| Titre : | Life history traits: A possible cause for the higher frequency of occurence of Zannichellia pedunculata than of Zannichellia obtusifolia in temporary marshes |
| Auteurs : | Patrick Grillas ; C. Van Wijck ; A. Bonis |
| Publisher : | Aquat Bot 42 p1-13 |
| Type de document : | Article |
| Année de publication : | 1991 |
| Mots-clés : | Camargue ; TdV ; Monocotyledonae ; Zannichellia ; Zannichellia pedunculata ; Zannichellia obtusifolia ; Autécologie végétale ; Evolution ; marais ; Milieu temporaire |
| Résumé : |
Zannichellia pedunculata Reichenb. andZannichellia obtusifolia Talavera, Garcia-Murillo & Smit have been recorded in the marshes of the Camargue (south of France). Of these species,Z. pedunculata is very common, butZ. obtusifolia is rare. In three neighbouring marshes,Z. pedunculata andZ. obtusifolia occur regularly together. These two species have a similar morphology. Some of their life history traits were compared experimentally in natural and artificial habitats.
At the two concentrations of Cl− studied (0 and 2 g l−1), the percentage germination ofZ. obtusifolia (100% and 96%, respectively) is equal to or higher than that ofZ. pedunculata (100% and 38%, respectively) when the seeds are not allowed to dry out. In contrast, when the seeds have undergone desiccation, the percentage germination ofZ. pedunculata is higher (94% and 64%, respectively) than that ofZ. obtusifolia (88% and 56%, respectively at the two concentrations of Cl−, 0 and 2 g l−1). Salinity and the date of flooding were found to affect the biomass of both species ofZannichellia similarly. After flooding in autumn,Zannichellia pedunculata is capable of producing fruit before the winter, butZ. obtusifolia does not do so until the following spring. The inability to reproduce in the autumn, and the negative influence of desiccation on the rate of germination and percentage germination, can explain whyZ. obtusifolia is uncommon in the Camargue marshes which are s |
Exemplaires (1)
| Code-barres | Cote | Support | Localisation | Section | Disponibilité |
|---|---|---|---|---|---|
| 5973 | 17632*(91193) *per | Périodique | Bibliothèque | Pdoc | Disponible |
