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Auteur Aurélie Boissezon |
Documents disponibles écrits par cet auteur (2)
trié(s) par (Pertinence décroissant(e), Titre croissant(e)) Affiner la rechercheNew insights into the ecology and phenology of two Characeae : N. opaca (Bruzelius) C. Agardh and N. gracilis (Sm.) C. Agardh / Dominique Auderset Joye in Botany letters, vol. 165, n°1 (Année 2018)
Titre : New insights into the ecology and phenology of two Characeae : N. opaca (Bruzelius) C. Agardh and N. gracilis (Sm.) C. Agardh Type de document : texte imprimé Auteurs : Dominique Auderset Joye, Auteur ; Aurélie Boissezon, Auteur Année de publication : 2018 Article en page(s) : pp. 91-102 Langues : Anglais (eng) Catégories : [ZG] Suisse
[habitats/milieux] ZH - Zones humidesMots-clés : cycle de vie growing degree days pond bed air exposure water chemistry light Résumé : "The study addressed the ecology and life cycle of two charophyte species, which are both at risk of extinction and on several Red Lists in Europe. Populations of Nitella opaca and N. gracilis, sometimes occurring together in three wetland ponds, were monitored for several years, and environmental data were also recorded. The pattern and timing of emergence (new shoots) and maturation of the sexual organs (antheridia, oogonia, and ripe oospores) were determined on plant samples collected regularly. The species phenophases were related to the environmental data. The results showed that species distribution can be linked to the water calcium content, a parameter that most differed in the three ponds. N. gracilis developed population only in ponds with very low calcium concentrations, whereas N. opaca had a wider tolerance. Following a pond bed air exposure in previous year, dense populations of N. opaca and N. gracilis were observed. None, or only a few individuals, were found when the waterbodies remained flooded the whole preceding year. Light and temperature affect differently the emergence of sex organs and the maturation of oospores. Both species differed in the timing of their phenophases. N. opaca appeared in March, reproduced and disappeared in July. N. gracilis was generally observed later in spring, and after full reproduction, the plants started a second cycle in late summer, while new oospore germination occurred. N. gracilis was perennial and reproduced all year long. Taking these results into account will help to design conservation plans for N. opaca and N. gracilis." (source : auteurs) Type de publication : périodique Référence biblio : Auderset Joye D., Boissezon A., 2018 - New insights into the ecology and phenology of two Characeae : N. opaca (Bruzelius) C. Agardh and N. gracilis (Sm.) C. Agardh. Botany letters, 165 (1) : 91-102. ID PMB : 67239 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=67239
in Botany letters > vol. 165, n°1 (Année 2018) . - pp. 91-102[article]Exemplaires(1)
Cote Localisation Disponibilité P0177-6 Brest Exclu du prêt
Titre : Temporal and spatial changes in population structure of the freshwater macroalga Nitellopsis obtusa (Desv.) J.Groves Type de document : texte imprimé Auteurs : Aurélie Boissezon, Auteur ; Dominique Auderset Joye, Auteur ; Teidy Garcia, Auteur Année de publication : 2018 Article en page(s) : pp. 103-114 Langues : Anglais (eng) Mots-clés : Starry stonewort  abundance  phenology  drought  degree-days  day duration Résumé : "Nitellopsis obtusa usually inhabits deep lakes, where the plants display vegetative growth and survive through the winter. In the present study we investigated a shallow lake where Nitellopsis reproduces sexually; we were interested in the effect of light conditions, temperature and water level on sexual reproduction of the species and its ability to survive lakebed drying. We estimated the distribution of all macrophyte species each July from 2009 to 2014 and correlated annual variations with fluctuations in hydrological conditions. We also sampled a variety of morphological characteristics of N. obtusa plants in nine periods throughout the 2009 and 2010 growth seasons and related them to water depth, day length and accumulated heat energy (growing degree-day) at the date of sampling. N. obtusa population was negatively impacted by decrease of water level, probably through the combined effects of competition with fast-growing pioneer species and lack of intrinsic ecological requirements. The fertility of N. obtusa could be interpreted as a response to disturbance in external conditions, leading to the production of long-lived and drought-resistant oospores. Development of male shoots prior to female shoots and their persistence throughout the season probably optimize the fertilization process. Sexual reproduction seems to be controlled by light and temperature conditions. An alternative hypothesis suggests that fertile and sterile populations belong to two distinct ecotypes." Type de publication : périodique Référence biblio : Boissezon A., Auderset Joye D., Garcia T., 2018 - Temporal and spatial changes in population structure of the freshwater macroalga Nitellopsis obtusa (Desv.) J.Groves. Botany letters, 165 (1) : 103-114. Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=67240
in Botany letters > vol. 165, n°1 (Année 2018) . - pp. 103-114[article]Exemplaires(1)
Cote Localisation Disponibilité P0177-6 Brest Exclu du prêt
