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Exemplaires(1)
| Cote | Localisation | Disponibilité |
|---|---|---|
| P0179-2 | Brest | Exclu du prêt |
Dépouillements
Ajouter le résultat dans votre panierEffects of fire disturbance on alpha and beta diversity and on beta diversity components of soil seed banks and aboveground vegetation / Mehdi Heydari in Plant Ecology and Evolution, vol. 150, n°3 (Année 2017)
Titre : Effects of fire disturbance on alpha and beta diversity and on beta diversity components of soil seed banks and aboveground vegetation Type de document : texte imprimé Auteurs : Mehdi Heydari, Auteur ; Reza Omidipour, Auteur ; Mehdi Abedi, Auteur ; Carol Baskin, Auteur Année de publication : 2017 Article en page(s) : pp. 247-256 Langues : Anglais (eng) Mots-clés : partitionnement additif de la diversité perturbation milieu semi-aride bois (lieu) Résumé : "Background and aims – Although an understanding of the effects of fire severity on diversity components of the soil seed bank (SSB) and aboveground vegetation (AGV) is important to inform conservation and restoration practices of biodiversity, the effects of fire severity on α- and β-diversity of SSB and AGV are poorly understood. While β-diversity is shaped by spatial turnover and nestedness, research on the effects of fire severity on these components of β-diversity is limited. We aimed to determine the effects of low and high fire severity on species richness and α- (within sample) and β- (among sample) diversity components on the relationship between the SSB and AGV. Since turnover and nestedness are components of β-diversity, we assessed their patterns of change after different fire intensities in the SSB and AGV. Methods – Soil seed bank samples were collected from the same 180 sample points used for measurement of AGV in semi-arid Quercus persica woodlands. Additive partitioning diversity was used to divide total diversity into α-and β-diversity of the SSB and the AGV. Total β-diversity of the SSB and AGV was additively partitioned into spatial turnover and nestedness. Key results – Fire severity had significant effects on α- and β-diversity of both the SSB and AGV. The highest and lowest richness and α- and β-diversity in both the SSB and AGV were found in low and high severity fire sites, respectively. Partitioning β-diversity of the SSB and the AGV into turnover and nestedness components revealed that spatial turnover was the main contributor to β-diversity. High fire severity significantly increased similarity between SSB and AGV. Conclusions – Low, but not high, severity fire can increase species diversity in the AGV and SSB, and it has the potential to serve as a tool for management and restoration of semi-arid Mediterranean regions, thereby enhancing plant diversity and structural heterogeneity. However, high severity fire may lead to loss of many species in both the SSB and the AGV resulting in loss of biodiversity." Type de publication : périodique Référence biblio : Heydari M., Omidipour R., Abedi M., Baskin C., 2017 - Effects of fire disturbance on alpha and beta diversity and on beta diversity components of soil seed banks and aboveground vegetation. Plant Ecology and Evolution, 150 (3) : 247-256. DOI : 10.5091/plecevo.2017.1344 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=66840
in Plant Ecology and Evolution > vol. 150, n°3 (Année 2017) . - pp. 247-256[article]Exemplaires(1)
Cote Localisation Disponibilité P0179-2 Brest Exclu du prêt
Titre : Effects of floral display, conspecific density and rewarding species on fruit set in the deceptive orchid Orchis militaris (Orchidaceae) Type de document : texte imprimé Auteurs : Thomas Henneresse, Auteur ; Renate A. Wesselingh, Auteur ; Daniel Tyteca, Auteur Année de publication : 2017 Article en page(s) : pp. 279-292 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Orchidaceae Mots-clés : conspecific density deceptive orchid food deception fruit set generalised food deception Orchis militaris pollination facilitation reward species richness Résumé : "Background and aims – About one third of orchid species do not produce any floral reward but have developed various strategies to attract pollinators. The most common system is food deception, which takes place through two types of attraction mechanisms: Batesian floral mimicry and generalised food deception. In rewardless species, fruit set is generally low and various factors, such as floral display size or density, are known to positively or negatively influence fruit set. This study aimed to clarify the deceptive pollination system in Orchis militaris and to investigate the effect of individual, population and environmental factors on fruit set in this orchid species. Methods – The effects of floral display size, con- and heterospecific density and rewarding species diversity were studied both at the scale of the individual plant (fourteen sites) and of the population (22 sites). Generalised linear (mixed) models and multivariate analysis were performed to examine which factors affect fruit set. Key Results – At the individual scale, the probability of setting fruit was influenced by several factors and their interaction, including floral display size, conspecific density, and heterospecific total density and richness. Fruit set was higher in medium-height vegetation than in short vegetation. Globularia bisnagarica was the only species whose density was significantly (and negatively) correlated with fruit set. At the population scale, none of the studied factors was significantly correlated to fruit set. Conclusions – In Orchis militaris, generalised food deception is the most likely strategy of pollinator attraction. This orchid species may benefit from the proximity of rewarding plants through the magnet-species effect, depending on the size of its floral display. The effect of con- and heterospecific density and rewarding species richness seem scale-dependent. © 2017 Botanic Garden Meise and Royal Botanical Society of Belgium." Type de publication : périodique Référence biblio : Henneresse T., Wesselingh R., Tyteca D., 2017 - Effects of floral display, conspecific density and rewarding species on fruit set in the deceptive orchid Orchis militaris (Orchidaceae). Plant Ecology and Evolution, 150 (3) : 279-292. DOI : 10.5091/plecevo.2017.1313 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=66841
in Plant Ecology and Evolution > vol. 150, n°3 (Année 2017) . - pp. 279-292[article]Exemplaires(1)
Cote Localisation Disponibilité P0179-2 Brest Exclu du prêt
Titre : Phenological and genetic characterization of Sedum hispanicum (Crassulaceae) in the Italian peninsula at the western margin of its distribution Type de document : texte imprimé Auteurs : Giovanna Pezzi, Auteur ; Fabrizio Buldrini, Auteur ; Antonio Mandolfo, Auteur ; Giovanna Puppi, Auteur ; Andrea Velli, Auteur ; Lucia Conte, Auteur Année de publication : 2017 Article en page(s) : pp. 293-303 Langues : Anglais (eng) Mots-clés : phénologie florale genetic variation gypsum vein ISSR markers Natura 2000 northern apennine stonecrop synchrony Résumé : "Background and aims – Sedum hispanicum acts as a pioneer species on the gypsum outcrops of Emilia Romagna region (Northern Italy). The species was studied in two Sites of Community Importance through a comparative phenological and genetic diversity analysis to provide insights into strategies adopted by the species for successful reproduction in the harsh conditions of these rocky outcrops. Methods – Phenology was examined in individuals from four sampling sites chosen in one study area (Gessi Bolognesi e Calanchi dell’Abbadessa, GB) from March to June in two years (2013 and 2015) with different spring temperatures. Reproductive and vegetative phenophases were compared among sites and over years. ISSR-based molecular analysis was performed to obtain genetic diversity measures on individuals collected at the same four GB sites and, for comparison, in a second area (Gessi di Monte Rocca, Monte Capra e Tizzano). Key results – Individuals at the four GB sites showed inter-annual differences in full flowering and leaf senescence, but intra-annual synchrony of all monitored phenophases. Moderate amounts of genetic diversity were observed in the two areas (P% = 79.67, 67.48; I = 0.209, 0.205; He = 0.118, 0.122). Low genetic structure (Φst = 0.05; Gst = 0.06) and high gene flow (Nm = 3.92) resulted within the GB area. Genetic differentiation was higher between the two areas (Φst = 0.37, Gst = 0.22). Evidence of inbreeding (s = 0.61) was found in the GB area. Conclusions – Inter-annual differences in timing of full flowering phenophase seem to be related chiefly to spring temperatures. The estimates of genetic diversity in S. hispanicum are comparable to those of autogamous and clonal species, while the partitioning of genetic diversity reflects the low structure typical of outcrossing species. Intra-annual flowering synchrony is likely to promote sexual reproduction. Sedum hispanicum seems to adopt multiple reproductive modes to overcome environmental extremes of gypsum outcrops. © 2017 Botanic Garden Meise and Royal Botanical Society of Belgium." Type de publication : périodique Référence biblio : Pezzi G., Buldrini F., Mandolfo A., Puppi G., Velli A., Conte L., 2017 - Phenological and genetic characterization of Sedum hispanicum (Crassulaceae) in the Italian peninsula at the western margin of its distribution. Plant Ecology and Evolution, 150 (3) : 293-303. DOI : 10.5091/plecevo.2017.1309 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=66842
in Plant Ecology and Evolution > vol. 150, n°3 (Année 2017) . - pp. 293-303[article]Exemplaires(1)
Cote Localisation Disponibilité P0179-2 Brest Exclu du prêt
