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Ajouter le résultat dans votre panierThe habitat factors that affect the composition of bryophyte and lichen communities on fallen logs / Irena Jansova in Preslia, 78 (2006)
Titre : The habitat factors that affect the composition of bryophyte and lichen communities on fallen logs Type de document : Électronique Auteurs : Irena Jansova ; Zdeněk Soldán (1957-) Année de publication : 2006 Article en page(s) : 67-86 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Bryophytes
[CBNPMP-Géographique] République TchèqueRésumé : The composition of cryptogam (bryophyte and lichen) communities on fallen logs was studied in two old-growth forests in the Czech Republic. Altogether, 85 species (22 liverworts, 44 mosses, and 19 lichens) were recorded. The presence and abundance of the different species on 350 logs was attributed to habitat factors (e.g. humidity, wood decay, wood softness, log diameter, bark cover, thickness of humus layer and tree species) that were recorded separately for each of the logs. The aim was to identify the factors significantly affecting the composition of cryptogam communities. For the different ecological groups of species (epiphytes, epixylic species, and ground flora) forwarded canonical correspondence analysis (CCA) selected thickness of humus layer and tree species as the factors explaining most variability. In addition, the extent of log surface covered by bark, humidity and log decay were selected as significant determinants of cryptogam community composition. Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=141982
in Preslia > 78 (2006) . - 67-86Jansova, Irena, Soldán, Zdeněk (1957-) 2006 The habitat factors that affect the composition of bryophyte and lichen communities on fallen logs. Preslia, 78: 67-86.Documents numériques
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Titre : Seasonal pattern of germination and seed longevity in the invasive species Heracleum mantegazzianum Type de document : Électronique Auteurs : Lenka Moracova ; Petr Pyšek ; Jan Pergl (1977-) ; Irena Perglova ; Vojtěch Jarošík (1958-2013) Année de publication : 2006 Article en page(s) : 287-301 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Plantes subspontanées, naturalisées, envahissantes
[CBNPMP-Géographique] République TchèqueMots-clés : Heracleum mantegazzianum Sommier & Levier Résumé : We investigated the effects of different temperature regimes and dry storage on germination of H. mantegazzianum (Apiaceae, native to Caucasus) seeds in the laboratory and linked the results with studies of seasonal seed bank depletion in a common garden experiment and under field conditions. Seeds were collected at seven sites in the Slavkovský les region, Czech Republic, cold-stratified for 2 months and germinated at seven temperature regimes. Under all temperature regimes, fresh seeds germinated to significantly higher percentages than older (1, 2, 3 years) seeds. For all storage lengths, seeds germinated best at alternating day/night temperatures of 20/5 °C. The length of the germination period had a significant effect only at low constant temperatures of 2 and 6 °C, where germination percentage increased between 2 and 6 months. Seasonal germination exhibited a distinct pattern, with rapid depletion of seed bank by the first spring after seed burial. Non-dormant seeds were present in the soil early in spring and late in autumn. The higher summer temperatures prevented dormancy breaking and another cold period of at least two months below 10 °C was needed to bring non-germinated seeds out of dormancy. The results suggest that (1) seed dormancy of H. mantegazzianum was not completely broken until the first spring, but that some seeds re-enter or retain dormancy during high summer temperatures and that (2) the threshold needed for breaking the dormancy was achieved gradually during the cold autumn and winter months. However, in a small fraction of seeds the dormancy breaking process took several years. Of seeds buried in 10 different regions of the Czech Republic, on average 8.8% survived 1 year, 2.7% 2 years and 1.2% remained viable and dormant after 3 years of burial. The ability of even small fraction of H. mantegazzianum seeds to survive for at least 3 years can result in re-invasion of this species into controlled sites. Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=142012
in Preslia > 78 (2006) . - 287-301Moracova, Lenka, Pyšek, Petr, Pergl, Jan (1977-), Perglova, Irena, Jarošík, Vojtěch (1958-2013) 2006 Seasonal pattern of germination and seed longevity in the invasive species Heracleum mantegazzianum. Preslia, 78: 287-301.Documents numériques
Article (2006)Adobe Acrobat PDF
Titre : Scale dependence of native and alien species richness in North American floras Type de document : Électronique Auteurs : Michael W Palmer Année de publication : 2006 Article en page(s) : 427-436 Langues : Anglais (eng) Catégories : [CBNPMP-Géographique] Etats-Unis
[CBNPMP-Thématique] Plantes subspontanées, naturalisées, envahissantesRésumé : I analyzed data from 1870 vascular floras from regions within North America to assess whether the determinants of native and alien diversity vary as a function of spatial grain. Moving window multiple regression revealed that richness of both native and alien species exhibit the expected species-area relationship, latitudinal gradient, elevation gradient, and year of publication effect. However, the strength of these factors varied between native and alien species, and as a function of scale. Alien diversity was more predictable than native diversity, and is more strongly related to elevation and latitude. For both groups, the latitudinal gradient is most pronounced at broad grains, and the elevational gradient is most pronounced at fine grains. Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=142470
in Preslia > 78 (2006) . - 427-436Palmer, Michael W 2006 Scale dependence of native and alien species richness in North American floras. Preslia, 78: 427-436.Documents numériques
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Titre : Scale and plant invasions : a theory of biotic acceptance Type de document : Électronique Auteurs : Thomas J. Stohlgren ; Catherine Jarnevich ; Geneva W Chong ; Paul H Evangelista Année de publication : 2006 Article en page(s) : 405-426 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Plantes subspontanées, naturalisées, envahissantes Résumé : We examined the relationship between native and alien plant species richness, cover, and estimated biomass at multiple spatial scales. The large dataset included 7051 1-m2 subplots, 1443 10-m2 subplots, and 727 100-m2 subplots, nested in 727 1000-m2 plots in 37 natural vegetation types in seven states in the central United States. We found that native and alien species richness (averaged across the vegetation types) increased significantly with plot area. Furthermore, the relationship between native and alien species richness became increasingly positive and significant from the plant neighbourhood scale (1-m2) to the 10-m2, 100-m2, and the 1000-m2 scale where over 80% of the vegetation types had positive slopes between native and alien species richness. Both native and alien plant species may be responding to increased resource availability and/or habitat heterogeneity with increased area. We found significant positive relationships between the coefficient of variation of native cover in 1-m2 subplots in a vegetation type (i.e. a measure of habitat heterogeneity), and both the relative cover and relative biomass of alien plant species. At the 1000-m2 scale, we did find weak negative relationships between native species richness and the cover, biomass, and relative cover of alien plant species. However, we found very strong positive relationships between alien species richness and the cover, relative cover, and relative biomass of alien species at regional scales. These results, along with many other field studies in natural ecosystems, show that the dominant general pattern in invasion ecology at multiple spatial scales is one of “biotic acceptance” where natural ecosystems tend to accommodate the establishment and coexistence of introduced species despite the presence and abundance of native species. Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=142478
in Preslia > 78 (2006) . - 405-426Stohlgren, Thomas J., Jarnevich, Catherine, Chong, Geneva W, Evangelista, Paul H 2006 Scale and plant invasions : a theory of biotic acceptance. Preslia, 78: 405-426.Documents numériques
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Titre : Who cites who in the invasion zoo : insights from an analysis of the most highly cited papers in invasion ecology Type de document : Électronique Auteurs : Petr Pyšek ; David Mark Richardson (1958-) ; Vojtěch Jarošík (1958-2013) Année de publication : 2006 Article en page(s) : 437-468 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Plantes subspontanées, naturalisées, envahissantes Résumé : The citation frequency of papers on invasion ecology published between 1981 and 2003 and that had accumulated at least 30 citations on the Web of Science on 9 August 2006 was analysed. The dataset comprised 329 papers and 27,240 citations. For each paper, the total number of citations was recorded and the annual citation rate (number of citations per year) was calculated. Papers were classified into broad research fields: plant invasions, animal invasions, biological control, and general papers (reviews and syntheses). Eight papers were cited more than 300 times, five of them dealt with general topics, and the mean value of the total number of citations across the whole data set is 82.8±73.1. The mean annual citation rate is 11.5±11.3 citations per year; six studies received on average at least 50 citations each year. About a half (50.8%) of papers in the data set deal with plant invasions. General papers are significantly more cited than papers from the other categories. The annual citation rate increased with time over the analysed period (1981–2003), by 1.0 citations per year. To compare the trends in invasion ecology with those in other fields of ecology, comparable data were compiled for population ecology and dynamics, and global change. The annual citation rate for invasion ecology as a whole increased faster than that for population ecology and dynamics, but not exponentially as is the case with studies on global change. The best-cited papers on invasion ecology were distributed among most of the top ecology journals. Those published in Oikos, Journal of Ecology, Ecological Applications and BioScience are cited 3.8–5.8 times more than the average for these journals (based on the impact factor). Papers on biodiversity, community ecology, impact, invasibility, dispersal, population ecology, competition, resources, genetical issues, biological control and species invasiveness received the highest total number of citations. However, measured by the annual citation rate, the hottest current topics in invasion ecology are the effect of global change on invasions, the role of natural enemies, character of the invasion process, evolutionary aspects, invasibility of communities and ecosystem processes. Some topics are disproportionally more cited than studied and vice versa. Studies on plant and animal invasions differ in focus: the topics of invasibility, biodiversity, resources, species invasiveness and population genetics are more emphasized in botanical studies, dispersal, competition, impact and pathways in papers dealing with animal invasions. Studies of grasslands and marine environment are most frequently cited in botanical and zoological studies, respectively. Most of the highly cited papers deal with multiple species; only 14 plant species and four animal species are the primary focus of one or more of the highly-cited papers. Twenty-two authors (4.5% of the total involved in the papers analysed), each with seven or more contributions cited at least 30 times, together contributed 49.4% of the most-cited papers, and attracted 55.6% of the total number of citations. Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=142484
in Preslia > 78 (2006) . - 437-468Pyšek, Petr, Richardson, David Mark (1958-), Jarošík, Vojtěch (1958-2013) 2006 Who cites who in the invasion zoo : insights from an analysis of the most highly cited papers in invasion ecology. Preslia, 78: 437-468.Documents numériques
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Titre : Pinus : a model group for unlocking the secrets of alien plant invasions ? Type de document : Électronique Auteurs : David Mark Richardson (1958-) Année de publication : 2006 Article en page(s) : 375–388 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Plantes subspontanées, naturalisées, envahissantes Mots-clés : Pinus Résumé : The global-scale natural experiment created by the widespread dissemination of most of the 111 species of pines (genus Pinus, family Pinaceae) has shed light on many aspects of plant invasion ecology. Introductions and the fate of alien pines have been well documented worldwide, facilitating the accurate labelling of species as “naturalized”, “invasive”, or “non-invasive” using objective criteria. Thirty species are naturalized and 21 are invasive. Three life-history traits that clearly separate invasive from non-invasive taxa define the inherent ability of species to disperse over long distances, win in competition against other plants, and to survive or proliferate under a range of disturbance regimes. The realization of colonization opportunities for potentially invasive pines is determined by extrinsic factors, especially those that mediate seedling establishment. Meta-analysis of many introduction/invasion events revealed the interplay of factors. Detailed studies of pine invasions have elucidated the roles of long-distance seed dispersal and propagule pressure in driving invasions. Enhanced understanding of the ecology of pine invasions has improved our ability to manage these invasions. No other speciose genus of plants has yielded important insights on so many facets of invasion ecology. Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=142487
in Preslia > 78 (2006) . - 375–388Richardson, David Mark (1958-) 2006 Pinus : a model group for unlocking the secrets of alien plant invasions ? Preslia, 78: 375–388.Documents numériques
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Titre : Flowering phenology and reproductive effort of the invasive alien plant Heracleum mantegazzianum Type de document : Électronique Auteurs : Irena Perglova ; Jan Pergl (1977-) ; Petr Pyšek Année de publication : 2006 Article en page(s) : 265-285 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Biologie de la reproduction
[CBNPMP-Thématique] Plantes subspontanées, naturalisées, envahissantesMots-clés : Heracleum mantegazzianum Sommier & Levier Résumé : Heracleum mantegazzianum is one of the most invasive species in the Czech flora. The present study describes its flowering phenology and assess the effectiveness of protandry in preventing selfing in this self-compatible species, describes the timing of flowering in a heavily invaded area of Slavkovský les (Czech Republic) and estimates fruit set in a large sample of plants, which provides reliable data on the often exaggerated fecundity of this species. The study of flowering phenology revealed that protandry is always effective only within individual flowers, where male and female flowering phases are completely separated. In contrast, anther dehiscence in some flowers can occasionally overlap with stigma receptivity in other flowers in the same umbel, providing an opportunity for geitonogamous (i.e. between-flower) selfing. Nevertheless, the potential for selfing in H. mantegazzianum is determined mainly by an overlap in the male and female flowering phases between umbels on the same plant; at least a short overlap between some umbels was observed in 99% of the plants at the Slavkovský les. Although the degree of protandry in H. mantegazzianum favours outcrossing, the opportunity to self may be of crucial importance for an invasive plant, especially if a single plant colonizes a new location. At Slavkovský les, flowering started within one week (from 20 to 27 June 2002) at all 10 sites. The duration of flowering of an individual plantwas on average 36 days,with maximum of 60 days, and increased significantly with the number of umbels on a plant. In the second half of August, the majority of the fruits were ripe and had started to be shed. The beginning of flowering of a plant was significantly negatively correlated with the number of umbels it had – the earlier a plant started to flower the more umbels it had produced. A significant negative relationship was also found between basal diameter and beginning of flowering; plants with large basal diameters started to flower earlier. An average plant at Slavkovský les produced 20,671 fruits. Of these, 44.6% were produced by the terminal umbel, 29.3% by secondary umbels on satellites, 22.6% by secondary umbels on branches and only 3.5% by tertiary umbels. The estimated fruit number of the most fecund plant was 46,470 – compared to an average plant, the proportional contribution of tertiary umbels increased relative to the primary umbel. This study revealed a significant positive relationship between fecundity and plant basal diameter. Although the results of this study indicate that the fecundity of this species is often overestimated in the literature, the number of fruits produced by H. mantegazzianum provides this invasive species with an enormous reproductive capacity. Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=142552
in Preslia > 78 (2006) . - 265-285Perglova, Irena, Pergl, Jan (1977-), Pyšek, Petr 2006 Flowering phenology and reproductive effort of the invasive alien plant Heracleum mantegazzianum. Preslia, 78: 265-285.Documents numériques
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Titre : Habitat variability and classification of Utricularia communities: Comparison of peat depressions in Slovakia and the Trebon basin Type de document : Électronique Auteurs : Daniel Dite ; Jana Navratilova ; Michal Hájek (1974-) ; Milan Valachovic ; Drahoslava Pukajova Année de publication : 2006 Article en page(s) : 331-343 Langues : Anglais (eng) Résumé : Vegetation with species of Utricularia and that dominated by Eleocharis quinqueflora, which occupy the same habitats. was studied in minerotrophic mires and oligotrophic wetlands associated with ponds. Relative towater and soil chemistry, the communities of Utricularia ochroleuca s.l. and U. intermedia occurred in mineral-poor and those of U. minor and U. australis in mineral-rich conditions. Rare stands with U. vulgaris occurred in conditions that were intermediate in mineral richness. Four communities belonging to the class Isoëto-Littorelletea were distinguished. Vegetation without bladderworts and dominated by E. quinqueflora occurs in calcareous fens and belongs to the class Scheuchzerio-Caricetea fuscae (the Caricion davallianae alliance). Vegetation with U. intermedia is characterized by high vascular plant cover and belongs to the class Scheuchzerio-Caricetea fuscae. Utricularia ochroleuca s.l. prefers open, acidic and waterlogged depressions in peat, whereas U. intermedia grows mostly in the shade under vegetation canopy. In this study, U. minor and U. australis have been found mainly in the more alkaline and mineral-rich habitats, and both species also tolerated extremely high mineral richness. Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=142971
in Preslia > 78 (2006) . - 331-343Dite, Daniel, Navratilova, Jana, Hájek, Michal (1974-), Valachovic, Milan, Pukajova, Drahoslava 2006 Habitat variability and classification of Utricularia communities: Comparison of peat depressions in Slovakia and the Trebon basin. Preslia, 78: 331-343.Documents numériques
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Titre : Syntaxonomical revision of the Molinionmeadows in the Czech Republic Type de document : Imprimé Auteurs : Marcela Havlová Année de publication : 2006 Article en page(s) : 87-101 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Groupements végétaux, phytosociologie
[LOTERRE-Biodiversité] PhytosociologieMots-clés : Molinion Résumé : A syntaxonomical revision of meadows of the Molinion caeruleae Koch 1926 alliance in the Czech Republic is presented. Of ten associations reported previously for the Czech Republic only two were distinguished using the Cocktail method – Molinietum caeruleae Koch 1926 and Junco effusi-Molinietum caeruleae Tüxen 1954. The former occurs on more base-rich soils, while the latter is found in more acidic habitats and characterized by the occurrence of species of Nardus grasslands. Results of this classification were compared with classifications of Molinion meadows for other countries of Central Europe. Main environmental gradients responsible for variation in species composition of Czech Molinion meadows were revealed by detrended correspondence analysis. For interpretation of these gradients correlations with Ellenberg indicator values and altitude were used. The main gradient positively correlates with soil base status, continentality, temperature and nutrients, and negatively with altitude. Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=150338
in Preslia > 78 (2006) . - 87-101Havlová, Marcela 2006 Syntaxonomical revision of the Molinionmeadows in the Czech Republic. Preslia, 78: 87-101.Documents numériques
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