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Background The Iberian Peninsula is a diverse region that contains several different bioclimatic areas within one confined space, leading to high biodiversity. Portugal distinguishes itself in this regard by having a high count of spider species (829) and a remarkable number of endemic spider species (42) for its size (approximately 88,890 km2). However, only one non-endemic species (Macrothele calpeiana) is currently protected by the Natura 2000 network and no endemic spider species (aside from Anapistula ataecina) has been assessed according to the IUCN Red List criteria. The objective of this paper is to assess all non-assessed endemic species (41) as well as M. calpeiana. New information The 43 assessed species belong to 15 families, the richest being Zodariidae, Dysderidae, Linyphiidae and Gnaphosidae. In general and despite the lack of information on more than half the species, general patterns and trends could be found. Only 18 species (including M. calpeiana and A. ataecina) had enough data to allow their EOO (extent of occurrence) and AOO (area of occurrence) to be quantified. Of these, we modelled the distribution of 14 epigean species, eight of which were found to be widespread. The remaining six fulfilled at least one of the criteria for threatened species. Four species are troglobiont, all of which meet the EOO and AOO thresholds for threatened species. The remaining 25 Portuguese endemics had no reliable information on their range. Only nine species out of the 43 are estimated to be in decline and 11 are stable, with the majority of species having no information on trends (23 species). Forest areas, sand dunes, shrublands and caves host the majority of species. As such, the threats to Portuguese endemics reflect the diversity of habitats they occupy. Urbanisation and climate change seem to be the most important threats to these species, although other factors are also important and represented across the data. A considerable proportion of the currently known Portuguese endemic species can be found in national protected areas, with higher prominence to the Serras de Aire e Candeeiros, Douro Internacional, Vale do Guadiana, Sudoeste Alentejano e Costa Vicentina and Arrábida Natural Parks. These correspond mostly to areas that have been particularly well sampled during the last two decades. [ABSTRACT FROM AUTHOR]

There is a growing interest in academia to provide biodiversity data to both the scientific community and the public. We present an internet database of the terrestrial lichens, bryophytes, vascular plants, molluscs, arthropods, vertebrates and coastal invertebrates of the Azores archipelago (Portugal, North Atlantic): the Azorean Biodiversity Portal (ABP, http://www.azoresbioportal.angra.uac.pt/). This is a unique resource for fundamental research in systematics, biodiversity, education and conservation management. The ABP was based on a regional species database (ATLANTIS), comprised of grid-based spatial incidence information for c. 5000 species. Most of the data rely on a comprehensive literature survey (dating back to the 19th century) as well as unpublished records from recent field surveys in the Azores. The ABP disseminates the ATLANTIS database to the public, allowing universal, unrestricted access to much of its data. Complementarily, the ABP includes additional information of interest to the general public (e.g. literature on Macaronesian biodiversity) together with images from collections and/or live specimens for many species. In this contribution we explain the implementation of a regional biodiversity database, its architecture, achievements and outcomes, strengths and limitations; we further include a number of suggestions in order to implement similar initiatives. [ABSTRACT FROM AUTHOR]

Aim Researchers measuring beta diversity have rarely concerned themselves with the problems of how complete the species lists of studied communities are, and of how the varying degrees of completeness can actually change estimates of beta diversity. No comprehensive assessment has been made regarding the behaviour of most beta diversity indices when applied to incomplete samples, a situation which is more common than usually recognized. Our objective was to assess the behaviour and robustness of a number of beta diversity measures for incidence data from undersampled communities. Location Mainland Portugal and the Azorean archipelago (North Atlantic). Methods Data from intensive sampling of spiders in mainland Portugal and arthropods in Azores were collected. We examined the properties of 15 beta diversity measures developed for incidence data. We simulated varying degrees of completeness, whereas computing beta diversity for selected pairs of samples. The robustness of these beta diversity accumulation curves was assessed for the purpose of finding the best measures for undersampled communities. Results The Harrison et al.β-2 and the Williams β-3 are particularly robust to undersampling. These measures are also insensitive to differences of alpha diversity (species richness) between communities, and therefore to nestedness. Colwell & Coddington βcc and the related Jaccard βj and Gaston et al.βg performed best of the measures sensitive to alpha diversity. They performed poorly, however, when compared communities exhibited very low values of beta diversity. In such cases, the Routledge βr performed the best. Main conclusions No index was found to perform without bias in all circumstances. Overall, β-2, β-3 and βcc (or related measures βj and βg) are recommended as they seem to be the most robust to undersampling. [ABSTRACT FROM AUTHOR]

Intensive fieldwork has been undertaken in Portugal in order to develop a standardized and optimized sampling protocol for Mediterranean spiders. The present study had the objectives of testing the use of semi-quantitative sampling for obtaining an exhaustive species richness assessment of spiders and testing the effects of day, time of day, collector and sampling method on the collected species richness and composition of a Mediterranean scrubland. The collecting summed 224 samples corresponding to one person-hour of effective fieldwork each. In total, 115 species were captured, of which 110 were recorded inside a delimited one-hectare plot, corresponding to more than 70% of the about 160 estimated species. Although no estimator reached the asymptote, the Michaelis-Menten curve behaviour indicates that the estimated richness should be accurate. Most different sampling approaches (day, time of day, collector and sampling method) were found to influence richness, abundance or composition of the samples to some extent, although sampling method had the strongest influence whereas “collector” showed no effect at all. The results support the idea that the only variables that need to be controlled in similar protocols are the sampling methods and the time of day when each method is executed. We conclude that populations in structurally simple habitats present narrower peaks of adult abundance, which implies higher percentages of juveniles in samples. Finally, results also indicate that habitats with a relatively simple structure like scrublands may require as much sampling effort, in order to reach similar proportions of captured species in relation to the estimated richness, as habitats that are much more complex. [ABSTRACT FROM AUTHOR]

1. Fields such as ecology, macroecology, and conservation biology rely on accurate and comparable data. This is especially important for mostly unknown and megadiverse taxa such as spiders and regions such as the Mediterranean. Short-term sampling programmes are increasingly seen as the best option for sampling spiders. Comparability of results, however, demands standard procedures both in methodology and in sampling period. Cost-efficiency dictates that this period should be the most species rich. 2. Pitfall trapping was conducted in 23 sites from north to south Portugal, comprising three large-scale environmental zones and many different habitat types, during 10 months in each site. The annual richness pattern, differences in this pattern between areas and habitats, the complementarity between sampling periods and possible environmental correlates of richness were studied. 3. May and June present the optimal time for collecting spiders in Mediterranean areas. Northern areas have a later peak in richness and dense tree-cover sites offer more flexibility for sampling, with a higher proportion of species present at each period throughout the year. 4. Day length is the environmental factor most correlated with species richness. Maximum daily temperature may reduce richness, especially in southernmost areas, where summer temperatures can be extremely harsh. 5. It is recommended that short-term sampling programmes, intended to give a reasonable picture of spider communities in Portugal and in the Iberian Peninsula (and possibly extending to all the Mediterranean), should be conducted during May or June, with variable flexibility according to area and habitat. The proposed suggestions should appeal to everyone working in the field, given the cost-efficiency and comparability of results by adopting a common standardised approach. [ABSTRACT FROM AUTHOR]