1,720,970 research outputs found
FIGURE 3 in Verbascum birjandense and V. urumiense (Scrophulariaceae), two new endemic species for Flora of Iran
No full textFIGURE 3. Holotype specimen of Verbascum urumiense SotoodehPublished as part of Sotoodeh, Arash, Attar, Farideh, Laitung, Beryl & Civeyrel, Laure, 2022, Verbascum birjandense and V. urumiense (Scrophulariaceae), two new endemic species for Flora of Iran, pp. 35-44 in Phytotaxa 538 (1) on page 40, DOI: 10.11646/phytotaxa.538.1.3, http://zenodo.org/record/633196
FIGURE 1 in Verbascum birjandense and V. urumiense (Scrophulariaceae), two new endemic species for Flora of Iran
No full textFIGURE 1. Holotype specimen of a) V. birjandense Sotoodeh, b) portion of an inflorescence, c) a flower showing 5 stamens with yellowish filament hairs.Published as part of Sotoodeh, Arash, Attar, Farideh, Laitung, Beryl & Civeyrel, Laure, 2022, Verbascum birjandense and V. urumiense (Scrophulariaceae), two new endemic species for Flora of Iran, pp. 35-44 in Phytotaxa 538 (1) on page 36, DOI: 10.11646/phytotaxa.538.1.3, http://zenodo.org/record/633196
Verbascum Linnaeus 1753
No full textDiagnostic key including morphological similar species 1. Basal leaves sessile......................................................................................................................................................... V. urumiense 1. Basal leaves petiolate.........................................................................................................................................................................2 2. Petiole winged....................................................................................................................................................................................3 2. Petiole unwinged................................................................................................................................................................................4 3. Stem angular. Calyx 3–6 mm long. Pedicel 2 times longer than the calyx..................................................................... V. speciosum 3. Stem rounded, striated or a little angular. Calyx 6–10 mm long. Pedicel a little longer than the calyx....................... V. songaricum 4. Calyx 4–6 mm long, filament hairs orange..................................................................................................................... V. erianthum 4. Calyx 2–4 mm long, filament hairs whitish-yellow...........................................................................................................................5 5. Calyx 3–4 mm long; pedicel 5–7 mm (a little longer than the calyx).......................................................................... V. birjandense 5. Calyx 2–3(–4) mm long; pedicel much longer than the calyx.............................................................................. V. cheiranthifoliumPublished as part of Sotoodeh, Arash, Attar, Farideh, Laitung, Beryl & Civeyrel, Laure, 2022, Verbascum birjandense and V. urumiense (Scrophulariaceae), two new endemic species for Flora of Iran, pp. 35-44 in Phytotaxa 538 (1) on page 42, DOI: 10.11646/phytotaxa.538.1.3, http://zenodo.org/record/633196
Ecological and evolutionary processes influencing the colonization of common ragweed (Ambrosia artemisiifolia L.) in France
No full textLa compréhension des mécanismes déterminant le succès des espèces invasives est une étape essentielle dans la gestion des invasions biologiques actuelles et la prédiction des futurs risques d’invasion. En adoptant un cadre d’étude conceptuel intégrant les processus écologiques et évolutifs, l’objectif de ce travail était d’analyser les déterminants de la colonisation de l’ambroisie à feuilles d’armoise en France. Tout d’abord, l’étude des interactions biotiques et abiotiques a permis de montrer la capacité de tolérance de l’ambroisie à l’herbivorie et au stress hydrique. L’ambroisie est capable de tolérer la défoliation grâce à une croissance compensatoire efficace, sans que sa reproduction en soit affectée. Cette forte tolérance à l’herbivorie est maintenue chez les populations introduites, malgré la faible pression des ennemis naturels dans la zone d’introduction. En condition de stress hydrique, l’ambroisie produit une biomasse racinaire supérieure aux espèces présentes dans les communautés qu’elle envahit. De plus, les différences dans les valeurs moyennes pour les traits mesurés suggèrent une occupation différente par l’ambroisie des niches écologiques disponibles. La comparaison en jardins communs de populations de l’aire d’origine avec des populations de l’aire d’introduction isolées et issues du foyer central d’invasion a montré que l’adaptation de l’ambroisie à son environnement reposait principalement sur la plasticité phénotypique plutôt que sur la différenciation des traits. Les études de génétiques quantitatives ont mis en évidence un potentiel évolutif élevé pour les traits liés à la germination. Les traits liés à la morphologie, à la phénologie et à la physiologie de la plante montrent une variance additive et une héritabilité plus faibles et donc un potentiel évolutif moindre. En revanche, la variation dans les normes de réaction indique un potentiel évolutif important de la plasticité phénotypique. La tolérance au stress hydrique et à l’herbivorie sont des facteurs qui potentiellement augmentent la capacité de l’ambroisie à coloniser une large gamme d’habitat. De plus, la plasticité phénotypique et le potentiel évolutif important peuvent favoriser une augmentation ou un déplacement de la niche écologique de l’espèce et ainsi favoriser l’expansion de son aire de répartitionUnderstanding of the mechanisms behind the success of the invasive species is essential to manage current biological invasions and to prevent the risks of the futures ones. Using a conceptual framework integrating ecological and evolutionary processes, this work aimed to analyse the factors of the common ragweed colonization in France. First of all, the study of biotic and abiotic interactions has shown the ability of common ragweed to tolerate herbivory and water stress. Common ragweed is able to buffer defoliation through an efficient compensatory growth with no consequence on the reproduction. Herbivory tolerance has been maintained in introduced populations even if herbivory pressure is low in the introduction area. Under water stress conditions, common ragweed displayed higher root biomass than the other species present in the communities it invades. In addition, differences in mean trait values suggest different niche occupation by common ragweed compared with its companion species. Common garden experiments comparing native populations vs. invasive isolated and invasive core populations have shown that adaptation ability is mainly due to phenotypic plasticity rather than trait differentiations. Quantitative genetic studies suggest a high evolutionary potential for germination traits. Morphological, phenological and physiological traits exhibit lower standard genetic variation and lower heritability and thus a lower evolutionary potential. However, variation in reaction norms suggests a high evolutionary potential for phenotypic plasticity. Herbivory and water stress tolerance are factors that potentially increase the ability to colonize à large range of habitats. Furthermore, phenotypic plasticity and evolutionary potential may also favour an increase or a shift in species ecological niche and hence may favour the distribution range expansio
Verbascum birjandense Sotoodeh 2022, sp. nov.
No full textVerbascum birjandense Sotoodeh, sp. nov., Figure 1. Type: — IRAN. Southern Khorasan: Birjand, Band darreh, Bagheran Mt., 1700 m, 10 May 2010, F. Attar & A. Zamani 42993 (holotype TUH!, isotype G!). Diagnosis: — Verbascum birjandense is similar to V. songaricum by having stellate and whitish indumentum, fasciculate flowers, reniform anthers, bi-bracteolate pedicels, and filament hairs extended up to the anthers. However, it differs from it by having rounded stem (vs. angular), obovate basal leaves (vs. oblong), petiole not winged (vs. winged), pedicel 5–7 mm long (vs. 5–12 mm), calyx size 3–4 mm long (vs. 6–10 mm), corolla 10–15 mm diam. (vs. 25–35 mm diam.), and capsule ovoid (vs. ovoid to ovoid-ellipsoid) (Figure 1a–c; Table 1). Plant perennial, basal leaves and stem glabrescent, upper inflorescence portion covered by sparse whitish stellate hairs. Stem 1–1.2 m tall, erect, round. Basal leaves obovate or spatulate, 14–17 × 5–8 cm, apex obtuse to mucronate, base cuneate, margin entire to indistinctly crenate; petiole 3–9 cm long. Cauline leaves, ovate, sessile, apex broadly acuminate, base rounded to cordate, margin indistinctly serrate, covered by sparse whitish stellate hairs. Inflorescence a lax panicle, clusters of 2–7 flowers at the axil of each bract; bracts 3–6 mm long, ovate, acuminate; bracteoles 2, up to 4 mm long; pedicel 5–7 mm long, longer than calyx; calyx 3–4 mm long, divided up to ¾ into five lobes, acute. Corolla yellow, 10–15 mm diam., stellate hairy outside, glabrous inside. Stamens 5, filament hairs yellow, up to the anther; anthers all reniform. Style 5–6 mm, stigma spathulate. Capsule acuminate, 5–7 × 3–4 mm, tomentose. Distribution and habitat: —This new species is only known from the type locality, endemic to Iran, an Irano-Turanian element, and distributed in southern Khorasan (Figure 2). This region is mountainous with an elevation varying between 1400 to 2500 m, has a cold, desertic, and semidesertic climate with hot summers and cold winters with a significant difference between day and night temperatures (Mood 2008, Mohammadi et al. 2020). The temperature on average is between minus 2 in winter and 35 degrees Celsius in summer. The average precipitation is 168 mm per year, falling mostly in winter and spring (Zohary 1973, Mohammadi et al. 2020). The soil is relatively saline composed of light calcareous silt (Zohary 1973, Mood 2008). The vegetation of this region includes Acantholimon erinaceum (Jaub. & Spach) Lincz., Acanthophyllum spp. C.A.Mey., Achillea tenuifolia Lam., Berberis vulgaris L., Bromus tectorum L., Cousinia afghanica C.Winkl., Dorema ammoniacum Don, Ferula assa-foetida L., Hymenocrater calycinus (Boiss.) Benth., Pistacia atlantica subsp. cabulica (Stocks) Rech. f., Solanum nigrum L., Tamarix indica Willd., Teucrium polium L., Verbascum speciosum Schrad., Veronica hispidula Boiss. & Huet, Ziziphora clinopodioides Lam. and Ziziphus jujuba Mill. Phenology: —Flowering and fruiting of Verbascum birjandense extend from May to July. Etymology: —The specific epithet of the new species refers to its type locality, Birjand city, Iran.Published as part of Sotoodeh, Arash, Attar, Farideh, Laitung, Beryl & Civeyrel, Laure, 2022, Verbascum birjandense and V. urumiense (Scrophulariaceae), two new endemic species for Flora of Iran, pp. 35-44 in Phytotaxa 538 (1) on pages 36-38, DOI: 10.11646/phytotaxa.538.1.3, http://zenodo.org/record/633196
Diversité des communautés et populations d'hyphomycètes aquatiques de cours d'eau forestiers (influence de la végétation riveraine)
No full textTOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF
Mise en garde des scientifiques du monde à l'humanité : deuxième avertissement [french translation of Ripple et al., 2017. World Scientists’ Warning to Humanity: A Second Notice. BioScience, 67 (12):1026-1028]
No full textTraduction Française de l'article: Ripple et al., 2017. World Scientists’ Warning to Humanity: A Second Notice. BioScience, 67 (12):1026-1028Cette traduction est publiée sur le site: http://scientistswarning.forestry.oregonstate.edu/En 1992, l'Union of Concerned Scientists a appelé à une meilleure gestion de l'environnement. Vingt-cinq ans plus tard, face à l’urgence de l’état environnemental de la planète, plus de 15 000 scientifiques internationaux engagés dans l’Alliance of Word Scientists émettent un deuxième avertissement à l'humanité. Cette mise en garde scientifique a été publiée sous la forme d’un article exceptionnel dans la revue BioScience (Ripple et al., 2017. World Scientists’ Warning to Humanity: A Second Notice. BioScience, 67 (12):1026-1028). Tous les scientifiques préoccupés par l’évolution du climat et la dégradation de l’environnement de la planète sont désormais invités à lire et à approuver cet article et à s'engager dans l’Alliance of Word Scientists : http://scientistswarning.forestry.oregonstate.edu/ Pour accéder à la version Française de l’article : http://scientistswarning.forestry.oregonstate.edu/sites/sw/files/French_Scientists%20_Warning_Laitung_Fumanal.pd
Vegetation diversity increases species richness of leaf-decaying fungal communities in woodland streams
No full textSubmerged leaf litter is a vital resource for many aquatic species in wood- land streams. However, forestry tends to lower the diversity of litter entering streams, which potentially impacts leaf-dependent species and the entire detritus-based food web. To overcome this problem, a guideline for sustainable forestry and ecosystem conservation lies in increasing litter diversity in managed forests. However, the way in and the extent to which such an increase changes the leaf decomposer communities are mostly unknown. In the present study, fungal communities were surveyed bimonthly in ten woodland headwater streams with contrasting tree diversity resulting in various proportions of leaf species in litter. A total of 79 aquatic hyphomycete species identified from conidia in stream water were listed. The differences in conidial abundance, richness and diversity between communities from the ten streams suggested a strong effect of local abundance and composition of leaf litter. Conidial abundance clearly distinguished two sets of streams, one dominated by oaks and hazel and the other by beech. The fungal richness in the ten streams showed a positive and significant correlation with the leaf species richness, accounting for 44 % of the total variance among streams. About 50 % more fungal species were found in streams with the highest leaf litter diversity, and several species were more frequent in such streams. No distinct species assemblages were however associated with any particular leaf species. These findings were interpreted as resulting from substrate preferences, but not specificity by the fungal species. This is supported by a manipulation in which the addition of a bulk of hazel leaves in a stream dominated by beech did not result in an increase in fungal richness over three months. Seasonal changes appeared to be the main factor controlling fungal species abundance. Overall, the results suggest a hierarchical pattern between riparian and aquatic biodiversity and provide an argument for the conservation of diverse tree species along streams
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
