Marques S.,Federal University of Pernambuco |
Barreiros J.P.,3nter for Ecology |
Barreiros J.P.,University of The Azores
Pan-American Journal of Aquatic Sciences | Year: 2015
This report is about two feeding behaviors of the silver porgy Diplodus argenteus in two rock reefs systems from the south Atlantic in Brazil. This species was a bottom feeder, which exhibited occasional and opportunistic behaviors.
Luis L.,University of Lisbon |
Luis L.,University of Amsterdam |
Bergamini A.,Swiss Federal Institute of forest |
Sim-Sim M.,University of Lisbon |
Sim-Sim M.,3nter for Ecology
Aquatic Botany | Year: 2015
Freshwater ecosystems and their associated organisms are among the most endangered in the world. Here we focus on bryophyte communities in streams characterized by a strong altitudinal gradient. The main purpose of this study was to determine the most important environmental variables affecting bryophyte species richness and composition and to quantify the relative importance of different sets of environmental variables. We studied bryophyte communities at upstream, intermediate and downstream sections of 16 streams distributed on the northern and southern side of Madeira Island in the Atlantic Ocean. We found that bryophyte species richness and composition was strongly affected by the measured environmental variables. Of particular importance were the geomorphological and hydrological variables as well as the chemical and physical properties of the streams. Temperature (or altitude) was highly correlated with other variables reflecting clear altitudinal gradients. While upstream communities were generally in a rather natural condition and rich in bryophyte species, downstream communities had less species and often anthropogenically modified stream banks. Due to the confounding of downstream areas with human influences and other variables such as temperature, the separate effects of these variables are not known. The relationship and the distributions of some bryophyte species/communities across the altitudinal range suggest that these riparian bryophyte communities may be sensitive to global warming. © 2015 Elsevier B.V.
Godinho S.,University of Évora |
Gil A.,3nter for Ecology |
Guiomar N.,University of Évora |
Neves N.,New University of Lisbon |
And 2 more authors.
Agroforestry Systems | Year: 2016
Mapping the land-cover pattern dominated by complex Mediterranean silvo-pastoral systems with an accuracy that enables precise monitoring of changing tree-cover density is still an open challenge. The main goal of this paper is to demonstrate the implementation and effectiveness of the Forest Canopy Density (FCD) model in producing a remote sensing-based and detailed map of montado canopy density over a large territory in southern Portugal. This map will make a fundamental contribution to accurately identifying and assessing High Nature Value farmland in montado areas. The results reveal that the FCD model is an effective approach to estimating the density classes of montado canopy (overall accuracy = 78.0 %, kappa value = 0.71). The study also shows that the FCD approach generated good user’s and producer’s accuracies for the three montado canopy-density classes. Globally, the results obtained show that biophysical indices such as the advanced vegetation index, the bare soil index, the shadow index and the thermal index are suitable for estimating and mapping montado canopy-density classes. These results constitute the first remote sensing-based product for mapping montado canopy density that has been developed using the FCD model. This research clearly demonstrates that this approach can be used in the context of Mediterranean agro-forestry systems. © 2014, Springer Science+Business Media Dordrecht.
Lopes S.T.,University of Lisbon |
Lopes S.T.,Center for Environmental and Marine Studies |
Dourado C.G.,University of Lisbon |
Dourado C.G.,Center for Environmental and Marine Studies |
And 10 more authors.
Journal of the Entomological Research Society | Year: 2015
Due to the difficulties associated with morphological identification of insects, it became necessary to resort to other identification tools, such as DNA barcoding, where the mitochondrial cytochrome c oxidase subunit I (COI) molecular marker is commonly used. The effectiveness of DNA-based identification of species relies on the availability of sequences in public databases for comparison. Nevertheless, there is still a large number of non-sequenced species in these databases, preventing a molecular identification. In this study, we generate COI barcode sequences, with a total of 658 bp, for the six studied Chrysomelidae species. Phylogenetic and sequence divergence analyses were also performed, which allowed the discrimination of all species under study, supporting once again the suitability of this genetic marker. The obtained sequences were added to BOLD and GenBank databases, contributing to the increase of records in online databases and making the identification of some Chrysomelidae species easier.
Florencio M.,3nter for Ecology |
Florencio M.,University of The Azores |
Florencio M.,Federal University of Goais |
Lobo J.M.,CSIC - National Museum of Natural Sciences |
And 6 more authors.
PLoS ONE | Year: 2015
Human-caused disturbances can lead to the extinction of indigenous (endemic and native) species, while facilitating and increasing the colonisation of exotic species; this increase can, in turn, promote the similarity of species compositions between sites if human-disturbed sites are consistently invaded by a regionally species-poor pool of exotic species. In this study, we analysed the extent to which epigean arthropod assemblages of four islands of the Azorean archipelago are characterised by nestedness according to a habitat-altered gradient. The degree of nestedness represents the extent to which less ubiquitous species occur in subsets of sites occupied by the more widespread species, resulting in an ordered loss/gain of species across environmental or ecological gradients. A predictable loss of species across communities while maintaining others may lead to more similar communities (i.e. lower beta-diversity). In contrast, anti-nestedness occurs when different species tend to occupy distinct sites, thus characterising a replacement of species across such gradients. Our results showed that an increase in exotic species does not promote assemblage homogenisation at the habitat level. On the contrary, exotic species were revealed as habitat specialists that constitute new and well-differentiated assemblages, even increasing the species compositional heterogeneity within human-altered landscapes. Therefore, contrary to expectations, our results show that both indigenous and exotic species established idiosyncratic assemblages within habitats and islands. We suggest that both the historical extinction of indigenous species in disturbed habitats and the habitat-specialised character of some exotic invasions have contributed to the construction of current assemblages. © 2015 Florencio et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Florencio M.,University of The Azores |
Florencio M.,3nter for Ecology |
Florencio M.,Federal University of Goais |
Rigal F.,University of The Azores |
And 11 more authors.
Biological Invasions | Year: 2016
Understanding the processes that lead to successful invasions is essential for the management of exotic species. We aimed to assess the comparative relevance of habitat (both at local and at regional scale) and plant features on the species richness of local canopy spiders of both indigenous and exotic species. In an oceanic island, Azores archipelago, we collected spiders in 97 transects belonging to four habitat types according to the degree of habitat disturbance, four types of plants with different colonisation origin (indigenous vs. exotic), and four types of plants according to the complexity of the vegetation structure. Generalised linear mixed models and linear regressions were performed separately for indigenous and exotic species at the local and regional landscape scales. At the local scale, habitat and plant origin explained the variation in the species richness of indigenous spiders, whereas exotic spider richness was poorly correlated to habitat and plant structure. The surrounding landscape matrix substantially affected indigenous spiders, but did not affect exotic spiders, with the exception of the negative effect exerted by native forests on the richness of exotic species. Our results revealed that the local effect of habitat type, plant origin and plant structure explain variations in the species richness observed at a regional scale. These results shed light on the mechanistic processes behind the role of habitat types in invasions, i.e., plant fidelity and plant structure are revealed as key factors, suggesting that native forests may act as physical barriers to the colonisation of exotic spiders. © 2016 Springer International Publishing Switzerland
M. Martins G.,3nter for Ecology |
M. Martins G.,University of The Azores |
Hipolito C.,3nter for Ecology |
Hipolito C.,University of The Azores |
And 8 more authors.
Marine Environmental Research | Year: 2016
In many coastal regions, vegetated habitats (e.g. kelps forests, seagrass beds) play a key role in the structure and functioning of shallow subtidal reef ecosystems, by modifying local environmental conditions and by providing food and habitat for a wide range of organisms. In some regions of the world, however, such idiosyncratic ecosystems are largely absent and are often replaced by less notable ecosystem formers. In the present study, we empirically compared the structure and functioning of two distinct shallow-water habitats present in the Azores: one dominated by smaller frondose brown macroalgae (Dictyotaceae and Halopteris) and one dominated by low-lying turfs. Two replicated areas of each habitat were sampled at two different times of the year, to assess spatial and temporal consistency of results. Habitats dominated by small fronds were significantly (ca. 3 times) more productive (when standardized per algal mass) compared to the turf-dominated habitats, and supported a distinct assemblage (both in terms of composition and abundance) of associated macrofauna. Unlike other well-known and studied vegetated habitats (i.e. kelp forests), however, no effects of habitat were found on the structure of benthonic fish assemblages. Results were spatially and temporally consistent suggesting that, in warmer temperate oceans, habitats dominated by species of smaller frondose brown algae can also play an important role in the structure and functioning of subtidal communities and may, to a certain extent, be considered analogous to other well-known vegetated habitats around the world (i.e. kelp forests, seagrass beds). © 2016 Elsevier Ltd
Fattorini S.,3nter for Ecology |
Fattorini S.,University of L'Aquila
Web Ecology | Year: 2016
Habitat fragmentation caused by urbanization is considered a prominent threat to biodiversity. Urban development creates a mosaic of natural fragments which can be occupied by organisms able to survive in small spaces. These fragments are a set of habitat islands separated by less suitable non-native habitats. Because of their isolation, communities of urban green spaces can be investigated using hypotheses developed in island biogeography. The "equilibrium theory of island biogeography" (ETIB) allows the formulation of some predictions about how various characteristics of green spaces (such as their area, shape, level of isolation, environmental heterogeneity, age) should influence species richness. Many studies found support for ETIB predictions, but results varied considerably according to the species' sensitivity to patch size, matrix characteristics, and history of the city. In some cases ETIB predictions were falsified. These contrasting results warn against making generalizations on conservation strategies only based on ETIB models. On the other hand, the ETIB may represent a useful framework for urban conservation, especially for small animals like insects, if the roles of other factors, such as the surrounding landscape, the specific needs of the species under study, and the history of the urbanization process, are taken into account. © 2016 Author(s).
Elias R.B.,3nter for Ecology |
Dias E.,University of The Azores
Phytotaxa | Year: 2014
Based on morphological, genetic and ecological data, we describe new infraspecific taxa of the Azorean endemic Juniperus brevifolia. J. brevifolia subsp. maritima is an erect shrub or small tree, found in Flores, Terceira, Pico and São Jorge , in coastal scrubs below 100 m. J. brevifolia subsp. brevifolia occurs in all islands of the archipelago except Graciosa, between 300 and 1500 m. J. brevifolia subsp. brevifolia var. brevifolia is a small to medium tree found between 300 and 1000 m. J. brevifolia subsp. brevifolia var. montanum is a small prostrate shrub, common in mountain scrubs and blanket bogs, between 850 and 1500 m. The most striking morphological differences of subsp. maritima are the larger leaves, seed cones and seeds. Phenological patterns of the subspecies also differ, notably in the periods of seed maturation and pollination. The distribution of taxa within islands is peripatric. Coastal populations (subsp. maritima) are small and isolated from the usually much larger subsp. brevifolia populations, above 300 m. In subsp. brevifolia the varieties are parapatric, since their ranges are adjacent to each other, occurring together in narrow contact zones. © 2014 Magnolia Press.