Recursos de colección

Repositorio da Universidade dos Açores (9.269 recursos)

O Repositório Institucional da Universidade dos Açores desenvolvido no âmbito do projecto RCAAP.

ARQ - CBM - Número 20A

Mostrando recursos 1 - 6 de 6

  1. Impact of vagrant predators on the native fauna: a Short-eared Owl (Asio flammeus) preying on Madeiran Storm Petrels (Oceanodroma castro) in the Azores.

    Bried, Joël
    The impact of introduced predators on the native fauna of oceanic islands has proven to be catastrophic in many cases. In some instances, however, predation is caused by very few individuals arrived without any human assistance. Here, I report on the impact of a vagrant Short-eared Owl on the small population (200 breeding pairs) of cool-season Madeiran Storm Petrels from Praia Islet (0.12 km2), off Graciosa Island, Azores archipelago. The owl fed almost exclusively on storm petrels and killed between one and two individuals every night. The number of prey remains found suggests that it must have been present on...

  2. New records of the fern hybrid Asplenium ×rouyi Viane (A. onopteris L. × A. scolopendrium L.) in the Azores (Aspleniaceae, Pteridophyta).

    Schäfer, Hanno
    Several individuals of the fern hybrid Asplenium × rouyi are recorded from Santa Maria Island, Azores. After the destruction of the single plant known on Faial Island, these are the only currently known living individuals of this extremely rare hybrid and should be protected by the local authorities.

  3. Contribution to the knowledge of the Coccinellidae (Insecta: Coleoptera) fauna from the Azores islands.

    Soares, António O.; Elias, Rui B.; Resendes, Roberto; Figueiredo, Helena
    An updated list of the Coccinellidae species of the Azores archipelago is presented. New records for S. Miguel: Nephus (Sidis) hiekei; Sta. Maria: Rodolia cardinalis; S. Jorge: Stethorus punctilium, Clitosthetus arcuatus, Scymnus nubilus, N. (Sidis) hiekei; Pico: R. cardinalis; Graciosa: C. arcuatus, S. (Scymnus) interruptus, N. (Sidis) hiekei, Lindorus lophantae and R. cardinalis; Corvo: S. nubilus, N. (Sidis) hiekei and Coccinella undecimpunctata. Regressions of species richness against area of the islands and distance from the nearest mainland were performed. No statistical significant correlation between species richness against area was found but a statistical significant negative correlation between the number of...

  4. Impact of Clethra arborea Aiton (Clethraceae) in a Special Protection Area of São Miguel Island, Azores.

    Moniz, João; Silva, Luís
    Clethra arborea Aiton (Clethraceae) is a tree endemic to Madeira Island, and a recent introduction to São Miguel Island at Tronqueira/Pico da Vara, a Special Protection Area (SPA) included in Natura 2000, habitat of the endemic bird Pyrrhula murina Godman (Aves: Fringillidae). In this work the impact of C. arborea on the native vegetation was evaluated. Microhabitats associated with C. arborea and with native trees, and areas with different degrees of infestation by C. arborea were compared for soil pH, soil conductivity, soil macronutrient availability, leaf litter production, number of seedlings and vegetation structure. There were no clear differences in...

  5. Seed production and vegetative growth of Hedychium gardnerianum Ker-Gawler (Zingiberaceae) in São Miguel Island (Azores).

    Cordeiro, Nuno; Silva, Luís
    Hedychium gardnerianum is an important plant invader in the Azores Archipelago. In this research we analysed fecundity, fertility, seed bank and vegetative growth of this herbaceous perennial at three sites at different altitudes in São Miguel Island. The mean number of spikes per hectare varied from 2.7 to 4.0x107. The mean numbers of fruits and seeds per hectare were 8.8x106 and 1.6x107, respectively. However, the number of seeds remaining in the soil was very low when compared to the same number at time of seed shed. Vegetative growth occurs by annual addition of one to four new corms to the...

  6. Azorean bryophyte communities - A revision of differential species.

    Sjögren, Erik
    Bryophyte alliances and associations of the nine Azorean islands have been described by the author in publications extending from 1978 to 1997. The present paper includes a revision of their differential species and their differential values. Alliances treated with suggestions of their associations (differential species of the alliances and associations in the relevé tables): Echinodion prolixi Sjn. 93 (epiphytic; mostly above 600 m in native cloud-zone forest types); Lepidozion azoricae Sjn 96 (epixylic; presence as the Echinodion prolixi); Aphanolejeuneo-Colurion Sjn. 78 (epiphyllous; presence as the Echinodion prolixi); Andoae-Nardion scalaris Sjn. 95 (epigeic; from ± 200-1000 m a.s.l.) Ptychomitrion azorici Sjn....

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