120 resultados para ECOFISIOLOGIA VEGETAL
Resumo:
La morfologia de les granes de 28 espècies de Delphinium recollides a Turquia ha estat estudiada per mitjà de la Microscòpia Electrònica de Rastreig (MER). Quatre tipus principals de granes són reportats: subgloboses amb anells continus de lamelles, subpiramidals amb esquames amples o primes, subpiramidals allargades amb esquames i sector-esferoïdals reticulades, que es corresponen amb les seccions reconegudes en els sistemes taxonòmics habituals del gènere, cosa que indica llur bona resolució taxonòmica. Es discuteixen les implicacions biogeogràfiques i sistemàtiques.
Resumo:
En aquest article es revisen els components de la fertilitat dels sòls mediterramis i es discuteix les seves característiques generals, així com la suposada oligotrofia que sovint se'ls ha atribuït. La tipologia d'aquests sòls i els cicles del N i P presenten alguns trets comuns que vénen determinats per trobar-se en n règim de clima mediterrani, tanmateix existeixen diferències remarcables que es relacionen, sobretot, amb el tipus de roca mare i que expliquen les diferències sovint atribuïdes als sòls de les cinc regions mediterrànies
Resumo:
Data about 89 taxa are presented. Arabis nova Vill. subsp. iberica Rivas Mart. ex Talavera, Cistus × nigricans Pourr. and Phacelia tanacetifolia Benth. are new records for the Catalan flora, and 15 taxa (Allium oporinanthum Brullo et al., Apera interrupta (L.) Beauv., Asplenium trichomanes L. subsp. trichomanes, Campanula affinis Schult., Carex sylvatica Huds. subsp. paui (Sennen) A. and O. Bolòs, Epilobium angustifolium L., Limonium hibericum Erben, Melilotus messanensis (L.) All., Minuartia funkii (Jord.) Graebner, Onosma triceros-perma subsp. catalaunica (Sennen) O. Bolòs and Vigo, Orchis palustris Jacq., Orchis simia Lam., Selaginella denticulata (L.) Spring, Stellaria neglecta Weihle in Bluff and Fingerh. and Vaccinium myrtillus L. are new records for Southern Catalonia.
Resumo:
Atmophytic Cyanophyta and Algae from limestone substrata. The walls of caves and tombs support an abundant colonization of light-dependent organisms. A total of 4 liverworts, 3 mosses, 7 lichens and 28 cyanophyta and algae are reported from 3 collecting sites. The development and specific composition of these organisms is related to microclimatic parameters. Opportunistic species present in soils are found on the mouth of hypogeal niches. Light attenuation allows the development of calcifying cyanophyta following a succesional pattern, each level having a different dominant species. Communities dominated by Scytonema julianum are replaced by Herpyzonema pulverulentum and, towards the less iluminated area, by Geitleria calcarea and Loriella sp. Key words: Caves, Light attenuation, Non vascular plants, Colonization, Calcifying cyanophyta, Scytonema julianum, Herpyzonema pulverulentum, Geitleria calcarea, Chlorophyta, Diatoms, Microclimatic gradient.
Resumo:
Descripció de la vegetació higronitròfila dels embassaments dels cursos superiors dels rius Segre i Noguera Pallaresa. Hom proposa els següents nous sintàxons: Xanthio-Polygonetum persicariae O. de Bolòs 1957 subass. rorippetosum sylvestris Molero and Romo, subss. nova i Filaginello uliginosae_Veronicetum peregrinae Molero and Romo, ass. nova, ambdues dins de l'aliança Chenopodion rubri Timar 1950; sobre llims lleugerament salins es presenta la nova associació Junco gerardi-Crypsietum schoenoidis Molero and Romo, inclosa dins d'aliança Heleochloion Br.-Bl. 1952
Resumo:
sum tini Molero, Sáez and Villar-, altered by the presence of certain thermophilous coastal species, and finicolous and residual in character, are found in a few exceptional enclaves. Finally, stress is laid on the need to introduce suitable measures for the protection of certain places in the Range, particularly the residual woods of the northern slopes, in view of the exceptional interest of the flora and landscape. Key words: Flora, Vegetation, Chorology, Cormophytes, Sierra de Alcubierre, Monegros, Ebro valley, Spain.
Resumo:
The contribution of the botanist Oriol de Bolòs to the fixation of the scientific vocabulary. We analyse the works of Oriol Bolòs concerning the scientific terminology, particularly that of botany. We remark synthetically the theoretical aspects and we comment some case examples. Key words: Oriol de Bolòs, Scientific terminology, Botany.
Resumo:
A report on the ultrastructural observations of the pit connections in three species of Gelidiocolax (G. margarifoides (Martin and Pocock) Fan and Papenfus, G. christianae Feldmann and G. deformans Seoane-Carnba) has been carried out. As has been described in other species, electrondense elements and myelinic figures, possibly formed by the endoplasmic reticulum, were condensed in a mass. This mass became a diabolos-shaped structure before the cytoplasm had finished its division and the septum had reached its complete development. Myelinic figures were usually found in the core of well formed pit plugs, but such figures were apparently substituted by granular material during the ontogeny. Key words: Gelidiocolax ultrastructure, Pit connection, Pit connection ultrastructure, Pit connection Ontogeny.
Els secans abandonats amb Taeniathero-Aegilopion Geniculatae a les comarques lleidatanes meridionals
Resumo:
el caso anterior, a comunidades de la Al. Rosmarino-Ericion o bien, en 10s mejores suelos (que s610 muy raramente son abandonados en la zona estudiada) a comunidades emparentadas con la Al. Pruno-Rubion ulmifolii.
Resumo:
L'anàlisi de nombrosos inventaris procedents dels Pirineus centrals i orientals ens ha dut a realitzar una revisió de I'aliança Polygonion avicularis Br.-Bl. ex Dich 1933 en aquesta àrea. Reconeixem fins al moment sis associacions per a les quals donem la seva caracterització florística i ecologica, així com la seva distribució als Pirineus catalans. Descrivim, a més, una subass. scleranthetosum uncinatae del Rumici-Spergularietum rubrae, comunitat altimontana i subalpina pròpia dels sòls calcigats.
Resumo:
This paper contains the conclusion of a mycological survey of western Catalonia. The first part of the results was published in Acta Bot. Barc. 45 (Homenatge a Oriol de Bolòs): 57-89. The present part covers the last two groups of Basidiomycota: the agarics (326 species) and the gasteromycetes (44 species). The data regarding the surveyed area, collection localities, abbreviations used in the information on ecology, collectors and identifiers are found in the mentioned first part, which contains records of 37 species of Myxomycota, 5 of Zygomycota, 101 of mitosporic fungi, 8 of Teliomycetes, 1 of Ustomycetes, 16 of Phragmobasidiomycetes and 92 of Aphyllophorales. Together with the first part, the results of our survey are a useful contribution to an improved understanding of the fungal component of plant communities of the dry, warm lowlands of the western Mediterranean region, and highlight the remarkable reproductive activity of the fungi observed during late Autumn and Winter, in the studied area.
Resumo:
The alliance Agropyro-Rumicion in the eastern half of the IberianPyrenees. This alliance, related to eurosiberian landscapes, is represented in the studied area by three associations, all them inhabiting wet and ruderalized soils: Mentho-Juncetum (very frequent and chiefly formed by Juncus inflexus and Mentha longifolia), Festuco-Caricetum (more sporadic and grassland-shaped) and Rorippo-Agrostietum (only recorded from the upper part of the river Ter, dominated by the rare Rorippa sylvestris and more or less related to the alliance Bidention in some way).
Resumo:
Spore germination in Rhizopogon abietis, R. luteolus, R. roseolus and R. villosulus was induced in the presence of Rhodotorula glutinis and activated charcoal, in agar medium (N6:5). In one R. roseolus sample, 51% of spores germinated within 35 days, allowing observation of the course of spore germination and the different developmental patterns of homokaryotic mycelia. In these plates, spores showed two times of germination. The spores that germinated early produced an apical germ tube. Later other spores germinated in proximity to young mycelium, by forming a germ vesicle. One of the hyphal growth patterns obtained (interruption-swelling-ramification) is similar to that reported for other fungi. With this technique for inducing spore germination, it is possible to obtain enough monosporic cultures to perform mating tests. Key words: Basidiomycotina, Hypogeous, Monosporic Cultures.
Resumo:
Fifty-five collections misidentified and stored in various institutional herbaria, under severa1 Rhizopogon species narnes, are revised. Among these, twelve belong to Ascomycotina and 9 were identified to species level; the other collections, immature fruitbodies wcre impossible to identify with the data available. Forty-two collections are Basidiomycotina and only an immature Scleroderma remain without identification to the species level.
Resumo:
La clasificación y el estudio de las comunidades arvenses presentan en ocasiones problemas metodológicos y conceptuales compartidos, en gran manera. con la vegetación ruderal. Una parte de estos problemas tiene su origen eh los cambios profundos que han sufrido los sistemas de cultivo durante los últimos decenios, después de siglos de tratamientos agricolas relativamente homogéneos. También en la introducción continuada y creciente de plantas alóctonas, muchas de las cuales hallan acomodo en los cultivos. Todo ello confluye causando transformaciones diversas en la vegetación arvense.