Browsing by Author "Carvalho, Rui"
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- Determinants of spider species richness in coastal dunes along a gradient of mediterraneityPublication . Carvalho, José Carlos; Cardoso, Pedro; Crespo, Luís C.; Henriques, Sérgio; Carvalho, Rui; Gomes, Pedro1. The Iberian Peninsula is one of the most relevant areas in terms of species richness, rarity and endemism in the Mediterranean Basin. Using spiders as a model, we studied the relative importance of environmental and non-environmental spatial variation along a gradient of mediterraneity on the western coast of the Iberian Peninsula. 2. We performed a spatially explicit analysis to evaluate the contribution of pure environmental and pure spatial effects and their shared influence on spider species richness by variation partitioning and principal coordinates of neighbour matrices (PCNM). We dissect the spatial variation of species richness into additive scale-specific models through PCNM analysis and estimate the relative importance of environmental variables for each model. 3. Variation partitioning revealed that 72.8% of species richness variation could be explained by the environmental (climate and dune stability) and spatial variables. Most of this variation (51.3%) corresponds to the environmental spatially structured component. 4. The influence of environmental variables was scale-dependent. At the broadest scales, the latitudinal-climatic gradient was the dominant factor that influenced spider species richness variation. At the finest scale, stability of the dune system was the most important component. 5. In conclusion, spider species richness patterns were determined mostly by spatially structured environmental variation. More importantly, this study shows that different environmental factors act at multiple scales. Hence, our results reinforce the importance of the incorporation of both local and broad-scale factors when examining species richness patterns.
- Differential temporal beta‐diversity patterns of native and non‐native arthropod species in a fragmented native forest landscapePublication . Matthews, Thomas J.; Sadler, Jon; Carvalho, Rui; Nunes, Rui; Borges, Paulo A. V.An important factor that hinders the management of non‐native species is a general lack of information regarding the biogeography of non‐natives, and, in particular, their rates of turnover. Here, we address this research gap by analysing differences in temporal beta‐diversity (using both pairwise and multiple‐time dissimilarity metrics) between native and non‐native species, using a novel time‐series dataset of arthropods sampled in native forest fragments in the Azores. We use a null model approach to determine whether temporal beta‐diversity was due to deterministic processes or stochastic colonisation and extinction events, and linear modelling selection to assess the factors driving variation in temporal beta‐diversity between plots. In accordance with our predictions, we found that the temporal beta‐diversity was much greater for non‐native species than for native species, and the null model analyses indicated that the turnover of non‐native species was due to stochastic events. No predictor variables were found to explain the turnover of native or non‐native species. We attribute the greater turnover of non‐native species to source‐sink processes and the close proximity of anthropogenic habitats to the fragmented native forest plots sampled in our study. Thus, our findings point to ways in which the study of turnover can be adapted for future applications in habitat island systems. The implications of this for biodiversity conservation and management are significant. The high rate of stochastic turnover of non‐native species indicates that attempts to simply reduce the populations of non‐native species in situ within native habitats may not be successful. A more efficient management strategy would be to interrupt source‐sink dynamics by improving the harsh boundaries between native and adjacent anthropogenic habitats.
- Habitat filtering and inferred dispersal ability condition across‐scale species turnover and rarity in Macaronesian island spider assemblagesPublication . Malumbres-Olarte, Jagoba; Rigal, François; Girardello, Marco; Cardoso, Pedro; Crespo, Luís C.; Amorim, Isabel R.; Arnedo, Miquel A.; Boieiro, Mário; Carvalho, José Carlos; Carvalho, Rui; Gabriel, Rosalina; Lamelas-López, Lucas; López, Heriberto; Paulo, Octávio S.; Pereira, Fernando; Pérez‐Delgado, Antonio J.; Rego, Carla; Romeiras, Maria M.; Ros-Prieto, Alejandra; Oromí, Pedro; Vieira, Ana; Emerson, Brent C.; Borges, Paulo A. V.AIM: Habitat diversity has been linked to the diversity and structure of island communities, however, little is known about patterns and processes within habitats. Here we aim to determine the contributions of habitat type and inferred dispersal frequency to the differences in taxonomic structure between assemblages in the same island habitat. LOCATION: The Macaronesian archipelagos (Azores, Madeira, the Canary Islands and Cabo Verde). TAXON: Spiders (Araneae). METHODS: We established forest and dry habitat sites (each with five plots) on two islands per archipelago. We collected spiders using standardised sampling protocols. We tested the differences in beta diversity separately for each habitat and for each inferred category of ballooning (an aerial dispersal strategy) frequency across geographic scales through nested non-parametric permutational multivariate analyses of variance. We then tested whether ballooning and habitat influenced heterogeneity in species composition (dispersion in beta diversity) in the two habitat types. We analysed the effects of habitat and ballooning on species abundance distribution (SAD) and rarity by fitting Gambin models and evaluating the contribution of ballooning categories to SAD. RESULTS: Communities of the same archipelago and habitat were taxonomically more similar, and beta diversity increased with geographic scale, being greater in dry habitats. There was greater species replacement among assemblages in dry habitats than in forests, with greater differences for rare ballooners. There were no differences in SAD between habitats although dry habitat sites seemed to harbour more species with low abundances (rare species) than forests. MAIN CONCLUSIONS: Habitat type does not only condition the differences between spider assemblages of the same habitat but also the scale at which they occur. These differences may be determined by the heterogeneity in the physical structure of each habitat as well as how much this structure facilitates aerial dispersal (ballooning), and should be considered in theories/hypotheses on island community assembly as well as in conservation strategies.
- Inventory of tiger- and ground-beetles (Coleoptera Caraboidea: Cicindelidae, Carabidae) from the Gorongosa National Park (Mozambique)Publication . Serrano, Artur R. M.; Carvalho, Rui; Boieiro, Mário; Borges, Paulo A. V.; Silva, Pedro MartinsThe Gorongosa National Park (Mozambique) is one of the most emblematic protected areas in Africa, well known for its vertebrate biodiversity and restoration ecology efforts following the Mozambican civil war in 1992. The invertebrate biodiversity of Gorongosa National Park is still poorly studied, although the scarce information available indicates the existence of a rich number of species, particularly ground-beetles. The study of Caraboidea beetles is key for designing conservation practices since they are frequently used as biodiversity and ecological indicators and provide valuable information to help decision making. Therefore, the diversity assessment of Caraboidea beetles using standardized methodologies, can be used to quantify the effects of climate change in areas identified as vulnerable to climate change, such as the Gorongosa National Park. We report the occurrence of five tiger-beetles (Cicindelidae) and 93 ground-beetles (Carabidae) species/morphospecies in Gorongosa National Park from a field survey funded by the ECOASSESS project. Sampling was performed in the four main habitat types present in the park (miombo tropical forest, mixed dry forest, transition forest and grasslands) between October 25th and November 25th. In this sampling window, the turnover of Caraboidea species from the dry season to the wet season was recorded for the first time. Twenty-eight species of ground-beetles are new records to Mozambique, including 4 new subgenera and 2 new genera. Additional information on species phenology and habitat preferences is also provided.
- Inventory of tiger- and ground-beetles (Coleoptera, Caraboidea, Cicindelidae and Carabidae) in two sampling seasons of the Gorongosa National Park, MozambiquePublication . Serrano, Artur; Baptista, Martim; Carvalho, Rui; Boieiro, Mário; Mendes, Sara; Bartz, M. L. C.; Timóteo, Sérgio; Pereira, Henrique; Aguiar, Carlos; Alves Da Silva, António; Alves, Joana; Briones, Maria; Borges, Paulo A. V.; Sousa, José; Martins da Silva, PedroABSTRACT: The Gorongosa National Park (Mozambique) is one of the most emblematic protected areas in Africa, well known for its vertebrate biodiversity and restoration ecology efforts following the Mozambican civil war in 1992. The invertebrate biodiversity of Gorongosa National Park is still poorly studied, although the scarce information available indicates the existence of a rich number of species, namely in the case of tiger- and ground-beetles (Coleoptera, Caraboidea). Moreover, the study of arthropod assemblages is key for designing conservation practices since they are potentially accurate biodiversity and ecological indicators. Hence, the diversity assessment of Caraboidea beetles using standardised methodologies is likely to provide a new insight for future conservation planning and help to quantify the effects of climate change in areas identified as vulnerable to anthropogenic pressures, such as the Gorongosa National Park.
- Long droughts decrease tiger- and ground-beetle’ beta diversity and community body size in savannas of the Gorongosa National Park (Mozambique)Publication . Martins da Silva, Pedro; Carvalho, Rui; Boieiro, Mário; Sousa, José Paulo; Serrano, ArturABSTRACT: We assessed the Caraboidea communities of Gorongosa National Park (GNP) in Mozambique. Influence of tropical rainfall, after a long period of drought, was evaluated on alpha and beta diversity of tiger- and ground-beetles in the main habitat types of the park: miombo forests, mixed forests, transitional forests, and grasslands (open savannas). Tiger- and ground-beetle communities were sampled by pitfall traps set up in 25 sites of each habitat type along three sampling periods, comprising the transition of dry season to the wet season. After the first rainfall, an increase in alpha diversity was observed across GNP habitats, particularly in grasslands. Higher values of beta diversity were observed between the dry and wet sampling periods, particularly in grasslands. In contrast, community dissimilarities between sampling periods were not significant in the transitional forests. Community body size in grasslands increased after the rainfall, partly due to the occurrence of caraboid species that were exclusive of forest habitats during drought. Transitional forests, as ecotone habitat areas, appeared to support grassland species during drought, serving also as a source of forest species that may colonize the open areas in the wet season. Forest species will probably be more threatened by climate aridification and future landscape changes due to climate change.
- Seasonal dynamics of arthropods in the humid native forests of Terceira Island (Azores)Publication . Borges, Paulo A. V.; Pimentel, Reinaldo M. S.; Carvalho, Rui; Nunes, Rui; Wallon, Sophie; Ros-Prieto, A.This work aims to provide a first detailed description of the results obtained in a seasonal abundance study of arthropods in the native pristine humid forest from Terceira Island (Azores). Ten sites were sampled during four years with SLAM (Sea, Land, and Air Malaise) traps targeting several arthropod taxa with good dispersal abilities as well as epigean species crawling into the trap. Samples were taken every three months in nine sites between 2012 and 2016 and monthly in one of the sites between 2014 and 2015. A total of 147 arthropod species and morphospecies were sampled mostly belonging to Hemiptera, Araneae and Coleoptera. Four endemic species, the tree lace-hopper Cixius azoterceirae, the capsid bug Pinalitus oromii, the bristletail Trigoniophthalmus borgesi and a morphospecies of Aleyrodidae accounted for 50% of all adult specimens. Most species peak in abundance in summer, but monthly data allowed the identification of other seasonal patterns.
- Standardised inventories of spiders (Arachnida, Araneae) of Macaronesia II : The native forests and dry habitats of Madeira archipelago (Madeira and Porto Santo islands)Publication . Malumbres-Olarte, Jagoba; Boieiro, Mário; Cardoso, Pedro; Carvalho, Rui; Crespo, Luís C.; Gabriel, Rosalina; Macías Hernández, Nuria; Paulo, Octávio S.; Pereira, Fernando; Rego, Carla; Ros Prieto, Alejandra; Silva, Isamberto; Vieira, Ana; Rigal, François; Borges, Paulo A. V.BACKGROUND: Here we present the data obtained from the samples collected as part of a large research project (MACDIV) which aims at understanding the drivers of spider (Araneae) community assembly in Macaronesian islands. To obtain the data, we applied the sampling protocol COBRA (Conservation Oriented Biodiversity Rapid Assessment), in twelve 50 m x 50 m native forest plots and five dry habitat plots on the island of Madeiraand in 5 dry habitat plots on the island of Porto Santo. Through this publication, we contribute to the knowledge of the arachnofauna of the Madeiran archipelago. NEW INFORMATION: From the samples that we collected, we obtained a total of 14,902 specimens, of which 49% were adults (7,263). We identified these specimens to 87 species and 18 morphospecies (undescribed), belonging to 26 families. Species of the family Linyphiidae dominated the samples, with 24 (morpho)species. Out of the 105 recorded (morpho)species, 34 were endemic, 26 native non-endemic, 22 introduced and 23 species of unknown origin. We report seven new records of possibly recently introduced species in the Madeiran archipelago. We also present 21 new records for Madeira island and 32 for Porto Santo (33 for the whole archipelago).
- Standardised inventories of spiders (Arachnida, Araneae) on touristic trails of the native forests of the Azores (Portugal)Publication . Carvalho, Rui; Cardoso, Pedro; Gil, Artur José Freire; Ferreira, Maria Teresa; Ramos, Cândida; Lamelas-López, Lucas; Pereira, Fernando; Malumbres-Olarte, Jagoba; Ros-Prieto, A.; Boieiro, Mário; Borges, Paulo A. V.In the Azores, as in many other temperate, semi-tropical and tropical islands, historical patterns of habitat loss have typically resulted in lowland clearance, meaning that the last remnants of the pre-human pristine forest that covered the major parts of oceanic islands are in the mountain areas (Gaspar et al. 2011). The communities of these mountain forests are of critical importance for the protection of current island biodiversity since they are home to many Azorean endemic species (Borges et al. 2017, Borges et al. 2018, Malumbres-Olarte et al. 2019) and provide a variety of ecosystem services (e.g. water storage, erosion control, pollination, pest-control, food supply, recreation and tourism), contributing to the local economy and welfare (Fernandez-Palacios et al. 2017). The recent increase in recreational tourist activities in native habitats of the Azores (SREA 2018) raises concerns about the use of trails being a threat to the already imperilled native forest biodiversity. Hiking trails in particular have been found to be promoting the spread of invasive plants (Barros and Pickering 2014), which may cause adverse cascading effects on arthropods. The spider communities of the Azores are exceptionally well known due to ongoing inventorying and monitoring projects carried out since 1999 (Borges et al. 2016, Emerson et al. 2017, Malumbres-Olarte et al. 2019). The protocol used in NETBIOME ISLANDBIODIV and in this project is part of a long term monitoring proposal for oceanic islands (Borges et al. 2018).
- The role of sheltered habitats in biodiversity conservation of species sensitive to drought: a case study using ground beetles (Coleoptera, Carabidae) in the Gorongosa National ParkPublication . Baptista, Martim; Carvalho, Rui; Boieiro, Mário; Bartz, M. L. C.; Mendes, Sara; Timóteo, Sérgio; Azevedo-Pereira, Henrique M.V.S.; Alves, Joana; Alves Da Silva, António; Briones, Maria J.I.; Serrano, Artur; Sousa, José Paulo; Martins da Silva, PedroIn the aftermath of 2019’ tropical cyclones Idai and Kenneth, we assessed ground beetle communities of the Gorongosa National Park (GNP) in Mozambique. The influence of habitat shelters, namely the buffering role of closed microhabitat conditions on Alpha diversity and community trait values during a long period of drought, was evaluated across the main habitat types of the park: miombo forests, mixed forests, transitional forests, and grasslands (open savannas). These habitat types comprised a distance gradient in relation to lake Urema, in the center of GNP. Miombo forests were farther from the lake while grasslands and transitional forests were in the floodplain area. Ground beetle communities were sampled using pitfall traps set up at 25 sites of each habitat type along an environmental gradient of tree canopy cover during the last twenty days of the dry season. Higher species richness of ground beetles was found in closed habitat shelters along the distance gradient to lake Urema. A higher functional diversity was also found along the canopy gradient, with larger sized and wingless species being more abundant in closed habitats than in open areas. This result highlights the crucial role of habitat closedness in the protection of sensitive ground beetles. In particular, the buffer effect of tree canopy and the protection of the understory plants and the litter layer was critical for the survival of hygrophilous species and will be key in conservation strategies to face climate aridification and habitat fragmentation.