previously but data were limited. While the Northern and Central lineages were separated by a known biogeographic barrier (Hunter Valley), the boundary between the Central and Southern lineages was not. We propose that during particularly cool glacial cycles, the high peaks of the Great Dividing Range and the narrow adjacent coastal plain resulted in a more significant north–south barrier for mesic taxa in southeastern Australia than has been previously appreciated. Similarly, located phylogeographic breaks in codistributed species highlight the importance of these regions in shaping the distribution of biodiversity in southeastern Australia and suggest the existence of three major refuge areas during the Pleistocene. Substructuring within the northern lineage also suggests the occurrence of multiple local refugia during some glacial cycles. Within the three major lineages, most brush-tailed rock-wallaby populations were locally highly structured, indicating limited dispersal by both sexes. The three identified lineages represent evolutionarily significant units and should be managed to maximize the retention of genetic diversity within this threatened species. PMID:24772286

  18. Plant Diversity Changes during the Postglacial in East Asia: Insights from Forest Refugia on Halla Volcano, Jeju Island

    PubMed Central

    Dolezal, Jiri; Altman, Jan; Kopecky, Martin; Cerny, Tomas; Janecek, Stepan; Bartos, Michael; Petrik, Petr; Srutek, Miroslav; Leps, Jan; Song, Jong-Suk

    2012-01-01

    Understanding how past climate changes affected biodiversity is a key issue in contemporary ecology and conservation biology. These diversity changes are, however, difficult to reconstruct from paleoecological sources alone, because macrofossil and pollen records do not provide complete information about species assemblages. Ecologists therefore use information from modern analogues of past communities in order to get a better understanding of past diversity changes. Here we compare plant diversity, species traits and environment between late-glacial Abies, early-Holocene Quercus, and mid-Holocene warm-temperate Carpinus forest refugia on Jeju Island, Korea in order to provide insights into postglacial changes associated with their replacement. Based on detailed study of relict communities, we propose that the late-glacial open-canopy conifer forests in southern part of Korean Peninsula were rich in vascular plants, in particular of heliophilous herbs, whose dramatic decline was caused by the early Holocene invasion of dwarf bamboo into the understory of Quercus forests, followed by mid-Holocene expansion of strongly shading trees such as maple and hornbeam. This diversity loss was partly compensated in the Carpinus forests by an increase in shade-tolerant evergreen trees, shrubs and lianas. However, the pool of these species is much smaller than that of light-demanding herbs, and hence the total species richness is lower, both locally and in the whole area of the Carpinus and Quercus forests. The strongly shading tree species dominating in the hornbeam forests have higher leaf tissue N and P concentrations and smaller leaf dry matter content, which enhances litter decomposition and nutrient cycling and in turn favored the selection of highly competitive species in the shrub layer. This further reduced available light and caused almost complete disappearance of understory herbs, including dwarf bamboo. PMID:22438890

  19. Mitochondrial DNA signature for range-wide populations of Bicyclus anynana suggests a rapid expansion from recent refugia.

    PubMed

    de Jong, Maaike A; Wahlberg, Niklas; van Eijk, Marleen; Brakefield, Paul M; Zwaan, Bas J

    2011-01-01

    This study investigates the genetic diversity, population structure and demographic history of the afrotropical butterfly Bicyclus anynana using mitochondrial DNA (mtDNA). Samples from six wild populations covering most of the species range from Uganda to South Africa were compared for the cytochrome c oxidase subunit gene (COI). Molecular diversity indices show overall high mtDNA diversity for the populations, but low nucleotide divergence between haplotypes. Our results indicate relatively little geographic population structure among the southern populations, especially given the extensive distributional range and an expectation of limited gene flow between populations. We implemented neutrality tests to assess signatures of recent historical demographic events. Tajima's D test and Fu's F(S) test both suggested recent population growth for the populations. The results were only significant for the southernmost populations when applying Tajima's D, but Fu's F(S) indicated significant deviations from neutrality for all populations except the one closest to the equator. Based on our own findings and those from pollen and vegetation studies, we hypothesize that the species range of B. anynana was reduced to equatorial refugia during the last glacial period, and that the species expanded southwards during the past 10.000 years. These results provide crucial background information for studies of phenotypic and molecular adaptation in wild populations of B. anynana. PMID:21731725

  20. Evidence for coal forest refugia in the seasonally dry Pennsylvanian tropical lowlands of the Illinois Basin, USA

    PubMed Central

    Stevenson, Robert A.; Van Hoof, Thomas B.; Mander, Luke

    2014-01-01

    The Moscovian plant macroflora at Cottage Grove southeastern Illinois, USA, is a key example of Pennsylvanian (323–299 Million years ago) dryland vegetation. There is currently no palynological data from the same stratigraphic horizons as the plant macrofossils, leaves and other vegetative and reproductive structures, at this locality. Consequently, reconstructions of the standing vegetation at Cottage Grove from these sediments lack the complementary information and a more regional perspective that can be provided by sporomorphs (prepollen, pollen, megaspores and spores). In order to provide this, we have analysed the composition of fossil sporomorph assemblages in two rock samples taken from macrofossil-bearing inter-coal shale at Cottage Grove. Our palynological data differ considerably in composition and in the dominance-diversity profile from the macrofossil vegetation at this locality. Walchian conifers and pteridosperms are common elements in the macroflora, but are absent in the sporomorph assemblages. Reversely, the sporomorph assemblages at Cottage Grove comprise 17 spore taxa (∼16% and ∼63% of the total assemblages) that are known from the lycopsid orders Isoetales, Lepidodendrales and Selaginallales, while Cottage Grove’s macrofloral record fails to capture evidence of a considerable population of coal forest lycopsids. We interpret our results as evidence that the Pennsylvanian dryland glacial landscape at Cottage Grove included fragmented populations of wetland plants living in refugia. PMID:25392752

  1. Pleistocene refugia and polytopic replacement of diploids by tetraploids in the Patagonian and Subantarctic plant Hypochaeris incana (Asteraceae, Cichorieae).

    PubMed

    Tremetsberger, Karin; Urtubey, Estrella; Terrab, Anass; Baeza, Carlos M; Ortiz, María Angeles; Talavera, María; König, Christiane; Temsch, Eva M; Kohl, Gudrun; Talavera, Salvador; Stuessy, Tod F

    2009-09-01

    We report the phylogeographic pattern of the Patagonian and Subantarctic plant Hypochaeris incana endemic to southeastern South America. We applied amplified fragment length polymorphism (AFLP) and chloroplast DNA (cpDNA) analysis to 28 and 32 populations, respectively, throughout its distributional range and assessed ploidy levels using flow cytometry. While cpDNA data suggest repeated or simultaneous parallel colonization of Patagonia and Tierra del Fuego by several haplotypes and/or hybridization, AFLPs reveal three clusters corresponding to geographic regions. The central and northern Patagonian clusters (approximately 38-51 degrees S), which are closer to the outgroup, contain mainly tetraploid, isolated and highly differentiated populations with low genetic diversity. To the contrary, the southern Patagonian and Fuegian cluster (approximately 51-55 degrees S) contains mainly diploid populations with high genetic diversity and connected by high levels of gene flow. The data suggest that H. incana originated at the diploid level in central or northern Patagonia, from where it migrated south. All three areas, northern, central and southern, have similar levels of rare and private AFLP bands, suggesting that all three served as refugia for H. incana during glacial times. In southern Patagonia and Tierra del Fuego, the species seems to have expanded its populational system in postglacial times, when the climate became warmer and more humid. In central and northern Patagonia, the populations seem to have become restricted to favourable sites with increasing temperature and decreasing moisture and there was a parallel replacement of diploids by tetraploids in local populations. PMID:19674310

  2. Glacial Geology of Wisconsin.

    ERIC Educational Resources Information Center

    Madison Public Schools, WI.

    This publication is a teacher's resource and guidebook for the presentation of the three filmstrips in the "Glacial Geology of Wisconsin" series. The first filmstrip is subtitled, "Evidence of the Glaciers," the second "How the Glaciers Reshaped the Landscape," and the third "Fossils of the Ice Age." Included are a list of objectives, an outline…

  3. First evidence of a Late Upper Palaeolithic human presence in Ireland

    NASA Astrophysics Data System (ADS)

    Dowd, Marion; Carden, Ruth F.

    2016-05-01

    The colonisation of North West Europe by humans and fauna following the Last Glacial Maximum (LGM) has been the subject of considerable discussion in recent decades and within multiple disciplines. Here we present new evidence that pushes back the date of human footfall in Ireland by up to 2500 cal BP to the Upper Palaeolithic. An assemblage of animal bones recovered from a cave in the west of Ireland during antiquarian excavations in 1903 included a butchered brown bear bone (patella) which was recently subjected to two independent radiocarbon dating processes; the resultant dates were in agreement: 12,810-12,590 cal BP and 12,810-12,685 cal BP. This find rewrites the antiquity of human occupation of Ireland and challenges the traditional paradigm that certain biota may have naturally colonised the island prior to human arrival.

  4. Mite dispersal among the Southern Ocean Islands and Antarctica before the last glacial maximum

    PubMed Central

    Mortimer, E.; Jansen van Vuuren, B.; Lee, J. E.; Marshall, D. J.; Convey, P.; Chown, S. L.

    2011-01-01

    It has long been maintained that the majority of terrestrial Antarctic species are relatively recent, post last glacial maximum, arrivals with perhaps a few microbial or protozoan taxa being substantially older. Recent studies have questioned this ‘recolonization hypothesis’, though the range of taxa examined has been limited. Here, we present the first large-scale study for mites, one of two dominant terrestrial arthropod groups in the region. Specifically, we provide a broad-scale molecular phylogeny of a biologically significant group of ameronothroid mites from across the maritime and sub-Antarctic regions. Applying different dating approaches, we show that divergences among the ameronothroid mite genera Podacarus, Alaskozetes and Halozetes significantly predate the Pleistocene and provide evidence of independent dispersals across the Antarctic Polar Front. Our data add to a growing body of evidence demonstrating that many taxa have survived glaciation of the Antarctic continent and the sub-Antarctic islands. Moreover, they also provide evidence of a relatively uncommon trend of dispersals from islands to continental mainlands. Within the ameronothroid mites, two distinct clades with specific habitat preferences (marine intertidal versus terrestrial/supralittoral) exist, supporting a model of within-habitat speciation rather than colonization from marine refugia to terrestrial habitats. The present results provide additional impetus for a search for terrestrial refugia in an area previously thought to have lacked ice-free ground during glacial maxima. PMID:20943685

  5. Fertile fathoms: Deep reproductive refugia for threatened shallow corals.

    PubMed

    Holstein, Daniel M; Smith, Tyler B; Gyory, Joanna; Paris, Claire B

    2015-01-01

    The persistence of natural metapopulations may depend on subpopulations that exist at the edges of species ranges, removed from anthropogenic stress. Mesophotic coral ecosystems (30-150 m) are buffered from disturbance by depth and distance, and are potentially massive reservoirs of coral diversity and fecundity; yet we know little about the reproductive capabilities of their constituent species and the potential for these marginal environments to influence patterns of coral reef persistence. We investigated the reproductive performance of the threatened depth-generalist coral Orbicella faveolata over the extent of its vertical range to assess mesophotic contributions to regional larval pools. Over equal habitat area, mesophotic coral populations were found to produce over an order of magnitude more eggs than nearby shallow populations. Positive changes with depth in both population abundance and polyp fecundity contributed to this discrepancy. Relative larval pool contributions of deeper living corals will likely increase as shallow habitats further degrade due to climate change and local habitat degradation. This is a compelling example of the potential for marginal habitat to be critical to metapopulation persistence as reproductive refugia. PMID:26196243

  6. Fertile fathoms: Deep reproductive refugia for threatened shallow corals

    PubMed Central

    Holstein, Daniel M.; Smith, Tyler B.; Gyory, Joanna; Paris, Claire B.

    2015-01-01

    The persistence of natural metapopulations may depend on subpopulations that exist at the edges of species ranges, removed from anthropogenic stress. Mesophotic coral ecosystems (30–150 m) are buffered from disturbance by depth and distance, and are potentially massive reservoirs of coral diversity and fecundity; yet we know little about the reproductive capabilities of their constituent species and the potential for these marginal environments to influence patterns of coral reef persistence. We investigated the reproductive performance of the threatened depth-generalist coral Orbicella faveolata over the extent of its vertical range to assess mesophotic contributions to regional larval pools. Over equal habitat area, mesophotic coral populations were found to produce over an order of magnitude more eggs than nearby shallow populations. Positive changes with depth in both population abundance and polyp fecundity contributed to this discrepancy. Relative larval pool contributions of deeper living corals will likely increase as shallow habitats further degrade due to climate change and local habitat degradation. This is a compelling example of the potential for marginal habitat to be critical to metapopulation persistence as reproductive refugia. PMID:26196243

  7. Fertile fathoms: Deep reproductive refugia for threatened shallow corals

    NASA Astrophysics Data System (ADS)

    Holstein, Daniel M.; Smith, Tyler B.; Gyory, Joanna; Paris, Claire B.

    2015-07-01

    The persistence of natural metapopulations may depend on subpopulations that exist at the edges of species ranges, removed from anthropogenic stress. Mesophotic coral ecosystems (30-150 m) are buffered from disturbance by depth and distance, and are potentially massive reservoirs of coral diversity and fecundity; yet we know little about the reproductive capabilities of their constituent species and the potential for these marginal environments to influence patterns of coral reef persistence. We investigated the reproductive performance of the threatened depth-generalist coral Orbicella faveolata over the extent of its vertical range to assess mesophotic contributions to regional larval pools. Over equal habitat area, mesophotic coral populations were found to produce over an order of magnitude more eggs than nearby shallow populations. Positive changes with depth in both population abundance and polyp fecundity contributed to this discrepancy. Relative larval pool contributions of deeper living corals will likely increase as shallow habitats further degrade due to climate change and local habitat degradation. This is a compelling example of the potential for marginal habitat to be critical to metapopulation persistence as reproductive refugia.

  8. Temporary refugia for coral reefs in a warming world

    NASA Astrophysics Data System (ADS)

    van Hooidonk, R.; Maynard, J. A.; Planes, S.

    2013-05-01

    Climate-change impacts on coral reefs are expected to include temperature-induced spatially extensive bleaching events. Bleaching causes mortality when temperature stress persists but exposure to bleaching conditions is not expected to be spatially uniform at the regional or global scale. Here we show the first maps of global projections of bleaching conditions based on ensembles of IPCC AR5 (ref. ) models forced with the new Representative Concentration Pathways (RCPs). For the three RCPs with larger CO2 emissions (RCP 4.5, 6.0 and 8.5) the onset of annual bleaching conditions is associated with ~ 510ppm CO2 equivalent; the median year of all locations is 2040 for the fossil-fuel aggressive RCP 8.5. Spatial patterns in the onset of annual bleaching conditions are similar for each of the RCPs. For RCP 8.5, 26% of reef cells are projected to experience annual bleaching conditions more than 5 years later than the median. Some of these temporary refugia include the western Indian Ocean, Thailand, the southern Great Barrier Reef and central French Polynesia. A reduction in the growth of greenhouse-gas emissions corresponding to the difference between RCP 8.5 and 6.0 delays annual bleaching in ~ 23% of reef cells more than two decades, which might conceivably increase the potential for these reefs to cope with these changes.

  9. European Domestic Horses Originated in Two Holocene Refugia

    PubMed Central

    Warmuth, Vera; Eriksson, Anders; Bower, Mim A.; Cañon, Javier; Cothran, Gus; Distl, Ottmar; Glowatzki-Mullis, Marie-Louise; Hunt, Harriet; Luís, Cristina; do Mar Oom, Maria; Yupanqui, Isabel Tupac; Ząbek, Tomasz; Manica, Andrea

    2011-01-01

    The role of European wild horses in horse domestication is poorly understood. While the fossil record for wild horses in Europe prior to horse domestication is scarce, there have been suggestions that wild populations from various European regions might have contributed to the gene pool of domestic horses. To distinguish between regions where domestic populations are mainly descended from local wild stock and those where horses were largely imported, we investigated patterns of genetic diversity in 24 European horse breeds typed at 12 microsatellite loci. The distribution of high levels of genetic diversity in Europe coincides with the distribution of predominantly open landscapes prior to domestication, as suggested by simulation-based vegetation reconstructions, with breeds from Iberia and the Caspian Sea region having significantly higher genetic diversity than breeds from central Europe and the UK, which were largely forested at the time the first domestic horses appear there. Our results suggest that not only the Eastern steppes, but also the Iberian Peninsula provided refugia for wild horses in the Holocene, and that the genetic contribution of these wild populations to local domestic stock may have been considerable. In contrast, the consistently low levels of diversity in central Europe and the UK suggest that domestic horses in these regions largely derive from horses that were imported from the Eastern refugium, the Iberian refugium, or both. PMID:21479181

  10. Mapping of glacial landforms from Seasat radar images

    NASA Technical Reports Server (NTRS)

    Ford, J. P.

    1984-01-01

    Glacial landforms in the drumlin drift belt of Ireland and the Alaska Range can be identified and mapped from Seasat synthetic-aperture radar (SAR) images. Drumlins cover 60 percent of the Ireland scene. The width/length ratio of individual drumlins can be measured on the SAR images, allowing regional differences in drumlin shape to be mapped. This cannot be done with corresponding Landsat multispectral scanner (MSS) images because of lower spatial resolution and because of shadowing effects that vary seasonally. The Alaska scene shows the extent and nature of morphological features such as medial and lateral moraines, stagnant ice, and fluted ground moraine in glaciated valleys. Perception of these features on corresponding Landsat MSS images is limited by seasonal diffrences in solar illumination. Because SAR is not affected by such differences or by cloud cover, it is particularly well suited for monitoring glacial movement. The disadvantage of distorted high-relief features on Seasat SAR images can be reduced in future SAR systems by modifying the radar illumination geometry.

  11. Ireland, Shaded Relief and Colored Height

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The island of Ireland comprises a large central lowland of limestone with a relief of hills surrounded by a discontinuous border of coastal mountains which vary greatly in geological structure. The mountain ridges of the south are composed of old red sandstone separated by limestone river valleys. Granite predominates in the mountains of Galway, Mayo and Donegal in the west and north-west and in Counties Down and Wicklow on the east coast, while a basalt plateau covers much of the north-east of the country. The central plain, which is broken in places by low hills, is extensively covered with glacial deposits of clay and sand. It has considerable areas of bog and numerous lakes. The island has seen at least two general glaciations and everywhere ice-smoothed rock, mountain lakes, glacial valleys and deposits of glacial sand, gravel and clay mark the passage of the ice.

    Two visualization methods were combined to produce this image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations.

    Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Geospatial

  12. Glacial atmospheric phosphorus deposition

    NASA Astrophysics Data System (ADS)

    Kjær, Helle Astrid; Dallmayr, Remi; Gabrieli, Jacopo; Goto-Azuma, Kumiko; Hirabayashi, Motohiro; Svensson, Anders; Vallelonga, Paul

    2016-04-01

    Phosphorus in the atmosphere is poorly studied and thus not much is known about atmospheric phosphorus and phosphate transport and deposition changes over time, though it is well known that phosphorus can be a source of long-range nutrient transport, e.g. Saharan dust transported to the tropical forests of Brazil. In glacial times it has been speculated that transport of phosphorus from exposed shelves would increase the ocean productivity by wash out. However whether the exposed shelf would also increase the atmospheric load to more remote places has not been investigated. Polar ice cores offer a unique opportunity to study the atmospheric transport of aerosols on various timescales, from glacial-interglacial periods to recent anthropogenic influences. We have for the first time determined the atmospheric transport of phosphorus to the Arctic by means of ice core analysis. Both total and dissolved reactive phosphorus were measured to investigate current and past atmospheric transport of phosphorus to the Arctic. Results show that glacial cold stadials had increased atmospheric total phosphorus mass loads of 70 times higher than in the past century, while DRP was only increased by a factor of 14. In the recent period we find evidence of a phosphorus increase over the past 50 yrs in ice cores close to human occupation likely correlated to forest fires. References: Kjær, Helle Astrid, et al. "Continuous flow analysis method for determination of dissolved reactive phosphorus in ice cores." Environmental science & technology 47.21 (2013): 12325-12332. Kjær, Helle Astrid, et al. "Greenland ice cores constrain glacial atmospheric fluxes of phosphorus." Journal of Geophysical Research: Atmospheres120.20 (2015).

  13. Glacial legacies on interglacial vegetation at the Pliocene-Pleistocene transition in NE Asia.

    PubMed

    Herzschuh, Ulrike; Birks, H John B; Laepple, Thomas; Andreev, Andrei; Melles, Martin; Brigham-Grette, Julie

    2016-01-01

    Broad-scale climate control of vegetation is widely assumed. Vegetation-climate lags are generally thought to have lasted no more than a few centuries. Here our palaeoecological study challenges this concept over glacial-interglacial timescales. Through multivariate analyses of pollen assemblages from Lake El'gygytgyn, Russian Far East and other data we show that interglacial vegetation during the Plio-Pleistocene transition mainly reflects conditions of the preceding glacial instead of contemporary interglacial climate. Vegetation-climate disequilibrium may persist for several millennia, related to the combined effects of permafrost persistence, distant glacial refugia and fire. In contrast, no effects from the preceding interglacial on glacial vegetation are detected. We propose that disequilibrium was stronger during the Plio-Pleistocene transition than during the Mid-Pliocene Warm Period when, in addition to climate, herbivory was important. By analogy to the past, we suggest today's widespread larch ecosystem on permafrost is not in climate equilibrium. Vegetation-based reconstructions of interglacial climates used to assess atmospheric CO2-temperature relationships may thus yield misleading simulations of past global climate sensitivity. PMID:27338025

  14. Glacial legacies on interglacial vegetation at the Pliocene-Pleistocene transition in NE Asia

    NASA Astrophysics Data System (ADS)

    Herzschuh, Ulrike; Birks, H. John B.; Laepple, Thomas; Andreev, Andrei; Melles, Martin; Brigham-Grette, Julie

    2016-06-01

    Broad-scale climate control of vegetation is widely assumed. Vegetation-climate lags are generally thought to have lasted no more than a few centuries. Here our palaeoecological study challenges this concept over glacial-interglacial timescales. Through multivariate analyses of pollen assemblages from Lake El'gygytgyn, Russian Far East and other data we show that interglacial vegetation during the Plio-Pleistocene transition mainly reflects conditions of the preceding glacial instead of contemporary interglacial climate. Vegetation-climate disequilibrium may persist for several millennia, related to the combined effects of permafrost persistence, distant glacial refugia and fire. In contrast, no effects from the preceding interglacial on glacial vegetation are detected. We propose that disequilibrium was stronger during the Plio-Pleistocene transition than during the Mid-Pliocene Warm Period when, in addition to climate, herbivory was important. By analogy to the past, we suggest today's widespread larch ecosystem on permafrost is not in climate equilibrium. Vegetation-based reconstructions of interglacial climates used to assess atmospheric CO2-temperature relationships may thus yield misleading simulations of past global climate sensitivity.

  15. Comparison and Evaluation of Aspects of Teacher Education in Northern Ireland and the Republic of Ireland

    ERIC Educational Resources Information Center

    McWilliams, Sandra; Cannon, Paraig; Farrar, Margaret; Tubbert, Brian; Connolly, Claire; McSorley, Fiona

    2006-01-01

    This paper critically considers teacher education in Northern Ireland and the Republic of Ireland. It was stimulated by an exchange programme between student teachers from Northern Ireland and the Republic of Ireland for a period of school-based work in each other's jurisdictions. It examines recent curricular developments, partnership with…

  16. Ocean Acidification Refugia of the Florida Reef Tract

    NASA Astrophysics Data System (ADS)

    Manzello, D.; Enochs, I.; Melo, N.; Gledhill, D. K.; Johns, E. M.

    2012-12-01

    Ocean acidification (OA) is expected to reduce the calcification rates of marine organisms, yet we have little understanding of how OA will manifest within dynamic, real-world systems. Natural CO2, alkalinity, and salinity gradients can significantly alter local carbonate chemistry, and thereby create a range of susceptibility for different ecosystems to OA. As such, there is a need to characterize this natural variability of seawater carbonate chemistry, especially within coastal ecosystems. Since 2009, carbonate chemistry data have been collected on the Florida Reef Tract (FRT). During periods of heightened productivity, there is a net uptake of total CO2 (TCO2) which increases aragonite saturation state (Ωarag) values on inshore patch reefs of the upper FRT. These waters can exhibit greater Ωarag than what has been modeled for the tropical surface ocean during preindustrial times, with mean (± std. error) Ωarag-values in spring = 4.69 (± 0.101). Conversely, Ωarag-values on offshore reefs generally represent oceanic carbonate chemistries consistent with present day tropical surface ocean conditions. This gradient is opposite from what has been reported for other reef environments. We hypothesize this pattern is caused by the photosynthetic uptake of TCO2 mainly by seagrasses and, to a lesser extent, macroalgae in the inshore waters of the FRT. These inshore reef habitats are therefore potential acidification refugia that are defined not only in a spatial sense, but also in time; coinciding with seasonal productivity dynamics. Coral reefs located within or immediately downstream of seagrass beds may find refuge from OA.

  17. Climate refugia: The physical, hydrologic and disturbance basis

    NASA Astrophysics Data System (ADS)

    Holden, Z. A.; Maneta, M. P.; Forthofer, J.

    2015-12-01

    Projected changes in global climate and associated shifts in vegetation have increased interest in understanding species persistence at local scales. We examine the climatic and physical factors that could mediate changes in the distribution of vegetation in regions of complex topography. Using massive networks of low-cost temperature and humidity sensors, we developed topographically-resolved daily historical gridded temperature data for the US Northern Rockies. We used the WindNinja model to create daily historical wind speed maps across the same domain. Using a spatially distributed ecohydrology model (ECH2O) we examine separately the sensitivity of modeled evapotranspiration and soil moisture to wind, radiation, soil properties, minimum temperature and humidity. A suite of physical factors including lower wind speeds, cold air drainage, solar shading and increased soil depth reduce evapotranspiration and increase late season moisture availability in valley bottoms. Evapotranspiration shows strong sensitivity to spatial variability in surface wind speed, suggesting that sheltering effects from winds may be an important factor contributing to mountain refugia. Fundamental to our understanding of patterns of vegetation change is the role of stand-replacing wildfires, which modify the physical environment and subsequent patterns of species persistence and recruitment. Using satellite-derived maps of burn severity for recent fires in the US Northern Rockies we examined relationships between wind speed, cold air drainage potential and soil depth and the occurrence of unburned and low severity fire. Severe fire is less likely to occur in areas with high cold air drainage potential and low wind speeds, suggesting that sheltered valley bottoms have mediated the severity of recent wildfires. Our finding highlight the complex physical mechanisms by which mountain weather and climate mediate fire-induced vegetation changes in the US Northern Rocky Mountains.

  18. Late-glacial recolonization and phylogeography of European red deer (Cervus elaphus L.).

    PubMed

    Meiri, Meirav; Lister, Adrian M; Higham, Thomas F G; Stewart, John R; Straus, Lawrence G; Obermaier, Henriette; González Morales, Manuel R; Marín-Arroyo, Ana B; Barnes, Ian

    2013-09-01

    The Pleistocene was an epoch of extreme climatic and environmental changes. How individual species responded to the repeated cycles of warm and cold stages is a major topic of debate. For the European fauna and flora, an expansion-contraction model has been suggested, whereby temperate species were restricted to southern refugia during glacial times and expanded northwards during interglacials, including the present interglacial (Holocene). Here, we test this model on the red deer (Cervus elaphus) a large and highly mobile herbivore, using both modern and ancient mitochondrial DNA from the entire European range of the species over the last c. 40,000 years. Our results indicate that this species was sensitive to the effects of climate change. Prior to the Last Glacial Maximum (LGM) haplogroups restricted today to South-East Europe and Western Asia reached as far west as the UK. During the LGM, red deer was mainly restricted to southern refugia, in Iberia, the Balkans and possibly in Italy and South-Western Asia. At the end of the LGM, red deer expanded from the Iberian refugium, to Central and Northern Europe, including the UK, Belgium, Scandinavia, Germany, Poland and Belarus. Ancient DNA data cannot rule out refugial survival of red deer in North-West Europe through the LGM. Had such deer survived, though, they were replaced by deer migrating from Iberia at the end of the glacial. The Balkans served as a separate LGM refugium and were probably connected to Western Asia with genetic exchange between the two areas. PMID:23927498

  19. Ploidy race distributions since the Last Glacial Maximum in the North American desert shrub, Larrea tridentata

    USGS Publications Warehouse

    Hunter, K.L.; Betancourt, J.L.; Riddle, B.R.; Van Devender, T. R.; Cole, K.L.; Geoffrey, Spaulding W.

    2000-01-01

    1 A classic biogeographic pattern is the alignment of diploid, tetraploid and hexaploid races of creosote bush (Larrea tridentata) across the Chihuahuan, Sonoran and Mohave Deserts of western North America. We used statistically robust differences in guard cell size of modern plants and fossil leaves from packrat middens to map current and past distributions of these ploidy races since the Last Glacial Maximum (LGM). 2 Glacial/early Holocene (26-10 14C kyr BP or thousands of radiocarbon years before present) populations included diploids along the lower Rio Grande of west Texas, 650 km removed from sympatric diploids and tetraploids in the lower Colorado River Basin of south-eastern California/south-western Arizona. Diploids migrated slowly from lower Rio Grande refugia with expansion into the northern Chihuahuan Desert sites forestalled until after ???4.0 14C kyr BP. Tetraploids expanded from the lower Colorado River Basin into the northern limits of the Sonoran Desert in central Arizona by 6.4 14C kyr BP. Hexaploids appeared by 8.5 14C kyr BP in the lower Colorado River Basin, reaching their northernmost limits (???37??N) in the Mohave Desert between 5.6 and 3.9 14C kyr BP. 3 Modern diploid isolates may have resulted from both vicariant and dispersal events. In central Baja California and the lower Colorado River Basin, modern diploids probably originated from relict populations near glacial refugia. Founder events in the middle and late Holocene established diploid outposts on isolated limestone outcrops in areas of central and southern Arizona dominated by tetraploid populations. 4 Geographic alignment of the three ploidy races along the modern gradient of increasingly drier and hotter summers is clearly a postglacial phenomenon, but evolution of both higher ploidy races must have happened before the Holocene. The exact timing and mechanism of polyploidy evolution in creosote bush remains a matter of conjecture. ?? 2001 Blackwell Science Ltd.

  20. Ploidy race distributions since the Last Glacial Maximum in the North American desert shrub, Larea tridentata

    USGS Publications Warehouse

    Hunter, Kimberly L.; Betancourt, Julio L.; Riddle, Brett R.; Van Devender, Thomas R.; Cole, K.L.; Spaulding, W.G.

    2001-01-01

    1. A classic biogeographic pattern is the alignment of diploid, tetraploid and hexaploid races of creosote bush (Larrea tridentata) across the Chihuahuan, Sonoran and Mohave Deserts of western North America. We used statistically robust differences in guard cell size of modern plants and fossil leaves from packrat middens to map current and past distributions of these ploidy races since the Last Glacial Maximum (LGM). 2 Glacial/early Holocene (26a??10 14C kyr bp or thousands of radiocarbon years before present) populations included diploids along the lower Rio Grande of west Texas, 650 km removed from sympatric diploids and tetraploids in the lower Colorado River Basin of south-eastern California/south-western Arizona. Diploids migrated slowly from lower Rio Grande refugia with expansion into the northern Chihuahuan Desert sites forestalled until after ~4.0 14C kyr bp. Tetraploids expanded from the lower Colorado River Basin into the northern limits of the Sonoran Desert in central Arizona by 6.4 14C kyr bp. Hexaploids appeared by 8.5 14C kyr bp in the lower Colorado River Basin, reaching their northernmost limits (~37A?N) in the Mohave Desert between 5.6 and 3.9 14C kyr bp. 3 Modern diploid isolates may have resulted from both vicariant and dispersal events. In central Baja California and the lower Colorado River Basin, modern diploids probably originated from relict populations near glacial refugia. Founder events in the middle and late Holocene established diploid outposts on isolated limestone outcrops in areas of central and southern Arizona dominated by tetraploid populations. 4 Geographic alignment of the three ploidy races along the modern gradient of increasingly drier and hotter summers is clearly a postglacial phenomenon, but evolution of both higher ploidy races must have happened before the Holocene. The exact timing and mechanism of polyploidy evolution in creosote bush remains a matter of conjecture.

  1. Temperature inverted haloclines provide winter warm-water refugia for manatees in southwest Florida

    USGS Publications Warehouse

    Stith, Bradley M.; Reid, James P.; Langtimm, Catherine A.; Swain, Eric D.; Doyle, Terry J.; Slone, Daniel H.; Decker, Jeremy D.; Soderqvist, Lars E.

    2010-01-01

    Florida manatees (Trichechus manatus latirostris) overwintering in the Ten Thousand Islands and western Everglades have no access to power plants or major artesian springs that provide warm-water refugia in other parts of Florida. Instead, hundreds of manatees aggregate at artificial canals, basins, and natural deep water sites that act as passive thermal refugia (PTR). Monitoring at two canal sites revealed temperature inverted haloclines, which provided warm salty bottom layers that generally remained above temperatures considered adverse for manatees. At the largest PTR, the warmer bottom layer disappeared unless significant salt stratification was maintained by upstream freshwater inflow over a persistent tidal wedge. A detailed three-dimensional hydrology model showed that salinity stratification inhibited vertical convection induced by atmospheric cooling. Management or creation of temperature inverted haloclines may be a feasible and desirable option for resource managers to provide passive thermal refugia for manatees and other temperature sensitive aquatic species.

  2. Mallow Springs, County Cork, Ireland

    NASA Astrophysics Data System (ADS)

    Aldwell, C. R.

    1996-03-01

    Because of its copious and reliable rainfall, Ireland has an abundance of springs. Many of the larger ones issue from the Carboniferous limestone that occurs in over 40% of the country. The spring water is mainly a calcium bicarbonate type with a temperature of about 10°C. In the 18th century, warm and cold springs were developed as spas in various parts of Ireland. The popularity of these springs was short and most were in major decline by 1850. Today only one cold spa at Lisdoonvarna, Co. Clare is still operating. Springs in Ireland were places of religious significance for the pre-Christian Druidic religion. In the Christian period they became holy wells, under the patronage of various saints. Cures for many different ailments were attributed to water from these wells.

  3. Cytomegalovirus Infection in Ireland

    PubMed Central

    Hassan, Jaythoon; O’Neill, Derek; Honari, Bahman; De Gascun, Cillian; Connell, Jeff; Keogan, Mary; Hickey, David

    2016-01-01

    Abstract Cytomegalovirus (CMV) infections occur worldwide and primary infection usually occurs in early childhood and is often asymptomatic whereas primary infection in adults may result in symptomatic illness. CMV establishes a chronic latent infection with intermittent periods of reactivation. Primary infection or reactivation associate with increased mortality and morbidity in those who are immunocompromised. Transplacental transmission may result in significant birth defects or long-term sensorineural hearing loss. We performed a study to determine the CMV seroprevalence and the association between HLA Class I alleles and frequency of CMV infection in Ireland. The presence of CMV IgG, a marker of previous CMV infection, was determined for a cohort of 1849 HLA typed solid organ transplant donors between 1990 and 2013. The presence of CMV IgG was correlated with HLA type. The CMV seroprevalence in solid organ transplant donors was 33.4% (range 22–48% per annum) over the time period 1990 to 2013. Multivariate logistic regression analysis showed that both age and HLA alleles were associated with CMV seropositivity. A significant and positive relationship between age and CMV seropositivity was observed (OR = 1.013, P < 0.001, CI [1.007, 1.019]). Chi-square analysis revealed that the female gender was independently associated with CMV seropositivity (P < 0.01). Seroprevalence in women of reproductive age (20–39 years) was significantly higher than men of the same age (37% vs 26%, P < 0.01). The frequencies of HLA-A1, HLA-A2, and HLA-A3 in our cohort were 40.8%, 48.8%, and 25.9%, respectively. Logistic regression analysis showed that the presence of HLA-A1 but not HLA-A2 or HLA-A3 was independently associated with CMV seronegativity (P < 0.01). Interestingly, individuals who co-expressed HLA-A2 and HLA-A3 alleles were significantly more likely to be CMV seropositive (P < 0.02). The frequencies of HLA-B5, HLA-B7, and HLA-B8 in our cohort

  4. Glacial North Atlantic: Sea-surface conditions reconstructed by GLAMAP 2000

    NASA Astrophysics Data System (ADS)

    Pflaumann, U.; Sarnthein, M.; Chapman, M.; D'Abreu, L.; Funnell, B.; Huels, M.; Kiefer, T.; Maslin, M.; Schulz, H.; Swallow, J.; van Kreveld, S.; Vautravers, M.; Vogelsang, E.; Weinelt, M.

    2003-09-01

    The response of the tropical ocean to global climate change and the extent of sea ice in the glacial nordic seas belong to the great controversies in paleoclimatology. Our new reconstruction of peak glacial sea surface temperatures (SSTs) in the Atlantic is based on census counts of planktic foraminifera, using the Maximum Similarity Technique Version 28 (SIMMAX-28) modern analog technique with 947 modern analog samples and 119 well-dated sediment cores. Our study compares two slightly different scenarios of the Last Glacial Maximum (LGM), the Environmental Processes of the Ice Age: Land, Oceans, Glaciers (EPILOG), and Glacial Atlantic Ocean Mapping (GLAMAP 2000) time slices. The comparison shows that the maximum LGM cooling in the Southern Hemisphere slightly preceeded that in the north. In both time slices sea ice was restricted to the north western margin of the nordic seas during glacial northern summer, while the central and eastern parts were ice-free. During northern glacial winter, sea ice advanced to the south of Iceland and Faeroe. In the central northern North Atlantic an anticyclonic gyre formed between 45° and 60°N, with a cool water mass centered west of Ireland, where glacial cooling reached a maximum of >12°C. In the subtropical ocean gyres the new reconstruction supports the glacial-to-interglacial stability of SST as shown by () [1981]. The zonal belt of minimum SST seasonality between 2° and 6°N suggests that the LGM caloric equator occupied the same latitude as today. In contrast to the CLIMAP reconstruction, the glacial cooling of the tropical east Atlantic upwelling belt reached up to 6°-8°C during Northern Hemisphere summer. Differences between these SIMMAX-based and published U37k- and Mg/Ca-based equatorial SST records are ascribed to strong SST seasonalities and SST signals that were produced by different planktic species groups during different seasons.

  5. Humid glacials, arid interglacials? Results from a multiproxy study of the loess-paleosol sequence Crvenka, Serbia

    NASA Astrophysics Data System (ADS)

    Zech, R.; Zech, M.; Markovic, S.; Huang, Y.

    2012-04-01

    The loess-paleosol sequences in the Carpathian Basin, southeast Europe, are up to tens of meters thick and provide valuable archives for paleoenvironmental and -climate change over several glacial-interglacial cycles. The Crvenka section spans the full last glacial cycle and is used in this multi-proxy study to reconstruct past climate conditions. Crvenka features the characteristic pattern in terms of grain size and weathering intensity, i.e. finer grain sizes and more intensive weathering in the paleosols compared to the glacial loess units. The analysis of plant-derived long-chain n-alkanes as molecular biomarkers for past vegetation indicates the presence of trees during glacials, which is consistent with other e.g. macrofossil findings and the notion that parts of southeast Europe served as tree-refugia. However, virtually tree-less grass steppes are reconstructed for the Eemian, the last interglacial. More humid conditions during glacials and more arid conditions during interglacials would be in good agreement with lake-level reconstructions from the Dead Sea, but they seem to be at odds with traditional interpretations of pollen and stable isotope records for the Mediterranean region. In order to further contribute to this issue, we performed compound-specific D/H analyses on the most abundant alkanes C29 and C31, which should mainly record past changes in the isotopic composition of precipitation. The absence of a clear signal towards more depleted values during glacials shows that the temperature-effect is not dominant and probably offset by a strong source-effect, namely the enrichment of the Mediterranean sea water during glacials. This very same source effect may generally need to be taken into account when interpreting terrestrial isotope records in the Mediterranean, which implies that more positive values during glacials may not necessarily indicate an amount-effect and more arid conditions.

  6. The Post-Glacial Species Velocity of Picea glauca following the Last Glacial Maximum in Alaska.

    NASA Astrophysics Data System (ADS)

    Morrison, B. D.; Napier, J.; Kelly, R.; Li, B.; Heath, K.; Hug, B.; Hu, F.; Greenberg, J. A.

    2015-12-01

    Anthropogenic climate change is leading to dramatic fluctuations to Earth's biodiversity that has not been observed since past interglacial periods. There is rising concern that Earth's warming climate will have significant impacts to current species ranges and the ability of a species to persist in a rapidly changing environment. The paleorecord provides information on past species distributions in relation to climate change, which can illuminate the patterns of potential future distributions of species. Particularly in areas where there are multiple potential limiting factors on a species' range, e.g. temperature, radiation, and evaporative demand, the spatial patterns of species migrations may be particularly complex. In this study, we assessed the change in the distributions of white spruce (Picea glauca) from the Last Glacial Maxima (LGM) to present-day for the entire state of Alaska. To accomplish this, we created species distribution models (SDMs) calibrated from modern vegetation data and high-resolution, downscaled climate surfaces at 60m. These SDMs were applied to downscaled modern and paleoclimate surfaces to produce estimated ranges of white spruce during the LGM and today. From this, we assessed the "species velocity", the rate at which white spruce would need to migrate to keep pace with climate change, with the goal of determining whether the expansion from the LGM to today originated from microclimate refugia. Higher species velocities indicate locations where climate changed drastically and white spruce would have needed to migrate rapidly to persist and avoid local extinction. Conversely, lower species velocities indicated locations where the local climate was changing less rapidly or was within the center of the range of white spruce, and indicated locations where white spruce distributions were unlikely to have changed significantly. Our results indicate the importance of topographic complexity in buffering the effects of climate change

  7. Inferring Multiple Refugia and Phylogeographical Patterns in Pinus massoniana Based on Nucleotide Sequence Variation and DNA Fingerprinting

    PubMed Central

    Lin, Chung-Jian; Huang, Chi-Chung; Huang, Chao-Ching; Chiang, Yu-Chung; Chiang, Tzen-Yuh

    2012-01-01

    Background Pinus massoniana, an ecologically and economically important conifer, is widespread across central and southern mainland China and Taiwan. In this study, we tested the central–marginal paradigm that predicts that the marginal populations tend to be less polymorphic than the central ones in their genetic composition, and examined a founders' effect in the island population. Methodology/Principal Findings We examined the phylogeography and population structuring of the P. massoniana based on nucleotide sequences of cpDNA atpB-rbcL intergenic spacer, intron regions of the AdhC2 locus, and microsatellite fingerprints. SAMOVA analysis of nucleotide sequences indicated that most genetic variants resided among geographical regions. High levels of genetic diversity in the marginal populations in the south region, a pattern seemingly contradicting the central–marginal paradigm, and the fixation of private haplotypes in most populations indicate that multiple refugia may have existed over the glacial maxima. STRUCTURE analyses on microsatellites revealed that genetic structure of mainland populations was mediated with recent genetic exchanges mostly via pollen flow, and that the genetic composition in east region was intermixed between south and west regions, a pattern likely shaped by gene introgression and maintenance of ancestral polymorphisms. As expected, the small island population in Taiwan was genetically differentiated from mainland populations. Conclusions/Significance The marginal populations in south region possessed divergent gene pools, suggesting that the past glaciations might have low impacts on these populations at low latitudes. Estimates of ancestral population sizes interestingly reflect a recent expansion in mainland from a rather smaller population, a pattern that seemingly agrees with the pollen record. PMID:22952747

  8. Groundwater vulnerability assessment of the Cork Harbour area, SW Ireland

    NASA Astrophysics Data System (ADS)

    Allen, A. R.; Milenic, D.

    2007-11-01

    In the Cork Harbour area of SW Ireland, high yield karst and intergranular gravel aquifers are extremely vulnerable to pollution from a variety of sources, mainly due to the limited protection afforded by the thin cover of low permeability glacial and alluvial overburden. The main potential sources of pollution are due to rapid urbanisation of the Cork city area and its attendant infrastructure, and increased industrialisation in the area, with numerous new industries, particularly pharmaceutical and chemical industries, located around Cork Harbour. Other potential sources of pollution are a number of landfills in the area and an oil refinery near the mouth of Cork Harbour. Traditional agricultural sources of pollution also exist, due to increased use of chemical fertilisers. Finally, the susceptibility to saline intrusion of the karst and gravel aquifers around Cork Harbour is high due to the long coastline of the harbour and the low-lying nature of the karst synclines with their superimposed buried valleys.

  9. Low Energy Schools in Ireland

    ERIC Educational Resources Information Center

    Heffernan, Martin

    2004-01-01

    Out of a commitment to reducing carbon dioxide emissions, Ireland's Department of Education and Science has designed and constructed two low energy schools, in Tullamore, County Offaly, and Raheen, County Laois. With energy use in buildings responsible for approximately 55% of the CO[subscript 2] released into the atmosphere and a major…

  10. Multiple evolutionary units and demographic stability during the last glacial maximum in the Scytalopus speluncae complex (Aves: Rhinocryptidae).

    PubMed

    Pulido-Santacruz, Paola; Bornschein, Marcos Ricardo; Belmonte-Lopes, Ricardo; Bonatto, Sandro L

    2016-09-01

    The Atlantic Forest (AF) of South America harbors one of the world's highest bird species richness, but to date there is a deficient understanding of the spatial patterns of genetic diversity and the evolutionary history of this biome. Here we estimated the phylogenetic and populational history of the widespread Mouse-colored Tapaculo (Scytalopus speluncae) complex across the Brazilian AF, using data from two mitochondrial genes and 12 microsatellite loci. Both markers uncovered several cryptic, mostly allopatric and well-supported lineages that may represent distinct species-level taxa. We investigated whether diversification in S. speluncae is compatible with the Carnaval-Moritz model of Pleistocene refugia. We found that northern lineages have high levels of genetic diversity, agreeing with predictions of more stable forest refugia in these areas. In contrast, southern lineages have lower levels of mtDNA diversity with a signature of population expansion that occurred earlier (∼0.2Mya) than the last glacial maximum. This result suggests that the AF may be stable enough to maintain endemic taxa through glacial cycles. Moreover, we propose that the "mid-Pleistocene climate transition" between 1.2 and 0.7million years ago, from a warmer to a colder climate, may have played an important but mostly overlooked role in the evolution of AF montane taxa. PMID:27233438

  11. Assessing climate refugia from a terrestrial vegetation vulnerability assessment for 29 types in California.

    NASA Astrophysics Data System (ADS)

    Thorne, J. H.; Bjorkman, J.; Boynton, R.; Stewart, J.; Holguin, A.; Schwartz, M.; Albright, W.

    2015-12-01

    We assessed the climate vulnerability of 29 terrestrial macrogroup vegetation types in the National Vegetation Classification Scheme covering 99% of California. Using a 2015 landcover map, we defined current and future climate exposure of each type by assessing conditions at all known locations. This approach identifies both areas of expected high stress and of climate refugia. Species distribution models of the vegetation types proved to over-predict the extent of occupied lands, compared to their mapped extents. Trait based components of the vulnerability assessment were far less influential on level of vulnerability than climate projection. Various cutoffs can be selected to describe refugia. Here we classed refugia as the 20% of climate conditions most frequently occupied by a type. Under CNRM CM5 RCP 4.5, of 70,143 km2 that are the most climate-insulated locations, 46,420 km2 move to higher levels of climate exposure. At the other extreme of climate projections tested, MIROC ESM RCP 8.5, 59,137 km2 are lost. Four macrogroups lose their refugia under CNRM 4.5: Pacific Northwest Conifer Forests, Mountain Riparian Scrub and Wet Meadow, Salt Marsh, and Great Basin Upland Scrub. Under MIROC 8.5 and additional 8 macrogroups lose the most commonly experienced climate: Subalpine Aspen Forests & Pine Woodlands, Non-Native Forest and Woodlands, North Coast Deciduous Scrub and Terrace Prairie, Coastal Dune and Bluff Scrub, Freshwater Marsh, Wet Mountain Meadow, Big Sagebrush Scrub, and Alpine Vegetation. These results raise interesting questions regarding the definition of refugia. We review the results and ask how appropriate they are for different ecosystem types.

  12. Molecular evidence for Pleistocene glacial cycles driving diversification of a North American desert spider, Agelenopsis aperta.

    PubMed

    Ayoub, Nadia A; Riechert, Susan E

    2004-11-01

    The influence of historical climatic vs. geological changes on species diversification patterns was investigated in a widely distributed North American desert spider, Agelenopsis aperta (Araneae: Agelenidae), with particular reference to Pleistocene glacial cycles and earlier patterns of mountain building. Levels of sequence divergence obtained from the mitochondrial gene, cytochrome oxidase I, dated to the Pleistocene, eliminating Rocky Mountain orogeny as a cause of diversification, as orogeny ended 4 million years ago. The results of phylogenetic and network analyses showed the presence of three geographically defined clades, which were consistent with the presence of at least three glacial refugia: (i) east of the Rocky Mountains; (ii) between the Rocky Mountains and Sierra Nevadas; and (iii) west of the Sierra Nevadas. In addition, populations within the Rocky Mountains exhibited significantly lower genetic diversity than populations east of the Rocky Mountains and the haplotypes found within the Rockies were a subset of eastern haplotypes. These patterns suggest that a post-Pleistocene range expansion occurred out of an eastern glacial refugium into the Rocky Mountains. Examination of phylogeographical studies of other North American desert taxa indicated that mountain building explained diversification patterns more effectively for some taxa but Pleistocene climate change was more important for others, including A. aperta. PMID:15488003

  13. Glacial legacies on interglacial vegetation at the Pliocene-Pleistocene transition in NE Asia

    PubMed Central

    Herzschuh, Ulrike; Birks, H. John B.; Laepple, Thomas; Andreev, Andrei; Melles, Martin; Brigham-Grette, Julie

    2016-01-01

    Broad-scale climate control of vegetation is widely assumed. Vegetation-climate lags are generally thought to have lasted no more than a few centuries. Here our palaeoecological study challenges this concept over glacial–interglacial timescales. Through multivariate analyses of pollen assemblages from Lake El'gygytgyn, Russian Far East and other data we show that interglacial vegetation during the Plio-Pleistocene transition mainly reflects conditions of the preceding glacial instead of contemporary interglacial climate. Vegetation–climate disequilibrium may persist for several millennia, related to the combined effects of permafrost persistence, distant glacial refugia and fire. In contrast, no effects from the preceding interglacial on glacial vegetation are detected. We propose that disequilibrium was stronger during the Plio-Pleistocene transition than during the Mid-Pliocene Warm Period when, in addition to climate, herbivory was important. By analogy to the past, we suggest today's widespread larch ecosystem on permafrost is not in climate equilibrium. Vegetation-based reconstructions of interglacial climates used to assess atmospheric CO2–temperature relationships may thus yield misleading simulations of past global climate sensitivity. PMID:27338025

  14. Kennebunk glacial advance: A reappraisal

    NASA Astrophysics Data System (ADS)

    Smith, Geoffrey W.

    1981-06-01

    Evidence for the Kennebunk glacial advance (readvance) in southwestern Maine is discussed in light of recent geologic mapping. Orientations of glacially produced lineations record the response of ice to major topographic controls and do not indicate glacial readvance. Minor end moraines and large stratified end moraines associated with deformed marine sediments of the Presumpscot Formation occur throughout the southwestern coastal zone. These features outline the general pattern of ice retreat from this part of the coastal zone and suggest that withdrawal of the last ice from southwestern Maine occurred with minor stillstands and local frontal fluctuations but without significant readvance. The Kennebunk glacial advance (readvance) appears to have been one of many local fluctuations of the ice front during general recession, occurring at about 13,200 yr B.P.

  15. Migration Patterns of Subgenus Alnus in Europe since the Last Glacial Maximum: A Systematic Review

    PubMed Central

    Douda, Jan; Doudová, Jana; Drašnarová, Alena; Kuneš, Petr; Hadincová, Věroslava; Krak, Karol; Zákravský, Petr; Mandák, Bohumil

    2014-01-01

    Background/Aims Recently, new palaeoecological records supported by molecular analyses and palaeodistributional modelling have provided more comprehensive insights into plant behaviour during the last Quaternary cycle. We reviewed the migration history of species of subgenus Alnus during the last 50,000 years in Europe with a focus on (1) a general revision of Alnus history since the Last Glacial Maximum (LGM), (2) evidence of northern refugia of Alnus populations during the LGM and (3) the specific history of Alnus in particular European regions. Methodology We determined changes in Alnus distribution on the basis of 811 and 68 radiocarbon-dated pollen and macrofossil sites, respectively. We compiled data from the European Pollen Database, the Czech Quaternary Palynological Database, the Eurasian Macrofossil Database and additional literature. Pollen percentage thresholds indicating expansions or retreats were used to describe patterns of past Alnus occurrence. Principal Findings An expansion of Alnus during the Late Glacial and early Holocene periods supports the presence of alders during the LGM in southern peninsulas and northerly areas in western Europe, the foothills of the Alps, the Carpathians and northeastern Europe. After glaciers withdrew, the ice-free area of Europe was likely colonized from several regional refugia; the deglaciated area of Scandinavia was likely colonized from a single refugium in northeastern Europe. In the more northerly parts of Europe, we found a scale-dependent pattern of Alnus expansion characterised by a synchronous increase of Alnus within individual regions, though with regional differences in the times of the expansion. In southern peninsulas, the Alps and the Carpathians, by contrast, it seems that Alnus expanded differently at individual sites rather than synchronously in whole regions. Conclusions Our synthesis supports the idea that northern LGM populations were important sources of postglacial Alnus expansion. The

  16. Politics and palliative care: Ireland.

    PubMed

    Smyth, Dion

    2011-05-01

    Éire, or in its English language form, Ireland, is a constitutional republic island state bordered by the Atlantic Ocean on its rugged north and rocky west coasts and the rough Irish Sea on the east. After a period of calm, financial promise, and prosperity, the so called Celtic tiger's roar is less pronounced at the moment. A recent change in the Irish government heralds a period of austerity after a decade or more of almost double-digit growth. PMID:21647082

  17. Republic of Ireland: abortion controversy.

    PubMed

    1998-01-01

    The problems associated with illegal abortion dominate public discussion in Ireland. While abortion is illegal in Ireland, the Supreme Court directed in 1992 that Irish women can go to Britain for abortions when their lives are thought to be at risk. Abortion was a constant feature during the Irish Presidential election campaign in October, while a dispute about the future of a 13-year-old girl's pregnancy dominated the headlines in November. The presidential election on October 30 resulted in a victory for one of the two openly anti-choice candidates, Mary McAleese, a lawyer from Northern Ireland. With a voter turnout of 47.6%, McAleese polled 45.2% of the votes cast. Although the president may refuse to sign bills which have been passed by parliament, McAleese has said that she will sign whatever bill is placed before her, even if it liberalizes abortion law in the republic. As for the case of the 13-year-old pregnant girl, she was taken into the care of Irish health authority officials once the case was reported to the police. However, the health board, as a state agency, is prevented by Irish law from helping anyone travel abroad for abortion. The girl was eventually given leave in a judgement by a High Court Judicial Review on November 28 to travel to England for an abortion. PMID:12321445

  18. The vegetation cover of New Zealand at the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Newnham, Rewi; McGlone, Matt; Moar, Neville; Wilmshurst, Janet; Vandergoes, Marcus

    2013-08-01

    A new reconstruction of the vegetation cover for New Zealand at the Last Glacial Maximum (LGM) is presented, based primarily on a database of 66 pollen site records and a more limited range of plant macrofossil and coleopteran records. Extensive forest is evident only from Auckland northwards. Conifer-broadleaf forest similar to that in the region today, but with Agathis australis scarce, persisted in the far north, whilst Nothofagus trees and a range of shrub taxa characterised the more open forests elsewhere in Northland. Survival of Nothofagus-dominated forest in coastal and exposed continental shelf locations to the southwest of Auckland and northwestern South Island is also indicated. Beyond these regions, vegetation cover comprised shrubland- and grassland-dominant communities, with the latter more prominent in eastern areas, to the south and presumably at higher altitudes. Nevertheless the survival of forest trees is indicated unambiguously in most regions apart from the eastern South Island. Thus the concept of 'micro glacial forest refugia' in New Zealand remains supported by this latest glacial vegetation reconstruction and we draw possible parallels with the developing but contentious concept of 'northern cryptic refugia' in Europe. Recent assertions that pollen and beetle reconstructions of the New Zealand LGM vegetation patterns diverge significantly are not supported by this analysis. Rather, the two proxies are readily reconciled if the term 'woody' as indicated by coleoptera is not restricted to tall forest trees but extended to the widespread woody shrub and small tree elements of the New Zealand flora. Regional distinctions in the LGM vegetation reconstruction concur broadly with the contemporary vegetation pattern, suggesting that, along with temperature depression and likely drier growing conditions, a zonal circulation regime with prominent southern westerly winds was important at 21 ka, as it is today. Pollen-climate modelling of the extent of

  19. Younger Dryas glaciation and climate in the Mourne Mountains, Northern Ireland

    NASA Astrophysics Data System (ADS)

    Barr, Iestyn; Devaney, Maia; Flood, Rory; Roberson, Sam

    2016-04-01

    Here we investigate glaciation and climate in the Mourne Mountains, Northern Ireland, during the Younger Dryas (YD; c. 12.9-11.7 ka BP), using a combination of field-mapping, remote sensing and glacier mass balance modelling. Results indicate that small, independent (likely snow-field fed) glaciers occupied the mountains during this period, with Equilibrium Line Altitudes (ELAs) ranging from ~ 450 to 708 m above sea level. Based on these estimates, mass balance modelling suggest a ~ 8°C reduction in mean annual temperature at the YD (assuming precipitation values comparable to present). Despite this, though the chronology and style of glacial retreat from the Last Glacial Maximum would suggest that the reconstructed glaciers relate to the YD, new radiocarbon dating of basal contact organics (conducted as part of this investigation) has been unable to conclusively verify a YD age.

  20. The role of glacial cycles in promoting genetic diversity in the Neotropics: the case of cloud forests during the Last Glacial Maximum

    PubMed Central

    Ramírez-Barahona, Santiago; Eguiarte, Luis E

    2013-01-01

    The increasing aridity during the Last Glacial Maximum (LGM) has been proposed as a major factor affecting Neotropical species. The character and intensity of this change, however, remains the subject of ongoing debate. This review proposes an approach to test contrasting paleoecological hypotheses by way of their expected demographic and genetic effects on Neotropical cloud forest species. We reviewed 48 paleoecological records encompassing the LGM in the Neotropics. The records show contrasting evidence regarding the changes in precipitation during this period. Some regions remained fairly moist and others had a significantly reduced precipitation. Many paleoecological records within the same region show apparently conflicting evidence on precipitation and forest stability. From these data, we propose and outline two demographic/genetic scenarios for cloud forests species based on opposite precipitation regimes: the dry refugia and the moist forests hypotheses. We searched for studies dealing with the population genetic structure of cloud forest and other montane taxa and compared their results with the proposed models. To date, the few available molecular studies show insufficient genetic evidence on the predominance of glacial aridity in the Neotropics. In order to disentangle the climatic history of the Neotropics, the present study calls for a general multi-disciplinary approach to conduct future phylogeographic studies. Given the contradictory paleoecological information, population genetic data on Neotropical cloud forest species should be used to explicitly test the genetic consequences of competing paleoecological models. PMID:23531632

  1. The role of glacial cycles in promoting genetic diversity in the Neotropics: the case of cloud forests during the Last Glacial Maximum.

    PubMed

    Ramírez-Barahona, Santiago; Eguiarte, Luis E

    2013-03-01

    The increasing aridity during the Last Glacial Maximum (LGM) has been proposed as a major factor affecting Neotropical species. The character and intensity of this change, however, remains the subject of ongoing debate. This review proposes an approach to test contrasting paleoecological hypotheses by way of their expected demographic and genetic effects on Neotropical cloud forest species. We reviewed 48 paleoecological records encompassing the LGM in the Neotropics. The records show contrasting evidence regarding the changes in precipitation during this period. Some regions remained fairly moist and others had a significantly reduced precipitation. Many paleoecological records within the same region show apparently conflicting evidence on precipitation and forest stability. From these data, we propose and outline two demographic/genetic scenarios for cloud forests species based on opposite precipitation regimes: the dry refugia and the moist forests hypotheses. We searched for studies dealing with the population genetic structure of cloud forest and other montane taxa and compared their results with the proposed models. To date, the few available molecular studies show insufficient genetic evidence on the predominance of glacial aridity in the Neotropics. In order to disentangle the climatic history of the Neotropics, the present study calls for a general multi-disciplinary approach to conduct future phylogeographic studies. Given the contradictory paleoecological information, population genetic data on Neotropical cloud forest species should be used to explicitly test the genetic consequences of competing paleoecological models. PMID:23531632

  2. Unpacking the mechanisms captured by a correlative species distribution model to improve predictions of climate refugia.

    PubMed

    Briscoe, Natalie J; Kearney, Michael R; Taylor, Chris A; Wintle, Brendan A

    2016-07-01

    Climate refugia are regions that animals can retreat to, persist in and potentially then expand from under changing environmental conditions. Most forecasts of climate change refugia for species are based on correlative species distribution models (SDMs) using long-term climate averages, projected to future climate scenarios. Limitations of such methods include the need to extrapolate into novel environments and uncertainty regarding the extent to which proximate variables included in the model capture processes driving distribution limits (and thus can be assumed to provide reliable predictions under new conditions). These limitations are well documented; however, their impact on the quality of climate refugia predictions is difficult to quantify. Here, we develop a detailed bioenergetics model for the koala. It indicates that range limits are driven by heat-induced water stress, with the timing of rainfall and heat waves limiting the koala in the warmer parts of its range. We compare refugia predictions from the bioenergetics model with predictions from a suite of competing correlative SDMs under a range of future climate scenarios. SDMs were fitted using combinations of long-term climate and weather extremes variables, to test how well each set of predictions captures the knowledge embedded in the bioenergetics model. Correlative models produced broadly similar predictions to the bioenergetics model across much of the species' current range - with SDMs that included weather extremes showing highest congruence. However, predictions in some regions diverged significantly when projecting to future climates due to the breakdown in correlation between climate variables. We provide unique insight into the mechanisms driving koala distribution and illustrate the importance of subtle relationships between the timing of weather events, particularly rain relative to hot-spells, in driving species-climate relationships and distributions. By unpacking the mechanisms

  3. Low Elevation Riparian Environments: Warm-Climate Refugia for Conifers in the Great Basin, USA?

    NASA Astrophysics Data System (ADS)

    Millar, C.; Charlet, D. A.; Westfall, R. D.; Delany, D.

    2015-12-01

    The Great Basin, USA, contains hundreds of small to large mountain ranges. Many reach alpine elevations, which are separated from each other by low-elevation basins currently inhospitable to conifer growth. Many of these ranges support montane and subalpine conifer species that have affinities to the Sierra Nevada or Rocky Mountains, and from which these conifers migrated during cool periods of the Pleistocene. Under Holocene climates, the Great Basin geography became a terrestrial island-archipelago, wherein conifer populations are isolated among ranges, and inter-range migration is highly limited. During warm intervals of the Holocene, conifers would be expected to have migrated upslope following favorable conditions, and extirpation would be assumed to result from continued warming. Independent patterns, repeating across multiple species' distributions, however, suggest that refugia were present in these ranges during warm periods, and that low elevation environments below the current main distributions acted as climatic refugia. We hypothesize that cool, narrow, and north-aspect ravines, which during cool climates support persistent or seasonal creeks and deciduous riparian communities, become available as conifer habitat when warming climates desiccate creeks and deplete riparian species. We further speculate that cold-air drainage, reduced solar insolation, lower wind exposure, and higher water tables in these topographic positions support populations of montane and subalpine conifers even during warm climate intervals when high elevations are unfavorable for conifer persistence. On return to cool climates, low elevation refugia become sources for recolonizing higher slopes, and/or continue to persist as relictual populations. We present several lines of evidence supporting this hypothesis, and speculate that low-elevation, extramarginal riparian environments might act as climate refugia for Great Basin conifers in the future as well.

  4. Palaeoclimate change drove diversification among isolated mountain refugia in the Australian arid zone.

    PubMed

    Pepper, Mitzy; Fujita, Matthew K; Moritz, Craig; Keogh, J Scott

    2011-04-01

    Refugia featured prominently in shaping evolutionary trajectories during repeated cycles of glaciation in the Quaternary, particularly in the Northern Hemisphere. The Southern Hemisphere instead experienced cycles of severe aridification but little is known about the temporal presence and role of refugia for arid-adapted biota. Isolated mountain ranges located in the Australian arid zone likely provided refugia for many species following Mio/Pliocene (<15 Ma) aridification; however, the evolutionary consequences of the recent development of widespread sand deserts is largely unknown. To test alternative hypotheses of ancient vs. recent isolation, we generated a 10 gene data set to assess divergence history among saxicolous geckos in the genus Heteronotia that have distributions confined to major rocky ranges in the arid zone. Phylogenetic analyses show that each rocky range harbours a divergent lineage, and substantial intraspecific diversity is likely due to topographic complexity in these areas. Old divergences (~4 Ma) among lineages pre-date the formation of the geologically young sand deserts (<1 Ma), suggesting that Pliocene climate shifts fractured the distributions of biota long before the spread of the deserts. PMID:21371147

  5. Possible refugia in the Alexander Archipelago of southeastern Alaska during the late Wisconsin glaciation

    USGS Publications Warehouse

    Carrara, P.E.; Ager, T.A.; Baichtal, J.F.

    2007-01-01

    The interpretation of the extent of late Wisconsin glaciation in southeastern Alaska has varied between geologists and biologists. Maps and reports of the region prepared by geologists commonly indicated that late Wisconsin ice extended as a large uniform front west to the edge of the continental shelf. However, the distribution of plants and animals in the region has led many biologists to suggest that there may have been ice-free areas that served as refugia during the late Wisconsin. Based on analyses of aerial photographs, topographic maps, and bathymetric charts, in conjunction with a review of previous literature and reconnaissance fieldwork throughout the region, this study presents data supporting a limited ice extent in the Alexander Archipelago during the late Wisconsin and identifies possible ice-free areas that may have served as refugia. These areas include (1) the Fairweather Ground, (2) the Herbert Graves Island area, (3) the western coast of southern Baranof Island and adjacent continental shelf, (4) Coronation Island and the adjacent continental shelf, (5) the Warren Island area, (6) the continental shelf from west of Heceta Island to Forrester Island in the south, (7) parts of the west coast of southern Dall Island, and (8) lowland areas in southern Prince of Wales Island. The identification of these possible refugia has bearing on the recolonization of the Alexander Archipelago, as they could have served as centers of biotic dispersal upon regional deglaciation and as stepping stones for early humans with a maritime tradition entering the western hemisphere from Asia. ?? 2007 NRC Canada.

  6. Phenylketonuria and the peoples of Northern Ireland.

    PubMed

    Zschocke, J; Mallory, J P; Eiken, H G; Nevin, N C

    1997-08-01

    The comparison of regional patterns of recessive disease mutations is a new source of information for studies of population genetics. The analysis of phenylketonuria (PKU) mutations in Northern Ireland shows that most major episodes of immigration have left a record in the modern genepool. The mutation 165T can be traced to the Palaeolithic people of western Europe who, in the Mesolithic period, first colonised Ireland. R408W (on haplotype 1) in contrast, the most common Irish PKU mutation, may have been prevalent in the Neolithic farmers who settled in Ireland after 4500 BC. No mutation was identified that could represent European Celtic populations, supporting the view that the adoption of Celtic culture and language in Ireland did not involve major migration from the continent. Several less common mutations can be traced to the Norwegian Atlantic coast and were probably introduced into Ireland by Vikings. This indicates that PKU has not been brought to Norway from the British Isles, as was previously argued. The rarity in Northern Ireland of IVS12nt1, the most common mutation in Denmark and England, indicates that the English colonialization of Ireland did not alter the local genepool in a direction that could be described as Anglo-Saxon. Our results show that the culture and language of a population can be independent of its genetic heritage, and give some insight into the history of the peoples of Northern Ireland. PMID:9254847

  7. Cyber-Bullying: The Situation in Ireland

    ERIC Educational Resources Information Center

    O'Moore, Mona

    2012-01-01

    This paper reports on the first major survey of cyber-bullying undertaken in Ireland. While preliminary results have been published they were based on a smaller and incomplete sample of 12-16 year olds living in Ireland. The preliminary results addressed the incidence level of cyber-bullying and that of the different subcategories of…

  8. Reconstructing the last Irish Ice Sheet 1: changing flow geometries and ice flow dynamics deciphered from the glacial landform record

    NASA Astrophysics Data System (ADS)

    Greenwood, Sarah L.; Clark, Chris D.

    2009-12-01

    The glacial geomorphological record provides an effective means to reconstruct former ice sheets at ice sheet scale. In this paper we document our approach and methods for synthesising and interpreting a glacial landform record for its palaeo-ice flow information, applied to landforms of Ireland. New, countrywide glacial geomorphological maps of Ireland comprising >39,000 glacial landforms are interpreted for the spatial, glaciodynamic and relative chronological information they reveal. Seventy one 'flowsets' comprising glacial lineations, and 19 ribbed moraine flowsets are identified based on the spatial properties of these landforms, yielding information on palaeo-ice flow geometry. Flowset cross-cutting is prevalent and reveals a highly complex flow geometry; major ice divide migrations are interpreted with commensurate changes in the flow configuration of the ice sheet. Landform superimposition is the key to deciphering the chronology of such changes, and documenting superimposition relationships yields a relative 'age-stack' of all Irish flowsets. We use and develop existing templates for interpreting the glaciodynamic context of each flowset - its palaeo-glaciology. Landform patterns consistent with interior ice sheet flow, ice stream flow, and with time-transgressive bedform generation behind a retreating margin, under a thinning ice sheet, and under migrating palaeo-flowlines are each identified. Fast ice flow is found to have evacuated ice from central and northern Ireland into Donegal Bay, and across County Clare towards the south-west. Ice-marginal landform assemblages form a coherent system across southern Ireland marking stages of ice sheet retreat. Time-transgressive, 'smudged' landform imprints are particularly abundant; in several ice sheet sectors ice flow geometry was rapidly varying at timescales close to the timescale of bedform generation. The methods and approach we document herein could be useful for interpreting other ice sheet histories

  9. Phylogeography and Post-Glacial Recolonization in Wolverines (Gulo gulo) from across Their Circumpolar Distribution

    PubMed Central

    Zigouris, Joanna; Schaefer, James A.; Fortin, Clément; Kyle, Christopher J.

    2013-01-01

    Interglacial-glacial cycles of the Quaternary are widely recognized in shaping phylogeographic structure. Patterns from cold adapted species can be especially informative - in particular, uncovering additional glacial refugia, identifying likely recolonization patterns, and increasing our understanding of species’ responses to climate change. We investigated phylogenetic structure of the wolverine, a wide-ranging cold adapted carnivore, using a 318 bp of the mitochondrial DNA control region for 983 wolverines (n = 209 this study, n = 774 from GenBank) from across their full Holarctic distribution. Bayesian phylogenetic tree reconstruction and the distribution of observed pairwise haplotype differences (mismatch distribution) provided evidence of a single rapid population expansion across the wolverine’s Holarctic range. Even though molecular evidence corroborated a single refugium, significant subdivisions of population genetic structure (0.01< ΦST <0.99, P<0.05) were detected. Pairwise ΦST estimates separated Scandinavia from Russia and Mongolia, and identified five main divisions within North America - the Central Arctic, a western region, an eastern region consisting of Ontario and Quebec/Labrador, Manitoba, and California. These data are in contrast to the nearly panmictic structure observed in northwestern North America using nuclear microsatellites, but largely support the nuclear DNA separation of contemporary Manitoba and Ontario wolverines from northern populations. Historic samples (c. 1900) from the functionally extirpated eastern population of Quebec/Labrador displayed genetic similarities to contemporary Ontario wolverines. To understand these divergence patterns, four hypotheses were tested using Approximate Bayesian Computation (ABC). The most supported hypothesis was a single Beringia incursion during the last glacial maximum that established the northwestern population, followed by a west-to-east colonization during the Holocene. This

  10. A tornado climatology for Ireland

    NASA Astrophysics Data System (ADS)

    Tyrrell, John

    The results of detailed records and site investigations of reported tornadoes, waterspouts and funnel clouds over the last 3 years (1999-2001) are presented. Part of the analysis also includes the more fragmented record from 1950. These results are placed in the context of the potential for the atmosphere to produce the type of severe convective weather over Ireland often associated with tornadoes. This has been characterised from an analysis of daily values of several extreme weather parameters, namely Convective Available Potential Energy (CAPE), Bulk Richardson Number (BRN) and Severe Weather (SWEAT), derived from upper air soundings at Valentia. It is concluded that this potential is slight, though sufficient to produce moderately intense tornadoes at times. The analysis of the tornado record demonstrates that the annual frequency of such severe events is highly variable. Nevertheless, there have been many as 30 per year, although the average frequency of 10 per year may be more typical. In contrast to neighbouring countries, tornadoes mostly occurred during the summer months, especially August. It suggested that the strong monthly and diurnal patterns in the data might have more complex explanations than appears at first sight, when the particular climatic circumstances of Ireland are taken into account. Tornado intensities have ranged between T0 and T6 (F0 and F3) and a relationship between tornado intensity, track length and track width is considered. Finally, the geographical distribution of tornado and funnel cloud events is presented and an interpretation is given that considers the possible role of the terrain and land surface conditions in the development of atmospheric environments conducive for tornado events in Ireland.

  11. Aspects of agricultural land use in Ireland

    NASA Astrophysics Data System (ADS)

    Lee, J.

    1986-02-01

    Ireland's soil regions consist largely of Luvisols, Cambisols, and Gleysols. Approximately 60% of Ireland's land area is subject to varying degrees of soil limitations. Twenty-five percent of the land area comprises wet lowland mineral soils. Ninety percent of Ireland's agricultural area comprises pasture, hay, and silage. Approximately 30% of the agricultural area is devoted to dairying, and 55% to cattle production. is devoted to dairying, and 55% to cattle production. Trends in agricultural land use indicate that tillage declined substantially while livestock showed a substantial increase particularly in the decade 1965 1975. Research concludes that over 2.8 million ha has a capacity to carry at least 100 LU/40 ha (100 acres). Levels of fertilizer use in Ireland are below EEC levels. The highest fertilizer use levels are associated with the eastern and southern areas of Ireland. Tillage crops occupy only 10% of the agricultural area, while they account for 26% of tertilizer and lime use.

  12. Ireland unveils new license regime

    SciTech Connect

    Not Available

    1992-11-23

    Ireland has unveiled new terns designed to integrate the licensing regime for oil and gas exploration and development. They apply to new exploration and development authorizations and replace the exclusive offshore licensing terns introduced in 1975. Holders of existing licenses are still subject to the 1975 terms but can choose the new terns under appropriate circumstances. Frontier exploration licenses are currently available to complement the standard and deepwater exploration licenses in use. Rental fees are now spread evenly over the duration of the license, thereby eliminating large upfront payments. Lease extensions also have been introduced to enable operators to judge commerciality of a discovery beyond the set license period.

  13. Sub-glacial volcanic eruptions

    USGS Publications Warehouse

    White, Donald Edward

    1956-01-01

    The literature on sub-glacial volcanic eruptions and the related flood phenomena has been reviewed as a minor part of the larger problem of convective and conductive heat transfer from intrusive magma. (See Lovering, 1955, for a review of the extensive literature on this subject.) This summary of data on sub-glacial eruptions is part of a program that the U.S. Geological Survey is conducting in connection with its Investigations of Geologic Processes project on behalf of the Division of Research, U.S. Atomic Energy Commission.

  14. Evolutionary refugia and ecological refuges: key concepts for conserving Australian arid zone freshwater biodiversity under climate change.

    PubMed

    Davis, Jenny; Pavlova, Alexandra; Thompson, Ross; Sunnucks, Paul

    2013-07-01

    Refugia have been suggested as priority sites for conservation under climate change because of their ability to facilitate survival of biota under adverse conditions. Here, we review the likely role of refugial habitats in conserving freshwater biota in arid Australian aquatic systems where the major long-term climatic influence has been aridification. We introduce a conceptual model that characterizes evolutionary refugia and ecological refugees based on our review of the attributes of aquatic habitats and freshwater taxa (fishes and aquatic invertebrates) in arid Australia. We also identify methods of recognizing likely future refugia and approaches to assessing the vulnerability of arid-adapted freshwater biota to a warming and drying climate. Evolutionary refugia in arid areas are characterized as permanent, groundwater-dependent habitats (subterranean aquifers and springs) supporting vicariant relicts and short-range endemics. Ecological refugees can vary across space and time, depending on the dispersal abilities of aquatic taxa and the geographical proximity and hydrological connectivity of aquatic habitats. The most important are the perennial waterbodies (both groundwater and surface water fed) that support obligate aquatic organisms. These species will persist where suitable habitats are available and dispersal pathways are maintained. For very mobile species (invertebrates with an aerial dispersal phase) evolutionary refugia may also act as ecological refugees. Evolutionary refugia are likely future refugia because their water source (groundwater) is decoupled from local precipitation. However, their biota is extremely vulnerable to changes in local conditions because population extinction risks cannot be abated by the dispersal of individuals from other sites. Conservation planning must incorporate a high level of protection for aquifers that support refugial sites. Ecological refuges are vulnerable to changes in regional climate because they have

  15. Evolutionary refugia and ecological refuges: key concepts for conserving Australian arid zone freshwater biodiversity under climate change

    PubMed Central

    Davis, Jenny; Pavlova, Alexandra; Thompson, Ross; Sunnucks, Paul

    2013-01-01

    Refugia have been suggested as priority sites for conservation under climate change because of their ability to facilitate survival of biota under adverse conditions. Here, we review the likely role of refugial habitats in conserving freshwater biota in arid Australian aquatic systems where the major long-term climatic influence has been aridification. We introduce a conceptual model that characterizes evolutionary refugia and ecological refuges based on our review of the attributes of aquatic habitats and freshwater taxa (fishes and aquatic invertebrates) in arid Australia. We also identify methods of recognizing likely future refugia and approaches to assessing the vulnerability of arid-adapted freshwater biota to a warming and drying climate. Evolutionary refugia in arid areas are characterized as permanent, groundwater-dependent habitats (subterranean aquifers and springs) supporting vicariant relicts and short-range endemics. Ecological refuges can vary across space and time, depending on the dispersal abilities of aquatic taxa and the geographical proximity and hydrological connectivity of aquatic habitats. The most important are the perennial waterbodies (both groundwater and surface water fed) that support obligate aquatic organisms. These species will persist where suitable habitats are available and dispersal pathways are maintained. For very mobile species (invertebrates with an aerial dispersal phase) evolutionary refugia may also act as ecological refuges. Evolutionary refugia are likely future refugia because their water source (groundwater) is decoupled from local precipitation. However, their biota is extremely vulnerable to changes in local conditions because population extinction risks cannot be abated by the dispersal of individuals from other sites. Conservation planning must incorporate a high level of protection for aquifers that support refugial sites. Ecological refuges are vulnerable to changes in regional climate because they have little

  16. Offshore evidence of postglacial relative sea-level change from eastern Ireland.

    NASA Astrophysics Data System (ADS)

    Callard, S. Louise; Long, Antony J.; Plets, Ruth M.; Cooper, J. Andrew; Belknap, Daniel F.; Edwards, Robin J.; Jackson, Derek W. T.; Kelley, Joseph T.; Long, David; Milne, Glenn A.; Monteys, Xavier; Quinn, Rory

    2014-05-01

    Field evidence and Glacial Isostatic Adjustment (GIA) models help constrain the extent of the British Irish Ice Sheet (BIIS) during and since the Last Glacial Maximum (LGM). Because of differential ice loading histories, relative sea-level (RSL) changes at sites from around the Irish Sea basin are complex. Existing GIA models are constrained using sea-level observations and some poorly dated and unevenly distributed ice margin data, but there is a paucity of RSL observations below -10 m OD that spans the Late Glacial, a period of abrupt RSL change that includes at least one meltwater pulse. Addressing this interval of time requires the collection of new field data from offshore regions around Ireland, taking advantage of recent advances in remote sensing techniques. This paper presents results from offshore eastern Ireland, one of seven areas targeted as part of a larger NERC funded project 'Late Glacial sea-level minima in the Irish Sea'. Previous research in this region has focused on dating raised marine sediments from exposed onshore coastal sections that represent periods of RSL highstands during the early deglaciation. However, the significance of these data for RSL reconstruction and hence their constraints on GIA models is debated. Here we use a combination of marine geophysics (multibeam bathymetry and backscatter, pinger sub-bottom profiler) vibro-coring and laboratory analyses to reconstruct Late Glacial RSL change from this region. The area's bathymetry demonstrate a strong glacial imprint on the northern side of the study area, with a large arcuate fan extending from Dundalk Bay to -18m, perhaps formed during a period of ice readvance, most likely during the Killard Point Stadial (c. 16.5 k cal a BP). Pinger seismic data allow the identification of six seismo-stratigraphic units, of which the most notable is a chaotic unit sitting on a prominent reflector that can be traced between -22 m to -50 m. The unit is interpreted as a gravel lag overlying

  17. Ireland

    Atmospheric Science Data Center

    2013-04-17

    article title:  An Irish Tale: One City, Two Asteroids     View Larger Image ... were recently commemorated by the official naming of two asteroids, "ArmaghObs" and "Ardmacha". The latter is the ancient Gaelic name ...

  18. Low but structured chloroplast diversity in Atherosperma moschatum (Atherospermataceae) suggests bottlenecks in response to the Pleistocene glacials

    PubMed Central

    Worth, James R. P.; Marthick, James R.; Jordan, Gregory J.; Vaillancourt, René E.

    2011-01-01

    Background and Aims The cool temperate rainforests of Australia were much reduced in range during the cold and dry glacial periods, although genetic evidence indicates that two key rainforest species, Nothofagus cunninghamii and Tasmannia lanceolata, survived within multiple locations and underwent only local range expansions at the end of the Last Glacial. To better understand the glacial response of a co-occurring but wind-dispersed and less cold-tolerant rainforest tree species, Atherosperma moschatum, a chloroplast phylogeographic study was undertaken. Methods A total of 3294 bp of chloroplast DNA sequence was obtained for 155 samples collected from across the species' range. Key Results The distribution of six haplotypes observed in A. moschatum was geographically structured with an inferred ancestral haplotype restricted to Tasmania, while three non-overlapping and endemic haplotypes were found on the mainland of south-eastern Australia. Last glacial refugia for A. moschatum are likely to have occurred in at least one location in western Tasmania and in Victoria and within at least two locations in the Great Dividing Range of New South Wales. Nucleotide diversity of A. moschatum was lower (π = 0·00021) than either N. cunninghamii (0·00101) or T. lanceolata (0·00073), and was amongst the lowest recorded for any tree species. Conclusions This study provides evidence for past bottlenecks having impacted the chloroplast diversity of A. moschatum as a result of the species narrower climatic niche during glacials. This hypothesis is supported by the star-like haplotype network and similar estimated rates of chloroplast DNA substitution for A. moschatum and the two more cold tolerant and co-occurring species that have higher chloroplast diversity, N. cunninghamii and T. lanceolata. PMID:21856633

  19. Floristic similarity, diversity and endemism as indicators of refugia characteristics and needs in the West

    USGS Publications Warehouse

    Malanson, George P.; Zimmerman, Dale L.; Fagre, Daniel B.

    2015-01-01

    The floras of mountain ranges, and their similarity, beta diversity and endemism, are indicative of processes of community assembly; they are also the initial conditions for coming disassembly and reassembly in response to climate change. As such, these characteristics can inform thinking on refugia. The published floras or approximations for 42 mountain ranges in the three major mountain systems (Sierra-Cascades, Rocky Mountains and Great Basin ranges) across the western USA and southwestern Canada were analysed. The similarity is higher among the ranges of the Rockies while equally low among the ranges of the Sierra-Cascades and Great Basin. Mantel correlations of similarity with geographic distance are also higher for the Rocky Mountains. Endemism is relatively high, but is highest in the Sierra-Cascades (due to the Sierra Nevada as the single largest range) and lowest in the Great Basin, where assemblages are allochthonous. These differences indicate that the geologic substrates of the Cascade volcanoes, which are much younger than any others, play a role in addition to geographic isolation in community assembly. The pattern of similarity and endemism indicates that the ranges of the Cascades will not function well as stepping stones and the endemic species that they harbor may need more protection than those of the Rocky Mountains. The geometry of the ranges is complemented by geology in setting the stage for similarity and the potential for refugia across the West. Understanding the geographic template as initial conditions for the future can guide the forecast of refugia and related monitoring or protection efforts.

  20. Simulating Climate Change in Ireland

    NASA Astrophysics Data System (ADS)

    Nolan, P.; Lynch, P.

    2012-04-01

    At the Meteorology & Climate Centre at University College Dublin, we are using the CLM-Community's COSMO-CLM Regional Climate Model (RCM) and the WRF RCM (developed at NCAR) to simulate the climate of Ireland at high spatial resolution. To address the issue of model uncertainty, a Multi-Model Ensemble (MME) approach is used. The ensemble method uses different RCMs, driven by several Global Climate Models (GCMs), to simulate climate change. Through the MME approach, the uncertainty in the RCM projections is quantified, enabling us to estimate the probability density function of predicted changes, and providing a measure of confidence in the predictions. The RCMs were validated by performing a 20-year simulation of the Irish climate (1981-2000), driven by ECMWF ERA-40 global re-analysis data, and comparing the output to observations. Results confirm that the output of the RCMs exhibit reasonable and realistic features as documented in the historical data record. Projections for the future Irish climate were generated by downscaling the Max Planck Institute's ECHAM5 GCM, the UK Met Office HadGEM2-ES GCM and the CGCM3.1 GCM from the Canadian Centre for Climate Modelling. Simulations were run for a reference period 1961-2000 and future period 2021-2060. The future climate was simulated using the A1B, A2, B1, RCP 4.5 & RCP 8.5 greenhouse gas emission scenarios. Results for the downscaled simulations show a substantial overall increase in precipitation and wind speed for the future winter months and a decrease during the summer months. The predicted annual change in temperature is approximately 1.1°C over Ireland. To date, all RCM projections are in general agreement, thus increasing our confidence in the robustness of the results.

  1. Extinction of refugia of hantavirus infection in a spatially heterogeneous environment

    NASA Astrophysics Data System (ADS)

    Kumar, Niraj; Parmenter, R. R.; Kenkre, V. M.

    2010-07-01

    We predict an abrupt observable transition, on the basis of numerical studies, of hantavirus infection in terrain characterized by spatially dependent environmental resources. The underlying framework of the analysis is that of Fisher equations with an internal degree of freedom, the state of infection. The unexpected prediction is of the sudden disappearance of refugia of infection in spite of the existence of supercritical (favorable) food resources, brought about by reduction of their spatial extent. Numerical results are presented and a theoretical explanation is provided on analytic grounds on the basis of the competition of diffusion of rodents carrying the hantavirus and nonlinearity present in the resource interactions.

  2. Two deeply divergent mitochondrial clades in the wild mouse Mus macedonicus reveal multiple glacial refuges south of Caucasus.

    PubMed

    Orth, A; Auffray, J-C; Bonhomme, F

    2002-11-01

    A survey of 77 individuals covering the range of Mus macedonicus from Georgia in the East to Greece and Bulgaria in the West and Israel in the South has shown the existence of two deeply divergent mitochondrial clades. The southern clade was until now undetected and characterises mice from Israel. Nuclear genes also show some amount of regional differentiation tending to separate the southern M. macedonicus from the northern ones. These results point towards the fact that the eastern Mediterranean short-tailed mouse, which was seen as a fairly homogeneous monotypic species, has in fact a more complex phylogeographic history than has been suspected, and that it warrants the existence of two subspecies. The reasons for this non-uniformity probably ought to be looked for in the history of faunal movements linked to glacial periods, underlining the possible existence of at least two refugia south of the Caucasus. PMID:12399993

  3. Extraterrestrial accretion and glacial cycles

    NASA Technical Reports Server (NTRS)

    Muller, R. A.

    1994-01-01

    We propose that the approx. 100-k.y. cycle seen in terrestrial glaciation is due to changes in meteor flux that come from changes in the Earth's orbit. This model can explain a 70-k.y. 'anomalous' period in climate data and the apparent discrepancy between present extraterrestrial fluxes and those in oceanic sediments. It can be tested by measuring Ir densities in sediments and ice during glacials and interglacials.

  4. Gridded climate data from 5 GCMs of the Last Glacial Maximum downscaled to 30 arc s for Europe

    NASA Astrophysics Data System (ADS)

    Schmatz, D. R.; Luterbacher, J.; Zimmermann, N. E.; Pearman, P. B.

    2015-06-01

    Studies of the impacts of historical, current and future global change require very high-resolution climate data (≤ 1 km) as a basis for modelled responses, meaning that data from digital climate models generally require substantial rescaling. Another shortcoming of available datasets on past climate is that the effects of sea level rise and fall are not considered. Without such information, the study of glacial refugia or early Holocene plant and animal migration are incomplete if not impossible. Sea level at the last glacial maximum (LGM) was approximately 125 m lower, creating substantial additional terrestrial area for which no current baseline data exist. Here, we introduce the development of a novel, gridded climate dataset for LGM that is both very high resolution (1 km) and extends to the LGM sea and land mask. We developed two methods to extend current terrestrial precipitation and temperature data to areas between the current and LGM coastlines. The absolute interpolation error is less than 1 and 0.5 °C for 98.9 and 87.8 %, respectively, of all pixels within two arc degrees of the current coastline. We use the change factor method with these newly assembled baseline data to downscale five global circulation models of LGM climate to a resolution of 1 km for Europe. As additional variables we calculate 19 "bioclimatic" variables, which are often used in climate change impact studies on biological diversity. The new LGM climate maps are well suited for analysing refugia and migration during Holocene warming following the LGM.

  5. Periodic isolation of the southern coastal plain of South Africa and the evolution of modern humans over late Quaternary glacial to interglacial cycles

    NASA Astrophysics Data System (ADS)

    Compton, J. S.

    2012-04-01

    Humans evolved in Africa, but where in Africa and by what mechanisms remain unclear. The evolution of modern humans over the last million years is associated with the onset of major global climate fluctuations, glacial to interglacial cycles, related to the build up and melting of large ice sheets in the Northern Hemisphere. During interglacial periods, such as today, warm and wet climates favored human expansion but during cold and dry glacial periods conditions were harsh and habitats fragmented. These large climate fluctuations periodically expanded and contracted African ecosystems and led to human migrations to more hospitable glacial refugia. Periodic isolation of relatively small numbers of humans may have allowed for their rapid evolutionary divergence from the rest of Africa. During climate transitions these divergent groups may have then dispersed and interbred with other groups (hybridization). Two areas at the opposite ends of Africa stand out as regions that were periodically isolated from the rest of Africa: North Africa (the Maghreb) and the southern coastal plain (SCP) of South Africa. The Maghreb is isolated by the Sahara Desert which periodically greens and is reconnected to the rest of Africa during the transition from glacial to interglacial periods. The SCP of South Africa is isolated from the rest of Africa by the rugged mountains of the Cape Fold Belt associated with inedible vegetation and dry climates to the north. The SCP is periodically opened when sea level falls by up to 130 m during glacial maxima to expose the present day submerged inner continental shelf. A five-fold expansion of the SCP receiving more rainfall in glacial periods may have served as a refuge to humans and large migratory herds. The expansive glacial SCP habitat abruptly contracts, by as much as one-third in 300 yr, during the rapid rise in sea level associated with glacial terminations. Rapid flooding may have increased population density and competition on the SCP to

  6. Ageing in Changing Community Contexts: Cross-Border Perspectives from Rural Ireland and Northern Ireland

    ERIC Educational Resources Information Center

    Walsh, Kieran; O'Shea, Eamon; Scharf, Thomas; Murray, Michael

    2012-01-01

    Ongoing demographic, social, economic and cultural changes point to the dynamic and continually changing contexts of rural areas in Ireland and Northern Ireland. However, the influence of such changes on the lives of older people remains under-explored, particularly the question of how older people perceive, connect to and engage in their…

  7. Cyberbullying, Schools and the Law: A Comparative Study in Northern Ireland and the Republic of Ireland

    ERIC Educational Resources Information Center

    Purdy, Noel; Mc Guckin, Conor

    2015-01-01

    Background: This study addresses the fast developing behavioural issue of cyberbullying in schools and its complex legal context. Purpose: This study set out to investigate teachers' perceptions of the extent of cyberbullying and the extent to which school leaders in Northern Ireland and the Republic of Ireland feel knowledgeable and confident…

  8. Revisiting the Iberian honey bee (Apis mellifera iberiensis) contact zone: maternal and genome-wide nuclear variations provide support for secondary contact from historical refugia.

    PubMed

    Chávez-Galarza, Julio; Henriques, Dora; Johnston, J Spencer; Carneiro, Miguel; Rufino, José; Patton, John C; Pinto, M Alice

    2015-06-01

    Dissecting diversity patterns of organisms endemic to Iberia has been truly challenging for a variety of taxa, and the Iberian honey bee is no exception. Surveys of genetic variation in the Iberian honey bee are among the most extensive for any honey bee subspecies. From these, differential and complex patterns of diversity have emerged, which have yet to be fully resolved. Here, we used a genome-wide data set of 309 neutrally tested single nucleotide polymorphisms (SNPs), scattered across the 16 honey bee chromosomes, which were genotyped in 711 haploid males. These SNPs were analysed along with an intergenic locus of the mtDNA, to reveal historical patterns of population structure across the entire range of the Iberian honey bee. Overall, patterns of population structure inferred from nuclear loci by multiple clustering approaches and geographic cline analysis were consistent with two major clusters forming a well-defined cline that bisects Iberia along a northeastern-southwestern axis, a pattern that remarkably parallels that of the mtDNA. While a mechanism of primary intergradation or isolation by distance could explain the observed clinal variation, our results are more consistent with an alternative model of secondary contact between divergent populations previously isolated in glacial refugia, as proposed for a growing list of other Iberian taxa. Despite current intense honey bee management, human-mediated processes have seemingly played a minor role in shaping Iberian honey bee genetic structure. This study highlights the complexity of the Iberian honey bee patterns and reinforces the importance of Iberia as a reservoir of Apis mellifera diversity. PMID:25930679

  9. Blooming Seas West of Ireland

    NASA Technical Reports Server (NTRS)

    2007-01-01

    For several weeks in May and early June, daily satellite images of the North Atlantic Ocean west of Ireland have captured partial glimpses of luxuriant blooms of microscopic marine plants between patches of clouds. On June 4, 2007, the skies over the ocean cleared, displaying the sea's spring bloom in brilliant color. A bright blue bloom stretches north from the Mouth of the River Shannon and tapers off like a plume of blue smoke north of Clare Island. (In the large image, a second bloom is visible to the north, wrapping around County Donegal, on the island's northwestern tip.) The image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite. Cold, nutrient-stocked water often wells up to the surface from the deeper ocean along coastal shelves and at the edges of ocean currents. When it does, it delivers a boost of nutrients that fuel large blooms of single-celled plants collectively known as phytoplankton. The plants are the foundation of the marine food web, and their proliferation in this area of the North Atlantic explains why the waters of western Ireland support myriad fisheries and populations of large mammals like seals, whales, and dolphins. Like plants on land, phytoplankton make their food through photosynthesis, harnessing sunlight for energy using chlorophyll and other light-capturing pigments. The pigments change the way light reflects off the surface water, appearing as colorful swirls of turquoise and green against the darker blue of the ocean. Though individually tiny, collectively these plants play a big role in Earth's carbon and climate cycles; worldwide, they remove about as much carbon dioxide from the atmosphere during photosynthesis as land plants do. Satellites are the only way to map the occurrence of phytoplankton blooms across the global oceans on a regular basis. That kind of information is important not only to scientists who model carbon and climate, but also to biologists and fisheries

  10. The NCI All Ireland Cancer Conference.

    PubMed

    Johnston; Daly; Liu

    1999-01-01

    The National Cancer Institute (NCI) has recently decided to embark on an international partnership with the developing cancer programs on the Island of Ireland (Northern Ireland and the Republic of Ireland) in an attempt to further improve the quality and range of cancer services available for patients. This Transatlantic Partnership called the All Ireland-NCI Cancer Consortium offers exciting opportunities in cancer treatment, education and research as the cancer-caring communities from both the Republic of Ireland and Northern Ireland prepare to join with the U.S. NCI in this major endeavor. The inaugural event of the partnership will be the NCI All Ireland Cancer Conference to be held in Belfast, October 3-6, 1999. (See www.allirelandcancer.com, for information on the conference.) Cancer is a significant cause of mortality and morbidity on the Island of Ireland. There are approximately 28,000 new cases and approximately 11,000 deaths from cancer each year. Therefore, Northern Ireland and the Republic of Ireland have among the highest cancer incidence and mortality rates in the Western World. In recent years there has been a major restructuring of cancer services in both parts of the Island. This is the result of several government reports such as the Campbell Report in Northern Ireland and the National Strategy Document for Cancer in the Republic of Ireland. The National Strategy Document proposes that cancer treatment services should be centered around primary care services, regional services, supra-regional centers and a national coordinating structure whereby the supra-regional centers deliver specialist surgery, medical and radiation oncology, rehabilitation and specialist palliative care. Three supra-regional cancer centers are being established in the cities of Dublin, Cork and Galway and a National Cancer Forum, which has served as a multidisciplinary advisory board to the Government, has pushed the development and implementation of this plan. This has

  11. Phylogeographic, ancient DNA, fossil and morphometric analyses reveal ancient and modern introductions of a large mammal: the complex case of red deer (Cervus elaphus) in Ireland

    NASA Astrophysics Data System (ADS)

    Carden, Ruth F.; McDevitt, Allan D.; Zachos, Frank E.; Woodman, Peter C.; O'Toole, Peter; Rose, Hugh; Monaghan, Nigel T.; Campana, Michael G.; Bradley, Daniel G.; Edwards, Ceiridwen J.

    2012-05-01

    The problem of how and when the island of Ireland attained its contemporary fauna has remained a key question in understanding Quaternary faunal assemblages. We assessed the complex history and origins of the red deer (Cervus elaphus) in Ireland using a multi-disciplinary approach. Mitochondrial sequences of contemporary and ancient red deer (dating from c 30,000 to 1700 cal. yr BP) were compared to decipher possible source populations of red deer in Ireland, in addition to craniometric analyses of skulls from candidate regions to distinguish between different colonization scenarios. Radiocarbon dating was undertaken on all bone fragments that were previously undated. Finally, a comprehensive review of the scientific literature, unpublished reports and other sources of data were also searched for red deer remains within Irish palaeontological and archaeological contexts. Despite being present in Ireland prior to the Last Glacial Maximum (LGM), there is a notable scarcity of red deer from the Younger Dryas stadial period until the Neolithic. The presence of red deer in Irish archaeological sites then occurs more frequently relative to other species. One population in the southwest of Ireland (Co. Kerry) shared haplotypes with the ancient Irish specimens and molecular dating and craniometric analysis suggests its persistence in Ireland since the Neolithic period. The synthesis of the results from this multi-disciplinary study all indicate that red deer were introduced by humans during the Irish Neolithic period and that one of these populations persists today. In conjunction with recent results from other species, Neolithic people from Ireland's nearest landmass, Britain, played a vital role in establishing its contemporary fauna and flora.

  12. Deep phylogeographic structuring of populations of the trapdoor spider Moggridgea tingle (Migidae) from southwestern Australia: evidence for long-term refugia within refugia.

    PubMed

    Cooper, Steven J B; Harvey, Mark S; Saint, Kathleen M; Main, Barbara Y

    2011-08-01

    Southwestern Australia has been recognized as a biodiversity hot spot of global significance, and it is particularly well known for its considerable diversity of flowering plant species. Questions of interest are how this region became so diverse and whether its fauna show similar diverse patterns of speciation. Here, we carried out a phylogeographic study of trapdoor spiders (Migidae: Moggridgea), a presumed Gondwanan lineage found in wet forest localities across southwestern Australia. Phylogenetic, molecular clock and population genetic analyses of mitochondrial (mtDNA) COI gene and ITS rRNA (internal transcribed spacer) data revealed considerable phylogeographic structuring of Moggridgea populations, with evidence for long-term (>3 million years) isolation of at least nine populations in different geographic locations, including upland regions of the Stirling and Porongurup Ranges. High levels of mtDNA divergence and no evidence of recent mitochondrial gene flow among valley populations of the Stirling Range suggest that individual valleys have acted as refugia for the spiders throughout the Pleistocene. Our findings support the hypothesis that climate change, particularly the aridification of Australia after the late Miocene, and the topography of the landscape, which allowed persistence of moist habitats, have been major drivers of speciation in southwestern Australia. PMID:21689192

  13. Phylogeography and demographic history of Lacerta lepida in the Iberian Peninsula: multiple refugia, range expansions and secondary contact zones

    PubMed Central

    2011-01-01

    Background The Iberian Peninsula is recognized as an important refugial area for species survival and diversification during the climatic cycles of the Quaternary. Recent phylogeographic studies have revealed Iberia as a complex of multiple refugia. However, most of these studies have focused either on species with narrow distributions within the region or species groups that, although widely distributed, generally have a genetic structure that relates to pre-Quaternary cladogenetic events. In this study we undertake a detailed phylogeographic analysis of the lizard species, Lacerta lepida, whose distribution encompasses the entire Iberian Peninsula. We attempt to identify refugial areas, recolonization routes, zones of secondary contact and date demographic events within this species. Results Results support the existence of 6 evolutionary lineages (phylogroups) with a strong association between genetic variation and geography, suggesting a history of allopatric divergence in different refugia. Diversification within phylogroups is concordant with the onset of the Pleistocene climatic oscillations. The southern regions of several phylogroups show a high incidence of ancestral alleles in contrast with high incidence of recently derived alleles in northern regions. All phylogroups show signs of recent demographic and spatial expansions. We have further identified several zones of secondary contact, with divergent mitochondrial haplotypes occurring in narrow zones of sympatry. Conclusions The concordant patterns of spatial and demographic expansions detected within phylogroups, together with the high incidence of ancestral haplotypes in southern regions of several phylogroups, suggests a pattern of contraction of populations into southern refugia during adverse climatic conditions from which subsequent northern expansions occurred. This study supports the emergent pattern of multiple refugia within Iberia but adds to it by identifying a pattern of refugia coincident

  14. Rapid characterisation of vegetation structure to predict refugia and climate change impacts across a global biodiversity hotspot.

    PubMed

    Schut, Antonius G T; Wardell-Johnson, Grant W; Yates, Colin J; Keppel, Gunnar; Baran, Ireneusz; Franklin, Steven E; Hopper, Stephen D; Van Niel, Kimberley P; Mucina, Ladislav; Byrne, Margaret

    2014-01-01

    Identification of refugia is an increasingly important adaptation strategy in conservation planning under rapid anthropogenic climate change. Granite outcrops (GOs) provide extraordinary diversity, including a wide range of taxa, vegetation types and habitats in the Southwest Australian Floristic Region (SWAFR). However, poor characterization of GOs limits the capacity of conservation planning for refugia under climate change. A novel means for the rapid identification of potential refugia is presented, based on the assessment of local-scale environment and vegetation structure in a wider region. This approach was tested on GOs across the SWAFR. Airborne discrete return Light Detection And Ranging (LiDAR) data and Red Green and Blue (RGB) imagery were acquired. Vertical vegetation profiles were used to derive 54 structural classes. Structural vegetation types were described in three areas for supervised classification of a further 13 GOs across the region. Habitat descriptions based on 494 vegetation plots on and around these GOs were used to quantify relationships between environmental variables, ground cover and canopy height. The vegetation surrounding GOs is strongly related to structural vegetation types (Kappa = 0.8) and to its spatial context. Water gaining sites around GOs are characterized by taller and denser vegetation in all areas. The strong relationship between rainfall, soil-depth, and vegetation structure (R(2) of 0.8-0.9) allowed comparisons of vegetation structure between current and future climate. Significant shifts in vegetation structural types were predicted and mapped for future climates. Water gaining areas below granite outcrops were identified as important putative refugia. A reduction in rainfall may be offset by the occurrence of deeper soil elsewhere on the outcrop. However, climate change interactions with fire and water table declines may render our conclusions conservative. The LiDAR-based mapping approach presented enables the

  15. Rapid Characterisation of Vegetation Structure to Predict Refugia and Climate Change Impacts across a Global Biodiversity Hotspot

    PubMed Central

    Schut, Antonius G. T.; Wardell-Johnson, Grant W.; Yates, Colin J.; Keppel, Gunnar; Baran, Ireneusz; Franklin, Steven E.; Hopper, Stephen D.; Van Niel, Kimberley P.; Mucina, Ladislav; Byrne, Margaret

    2014-01-01

    Identification of refugia is an increasingly important adaptation strategy in conservation planning under rapid anthropogenic climate change. Granite outcrops (GOs) provide extraordinary diversity, including a wide range of taxa, vegetation types and habitats in the Southwest Australian Floristic Region (SWAFR). However, poor characterization of GOs limits the capacity of conservation planning for refugia under climate change. A novel means for the rapid identification of potential refugia is presented, based on the assessment of local-scale environment and vegetation structure in a wider region. This approach was tested on GOs across the SWAFR. Airborne discrete return Light Detection And Ranging (LiDAR) data and Red Green and Blue (RGB) imagery were acquired. Vertical vegetation profiles were used to derive 54 structural classes. Structural vegetation types were described in three areas for supervised classification of a further 13 GOs across the region. Habitat descriptions based on 494 vegetation plots on and around these GOs were used to quantify relationships between environmental variables, ground cover and canopy height. The vegetation surrounding GOs is strongly related to structural vegetation types (Kappa = 0.8) and to its spatial context. Water gaining sites around GOs are characterized by taller and denser vegetation in all areas. The strong relationship between rainfall, soil-depth, and vegetation structure (R2 of 0.8–0.9) allowed comparisons of vegetation structure between current and future climate. Significant shifts in vegetation structural types were predicted and mapped for future climates. Water gaining areas below granite outcrops were identified as important putative refugia. A reduction in rainfall may be offset by the occurrence of deeper soil elsewhere on the outcrop. However, climate change interactions with fire and water table declines may render our conclusions conservative. The LiDAR-based mapping approach presented enables the

  16. A Brief History of the Potato in Ireland.

    ERIC Educational Resources Information Center

    Social Education, 2000

    2000-01-01

    Provides historical information on the potato in Ireland focusing on how the potato arrived in Ireland and the advantages and disadvantages of the potato as a food crop. Discusses the Irish potato famine in Ireland, effects of the famine, and the government's laissez-faire response. Includes a list of questions. (CMK)

  17. Polish women's experiences of breastfeeding in Ireland.

    PubMed

    Szafranska, Marcelina; Gallagher, Louise

    2016-01-01

    Exclusive breastfeeding among Polish mothers at three-four months (38.6 per cent) is in keeping with the low rates of breastfeeding in Ireland overall (Begley et al 2008), and suggests that Polish women have begun to adopt the infant feeding practices of Irish women. Therefore, the aim of this study was to explore the factors that influence Polish women's decisions to initiate and continue breastfeeding in Ireland. A descriptive qualitative approach was utilised to explore participants' perspectives of breastfeeding. Results showed that professional and family support are key to a successful breastfeeding experience for these mothers. Recommendations include further individualised support in order to meet the needs of Polish women breastfeeding in Ireland. PMID:26975131

  18. Richness of Colchic vegetation: comparison between refugia of south-western and East Asia

    PubMed Central

    Kikvidze, Zaal; Ohsawa, Masahiko

    2001-01-01

    Background The Colchis is one of the species-rich refugia and a centre of biological diversity in western Eurasia. We analysed patterns of richness, endemism and invasions in relation to taxonomy (family membership), life form, certain habitats in the Colchis, and compared them to patterns found for Japan. Results We found that in the Colchis perennials are significantly over-represented in endemic species, and that they typically occur on limestone soils and in alpine tall herbaceous vegetation. The Asteraceae produce significantly large number of both endemic and alien species, whereas the Poaceae are over-represented in alien species but under-represented in endemics. Likewise, the Apiaceae are over-represented in endemics, whereas the Euphorbiaceae are over-represented in alien species. Similar patterns have been found in Yakushima, Japan. The Morisita-Horn index of similarity between these two sites was 0.83 (based on family size). Although the flora of Adjara comprised of fewer families than the flora of Yakushima, the largest families are richer in species in the flora of Adjara than in the flora of Yakushima. Conclusions Floristic analysis of refugia of western Eurasia and their comparison with geographically distant areas can provide useful data for plant ecological and evolutionary studies. Potentially, such studies can produce testable hypotheses on plant migrations and on their historical geography. For example, the data presented in this study indicate that more severe conditions in the Pleistocene and geographical isolation of the Colchis may be responsible for the higher relative importance of adaptive radiation in the shaping of its modern flora. PMID:11801200

  19. Brook trout movement in response to temperature, flow, and thermal refugia within a complex Appalachian riverscape

    USGS Publications Warehouse

    Petty, J. Todd; Hansbarger, Jeff L.; Huntsman, Brock M.; Mazik, Patricia M.

    2012-01-01

    We quantified movements of brook trout Salvelinus fontinalis and brown trout Salmo trutta in a complex riverscape characterized by a large, open-canopy main stem and a small, closed-canopy tributary in eastern West Virginia, USA. Our objectives were to quantify the overall rate of trout movement and relate movement behaviors to variation in streamflow, water temperature, and access to coldwater refugia. The study area experienced extremely high seasonal, yearly, and among-stream variability in water temperature and flow. The relative mobility of brook trout within the upper Shavers Fork watershed varied significantly depending on whether individuals resided within the larger main stem or the smaller tributary. The movement rate of trout inhabiting the main stem during summer months (50 m/d) was an order of magnitude higher than that of tributary fish (2 m/d). Movement rates of main-stem-resident brook trout during summer were correlated with the maximum water temperature experienced by the fish and with the fish's initial distance from a known coldwater source. For main-stem trout, use of microhabitats closer to cover was higher during extremely warm periods than during cooler periods; use of microhabitats closer to cover during warm periods was also greater for main-stem trout than for tributary inhabitants. Main-stem-resident trout were never observed in water exceeding 19.5°C. Our study provides some of the first data on brook trout movements in a large Appalachian river system and underscores the importance of managing trout fisheries in a riverscape context. Brook trout conservation in this region will depend on restoration and protection of coldwater refugia in larger river main stems as well as removal of barriers to trout movement near tributary and main-stem confluences.

  20. When a Refuge is No More: Higher than Expected Wildfire Severity in Historical Forest Refugia

    NASA Astrophysics Data System (ADS)

    Bleeker, T.; Kolden, C.; Camp, A. E.; Hessburg, P. F., Sr.; Poulos, H.

    2014-12-01

    Global climate change is an increasingly important driver of changes in the biogeograpraphy of vegetation. Such changes have primarily been characterized by gradual shifts in species distribution; however, major disturbances acting in concert with climate change may result in a sudden 'jump' in biogeographical distribution. This study examines the effects of wildfire on forest composition along an environmental gradient in the eastern Cascade Mountains of Central Washington, USA. A previous study by Camp et al. (1997) examined three drainages in this complex mountainous landscape to identify and characterize historic wildfire refugia based on topographic characteristics and forest age and species composition. These drainages subsequently burned in the 2012 Table Mountain and Peavine Canyon fires. In 2014 the Camp et al. plots were re-established and re-sampled to (1) assess burn severity using the Composite Burn Index (CBI) protocol and (2) assess fire effects upon the individual trees in each study plot. Remotely sensed imagery classified using the differenced Normalized Burn Ratio (dNBR) indicated these fires burned more intensely than historical fires in the region, providing a potential harbinger of future fire severity under climate change. Analysis of burn severity revealed that the fire burned across the entire environmental gradient of the drainages, with no significant difference in burn occurrence or burn severity between refugial and non-refugial plots as designated by Camp et al.; this suggests that historical wildfire refugia may no longer prove sustainable in an era of climate change. Additionally, trees characteristic of warmer and drier climates experienced lower fire mortality than trees typical of cooler and moister climates. If future reseeding and recruitment in the forest favors more xeric tree species, the 2012 fires may prove to be the disturbance event that precipitates a 'jump' in the biogeographic distribution of trees in these drainages.

  1. Color perception influences microhabitat selection of refugia and affects monitoring success for a cryptic anuran species.

    PubMed

    Cohen, Bradley S; MacKenzie, Michelle L; Maerz, John C; Farrell, Christopher B; Castleberry, Steven B

    2016-10-01

    Perceptual-biases are important for understanding an animal's natural history, identifying potential ecological traps, and for developing effective means to monitor individuals and populations. Despite research demonstrating anurans having a positive phototactic response towards blue colors, we do not yet understand if color cues are used functionally beyond sexual selection. The aim of our study was to determine if color cues are used in selecting microhabitat, and if anuran's blue-positive phototactic response could increase selection of artificial PVC refugia used to monitor cryptic camouflaging anuran species. We captured 32 Cope's Gray Treefrogs and placed them in mesh enclosures with three PVC tubes painted blue, brown, and white. Concurrently, we placed blue, brown, or unpainted white PVC tubes in stratified arrays around a treefrog breeding pond, and counted the number of occasions treefrogs occupied different colored PVC tubes. In the confined choice experiment, treefrogs selected blue tubes (48.3%) significantly more often than brown (28.5%) or white (23.2%) tubes. Our field experiment mirrored these findings (52.0% of capture events in blue, 29.0% in brown, and 19.0% in unpainted white tubes). Our results suggest color influences Cope's Gray Treefrog microhabitat selection, and they utilize color vision when choosing refugia. We demonstrate simple, small changes based on perceptual-biases can induce behaviors that may in turn have large impacts on sampling techniques used in monitoring and inventorying. Incorporating non-traditional physiological measures into animal inventorying and monitoring programs can be used in the future to improve conservation efforts. PMID:27235736

  2. Obsidian hydration dates glacial loading?

    PubMed

    Friedman, I; Pierce, K L; Obradovich, J D; Long, W D

    1973-05-18

    Three different groups of hydration rinds have been measured on thin sections of obsidian from Obsidian Cliff, Yellowstone National Park, Wyoming. The average thickness of the thickest (oldest) group of hydration rinds is 16.3 micrometers and can be related to the original emplacement of the flow 176,000 years ago (potassium-argon age). In addition to these original surfaces, most thin sections show cracks and surfaces which have average hydration rind thicknesses of 14.5 and 7.9 micrometers. These later two hydration rinds compare closely in thickness with those on obsidian pebbles in the Bull Lake and Pinedale terminal moraines in the West Yellowstone Basin, which are 14 to 15 and 7 to 8 micrometers thick, respectively. The later cracks are thought to have been formed by glacial loading during the Bull Lake and Pinedale glaciations, when an estimated 800 meters of ice covered the Obsidian Cliff flow. PMID:17806883

  3. Obsidian hydration dates glacial loading?

    USGS Publications Warehouse

    Friedman, I.; Pierce, K.L.; Obradovich, J.D.; Long, W.D.

    1973-01-01

    Three different groups of hydration rinds have been measured on thin sections of obsidian from Obsidian Cliff, Yellowstone National Park, Wyoming . The average thickness of the thickest (oldest) group of hydration rinds is 16.3 micrometers and can be related to the original emplacement of the flow 176,000 years ago (potassium-argon age). In addition to these original surfaces, most thin sections show cracks and surfaces which have average hydration rind thicknesses of 14.5 and 7.9 micrometers. These later two hydration rinds compare closely in thickness with those on obsidian pebbles in the Bull Lake and Pinedale terminal moraines in the West Yellowstone Basin, which are 14 to 15 and 7 to 8 micrometers thick, respectively. The later cracks are thought to have been formed by glacial loading during the Bull Lake and Pinedale glaciations, when an estimated 800 meters of ice covered the Obsidian Cliff flow.

  4. Glacial history of the North Atlantic marine snail, Littorina saxatilis, inferred from distribution of mitochondrial DNA lineages.

    PubMed

    Panova, Marina; Blakeslee, April M H; Miller, A Whitman; Mäkinen, Tuuli; Ruiz, Gregory M; Johannesson, Kerstin; André, Carl

    2011-01-01

    The North Atlantic intertidal gastropod, Littorina saxatilis (Olivi, 1792), exhibits extreme morphological variation between and within geographic regions and has become a model for studies of local adaptation; yet a comprehensive analysis of the species' phylogeography is lacking. Here, we examine phylogeographic patterns of the species' populations in the North Atlantic and one remote Mediterranean population using sequence variation in a fragment of the mitochondrial cytochrome b gene (607 bp). We found that, as opposed to many other rocky intertidal species, L. saxatilis has likely had a long and continuous history in the Northwest Atlantic, including survival during the last glacial maximum (LGM), possibly in two refugia. In the Northeast Atlantic, several areas likely harboured refugial populations that recolonized different parts of this region after glacial retreat, resulting in strong population structure. However, the outlying monomorphic Venetian population is likely a recent anthropogenic introduction from northern Europe and not a remnant of an earlier wider distribution in the Mediterranean Sea. Overall, our detailed phylogeography of L. saxatilis adds an important piece to the understanding of Pleistocene history in North Atlantic marine biota as well as being the first study to describe the species' evolutionary history in its natural range. The latter contribution is noteworthy because the snail has recently become an important model species for understanding evolutionary processes of speciation; thus our work provides integral information for such endeavours. PMID:21412417

  5. Glacial survival may matter after all: nunatak signatures in the rare European populations of two west-arctic species.

    PubMed

    Westergaard, Kristine B; Alsos, Inger G; Popp, Magnus; Engelskjøn, Torstein; Flatberg, Kjell I; Brochmann, Christian

    2011-01-01

    Biogeographers claimed for more than a century that arctic plants survived glaciations in ice-free refugia within the limits of the North European ice sheets. Molecular studies have, however, provided overwhelming support for postglacial immigration into northern Europe, even from the west across the Atlantic. For the first time we can here present molecular evidence strongly favouring in situ glacial persistence of two species, the rare arctic-alpine pioneer species Sagina caespitosa and Arenaria humifusa. Both belong to the 'west-arctic element' of amphi-Atlantic disjuncts, having their few and only European occurrences well within the limits of the last glaciation. Sequencing of non-coding regions of chloroplast DNA revealed only limited variation. However, two very distinct and partly diverse genetic groups, one East and one West Atlantic, were detected in each species based on amplified fragment length polymorphisms (AFLPs), excluding postglacial dispersal from North America as explanation for their European occurrences. Patterns of genetic diversity and distinctiveness indicate that glacial populations existed in East Greenland and/or Svalbard (A. humifusa) and in southern Scandinavia (S. caespitosa). Despite their presumed lack of long-distance dispersal adaptations, intermixed populations in several regions indicate postglacial contact zones. Both species are declining in Nordic countries, probably due to climate change-induced habitat loss. Little or no current connectivity between their highly fragmented and partly distinct populations call for conservation of several populations in each geographic region. PMID:21156004

  6. The Language Planning Situation in Ireland

    ERIC Educational Resources Information Center

    Laoire, Muiris O.

    2005-01-01

    Language planning for the Irish language in the Republic of Ireland has featured prominently in international language policy and planning literature over the years. Researchers in the field may not be up to date, however, with recent developments in the area of Irish language planning and their impact on the language ecology. This monograph…

  7. Family SMEs in Ireland as Learning Organizations

    ERIC Educational Resources Information Center

    Birdthistle, Naomi

    2008-01-01

    Purpose: The purpose of this paper is to investigate whether small and medium-sized family businesses in Ireland have the potential to be classified as learning organizations. Design/methodology/approach: The research methodology adopted for this study is that of multiple-case studies. In this research, personal interviews were selected as the…

  8. The Harp: The Symbol of Ireland.

    ERIC Educational Resources Information Center

    Hardy, Donna Dee

    The harp as a symbol of the Irish people is discussed. The first part of the paper discusses the early use of the harp in Irish society and how the magical powers of this instrument affected the natives and invaders of the small island for centuries. From the time of the Celtic occupation of Ireland in 500 BC, music played by harpers has been…

  9. Vocational Education and Training in Ireland.

    ERIC Educational Resources Information Center

    Gallaher, Leo

    This monograph describes the various approaches to vocational training in Ireland. The report was compiled from existing statistics, various studies, and interviews with representatives of all the organizations, colleges, companies, and institutes involved in vocational training. Section 1 provides background information on political structures,…

  10. Regional health library service in northern Ireland.

    PubMed Central

    Crawford, D S

    1990-01-01

    The regional medical library service provided to physicians, hospitals, nurses, social workers, and health care administrators throughout Northern Ireland by the Queen's University of Belfast is described. A brief outline of the National Health Service in the United Kingdom is given, and the library service is described in terms of collections, cataloging, interlibrary loan, and reference. PMID:2224299

  11. Strategic Planning in Ireland's Institutes of Technology

    ERIC Educational Resources Information Center

    Elwood, Larry; Rainnie, Al

    2012-01-01

    This article focuses upon Ireland's institute of technology sector, which has been transformed from a 1970s technical orientation to its broader current role of research and higher education provision. The transformational shifts experienced by institutes over the previous three decades have been profound: increased autonomy, new managerial and…

  12. Entrepreneurship Education: Ireland's Solution to Economic Regeneration?

    ERIC Educational Resources Information Center

    O'Connor, John; Fenton, Mary; Barry, Almar

    2012-01-01

    The significance of entrepreneurship has come into sharper focus as enterprise and innovation are being flagged as solutions to regenerate the Irish economy. The Irish Innovation Task Force believes that Ireland could become an "innovation hub", attracting foreign risk capital and international and indigenous entrepreneurs to start and grow…

  13. New OBS network deployment offshore Ireland

    NASA Astrophysics Data System (ADS)

    Le Pape, Florian; Bean, Chris; Craig, David; Jousset, Philippe; Horan, Clare; Hogg, Colin; Donne, Sarah; McCann, Hannah; Möllhoff, Martin; Kirk, Henning; Ploetz, Aline

    2016-04-01

    With the presence of the stormy NE Atlantic, Ireland is ideally located to investigate further our understanding of ocean generated microseisms and use noise correlation methods to develop seismic imaging in marine environments as well as time-lapse monitoring. In order to study the microseismic activity offshore Ireland, 10 Broad Band Ocean Bottom Seismographs (OBSs) units including hydrophones have been deployed in January 2016 across the shelf offshore Donegal and out into the Rockall Trough. This survey represents the first Broadband passive study in this part of the NE Atlantic. The instruments will be recovered in August 2016 providing 8 months worth of data to study microseisms but also the offshore seismic activity in the area. One of the main goal of the survey is to investigate the spatial and temporal distributions of dominant microseism source regions, close to the microseism sources. Additionally we will study the coupling of seismic and acoustic signals at the sea bed and its evolution in both the deep water and continental shelf areas. Furthermore, the survey also aims to investigate further the relationship between sea state conditions (e.g. wave height, period), seafloor pressure variations and seismic data recorded on both land and seafloor. Finally, the deployed OBS network is also the first ever attempt to closely monitor local offshore earthquakes in Ireland. Ireland seismicity although relatively low can reduce slope stability and poses the possibility of triggering large offshore landslides and local tsunamis.

  14. Regional health library service in northern Ireland.

    PubMed

    Crawford, D S

    1990-10-01

    The regional medical library service provided to physicians, hospitals, nurses, social workers, and health care administrators throughout Northern Ireland by the Queen's University of Belfast is described. A brief outline of the National Health Service in the United Kingdom is given, and the library service is described in terms of collections, cataloging, interlibrary loan, and reference. PMID:2224299

  15. The National Maritime College of Ireland

    ERIC Educational Resources Information Center

    Greville, Eamonn

    2005-01-01

    The new National Maritime College of Ireland is regarded as the country's most exciting and innovative development in maritime training and education and is the first tertiary institution to be built and operated under the government's Public Private Partnership (PPP) model of procurement. The project is the outcome of a partnership between Cork…

  16. Late Quaternary vegetation of Chukotka (Northeast Russia), implications for Glacial and Holocene environments of Beringia

    NASA Astrophysics Data System (ADS)

    Anderson, Patricia M.; Lozhkin, Anatoly V.

    2015-01-01

    Two lake records from the Kankaren region of southern Chukotka, when combined with other palynological and macrofossil data, document spatial and temporal variations in the regional vegetation history since ˜21,000 14C/25,400 cal yr BP. Full-glacial environments were severely cold and arid in central and northern Chukotka, whereas southern sites experienced conditions that were relatively moist, although still drier than present. Southern Chukotka may represent a western extension of environments of the land bridge proper, including a possible 'moisture' barrier to intercontinental migration. Shrub Betula tundra established earliest in southern Chukotka (˜15,800-14,000 14C/19,000-16,700 cal yr BP; ˜13,000 14C/15,300 cal yr BP central and north), Pinus pumila earliest in the north (˜9600 14C/11,100 cal yr BP; ˜7600 14C/8400 cal yr BP south), and shrub Alnus earliest in both the south and north (˜12,000-11,000 14C/13,800-12,900 cal yr BP). These patterns support the presence of cryptic refugia for Betula and Alnus in Chukotka during the full glaciation. In contrast, P. pumila probably migrated into Chukotka from populations located in the northern coastal lowlands and from mountainous regions of southwestern Beringia. Evidence for a thermal optimum (˜11,000-8000 14C/12,900-9000 cal yr BP) is strong in northern Chukotka but is absent in central and southern areas.

  17. Genetic variability and glacial origins of yellow perch (Perca flavescens) in North America

    USGS Publications Warehouse

    Todd, Thomas N.; Hatcher, Charles O.

    1993-01-01

    Starch–gel electrophoresis was used to analyze muscle and liver tissue for variation in 13 enzymes representing 31 presumptive loci in yellow perch (Perca flavescens) from 13 localities scattered throughout the natural geographic range of the species in North America. Ten loci were polymorphic, but only three, alcohol dehydrogenase (ADH-1*), glucose-6-phosphate isomerase (GPI-1*), and phosphoglucomutase (PGM-2*), exhibited polymorphisms at relatively high frequencies across localities. Western populations were fixed for one allele at ADH-1*, eastern populations were fixed for another allele, and populations from intermediate locations in Lake Ontario and Pennsylvania had both alleles. The distributions of alleles at GPI-1* and PGM-2*were similar to that of ADH-1*, exhibiting strong differences between eastern and western populations, although the delineation was not as clear. Western populations were much less variable than eastern populations, and the distribution of alleles indicated that the two groups were derived from Mississippi and Atlantic glacial refugia. Populations near the physiographic discontinuity between the Mississippi and Atlantic drainages in western New York and Pennsylvania exhibited an admixture of typically western and eastern alleles. Such observations are consistent with the mixed faunal history of the region and limited postglacial dispersal of western and eastern populations across the boundary.

  18. New insights on postglacial colonization in western Europe: the phylogeography of the Leisler's bat (Nyctalus leisleri).

    PubMed

    Boston, Emma S M; Ian Montgomery, W; Hynes, Rosaleen; Prodöhl, Paulo A

    2015-04-01

    Despite recent advances in the understanding of the interplay between a dynamic physical environment and phylogeography in Europe, the origins of contemporary Irish biota remain uncertain. Current thinking is that Ireland was colonized post-glacially from southern European refugia, following the end of the last glacial maximum (LGM), some 20 000 years BP. The Leisler's bat (Nyctalus leisleri), one of the few native Irish mammal species, is widely distributed throughout Europe but, with the exception of Ireland, is generally rare and considered vulnerable. We investigate the origins and phylogeographic relationships of Irish populations in relation to those across Europe, including the closely related species N. azoreum. We use a combination of approaches, including mitochondrial and nuclear DNA markers, in addition to approximate Bayesian computation and palaeo-climatic species distribution modelling. Molecular analyses revealed two distinct and diverse European mitochondrial DNA lineages, which probably diverged in separate glacial refugia. A western lineage, restricted to Ireland, Britain and the Azores, comprises Irish and British N. leisleri and N. azoreum specimens; an eastern lineage is distributed throughout mainland Europe. Palaeo-climatic projections indicate suitable habitats during the LGM, including known glacial refugia, in addition to potential novel cryptic refugia along the western fringe of Europe. These results may be applicable to populations of many species. PMID:25716786

  19. New insights on postglacial colonization in western Europe: the phylogeography of the Leisler's bat (Nyctalus leisleri)

    PubMed Central

    Boston, Emma S. M.; Ian Montgomery, W.; Hynes, Rosaleen; Prodöhl, Paulo A.

    2015-01-01

    Despite recent advances in the understanding of the interplay between a dynamic physical environment and phylogeography in Europe, the origins of contemporary Irish biota remain uncertain. Current thinking is that Ireland was colonized post-glacially from southern European refugia, following the end of the last glacial maximum (LGM), some 20 000 years BP. The Leisler's bat (Nyctalus leisleri), one of the few native Irish mammal species, is widely distributed throughout Europe but, with the exception of Ireland, is generally rare and considered vulnerable. We investigate the origins and phylogeographic relationships of Irish populations in relation to those across Europe, including the closely related species N. azoreum. We use a combination of approaches, including mitochondrial and nuclear DNA markers, in addition to approximate Bayesian computation and palaeo-climatic species distribution modelling. Molecular analyses revealed two distinct and diverse European mitochondrial DNA lineages, which probably diverged in separate glacial refugia. A western lineage, restricted to Ireland, Britain and the Azores, comprises Irish and British N. leisleri and N. azoreum specimens; an eastern lineage is distributed throughout mainland Europe. Palaeo-climatic projections indicate suitable habitats during the LGM, including known glacial refugia, in addition to potential novel cryptic refugia along the western fringe of Europe. These results may be applicable to populations of many species. PMID:25716786

  20. Record of glacial Lake Missoula floods in glacial Lake Columbia, Washington

    NASA Astrophysics Data System (ADS)

    Hanson, Michelle A.; Clague, John J.

    2016-02-01

    During the last glaciation (marine oxygen isotope stage 2), outburst floods from glacial Lake Missoula deposited diagnostic sediments within glacial Lake Columbia. Two dominant outburst flood lithofacies are present within glacial Lake Columbia deposits: a flood expansion bar facies and a finer-grained hyperpycnite facies. We conclude that the flood sediments have a glacial Lake Missoula source because: (1) current indicators indicate westward flow through the lake, and upvalley flow followed by downvalley flow in tributary valleys; (2) no flood sediments are found north of a certain point; (3) there is a dominance of Belt-Purcell Supergroup clasts in a flood expansion bar; and (4) some of the finer-grained beds have a pink colour, reflective of glacial Lake Missoula lake-bottom sediments. A new radiocarbon age of 13,400 ± 100 14C BP on plant detritus found below 37 flood beds helps constrain the timing of outburst flooding from glacial Lake Missoula.

  1. Multiple Pleistocene refugia and Holocene range expansion of an abundant southwestern American desert plant species (Melampodium leucanthum, Asteraceae).

    PubMed

    Rebernig, Carolin A; Schneeweiss, Gerald M; Bardy, Katharina E; Schönswetter, Peter; Villaseñor, Jose L; Obermayer, Renate; Stuessy, Tod F; Weiss-Schneeweiss, Hanna

    2010-08-01

    Pleistocene climatic fluctuations had major impacts on desert biota in southwestern North America. During cooler and wetter periods, drought-adapted species were isolated into refugia, in contrast to expansion of their ranges during the massive aridification in the Holocene. Here, we use Melampodium leucanthum (Asteraceae), a species of the North American desert and semi-desert regions, to investigate the impact of major aridification in southwestern North America on phylogeography and evolution in a widespread and abundant drought-adapted plant species. The evidence for three separate Pleistocene refugia at different time levels suggests that this species responded to the Quaternary climatic oscillations in a cyclic manner. In the Holocene, once differentiated lineages came into secondary contact and intermixed, but these range expansions did not follow the eastwardly progressing aridification, but instead occurred independently out of separate Pleistocene refugia. As found in other desert biota, the Continental Divide has acted as a major migration barrier for M. leucanthum since the Pleistocene. Despite being geographically restricted to the eastern part of the species' distribution, autotetraploids in M. leucanthum originated multiple times and do not form a genetically cohesive group. PMID:20670366

  2. Using Distributed Temperature Sensing to Locate and Quantify Thermal Refugia: Insights Into Radiative & Hydrologic Processes

    NASA Astrophysics Data System (ADS)

    Bond, R. M.; Stubblefield, A. P.

    2012-12-01

    Stream temperature plays a critical role in determining the overall structure and function of stream ecosystems. Aquatic fauna are particularly vulnerable to projected increases in the magnitude and duration of elevated stream temperatures from global climate change. Northern California cold water salmon and trout fisheries have been declared thermally impacted by the California State Water Resources Control Board. This study employed Distributed Temperature Sensing (DTS) to detect stream heating and cooling at one meter resolution along a one kilometer section of the North Fork of the Salmon River, a tributary of the Klamath River, northern California, USA. The Salmon River has an extensive legacy of hydraulic gold mining tailing which have been reworked into large gravel bars; creating shallow wide runs, possibly filling in pools and disrupting riparian vegetation recruitment. Eight days of temperature data were collected at 15 minute intervals during July 2012. Three remote weather stations were deployed during the study period. The main objectives of this research were: one, quantify thermal inputs that create and maintain thermal refugia for cold water fishes; two, investigate the role of riparian and topographic shading in buffering peak summer temperatures; and three, create and validate a physically based stream heating model to predict effects of riparian management, drought, and climate change on stream temperature. DTS was used to spatially identify cold water seeps and quantify their contribution to the stream's thermal regime. Along the one kilometer reach, hyporheic flow was identified using DTS. The spring was between 16-18°C while the peak mainstem temperature above the spring reached a maximum of 23°C. The study found a diel heating cycle of 5°C with a Maximum Weekly Average Temperature (MWAT) of over 22°C; exceeding salmon and trout protective temperature standards set by USEPA Region 10. Twenty intensive fish counts over five days were

  3. Observational and Model Constraints on Glacial Erosion

    NASA Astrophysics Data System (ADS)

    Ehlers, T. A.; Enkelmann, E.; Yanites, B. J.

    2012-12-01

    Quantifying the controls on glacial erosion over geologic timescales is necessary to understand the role of Cenozoic climate change on the development of modern mountain belts. Unfortunately, understanding the spatial distribution of glacial erosion during repeated glaciations has proven difficult. We present results that integrate bedrock and detrital thermochronometer cooling ages with a glacial landscape evolution model. We use this to quantify the spatial distribution and temporal variability of glacial erosion in the Coast Mountains, British Columbia, Canada. A total of 100 apatite (U-Th)/He and 106 fission track single grain ages are presented from modern outwash of the Tiedemann Glacier whose catchment elevations range from 530-3960 m a.s.l.. Detrital thermochronometer ages utilize the tendency of thermochronometer cooling ages to increase with elevation and provide a sediment tracer for the elevation that eroded sediment is derived from. Bedrock ages used include 79 apatite (U-Th)/He ages collected in multiple catchments. Erosion rates derived from bedrock ages are compared to predicted erosion rates from a shallow-ice approximation glacial landscape evolution model of the region. Results from the observed distribution of detrital ages indicate that maximum glacial erosion occurs between elevations of 1200-1800m. Furthermore, near-uniform erosion is documented beneath the glacier with nearly all sediment derived from between elevations of 650- 3000 m a.s.l. Second, comparison of erosion rates derived from bedrock thermochronometer ages with the landscape evolution model suggest that a linear glacial sliding velocity is the primary control on erosion (r2=0.6). This result is important as it provides observational validation of the linear slide velocity erosion rule for million-year timescales. Finally, comparison of model and thermochronometer derived erosion rates reveals that active subglacial erosion occurs for only ~10-20% of a glacial-interglacial cycle

  4. A fresh look at glacial foods

    USGS Publications Warehouse

    Colman, Steven M.

    2002-01-01

    Over the last 20 years, it has become clear that ice ages are characterized by glacial as well as climatic instability on millennial time scales. In his Perspective, Colman highlights two recent papers investigating the role of glacial meltwater and continental drainage in this instability. The results suggest a fundamental instability feedback between ocean circulation and ice sheet dynamics and provides an explanation for why instability was greatest at times of intermediate ice volume.

  5. Glacial migrations of plants: island biogeographical evidence.

    PubMed

    Simpson, B B

    1974-08-23

    Analyses of the floras of the high north Andean habitat islands (paramos) and the Galápagos Islands show that plant species diversity conforms to the MacArthur and Wilson model of island biogeography but that immigration occurred primarily during glacial periods. Modern plant species diversity is more significantly correlated with area and distance measures of the glacial forms of the islands than with similar measures of the present-day islands. PMID:17736375

  6. Analysis of recent glacial earthquakes in Greenland

    NASA Astrophysics Data System (ADS)

    Olsen, K.; Nettles, M.

    2015-12-01

    Large calving events at Greenland's outlet glaciers produce teleseismically detectable glacial earthquakes. These events are observed in the seismic record for the past 22 years, but the complete catalog of glacial earthquakes still numbers only ~300. The annual occurrence of these long-period events has increased over time, which makes recent years especially valuable in expanding the global dataset. Glacial earthquakes from 1993- 2010 have been analyzed systematically (Tsai and Ekström, 2007; Veitch and Nettles, 2012). Here, we analyze more recent events using the same centroid—single-force (CSF) approach as previous authors, focusing initially on data from 2013. In addition, we perform a focused study of selected events from 2009-2010 to assess the reliability of the force azimuths obtained from such inversions. Recent spatial and temporal patterns of glacial earthquakes in Greenland differ from those in previous years. In 2013, three times as many events occurred on the west coast as on the east, and these events originated predominantly from two glaciers: Jakobshavn Glacier on the west coast and Helheim Glacier on the east. Kangerdlugssuaq Glacier, on the east coast, produced no glacial earthquakes in 2013, though it produced many events in earlier years. Previous CSF results for glacial earthquakes show force azimuths perpendicular to the glacier front during a calving event, with force plunges near horizontal. However, some azimuths indicate forces initially oriented upglacier, while others are oriented downglacier (seaward). We perform a set of experiments on events from 2009 and 2010 and find two acceptable solutions for each glacial earthquake, oriented 180° apart with plunges of opposite sign and centroid times differing by approximately one half of the assumed duration of the earthquake time function. These results suggest the need for a more complex time function to model glacial earthquakes more accurately.

  7. Post-glacial dispersal patterns of Northern pike inferred from an 8800 year old pike (Esox cf. lucius) skull from interior Alaska

    NASA Astrophysics Data System (ADS)

    Wooller, Matthew J.; Gaglioti, Benjamin; Fulton, Tara L.; Lopez, Andres; Shapiro, Beth

    2015-07-01

    The biogeography of freshwater fish species during and after late-Pleistocene glaciations relate to how these species are genetically organized today, and the management of these often disjunct populations. Debate exists concerning the biogeography and routes of dispersal for Northern pike (Esox lucius) after the last glaciation. A hypothesis to account for the relatively low modern genetic diversity for E. lucius is post-glacial radiation from refugia, including lakes from within the un-glaciated portions of eastern Beringia. We report the remains of a Northern pike (E. cf. lucius) skull, including bones, teeth, bone collagen and ancient DNA. The remains were preserved at a depth of between 440 and 446 cm in a 670 cm long core of sediment from Quartz Lake, which initiated at ˜11,200 cal yr BP in interior Alaska. A calibrated accelerator mass spectrometer (AMS) radiocarbon age of the collagen extracted from the preserved bones indicated that the organism was dated to 8820 cal yr BP and is bracketed by AMS values from analyses of terrestrial plant macrofossils, avoiding any potential aquatic reservoir effect that could have influenced the radiocarbon age of the bones. Scanning electron microscope images of the specimen show the hinged tooth anatomy typically of E. lucius. Molar C:N (3.5, 1σ = 0.1) value of the collagen from the specimen indicated well-preserved collagen and its mean stable nitrogen isotope value is consistent with the known predatory feeding ecology of E. lucius. Ancient DNA in the bones showed that the specimen was identical to modern E. lucius. Our record of E. lucius from interior Alaska is consistent with a biogeographic scenario involving rapid dispersal of this species from glacial refugia in the northern hemisphere after the last glaciation.

  8. 69 FR 11040 - Electrolytic Manganese Dioxide From Australia, Greece, Ireland, Japan, and South Africa

    Federal Register 2010, 2011, 2012, 2013, 2014

    2004-03-09

    ... COMMISSION Electrolytic Manganese Dioxide From Australia, Greece, Ireland, Japan, and South Africa AGENCY... terminating its antidumping investigations on electrolytic manganese dioxide from Australia, Greece, Ireland... dioxide from Australia, Greece, Ireland, Japan, and South Africa (investigations Nos. 731-TA-1048 and...

  9. Phytoplankton bloom off the coast of Ireland

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Irish Sea (right) is full of phytoplankton in this true-color image from January 15, 2002. The Irish Sea separates Ireland (center) from the United Kingdom (right). In this image the water of both the Irish and Celtic (lower right) Seas appears quite turbid, being a milky blue-green compared to the clearer waters of the open Atlantic (left). This milky appearance is likely due to the growth of marine plants called phytoplankton. Despite the fact that Ireland is at the same latitude as southern Hudson Bay, Canada, it remains green year round, thanks to the moderating effect on temperatures of the Atlantic Ocean. The Gulf Stream bring warmer waters up from the tropics, and southwesterly winds bring warmer air to the country, thus moderating seasonal temperature extremes.

  10. Human evolution out of Africa: the role of refugia and climate change.

    PubMed

    Stewart, J R; Stringer, C B

    2012-03-16

    Although an African origin of the modern human species is generally accepted, the evolutionary processes involved in the speciation, geographical spread, and eventual extinction of archaic humans outside of Africa are much debated. An additional complexity has been the recent evidence of limited interbreeding between modern humans and the Neandertals and Denisovans. Modern human migrations and interactions began during the buildup to the Last Glacial Maximum, starting about 100,000 years ago. By examining the history of other organisms through glacial cycles, valuable models for evolutionary biogeography can be formulated. According to one such model, the adoption of a new refugium by a subgroup of a species may lead to important evolutionary changes. PMID:22422974