bluuebunny/crossref_metadata_2025_split huggingface dataset:
Historical biogeography of olive domestication (Olea europaeaL.) as revealed by geometrical morphometry applied to biological and archaeological material
Authors: Terral Jean‐Frédéric , Alonso Natalia , Capdevila Ramon Buxó i , Chatti Noureddine , Fabre Laurent , Fiorentino Girolamo , Marinval Philippe , Jordá Guillem Pérez , Pradat Bénédicte , Rovira Núria , Alibert Paul 
Published: October 2010

AbstractAim This study intends to improve our understanding of historical biogeography of olive domestication in the Mediterranean Basin, particularly in the north‐western area.Location Investigations were performed simultaneously on olive stones from extant wild populations, extant cultivated varieties from various Mediterranean countries, and archaeological assemblages of Spanish, French and Italian settlements.Methods A combination of morphometrics (traditional and geometrical) allowed us to study both the size and shape of endocarp structure. Concerning shape, a size‐standardized method coupled with fitted polynomial regression analysis was performed.Results We found morphological criteria for discriminating between wild and cultivated olive cultivars, and established patterns of morphological variation of olive material according to the geographical origin (for extant material) and to the age of the olive forms (for archaeological material). Levels of morphological convergences and divergences between wild olive populations and cultivated varieties are presented as evidence.Main conclusions Morphological changes of endocarps of olive under domestication at both geographical and chronological scales provide new criteria for the identification of olive cultivars. They allow to determine the origins of cultivated forms created and/or introduced in the north‐western Mediterranean regions and to understand how human migrations affected the rest of the Western Mediterranean regions. A model of diffusion of olive cultivation is proposed. It shows evidence of an indigenous origin of the domestication process, which is currently recognized in the north‐western area since the Bronze Age.
The biogeography of aquatic macrophytes in North America since the Last Glacial Maximum
Authors: Sawada M. , Viau A. E. , Gajewski K. 
Published: October 2010

AbstractAimTo document the post‐glacial migration of the major aquatic macrophytes of North America.LocationNorth America north of Mexico.MethodsAquatic macrophyte pollen were extracted from the North American Pollen Database. The modern pollen distribution was mapped and related to the climate to document the geographical and climatic constraints on these taxa. The fossil pollen were mapped at 2‐ka intervals for the past 21 ka.ResultsNumerous genera were present in ice‐free Alaska during the Last Glacial Maximum, and south of the Laurentide Ice Sheet in the southeast. Those taxa with the widest modern climatic ranges migrated rapidly into ice‐marginal areas, first in the west and then in the east of North America. Subsequent changes in the range and abundance were smaller.Main conclusionsThere were four migration routes of aquatic macrophytes during the late‐glacial and post‐glacial periods: a southward migration from Alaska between 14–13 and ka, a northern migration in the west at the same time into the ice‐free Cordilleran region, and movements east and west of Appalachia as early as 19 ka for some taxa into the lower Mississippi and into the upper Mississippi and Great Lakes by 11 ka. As the Laurentide ice sheet wasted, aquatic taxa with the broadest contemporary temperature tolerances rapidly occupied ice‐marginal environments.
Australian biogeographical connections and the phylogeny of large genera in the plant family Myrtaceae
Authors: Ladiges Pauline Y. , Udovicic Frank , Nelson Gareth 
Published: October 2010

AbstractAimTo compare the phylogeny of the eucalypt and melaleuca groups with geological events and ages of fossils to discover the time frame of clade divergences.LocationAustralia, New Caledonia, New Guinea, Indonesian Archipelago.MethodsWe compare published molecular phylogenies of the eucalypt and melaleuca groups of the plant family Myrtaceae with geological history and known fossil records from the Cretaceous and Cenozoic.ResultsThe Australasian eucalypt group includes seven genera, of which some are relictual rain forest taxa of restricted distribution and others are species‐rich and widespread in drier environments. Based on molecular and morphological data, phylogenetic analyses of the eucalypt group have identified two major clades. The monotypicArillastrumendemic to New Caledonia is related in one clade to the more species‐richAngophora,CorymbiaandEucalyptusthat dominate the sclerophyll vegetation of Australia. Based on the time of rifting of New Caledonia from eastern Gondwana and the age of fossil eucalypt pollen, we argue that this clade extends back to the Late Cretaceous. The second clade includes three relictual rain forest taxa, withAllosyncarpiafrom Arnhem Land the sister taxon toEucalyptopsisof New Guinea and the eastern Indonesian archipelago, andStockwelliafrom the Atherton Tableland in north‐east Queensland. As monsoonal, drier conditions evolved in northern Australia, Arnhem Land was isolated from the wet tropics to the east and north during the Oligocene, segregating ancestral rain forest biota. It is argued also that the distribution of species inEucalyptopsisandEucalyptussubgenusSymphyomyrtusendemic in areas north of the stable edge of the Australian continent, as far as Sulawesi and the southern Philippines, is related to the geological history of south‐east Asia‐Australasia. Colonization (dispersal) may have been aided by rafting on micro‐continental fragments, by accretion of arc terranes onto New Guinea and by land brought into closer proximity during periods of low sea‐level, from the Late Miocene and Pliocene. The phylogenetic position of the few northern, non‐Australian species ofEucalyptussubgenusSymphyomyrtussuggests rapid radiation in the large Australian sister group(s) during this time frame. A similar pattern, connecting Australia and New Caledonia, is emerging from phylogenetic analysis of theMelaleucagroup (Beaufortiasuballiance) within Myrtaceae, withMelaleucabeing polyphyletic.Main conclusionThe eucalypt group is an old lineage extending back to the Late Cretaceous. Differentiation of clades is related to major geological and climatic events, including rifting of New Caledonia from eastern Gondwana, development of monsoonal and drier climates, collision of the northern edge of the Australian craton with island arcs and periods of low sea level. Vicariance events involve dispersal of biota.
A mesoscale analysis of floristic patterns in the south‐west Finnish Archipelago
Authors: Korvenpää Turkka , Von Numers Mikael , Hinneri Sakari 
Published: October 2010

AbstractAimTo identify the ecological gradients based on the flora on a mesoscale in an archipelago. To interpret the results of the ordination and the classification of a grid cell‐based botanical data set, with several environmental and geographical attributes. To compare the mesoscale distribution patterns of vascular plants with patterns previously observed on an island scale, and to develop a floristic zonation of the study area.LocationThe south‐west Finnish Archipelago.MethodsVascular plant species‐lists from over 1500 localities were assigned to 5 × 5 km grid cells. The grid cell‐based floristic data were subjected to both unconstrained [detrended correspondence analysis (DCA)] and constrained [detrended canonical correspondence analysis (DCCA)] gradient analyses. The results of DCA were interpreted with calculated weighted averages of Ellenberg's indicator values for vascular plants, the number of occurring taxa and indices for the strength of human influence and the occurrence of limestone. The results of DCCA were interpreted with geographical attributes of the grid cells and the occurrence of limestone. The grid cells were clustered using two‐way indicator species analysis (twinspan).ResultsBoth the unconstrained and the constrained ordinations gave consistent and interpretable results. The main ecological gradient runs from the grid cells containing species‐rich islands with high human impact to grid cells containing species‐poor islands with low human impact. This gradient also represents the continuum from areas with large islands near the mainland, to the outermost areas at the edge of the open sea. The secondary gradient was shown to be a gradient of soil reaction.twinspangave a clustering primarily based on the location of the grid cells on an inner–outer archipelago gradient, but the occurrence of limestone also influenced the classification. The archipelago was divided into five non‐homogeneous areas based on thetwinspanclusters. The detected gradients correspond well with the gradients detected in a similar island‐level analysis.Main conclusionsThe two major ecological gradients in the study area seem to be robust, which is indicated by the similar results obtained both on an island and on a mesoscale. A shift from local and regional processes to broader geographical gradients probably starts to occur at the applied scale. The distribution patterns are strongly affected by the inner–outer archipelago gradient and the occurrence of limestone.
A comparison of taiga flora in north‐eastern Russia and Alaska/Yukon
Authors: Swanson David K. 
Published: October 2010

AbstractAim  To understand the similarities and differences between the taiga floras of far north‐eastern Asia and north‐western North America in the light of their Tertiary and Quaternary histories. Does the taiga flora follow the tundra pattern (Asian–American commonality of species as a result of continuity through the Quaternary), the temperate forest pattern (distinct species because of late Tertiary disjunction), a combination of these two patterns, or some pattern unique to the taiga?Location  The taiga regions of interior Alaska and the Yukon in North America (the ‘Alaskan taiga’), and the Kolyma and eastern Indigirka River basins in Russia (the ‘Kolyma taiga’). The study areas include both forested and unforested habitats below elevational treeline. The two regions have similar climate and topography and were linked via the Bering Land Bridge in the Tertiary and for several extended periods during Quaternary cold periods.Methods  Systematic comparison of the vascular floras of the two regions from published sources; and review of palaeoecological literature for the region.Results  Of the 796 species found in the study areas, 27% occur only in the Alaskan taiga, 35% occur only in the Kolyma taiga, and 38% occur in both the regions. The following subsets of species show a high proportion of species in common between the study areas (subsets are not mutually exclusive): plants that occur on the tundra and the taiga, non‐flowering plants, abundant taiga understory plants, and wetland and aquatic plants. A lower proportion of shared plants was noted for warm, south‐facing steppe communities. No tree species are common to both areas.Main conclusions  The Bering Strait region in the Quaternary has acted as a biogeographical filter for taiga plants. Significant divergence between northeast Asia and northwest North America has developed among the more southerly ranging fraction of the flora (e.g. trees), while the more cosmopolitan and the most cold‐adapted elements of the taiga flora are common to both areas. Many plants in the former group have been disjunct between Asia and North America for millions of years, while many plants in the latter group have probably maintained continuity between the study areas via the Bering Land Bridge through much of the late Tertiary and Quaternary periods. Repeated extirpation of the less cold‐adapted species from both study areas during Pleistocene cold periods has probably enhanced floristic differences between the two regions.
Exotic plant invasions of vernal pools in the Central Valley of California, USA
Authors: Gerhardt Fritz , Collinge Sharon K. 
Published: October 2010

AbstractAim To better understand patterns of community invasibility, we examined exotic plant invasions along an environmental gradient found in vernal pools in the Central Valley of California. Specifically, we analysed the distribution and abundance of exotic plants in relation to pool size, seasonal inundation, soil and nutrient properties, the native plant community, and disturbance history.Location We studied patterns of exotic plant invasions in a complex of natural and restored vernal pools at Travis Air Force Base near Fairfield, California.Methods In thirty natural and thirty restored pools, we conducted field surveys to measure the distribution and abundance of exotic and native plants and several descriptors of the abiotic environment. We used multiple linear regressions to analyse exotic species richness and cover and the abundances of individual exotic species in relation to pool type, fire history, pool size, water depth, native plant cover, and six soil and nutrient properties.Results Exotic species richness was greater in burned than unburned pools, and exotic plant cover was greater in natural than restored pools. Both exotic species richness and cover decreased with increasing water depth. Exotic species richness was not related to native plant cover, but exotic plant cover decreased with increasing native plant cover. Eighteen of the nineteen most common exotic species showed significant relationships with pool type (twelve species), water depth (eleven species), fire history (nine species), native plant cover (six species), and pool size (five species). Most species increased in abundance with decreasing water depth (nine species) or were more abundant in natural (eight species) or burned pools (six species).Main conclusions These results suggest that both abiotic factors, especially those associated with seasonal inundation, and interactions with the native plant community play important roles in determining the invasibility of vernal pool plant communities. In particular, abiotic constraints may limit exotic plant invasions in more stressful environments, and interactions with the native plant community may limit invasions in more benign environments.
Biogeography ofPlagiochila(Hepaticae): natural species groups span several floristic kingdoms
Authors: Groth Henk , Lindner Melanie , Wilson Rosemary , Hartmann Florian A. , Schmull Michaela , Rob Gradstein S. , Heinrichs Jochen 
Published: October 2010

AbstractAimThis paper presents a synthesis of our recent results regarding the biogeography ofPlagiochilausing a molecular approach, and documents intercontinental ranges within this largest genus of the hepatics.MethodsA maximum likelihood analysis of sixty‐one nrITS sequences ofPlagiochilawas performed and the molecular topology obtained was compared with morphological, phytochemical and geographical data.ResultsOur molecular data set allowed the identification of elevenPlagiochilasections, the majority of which cover at least two floristic kingdoms. Seven sections have species in Europe (sect.Arrectae,Carringtoniae,Fuscoluteae,Glaucescentes,Plagiochila,Rutilantes,Vagae).Plagiochilaspecies from Atlantic Europe are usually close to or conspecific with neotropical taxa, whereas species widespread in Europe are closely related to Asian ones and not to those in the Neotropics.Plagiochilasect.Arrectaerepresents a neotropical – Atlantic European clade. The section is not closely related – as has often been suggested – to the morphologically similar sect.Zonataefrom Asia and western North America. Sequence data show that the AfricanP. integerrimaand the neotropicalP. subplanaare members of the Asian sect.Cucullatae(sect.Ciliatae, syn. nov.), which becomes pantropical in distribution. An ITS sequence ofP. boryanafrom Uganda confirms the Afro‐American range of the primarily neotropical sect.Hylacoetes. Similarities in sporophyte morphology between the sect.Cucullataeand sect.Hylacoetesare the result of parallel evolution.Main conclusionsOur results indicate that intercontinental ranges at section and species level are common inPlagiochila.Carl's (1931)subdivision ofPlagiochilainto sections restricted to one floristic kingdom is outdated. Biogeographical patterns inPlagiochilaare not dissimilar to those of other groups of bryophytes but elucidation of the geographical ranges of the taxa requires a molecular approach.Contrary to earlier belief, mostPlagiochilaspecies from Atlantic Europe do not have close relatives in Asia but are conspecific with or closely related to species from tropical America.
Climatic and biophysical controls on conifer species distributions in mountain forests of Washington State, USA
Authors: McKenzie Donald , Peterson David W. , Peterson David L. , Thornton Peter E. 
Published: October 2010

AbstractAimThe purpose of this study was to quantify relationships between conifer species distributions and climatic and biophysical variables, in order to provide better insight into the potential for redistribution of species on the landscape in response to climatic change.LocationData are from 10,653 georeferenced sites in Washington State, USA, along a longitudinal gradient from west of the crest of the Cascade Range to the beginnings of the western slope of the Rocky Mountains, and across two physiographic provinces, the Northern Cascades, characterized by steep, rugged topography, and the Okanogan Highlands, presenting moderate slopes and broad rounded summits.MethodsTree data were drawn from the USDA Forest Service Area Ecology Program database, collected in mature, undisturbed stands. We compared simple climatic variables (annual temperature, growing‐degree days, annual and seasonal precipitation) to biophysical variables (soil, hydrologic, and solar radiation) derived from climatic variables. Climatic and biophysical variables were taken from the output of climatological and hydrological simulation models and estimated for each plot in the tree database. Generalized linear models were used, for each of fourteen tree species, at multiple spatial extents, to estimate the probability of occurrence of that species as a function of climatic and biophysical predictors. Models were validated by a combination of bootstrapping and estimating receiver operating characteristic (ROC) curves.ResultsFor the majority of species, we were able to fit variables representing both moisture and temperature gradients, and in all but a few cases these models identified a unimodal response of species occurrence to these gradients. In some cases the ecological/environmental niche of a species had been clearly captured by the model, whereas in others a longer gradient in the predictor variable(s) would be needed. Responses of most species were consistent across three spatial scales.Main conclusionsBy identifying the ecological niches of multiple species, we can forecast their redistribution on the landscape in response to climatic change, evaluate the predictions of simulation models, and alert managers to particularly sensitive or vulnerable ecosystems and landscapes.
Biogeography and phylogeny of the New Zealand cicada genera (Hemiptera: Cicadidae) based on nuclear and mitochondrial DNA data
Authors: Arensburger Peter , Buckley Thomas R. , Simon Chris , Moulds Max , Holsinger Kent E. 
Published: October 2010

AbstractAim Determine the geographical and temporal origins of New Zealand cicadas.Location New Zealand, eastern Australia and New Caledonia.Methods DNA sequences from 14 species of cicadas from New Zealand, Australia, and New Caledonia were examined. A total of 4628 bp were analysed from whole genome extraction of four mitochondrial genes (cytochrome oxidase subunits I and II, and ribosomal 12S and 16S subunits) and one nuclear gene (elongation factor‐1 alpha). These DNA sequences were aligned and analysed using standard phylogenetic methods based primarily on the maximum likelihood optimality criterion. Dates of divergences between clades were determined using several molecular clock methods.Results New Zealand cicadas form two well‐defined clades. One clade groups with Australian taxa, the other with New Caledonian taxa. The molecular clock analyses indicate that New Zealand genera diverged from the Australian and New Caledonian genera within the last 11.6 Myr.Main conclusions New Zealand was likely colonized by two or more invasions. One NZ lineage has its closest relatives in Australia and the other in New Caledonia. These invasions occurred well after New Zealand became isolated from other land masses, therefore cicadas must have crossed large bodies of water to reach New Zealand.
Phylogeography ofPtychadena mascareniensissuggests transoceanic dispersal in a widespread African‐Malagasy frog lineage
Authors: Vences Miguel , Kosuch Joachim , Rödel Mark‐Oliver , Lötters Stefan , Channing Alan , Glaw Frank , Böhme Wolfgang 
Published: October 2010

AbstractAim The Mascarene ridged frog,Ptychadena mascareniensis, is the only African amphibian species thought to occur on Madagascar and on the Seychelles and also Mascarene islands. We explored its phylogenetic relationships and intraspecific genetic differentiation to contribute to the understanding of transoceanic dispersal in amphibians.Methods Fragments of the mitochondrial 16S rRNA gene were sequenced from specimens collected over most of the distribution area ofP. mascareniensis, including populations from Madagascar, Mascarenes and Seychelles.Results We identified five deeply divergent clades having pairwise divergences >5%, which probably all represent cryptic species in aP. mascareniensiscomplex. One of these seems to be restricted to Madagascar, the Mascarenes and the Seychelles. Sequences obtained from topotypic material (Réunion) were identical to the most widespread haplotype from Madagascar. The single Mauritian/Seychellean haplotype differed by only one mutation from a Malagasy haplotype.Main conclusions It is likely that the Mascarene and Seychellean populations were introduced from Madagascar by humans. In contrast, the absence of the Malagasy haplotypes from Africa and the distinct divergences among Malagasy populations (16 mutations in one divergent hapolotype from northern Madagascar) suggest that Madagascar was populated byPtychadenabefore the arrival of humansc.2000 years ago. Because Madagascar has been separated from Africa since the Jurassic, this colonization must have taken place by overseas rafting, which may be a more widespread dispersal mode in amphibians than commonly thought.