|
Exemplaires(0)
| Disponibilité | ||
|---|---|---|
| aucun exemplaire | ||
Dépouillements
Ajouter le résultat dans votre panierFitness and growth of the ephemeral mudflat species Cyperus fuscus in river and anthropogenic habitats in response to fluctuating water-levels / Jörg Böckelmann in Flora, vol. 234 (Année 2017)
Titre : Fitness and growth of the ephemeral mudflat species Cyperus fuscus in river and anthropogenic habitats in response to fluctuating water-levels Type de document : texte imprimé Auteurs : Jörg Böckelmann, Auteur ; Karin Tremetsberger, Auteur ; Katerina Sumberova, Auteur ; Heinrich Grausgruber, Auteur ; Karl-Georg Bernhardt, Auteur Année de publication : 2017 Article en page(s) : pp. 135-149 Langues : Anglais (eng) Catégories : [habitats/milieux] ZH - Zones humides Mots-clés : Flooding Isoëto-Nanojuncetea Secondary habitats Phenotypic plasticity Soil seed bank végétation Résumé : "Cyperus fuscus is a representative of threatened ephemeral wetland plant communities in summer-dry shoreline habitats. We compared variation and plasticity in traits related to fitness and growth of plants germinating from the soil seed bank and established plants from river and secondary anthropogenic habitats. Plants from sites at rivers, fishponds and fish storage ponds were cultivated and selfed to get homogenous seed material for a germination and an environmental manipulation experiment involving three different water regimes. Differences in traits and their plasticities were evaluated by means of linear mixed models. Cyperus fuscus followed a low-oxygen escape strategy when flooded. Seeds of plants derived from the soil seed bank germinated faster than seeds of plants derived from established plants suggesting that short-term selection of genotypes is mediated by the particular conditions on the site during germination. The experiment revealed significant differences between river and secondary habitats as well as between the soil seed bank and established plants. For example, plants from river habitats produced the highest number of culms with inflorescences. The difference was most evident under partial submergence. Plants from fish storage ponds rapidly reached the reproductive phase, but produced less culms with inflorescences. This seemingly allows them to cope with numerous and irregular disturbances and intensive substrate moisture changes. Our results suggest that populations have adapted to conditions at secondary habitats provided by fish farming during the last centuries." Type de publication : périodique Référence biblio : Böckelmann J., Tremetsberger K., Sumberova K., Grausgruber H., Bernhardt K.-G., 2017 - Fitness and growth of the ephemeral mudflat species Cyperus fuscus in river and anthropogenic habitats in response to fluctuating water-levels. Flora, 234 : 135-149. DOI : 10.1016/j.flora.2017.07.012 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=66243
in Flora > vol. 234 (Année 2017) . - pp. 135-149[article]Exemplaires(0)
Disponibilité aucun exemplaire
Titre : Extracellular ice management in the frost hardy horsetail Equisetum hyemale L Type de document : texte imprimé Auteurs : Rena Schott, Auteur ; Dagmar Voigt, Auteur ; Anita Roth-Nebelsick, Auteur Année de publication : 2017 Article en page(s) : pp. 207-214 Langues : Anglais (eng) Mots-clés : Equisetum hyemale acclimatation chlorenchyma cold storage cold tolerance cortex crystals freezing frost ice intercellular spaces pith scanning electron microscopy shoots été hiver Résumé : "Formation of extracellular ice at specific positions in the plant interior is a common and probably essential component of plant cold hardiness. Studies on extracellular freezing in spore-bearing plants are, however, scarce. In this study, extracellular ice formation in the cold hardy horsetail Equisetum hyemale L. is analyzed. Horsetails show an extensive system of intercellular air spaces which are probably crucial for internal ice storage during winter. Previous studies emphasized the spacious pith cavity as the main place for ice crystal growth. Shoots were studied during summer and in the frozen state in winter, after natural acclimatization, by using digital (incident light) microscopy, Scanning Electron Microscopy and Cryo Scanning Electron Microscopy. It was shown that the vallecular canals also contain a large share of ice bodies under freezing conditions. The vallecular canals, which are directly seated within the cortex and whose interior is directly connected to the cortex via gaps in the canal wall, were often and rapidly filled with ice. The pith cavity also contained ice, depending on the position along the shoot and the internode. The carinal canals contained almost no ice crystals. Furthermore, some ice crystals were detected in the intercellular spaces of the chlorenchyma and the substomatal chamber. The stomatal antechamber, however, was always ice-free, probably due to the presence of water-repellent wax crystals. The results of this study support available evidence for the crucial role of pre-existing extensive lacunae for extracellular ice formation in E. hyemale. Furthermore, the findings indicate that anatomical details of canal structure and position are important for the pattern of extracellular ice accumulation." Type de publication : périodique Référence biblio : Schott R., Voigt D., Roth-Nebelsick A., 2017 - Extracellular ice management in the frost hardy horsetail Equisetum hyemale L. Flora, 234 : 207-214. DOI : 10.1016/j.flora.2017.07.018 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=66244
in Flora > vol. 234 (Année 2017) . - pp. 207-214[article]Exemplaires(0)
Disponibilité aucun exemplaire
Titre : Do Ellenberg?s indicator values apply to the vascular plants colonizing decaying logs in mountain forests ? Type de document : texte imprimé Auteurs : Damian Chmura, Auteur ; Jan Zarnowiec, Auteur ; Monika Staniaszek-Kik, Auteur Année de publication : 2017 Article en page(s) : pp. 15-23 Langues : Anglais (eng) Catégories : [habitats/milieux] 4 - Forêts
[Thèmes] Flore vasculaire (phanérogames et cryptogames vasculaires)
[Thèmes] MontagneMots-clés : valeur indicatrice d'Ellenberg étalonnage Résumé : "We investigated the applicability of EllenbergÂ’s indicator values (EIVs) on coarse woody debris (CWD). Given that a small number of vascular plant species forms the pool of potential colonizers, we wanted to examine whether the properties of decaying logs and site characteristics can be predicted using EIVs. A comparison was made between the EIVs of the flora inhabiting mineral soil and plants colonizing 364 decaying logs of Picea abies and Fagus sylvatica in the Karkonosze Mts., southern Poland. We used correlation tests to assess the relationships between the mean and weighted EIVs and the decomposition stage of a decaying log, light conditions and moisture as well as the altitude at which the dead logs were lying. There were no significant differences in the mean EIVs between the species growing on mineral soil and CWD, except for the soil reaction, which was higher on the spruce logs. The plants colonizing decaying downed trees reflect the climatic conditions and altitude, i.e. elevation index, approximated heat load and vegetational gradient better than the edaphic conditions, i.e. the properties of dead wood such as its decomposition and moisture. We concluded that, in spite of the fact that in terms of biotopes fallen trees can be treated as synusia in forest communities, bioindication using the EIVs is not only possible but also predictable. Species that are present on CWD thus should be included in assessments of forest habitat conditions." (source : auteur) Type de publication : périodique Référence biblio : Chmura D., Zarnowiec J., Staniaszek-Kik M., 2017 - Do Ellenberg?s indicator values apply to the vascular plants colonizing decaying logs in mountain forests ? Flora, 234 : 15-23. Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=66245
in Flora > vol. 234 (Année 2017) . - pp. 15-23[article]Exemplaires(0)
Disponibilité aucun exemplaire
Titre : Divergent adaptations in different parts of introduced range in tetraploid Vicia cracca Type de document : texte imprimé Auteurs : Zuzana LÃblová, Auteur ; Anezka Eliasova, Auteur ; Zuzana Münzbergová, Auteur Année de publication : 2017 Article en page(s) : pp. 245-255 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Vicia cracca
[ZG] Amérique du nord
[ZG] EuropeMots-clés : capacité d'adaptation cytotype plante native plante invasive plante polyploïde Résumé : "Understanding causes of species invasiveness is a necessary condition for effective mitigation of invasive species. One of the key characteristics supporting species invasiveness may be species ability to adapt to wide range of environmental conditions. It has been hypothesized that increased ability to adapt to wide range of conditions may be related to polyploidization. Experimental studies comparing the ability to adapt to novel conditions between native and invasive populations of different cytotypes of the same species are, however, still largely missing.
We used Vicia cracca, a species known to occur in two different cytotypes in its native range in Europe and being an important invader in North America. We investigate if known cytotypes of Vicia cracca from the native and invasive range differ in their ability to adapt to environmental variation. To do this, we grew plants of both cytotypes from the native and invasive range in a common garden and exposed half of the plants to experimental shading to simulate environmental variation potentially occurring at the localities of the species.
The study confirmed previous expectation that only polyploid plants occur in the invasive range. The study, however, did not support the expectation that the tetraploids would be superior to the diploids from the native range or have better ability to cope with shading. The performance and plasticity of tetraploids from the invasive range was in most cases different from the European tetraploids and differed between the two areas in the invasive range. This may suggest that the tetraploids underwent strong post-invasive evolution and have adapted in different ways to the specific condition of the different parts of the invaded area. Alternatively, it may indicate that the invasive range was created by colonizers from different areas possessing distinct adaptations." (source : auteurs)Type de publication : périodique Référence biblio : LÃblová Z., Eliasova A., Münzbergová Z., 2017 - Divergent adaptations in different parts of introduced range in tetraploid Vicia cracca. Flora, 234 : 245-255. DOI : 10.1016/j.flora.2017.07.010 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=66246
in Flora > vol. 234 (Année 2017) . - pp. 245-255[article]Exemplaires(0)
Disponibilité aucun exemplaire
