169 research outputs found

    Cirsium species show disparity in patterns of genetic variation at their range-edge, despite similar patterns of reproduction and isolation

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    Genetic variation was assessed across the UK geographical range of Cirsium acaule and Cirsium heterophyllum. A decline in genetic diversity and increase in population divergence approaching the range edge of these species was predicted based on parallel declines in population density and seed production reported seperately. Patterns were compared with UK populations of the widespread Cirsium arvense.Populations were sampled along a latitudinal transect in the UK and genetic variation assessed using microsatellite markers. Cirsium acaule shows strong isolation by distance, a significant decline in diversity and an increase in divergence among range-edge populations. Geographical structure is also evident in C. arvense, whereas no such patterns are seen in C.heterophyllum. There is a major disparity between patterns of genetic variation in C. acaule and C. heterophyllum despite very similar patterns in seed production and population isolation in these species. This suggests it may be misleading to make assumptions about the geographical structure of genetic variation within species based solely on the present-day reproduction and distribution of populations

    Influence of phenological barriers and habitat differentiation on the population genetic structure of the balearic endemic Rhamnus ludovici-salvatoris Chodat and R. alaternus L

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    [EN] Rhamnus ludovici-salvatoris, endemic to the Gymnesian Islands, coexists with the related and widespread R. alaternus in Mallorca and Menorca. In both species, the population genetic structure using RAPD, and flowering during a 3-year period to check for possible phenological barriers, were analyzed. Rhamnus ludovici-salvatoris showed lower genetic diversity and stronger population structure than R. alaternus, the Cabrera population being less diverse and the most differentiated. Rhamnus ludovici-salvatoris flowered one month later, although flowering of both species coincided sporadically. These congeners seem to have diverged through isolation by time and differentiation in habitat. The population genetic structure of R. ludovici-salvatoris could mainly be due to the existence of small populations on the one hand, and a gene flow caused by rare hybridization events on the other, which may also explain the presence of morphologically intermediate individuals in Menorca. The conservation of R. ludovici-salvatoris populations may include population reinforcements and other in situ interventions.Ferriol Molina, M.; Llorens García, L.; Gil, L.; Boira Tortajada, H. (2009). Influence of phenological barriers and habitat differentiation on the population genetic structure of the balearic endemic Rhamnus ludovici-salvatoris Chodat and R. alaternus L. Plant Systematics and Evolution. 277(1-2):105-116. doi:10.1007/s00606-008-0110-3S1051162771-2Affre L, Thompson JD, Debussche M (1997) Genetic structure of continental and island populations of the Mediterranean endemic Cyclamen balearicum (Primulaceae). Amer J Bot 84(4): 437–451BOIB (2005) Decreto 75/2005. BOIB 106: 29–32Bolmgren K, Oxelman B (2004) Generic limits in Rhamnus L. s.l. (Rhamnaceae) inferred from nuclear and chloroplast DNA sequence phylogenies. Taxon 53(2):383–390Bolòs O, Molinier R (1958) Recherches phytosociologiques dans l’île de Majorque. Collectanea Botanica 34:699–865Cardona MA (1979) Consideracions sobre l’endemisme i l’origen de la flora de las Illes Balears. Butlletí del Institut Catalá de Historia Natural 44 (Sec. Bot. 3):7–15Cardona MA, Contandriopoulos J (1979) Endemism and evolution in the islands of the Western Mediterranean. In: Bramwell D (ed) Plants and islands. Academic Press, London, pp 133–169Chodat L (1924) Contributions à la Géo-Botanique de Majorque. PhD Thesis, Université de Genève—Institut de Botanique, SwitzerlandCollins D, Mill RR, Moller M (2003) Species separation of Taxus baccata, T. canadensis, and T. cuspidata (Taxaceae) and origins of their reputed hybrids inferred from RAPD and cpDNA data. Amer J Bot 90(2):175–182Cronk QCB (1997) Islands: stability, diversity, conservation. Biodivers Conserv 6(3):477–493Doyle JJ, Doyle JL (1990) Isolation of plant DNA from fresh tissue. Focus 12:13–15Ducarme V, Wesselingh RA (2005) Detecting hybridization in mixed populations of Rhinanthus minor and Rhinanthus angustifolius. Folia Geobot 40(2/3):151–161Englishloeb GM, Karban R (1992) Consequences of variation in flowering phenology for seed head herbivory and reproductive success in Erigeron glaucus (Compositae). Oecologia 89:588–595Gautier F, Caluzon G, Suk JP, Violanti D (1994) Age et durée de la crise de salinité Messinienne. Comptes Rendus de l’Académie des Sciences de Paris 318:1103–1109Gerard PR, Fernandez-Manjarres JF, Frascaria-Lacoste N (2006) Temporal cline in a hybrid zone population between Fraxinus excelsior L. and Fraxinus angustifolia Vahl. Molec Ecol 15:3655–3667Gil L, Llorens L, Tébar FJ, Costa M (1995) La vegetación de la isla de Cabrera. In: Guía de la excursión geobotánica de las XV Jornadas de Fitosociología. Datos sobre la vegetación de Cabrera. Palma de Mallorca: Universitat de les Illes Balears, pp 51–77Gulías J, Flexas J, Abadía A, Medrano H (2002) Photosynthetic responses to water deficit in six Mediterranean sclerophyll species: possible factors explaining the declining distribution of Rhamnus ludovici-salvatoris, and endemic Balearic species. Tree Physiol 22:687–697Gulías J, Traveset A, Riera N, Mus M (2004) Critical stages in the recruitment process of Rhamnus alaternus L. Ann Bot 93:723–731Gustafsson S, Sjögren-Gulve P (2002) Genetic diversity in the rare orchid, Gymnadenia odoratissima and a comparison with the more common congener, G. conopsea. Conserv Genet 3:225–234Gustafsson S (2003) Population genetic analyses in the orchid genus Gymnadenia—a conservation genetic perspective. PhD Thesis, Uppsala University, SwedenGustafsson S, Lönn M (2003) Genetic differentiation and habitat preference of flowering-time variants within Gymnadenia conopsea. Heredity 91:284–292Harris W (1996) Genecological aspects of flowering patterns of populations of Kunzea ericoides and K. sinclairii (Myrtaceae). New Zealand J Bot 34:333–354Hendry AP, Dray T (2005) Population structure attributable to reproductive time: isolation by time and adaptation by time. Molec Ecol 14:901–916Hosokawa K, Minami M, Kawahara K, Nakamura I, Shibata T (2000) Discrimination among three species of medicinal Scutellaria plants using RAPD markers. Pl Med 66:270–272Huang Z, Liu L, Zhou T, Ju B (2005) Effects of environmental factors on the population genetic structure in chukar partridge (Alectoris chukar). J Arid Environ 62:427–434Juan A, Crespo MB, Cowan RS, Lexer C, Fay F (2004) Patterns of variability and gene flow in Medicago citrina, an endangered endemic of islands in the western Mediterranean, as revealed by amplified fragment length polymorphism (AFLP). Molec Ecol 13:2679–2690Krijgsman W, Hilgen FJ, Raffi I, Sierro FJ, Wilson DS (1999) Chronology, causes and progression of the Messinian salinity crisis. Nature 400:652–655Lamont BB, He T, Enright NJ, Krauss SL, Miller BP (2003) Anthropogenic disturbance promotes hybridization between Banksia species by altering their biology. J Evol Biol 16:551–557Lennartsson T (1997) Seasonal differentiation—a conservative reproductive barrier in two grassland Gentianella (Gentianaceae) species. Pl Syst Evol 208:45–69Martinez-Solis I, Iranzo J, Estrelles E, Ibars AM (1993) Leaf domatia in the section Alaternus (Miller) DC. of the genus Rhamnus (Rhamnaceae). Bot J Linn Soc 112:311–318McIntosh ME (2002) Flowering phenology and reproductive output in two sister species of Ferocactus (Cactaceae). Pl Ecol 159:1–13Nei M (1973) Analysis of gene diversity in subdivided populations. Proc Natl Acad Sci USA 70:3321–3323Nei M (1978) Estimation of average heterozigosity and genetic distance from a small number of individuals. Genetics 89:583–590Nei M, Li W (1979) Mathematical model for studying genetic variation in terms of restriction endonucleases. Proc Natl Acad Sci USA 79:5269–5273Nybom H, Bartish IV (2000) Effects of life history traits and sampling strategies on genetic diversity estimates obtained with RAPD markers in plants. Perspect Pl Ecol Evol Syst 3(2):93–114Oostermeijer JGB, Luijten SH, Ellis-Adam AC, den Nijs JCM (2002) Future prospects for the rare, late-flowering Gentianella germanica and Gentianopsis ciliata in Dutch nutrient-poor calcareous grasslands. Biol Conserv 104:339–350Pease CM, Lande R, Bull JJ (1989) A model of population growth, dispersal and evolution in a changing environment. Ecology 70(6):1657–1664Perron M, Gordon AG, Bousquet J (1995) Species-specific RAPD fingerprints for the closely related Picea mariana and P. rubens. Theor Appl Genet 91:142–149Pierce S, Ceriani RM, Villa M, Cerabolini B (2006) Quantifying relative extinction risks and targeting intervention for the orchid flora of a natural park in the European prealps. Conserv Biol 20(6):1804–1810Richardson JE, Fay MF, Cronk QCB, Bowman D, Chase MW (2000) A phylogenetic analysis of Rhamnaceae using rbcL and trnL-F plastid DNA sequences. Amer J Bot 87(9):1309–1324Roselló JA, Sáez L (2000) Index Balearicum: an annotated check-list of the vascular plants described from the Balearic Islands. Collect Bot 25(1):3–203Roselló JA, Cebrián MC, Mayol M (2002) Testing taxonomic and biogeographical relationships in a narrow mediterranean endemic complex (Hippocrepis balearica) using RAPD markers. Ann Bot 89:321–327Sales E, Nebauer SG, Mus M, Segura J (2001) Population genetic study in the Balearic plant species Digitalis minor (Scrophulariaceae) using RAPD markers. Amer J Bot 88(10):1750–1759Sherwin WB, Moritz C (2000) Managing and monitoring genetic erosion. In: Young AG, Clarke GM (eds) Genetics, demography and viability of fragmented populations. Cambridge University Press, Cambridge, pp 9–34Sneath PHA, Sokal RR (1973) Numerical taxonomy. Freeman and Co., San FranciscoTraveset A, Gulías J, Riera N, Mus M (2003) Transition probabilities from pollination to establishment in a rare dioecious shrub species (Rhamnus ludovici-salvatoris) in two habitats. J Ecol 91:427–437Tutin TG, Heywood VH, Burges NA, Valentine DH, Walters SM, Webb DA (eds) (2001) Flora Europaea, vol 2. Rosaceae to Umbelliferae. Cambridge University Press, CambridgeWright S (1931) Evolution in Mendelian populations. Genetics 16:97–159Zimmerman M (1980a) Reproduction in Polemonium: pre-dispersal seed predation. Ecology 61:502–506Zimmerman M (1980b) Reproduction in Polemonium: competition for pollinators. Ecology 61:497–50

    Influence of fire prevention management strategies on the diversity of butterfly fauna in the eastern Pyrenees

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    Fire prevention management is becoming a necessity in many Mediterranean locations to regulate fire of natural or human origin. However, very few studies have determined the real effects of the strategies adopted on local fauna. Butterflies are sensitive to local changes and they can thus serve as indicators of environmental changes. Three different types of fire prevention management approaches in three different localities in the Eastern Pyrenees (France) were performed and the butterfly community composition was investigated. We show that of the 80 species of butterflies observed, 36 % can be considered as biological markers. An original objective treatment of data using hierarchical distance analysis combined with a neural network analysis (Self-Organizing Maps) was applied in this study. Our conclusions are that the overall number of species is maintained independently of the fire prevention type but that some important changes are observed among butterfly communities, with a clear reduction of the numbers of endemic/specialized species in favour of generalist ones for the two most drastic fire prevention management approaches studied here. The influence of such approaches is discussed on the basis of the conservation of Mediterranean species of Lepidoptera

    The relation between early constructive play and mathematical word problem solving is mediated by spatial ability. A path analysis in sixth grade students.

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    The scientific literature shows that constructive play activities are positively related to children's spatial ability. Likewise, a close positive relation is found between spatial ability and mathematical word problem-solving performances. The relation between children's constructive play and their performance on mathematical word problems is, however, not reported yet. The aim of the present study was to investigate whether spatial ability acted as a mediator in the relation between constructive play and mathematical word problem-solving performance in 128 sixth-grade elementary school children. This mediating role of spatial ability was tested by utilizing the current mediation approaches suggested by Preacher and Hayes (2008). Results showed that 38.16% of the variance in mathematical word problem-solving performance is explained by children's constructive play activities and spatial ability. More specifically, spatial ability acted as a partial mediator, explaining 31.58% of the relation between constructive play and mathematical word problem-solving performance. © 2014 Oostermeijer, Boonen and Jolles
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