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Biotic interactions in hawaiian high elevation ecosystems / Lloyd L. Loope
Titre : Biotic interactions in hawaiian high elevation ecosystems Type de document : texte imprimé Auteurs : Lloyd L. Loope, Auteur ; Arthur C. Medeiros, Auteur Importance : pp. 337-354 Langues : Anglais (eng) Catégories : [ZG] Hawaï Résumé : "High elevation shrublands occur above the tradewind inversion (c. 2000 m), on the geologically young (< 1 000 000 years old) volcanoes of Maui (Haleakala volcano) and Hawaiian (Mauna Kea, Mauna Loa and Hualalai volcanoes). Except for Mauna Loa, which recently erupted at the 3000 m level in 1984, these volcanoes are quiescent. Vegetation of the high elevation Hawaiian volcanoes consists of shrubs (Styphelia, Coprosma, Vaccinium, Dubautia, Dodonaea, Geranium), small trees (Sophora, Myoporum, Santalum), perennial graminoids (Deschampsia, Agrostis, Trisetum, Luzula, Carex), and other perennial herbaceous species (Pteridium aquilinum, Asplenium, Silene, Sanicula, etc.). With increasingly severe climatic conditions at higher elevations and with proximity to a mountain's summit, vegetation becomes more sparse and smaller in stature. Vegetation at the uppermost limit consists of prostrate shrubs, grasses, and ferns (Hartt & Neal 1940; Fosberg 1959; Mueller-Dombois & Krajina 1968; Whiteaker 1983). The fresh lava substrates of Mauna Loa (elevation 4170 m) result in much less development of soil and vegetation there than on older Mauna Kea (4207 m) and Haleakala (3056 m), both of which have extensive outcrops of cinder and ash deposits (Fosberg 1959). Hualalai Volcano (2522 m) barely reaches into the high elevation zone.
Mean temperature in the Hawaiian Islands decreases upward on the volcanoes at a rate of about 0.53 °C per 100 m." (source : auteur)Type de publication : article de livre Référence biblio : Loope L.-L., Medeiros A., 1994 - Biotic interactions in hawaiian high elevation ecosystems. In : 1994 - Tropical alpine environments : plant form and function. Cambridge University Press, 337-354. ID PMB : 7602 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=7602 Exemplaires(0)
Disponibilité aucun exemplaire Functional significance of inflorescence pubescence in tropical alpine species of Puya / Gregory A. Miller
Titre : Functional significance of inflorescence pubescence in tropical alpine species of Puya Type de document : texte imprimé Auteurs : Gregory A. Miller, Auteur Importance : pp. 195-213 Langues : Anglais (eng) Catégories : [ZG] Amérique du sud
[ZG] HawaïRésumé : "Tropical alpine environments are extreme and can generate very powerful selection pressures. Because of their simplicity they can provide valuable models for the study of evolution (Bradshaw 1971). The arborescent rosette growth form is a dominant feature across tropical alpine landscapes and has been the subject of detailed comparative ecological studies (Smith 1979, 1980, 1981; Smith & Young 1982; Young 1985 and Chapter 14). Alpine plant communities of most tropical alpine regions are distinguished from those of temperate latitudes by the presence of these giant rosette plants (Hedberg 1964; Cuatrecasas 1968; Smith 1981), with each major region possessing a unique flora. It has been assumed that the giant rosette form is an adaptive response to tropical alpine environments (Hedberg 1964; Mabberley 1973; Smith 1981), and an example of convergent evolution by different plant families to similar ecological conditions.
A notable feature of tropical alpine systems worldwide is the prevalence of pubescence, particularly among arborescent rosette plants. Most giant rosettes, including Senecio and Lobelia in Afroalpine areas (Hedberg 1964), Lupinus, Espeletia and Puya in the páramos of South America (Heilborn 1925; Smith 1981; Miller 1986), and Argyroxiphium in Hawaii (Carlquist 1974 and Chapter 16), produce dense pubescence on their leaves and/or inflorescences." (source : auteur)Type de publication : article de livre Référence biblio : Miller G.-A., 1994 - Functional significance of inflorescence pubescence in tropical alpine species of Puya. In : 1994 - Tropical alpine environments : plant form and function. Cambridge University Press, 195-213. ID PMB : 7610 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=7610 Exemplaires(0)
Disponibilité aucun exemplaire Huperzia continentalis (Lycopodiaceae), a New Species of Gemmiferous Firmoss Separated from Huperzia haleakalae / Weston Testo in Systematic Botany, vol. 41, n°4 (Année 2016)
[article]
Titre : Huperzia continentalis (Lycopodiaceae), a New Species of Gemmiferous Firmoss Separated from Huperzia haleakalae Type de document : texte imprimé Auteurs : Weston Testo, Auteur ; Arthur Haines, Auteur ; Arthur V. Gilman, Auteur Année de publication : 2016 Article en page(s) : pp. 894-901 Langues : Anglais (eng) Catégories : [ZG] Hawaï
[Espèces (in biblio)] HuperziaMots-clés : espèce végétale circumboréale Résumé : "A new species of gemmiferous clubmoss, Huperzia continentalis, is described. This species is most abundant in northwestern North America, but also occurs in Greenland, northern Europe, and northeastern Siberia. Material of this species was previously treated as Huperzia haleakalae, but detailed morphological study shows that the species differ by color, leaf size and shape, and gemma distribution. With the recognition of Huperzia continentalis, H. haleakalae is only known from the type, collected on Maui in 1840, and is likely extinct. Huperzia continentalis is also compared to similar species of Huperzia with which it co-occurs; it is readily distinguished from these taxa by plant size, leaf dimensions, and the size and distribution of gemmae. Hybrids between H. continentalis and four other Huperzia species are discussed." (source : auteurs) Type de publication : périodique Référence biblio : Testo W., Haines A., Gilman A., 2016 - Huperzia continentalis (Lycopodiaceae), a New Species of Gemmiferous Firmoss Separated from Huperzia haleakalae. Systematic Botany, 41 (4) : 894-901. ID PMB : 65319 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=65319
in Systematic Botany > vol. 41, n°4 (Année 2016) . - pp. 894-901[article]Exemplaires(0)
Disponibilité aucun exemplaire Une île hawaiienne, trois paradis tropicaux / Emilie Nault-Simard in Quatre-temps, vol. 37, n°4 (Hiver 2013-2014)
[article]
Titre : Une île hawaiienne, trois paradis tropicaux Type de document : texte imprimé Auteurs : Emilie Nault-Simard, Auteur Année de publication : 2013 Article en page(s) : pp. 3-6 Langues : Français (fre) Catégories : [ZG] Hawaï
[Thèmes] Jardin botaniqueRésumé : "Luxuriants, verdoyants, les jardins botaniques tropicaux de l'île de Kaua'i, dans l'archipel hawaiien, sont de précieuses oasis où pousse une flore unique au monde." (source : auteur) Type de publication : périodique Référence biblio : Nault-Simard E., 2013 - Une île hawaiienne, trois paradis tropicaux. Quatre-temps, 37 (4) : 3-6. ID PMB : 56619 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=56619
in Quatre-temps > vol. 37, n°4 (Hiver 2013-2014) . - pp. 3-6[article]Exemplaires(1)
Cote Localisation Disponibilité P0186 Brest Exclu du prêt Population dynamics and flowering in a hawaiian alpine rosette plant, Argyroxiphium sandwicense / Philip Rundel
Titre : Population dynamics and flowering in a hawaiian alpine rosette plant, Argyroxiphium sandwicense Type de document : texte imprimé Auteurs : Philip Rundel, Auteur ; M.S. Witter, Auteur Importance : pp. 295-306 Langues : Anglais (eng) Catégories : [ZG] Hawaï Résumé : "A notable feature of tropical alpine floras in many parts of the world is the presence of rosette plants with monocarpic growth habits. These long-lived perennials flower only once in their lives, producing a giant inflorescence with large numbers of flowers before the parent plant dies. In the South American páramos of Venezuela, species of Espeletia (Asteraceae) provide classic examples of this life-form (Cuatrecasas 1986; Berry & Calvo, Chapter 13)). Giant species of Afroalpine Lobelia (Campanulaceae) reach to 5–6 m in height when flowering before dying, and form one of the most spectacular elements of the flora of the tropical African highlands (Mabberley 1974; Young, Chapter 14). On Tenerife in the Canary Islands, two alpine species of Echium (Boraginaceae) have also evolved rosette growth forms and a monocarpic habit (Carlquist 1974). In each of these groups, the monocarpic rosette plants have evolved from polycarpic ancestors with a shrubby growth form.
Argyroxiphium sandwicense (Asteraceae) provides another well-known example of the evolution of a monocarpic rosette plant in a tropical alpine environment. The genus Argyroxiphium, with five species, is one of three genera of Hawaiian tarweeds that have evolved from a monophyletic North American origin (Carr 1985; Witter & Carr 1988; Baldwin et al. 1991). This group displays a remarkable diversity of growth forms and adaptive morphologies. Monocarpic rosette plants have evolved not only in species of Argyroxiphium in bog and in alpine habitats, but also in Wilkesia gymnoxiphium, a stalked rosette plant in scrub and open forest habitats." (source : auteurs)Type de publication : article de livre Référence biblio : Rundel P., Witter M.-S., 1994 - Population dynamics and flowering in a hawaiian alpine rosette plant, Argyroxiphium sandwicense. In : 1994 - Tropical alpine environments : plant form and function. Cambridge University Press, 295-306. ID PMB : 7605 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=7605 Exemplaires(0)
Disponibilité aucun exemplaire