DCA - Artigos em Revistas Internacionais / Articles in International Journals
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Browsing DCA - Artigos em Revistas Internacionais / Articles in International Journals by Author "Aguiar, Carlos"
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- Canopy insect herbivores in the Azorean Laurisilva forests: key host plant species in a highly generalist insect communityPublication . Ribeiro, Sérvio P.; Borges, Paulo A. V.; Gaspar, Clara; Melo, Catarina; Serrano, Artur R. M.; Amaral, João; Aguiar, Carlos; André, Genage; Quartau, José A.This article explores patterns of insect herbivore distribution in the canopy of the Laurisilva forests on seven islands in the Azores archipelago. To our knowledge, this is one of the first extensive studied of this type in tree or shrub canopies of oceanic island ecosystems. One of the most frequently debated characteristics of such ecosystems is the likely prevalence of vague, ill-defined niches due to taxonomic disharmony, which may have implications for insect-plant interactions. For instance, an increase in ecological opportunities for generalist species is expected due to the lack of predator groups and reduced selection for chemical defence in host plants. The following two questions were addressed: 1) Are specialists rare species, and insect herbivore species randomly distributed among host plant species in the Azores? 2) Are the variances in insect herbivore species composition, frequency and richness explained by host plants or by regional island effects? We expect a proportional distribution of herbivore species between host plants, influenced by host frequency and distinct island effects; otherwise, deviation from expectation might suggest habitat preference for specific host tree crowns. Canopy beating tray samples were performed on seven islands, comprising 50 transects with 1 to 3 plant species each (10 replicates per species), giving 1320 samples from ten host species trees or shrubs in total. From a total of 129 insect herbivore species, a greater number of herbivore species was found on Juniperus brevifolia (s=65) and Erica azorica (s=53). However, the number of herbivore species per individual tree crown was higher for E. azorica than for any other host, on all islands, despite the fact that it was only the fourth more abundant plant. In addition, higher insect species richness and greater insect abundance were found on the trees of Santa Maria Island, the oldest in the archipelago. Insect species composition was strongly influenced by the presence of E. azorica, which was the only host plant with a characteristic fauna across the archipelago, whereas the fauna of other plant crowns was grouped by islands. The great insect occurrence on E. azorica reflects strong habitat fidelity, but only four species were clearly specialists. Our findings indicate a broadly generalist fauna. The simplicity of Azorean Laurisilva contributed to the understanding of insect-plant mechanisms in canopy forest habitats.
- A new species of Orthomus Chaudoir, 1838 (Coleoptera Carabidae) from Madeira Island (Macaronesia) and notes on related speciesPublication . Serrano, Artur R. M.; Aguiar, Carlos; Boieiro, Mário; Borges, Paulo A. V.; Rego, Carla; Amorim, Isabel R.; Ribeiro, Sérvio P.; Pereira, Fernando E. A.Neste estudo é descrita uma nova espécie de carabídeo (Coleoptera, Carabidae) da ilha da Madeira, FANAL e RIBEIRO BONITO: Orthomus (Nesorthomus) susanae Serrano & Borges, n. sp. Os adultos foram capturados através de armadilhas de queda. São dados os principais caracteres diagnosticantes nomeadamente os da genitália masculina. Um mapa com a sua distribuição na Madeira é apresentado. As principais afinidades com as espécies mais próximas de Orthomus (Nesorthomus) são discutidas, assim como é facultada uma chave dicotómica para os machos das oito espécies conhecidas para o arquipélago da Madeira.
- Ranking protected areas in the Azores using standardised sampling of soil epigean arthropodsPublication . Borges, Paulo A. V.; Aguiar, Carlos; Amaral, João; Amorim, Isabel R.; André, Genage; Arraiol, Anabela; Baz, Arturo; Dinis, Francisco; Enghoff, H.; Gaspar, Clara; Ilharco, Fernando A.; Mahnert, Volker; Melo, Catarina; Pereira, Fernando E. A. P.; Quartau, José A.; Ribeiro, Sérvio P.; Ribes, Jordi; Serrano, Artur R. M.; Sousa, António B.; Strassen, R. Z.; Vieira, Luís; Vieira, Virgílio; Vitorino, Álvaro; Wunderlich, JoergNineteen areas in seven of the nine Azorean islands were evaluated for species diversity and rarity based on soil epigean arthropods. Fifteen out of the 19 study areas are managed as Natural Forest Reserves and the remaining four were included due to their importance as indigenous forest cover. Four of the 19 areas are not included in the European Conservation network, NATURA 2000. Two sampling replicates were run per study area, and a total of 191 species were collected; 43 of those species (23%) are endemic to the archipelago and 12 have yet to be described. To produce an unbiased multiple-criteria index (importance value for conservation, IV-C) incorporating diversity and rarity based indices, an iterative partial multiple regression analysis was performed. In addition, an irreplaceability index and the complementarity method (using both optimisation and heuristic methods) were used for priority-reserves analyses. It was concluded that at least one well-managed reserve per island is absolutely necessary to have a good fraction of the endemic arthropods preserved. We found that for presence/absence data the suboptimal complementarity algorithm provides solutions as good as the optimal algorithm. For abundance data, optimal solutions indicate that most reserves are needed if we want that at least 50% of endemic arthropod populations are represented in a minimum set of reserves. Consistently, two of the four areas not included in the NATURA 2000 framework were considered of high priority, indicating that vascular plants and bird species used to determine NATURA 2000 sites are not good surrogates of arthropod diversity in the Azores. The most irreplaceable reserves are those located in older islands, which indicates that geological history plays an important role in explaining faunal diversity of arthropods in the Azores. Based both on the uniqueness of species composition and high species richness, conservation efforts should be focused on the unmanaged Pico Alto region in the archipelago’s oldest island, Santa Maria.