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Background: In September 2012, a comprehensive survey of Pico Island was conducted along an elevational transect, starting at Manhenha (10 m a.s.l.) and culminating at the Pico Mountain caldera (2200 m a.s.l.). The primary objective was to systematically inventory the bryophytes inhabiting the best-preserved areas of native vegetation environments. Twelve sites were selected, each spaced at 200 m elevation intervals. Within each site, two 10 m x 10 m plots were established in close proximity (10-15 m apart). Within these plots, three 2 m x 2 m quadrats were randomly selected and sampled for bryophytes using microplots measuring 10 cm x 5 cm, which were then collected into paper bags. Six substrates were surveyed in each quadrat: rock, soil, humus, organic matter, tree bark and leaves/fronds. Three replicates were obtained from all substrates available and colonised by bryophytes, resulting in a maximum of 18 microplots per quadrat, 54 microplots per plot, 108 microplots per site, and a total of 1296 microplots across the 12 sites on Pico Island. New information: Two-thirds of the maximum expected number of microplots (n = 878; 67.75%) were successfully collected, yielding a total of 4896 specimens. The vast majority (n = 4869) were identified at the species/subspecies level. The study identified a total of 70 moss and 71 liverwort species or subspecies. Elevation levels between 600-1000 m a.s.l., particularly in the native forest plots, exhibited both a higher number of microplots and greater species richness. This research significantly enhanced our understanding of Azorean bryophyte diversity and distribution, contributing valuable insights at both local and regional scales. Notably, two new taxa for the Azores were documented during the MOVECLIM study, namely the pleurocarpous mosses Antitrichia curtipendula and Isothecium interludens. [ABSTRACT FROM AUTHOR]

The impact of climate change on islands is expected to cause dramatic consequences on native biodiversity. However, limited data are available for arthropod communities in island agroecosystems. In this study, we simulate a small-scale climatic change (average of +1.2°C), using Open Top Chambers (OTCs) in forage crops in the Azores Archipelago (Portugal) and test the responses of arthropod communities associated with intensively-managed pastures. At three sites, twenty 1 x 1 m plots were established: 10 treatment plots with OTCs and 10 control plots. Arthropods were sampled with pitfall traps on two sampling events (winter and summer of 2020). When considering all species collected, arthropods' abundance was lower in OTCs. Specific taxa, namely spiders and beetles, showed a fast response to the OTCs' presence. The assemblage of non-indigenous spiders well adapted to pastures showed a significant difference in diversity with a slightly greater richness, but lower abundance inside the warmer plots. However, the presence of OTCs resulted in a decrease in beetle richness and abundance. This decline may be attributed to the multiple effects of warming. Therefore, it is imperative to conduct further investigations to elucidate the ecological processes that underlie the observed patterns. [ABSTRACT FROM AUTHOR]

Background: The data we present are part of the project PASTURCLIM (Impact of climate change on pasture's productivity and nutritional composition in the Azores). The project aims to assess the consequences of climate change (e.g. temperature increase) on the grass production and its quality for forage, as well as to assess changes in the arthropod communities associated with the Azorean intensive pastures. An in situ experiment was set up using Open Top Chambers (OTCs), in order to simulate an increasing of temperature (average of +1.2°C) on pastures. In this contribution, we present the data relative to the arthropod sampling. New information: We provide an inventory of all arthropods recorded inside OTCs and in control plots in three intensively managed pastures dominated by grasses in Terceira Island (Azores): two of them dominated by ryegrass, Lolium multiflorum Lam. (Poaceae), located respectively at 186 m and 301 m above sea level; and one field dominated by common velvetgrass, Holcus lanatus L. (Poaceae), located at an altitude of 385 m. A total of 41351 specimens were collected. Organisms collected belong to four classes, 15 orders, 60 families and 171 species/morphospecies (including 34 taxa identified only at order, family or genus level). Therefore, for only 137 taxa, we have a scientific name associated (n = 38918). A total of 75% of the species (n = 129 species) are considered introduced (including all the species with indeterminate colonisation status that are possibly also exotic species (n = 7622)), representing 71% of the total abundance (n = 29664 specimens). A total of 19% of the species (n = 33 species) are considered native nonendemic representing 28% of the total abundance (n = 11608 specimens). Only one endemic species was sampled, the wolf spider Pardosa acorensis Simon, 1883 (1% of the species), representing 0.2% of the total abundance (n = 79 specimens). Spiders (5056 specimens) and beetles (18310 specimens) were the dominant taxa representing, respectively, 20 and 78 morphospecies. Since the main aim of this study was to have a better knowledge on arthropod communities present in Azorean pastures under a simulated temperature increase, the principal novelty of this paper is the contribution with distribution and abundance data to a baseline knowledge on the future consequences of climate changes on arthropod communities in Azorean pastures. [ABSTRACT FROM AUTHOR]

Background: The data we present are part of the CUARENTAGRI project, which involves all archipelagos of the Macaronesia (Azores, Madeira, Canary Islands and Cabo Verde). The project aims to: i) identify and evaluate the risks associated with the introduction of new arthropod pests; ii) study the population dynamics of selected arthropod pest species currently responsible for the damage of key target crops and iii) develop monitoring systems, based on prediction and/or population dynamics of the crop pests, creating warnings and a phytosanitary prevention system. In this contribution, we compile data for three Azorean Islands (Terceira, São Jorge and São Miguel Islands), where pheromonebaited traps were placed in pastures, potato fields and several orchards' types (apples, banana, chestnuts, olives, orange and strawberry), during three consecutive years (2020, 2021 and 2022). New information: A total of 114,827 specimens of insects (Arthropoda, Insecta) were collected, belonging to four orders, six families and ten recorded pest species. A total of eight species are considered introduced (Cosmopolites sordidus (Germar, 1824), Drosophila suzukii (Matsumura, 1931), Bactrocera oleae (Rossi, 1790), Ceratitis capitata (Wiedemann, 1824), Phthorimaea operculella (Zeller, 1873), Cydia pomonella (Linnaeus, 1758), Cydia splendana (Hübner, 1799) and Grapholita molesta (Busck, 1916); n = 84,986 specimens) and two native non-endemic (Mythimna unipuncta (Haworth, 1809) and Spodoptera littoralis (Boisduval, 1833); n = 17,465 specimens). This study intended to contribute to a better knowledge of the arthropods pests that can affect the Azorean crops and will serve as a baseline for future monitoring actions, pest risk assessments and prevention systems. [ABSTRACT FROM AUTHOR]

Background: Mountain insect biodiversity is unique, but is menaced by different drivers, particularly climate and land-use changes. In mainland Portugal, the highest mountain - Serra da Estrela - is one of the most important biodiversity hotspots, being classified as Natural Park since 1976. Many lepidopteran and odonate species, including rare and protected species, are known to occur in Serra da Estrela, but basic knowledge on their abundance, distribution and ecology is still lacking. Standardised sampling of these communities is crucial to provide valuable biological information to support short-term decision-making for conservation management, setting simultaneously the standards for mountain biodiversity monitoring aiming to tackle the effects of environmental change in the long-term. New information: This study reports novel information on lepidopteran and odonate species diversity, distribution and abundance from Serra da Estrela Natural Park (Portugal). Seventy-two lepidopteran and 26 odonate species were sampled in this protected area, including the first findings of Apatura ilia (Denis & Schiffermüller, 1775), Macromia splendens (Pictet, 1843) and Vanessa virginiensis (Drury, 1773). New populations of Euphydrias aurinia (Rottemburg, 1775) and Oxygastra curtisii (Dale, 1834), protected species under the Habitats Directive, were found in this Natural Park and novel distribution and ecological data were collected for most species, including several rare species and subspecies [e.g. Aeshna juncea (Linnaeus, 1758), Coenonympha glycerion iphioides Staudinger, 1870, Cyaniris semiargus (Rottemburg, 1775) and Sympetrum flaveolum (Linnaeus, 1758)]. All data were collected using standardised sampling allowing its use as a baseline for biodiversity monitoring in Serra da Estrela. [ABSTRACT FROM AUTHOR]

One of the aims of island biogeography theory is to explain the number of species in an archipelago. Traditionally, the variables used to explain the species richness on an island are its area and distance to the mainland. However, increasing evidence suggests that accounting for other variables is essential for better estimates. In particular, the distance between islands should play a role in determining species richness. This work uses a Bayesian framework using Gaussian processes to assess whether distance to neighbouring islands (spatial autocorrelation) can better explain arthropod species richness patterns in the Azores Archipelago and in the Canary Islands. This method is flexible and allows the inclusion of other variables, such as maximum altitude above sea level (elevation). The results show that accounting for spatial autocorrelation provides the best results for both archipelagos, but overall, spatial autocorrelation seems to be more important in the Canary archipelago. Similarly, elevation plays a more important role in determining species richness in the Canary Islands. We recommend that spatial autocorrelation should always be considered when modelling an archipelago's species richness. [ABSTRACT FROM AUTHOR]

Background: Long-term studies are key to understand the drivers of biodiversity erosion, such as landuse change and habitat degradation, climate change, invasive species or pollution. The long-term project SLAM (Long Term Ecological Study of the Impacts of Climate Change in the natural forest of Azores) started in 2012 and focuses on arthropod monitoring, using SLAM (Sea, Land and Air Malaise) traps, aiming to understand the impact of the drivers of biodiversity erosion on Azorean native forests (Azores, Portugal). This is the fourth contribution including SLAM project data and the second focused on the spider fauna (Arachnida, Araneae) of native forests on two islands (Pico and Terceira). In this contribution, we describe data collected between 2019 and 2021 and we analyse them together with a previously published database that covered the 2012-2019 period, in order to describe changes in species abundance patterns over the last ten years. New information: We present abundance data of Azorean spider species for the 2019-2021 period in two Azorean Islands (Terceira and Pico). We also present analyses of species distribution and abundance of the whole sampling period. In the period of 2019-2021, we collected a total of 5110 spider specimens, of which 2449 (48%) were adults. Most juveniles, with the exception of some exotic Erigoninae, were also included in the data presented in this paper, since the low diversity of spiders in the Azores allows a relatively precise specieslevel identification of this life-stage. We recorded a total of 45 species, belonging to 39 genera and 16 families. The ten most abundant species were composed mostly of endemic or native non-endemic species and only two exotic species (Tenuiphantes tenuis (Blackwall, 1852) and Dysdera crocata C. L. Koch, 1838). They included 4308 individuals (84%) of all sampled specimens and were the dominant species in Azorean native forests. The family Linyphiidae was the richest and most abundant taxon, with 15 (33%) species and 2630 (51%) specimens. We report Cheiracanthium mildei L. Koch, 1864, a non-native species, from Pico Island for the first time. We found no new species records on Terceira Island. This publication contributes to increasing the baseline information for future longterm comparisons of the spiders on the studied sites and the knowledge of the arachnofauna of the native forests of Terceira and Pico, in terms of species abundance, distribution and diversity across seasons for a 10 years period. [ABSTRACT FROM AUTHOR]

The data we present consist of an updated checklist of the Azorean Staphylinidae (Insecta, Coleoptera), by compiling new identified records of three recent published studies about Azorean arthropods. In general, the records were obtained from different standardised sampling campaigns and from non-standardised observations. The presented records were collected between July 1999 and September 2020, in five islands of the Azores Archipelago: Flores, Graciosa, Terceira, São Miguel and Santa Maria. The samples include records collected in several habitat types, such as native, mixed and exotic forests, pasturelands and agricultural areas (maize fields, orchards, citrus areas and vineyards). This inventory represents the most updated checklist and knowledge about Staphylinidae in Azores and new information includes one new exotic rove-beetle for the Azores (Thecturota tenuissima Casey, 1893) and seven new islands records. [ABSTRACT FROM AUTHOR]

This study explores the composition and structure of species communities associated with the native Azorean tree species Laurus azorica (Seub) Franco (Magnoliophyta, Magnoliopsida, Laurales, Lauraceae). Communities were sampled in six Islands covering the occidental (Flores), central (Faial, Pico, Terceira) and eastern (São Miguel, Santa Maria) groups of Azores Archipelago during the BALA project, using standardised sampling protocols for surveying canopy arthropod fauna. In addition, the study characterises the distribution of species regarding their colonisation status and feeding modes and, finally, compares communities of different Islands. Ninety-four arthropod species totalling 10,313 specimens were collected on L. azorica. The Arthropod community was dominated by Hemiptera species, most of them being herbivores. Endemic and native species showed a very high abundance representing about 94% of the total species abundance. However, despite introduced species being represented by few individuals (6% of the total abundance), their diversity was remarkable (28 species and no significant difference with diversity found in endemic and native species communities). Analysis of rarity patterns revealed a stable community of endemic species (alpha gambin SAD model approaching a log-normal shape), intermediate stable community of native species (alpha SAD gambin model approaching a poisson log-normal) and a less stable community of introduced species (alpha SAD gambin model approaching a log-series shape). A dissimilarity analysis revealed high similarity between communities of Terceira and Pico and high dissimilarity between Flores and Faial communities. We observed a clear individualisation of the different islands when considering endemic species, whereas we observed high overlap when considering native and introduced species groups. Canopy community distribution confirms the results obtained in a previous study which suggest the stability of native and endemic arthropods species communities over introduced species community in native forests fragments. Arthropod species were richer than bryophytes, lichens and vascular plants species. We found that L. azorica serve as the substrate for very few vascular plants species (four epiphytes species), which were present in all Islands, except Elaphoglossum semicylindricum, which does not occur in Santa Maria. L. azorica shelters a significant number of bryophytes and lichens species. Thirty-two lichens and 92 bryophyte species, including 57 liverworts and 35 mosses, are referred to this phorophyte. Five bryophyte species, all Azorean endemics, are considered Endangered by IUCN Criteria. L. azorica harbours a poor community of epiphyte vascular plant species and all of them were ferns, but the community of bryophytes and lichens are not negligible although very low compared to the community found on other previously studied Azorean trees, the Azorean cedar Juniperus brevifolia. The present study shows that most islands present particular species distribution patterns without geographical correlation and that conservation programmes should be adapted to each Island. The study, therefore, calls for a specialisation of conservation programmes for each of the Islands. [ABSTRACT FROM AUTHOR]

Background A recently-published review from 2021 presents a comprehensive checklist of ladybeetles of Portugal, including the Azores and Madeira Archipelagos. Until then, the available information was very scattered and based on a single revision dating back to 1986, a few international catalogues and databases, individual records and studies on communities of agroecosystems. However, no information was available on faunal composition across the Azorean islands and their habitats, using standardised inventories. Here, we present data about the biodiversity of ladybeetles and their distribution and abundance in five Islands of the Azores (Faial, Graciosa, Pico, São Jorge and São Miguel). Surveys included herbaceous and arboreal habitats from native to anthropogenic-managed habitats: ruderal road vegetation, vegetable garden, mixed forest of endemic and non-native host plants, coastal prairies, coastal mixed vegetation, cornfields and urban areas. We aimed to contribute to the ongoing effort to document the terrestrial biodiversity of Portugal, including the Archipelago of the Azores, within the research project AZORESBIOPORTAL-- PORBIOTA (ACORES-01-0145-FEDER-000072). New information In this study, a total of 1,487 specimens of Coccinellidae belonging to 19 species are reported for several habitats. The listed species are from one single sub-familiy (Coccinellinae) and six tribes; Chilocorini (one species), Coccidulini (three species), Coccinellini (six species), Noviini (one species), Scymnini (seven species), Stethorini (one species). The number of species collected per island differed; Faial (10 species), Graciosa (four species), Pico (seven species), São Jorge (seven species) and São Miguel (12 species). For six species, new island records are given. Currently, the number of species known to occur in the Azores are 32, including two doubtful records. The majority of species are Scymnini, being Scymnus (Scymnus) interruptus (Goeze, 1777) and Scymnus (Scymnus) nubilus Mulsant, 1850, the most abundant species (relative abundance 71.1%). This database will be the baseline of a long-term monitoring project allowing assessment of the impact of ongoing global changes in the distribution and abundance of ladybeetles. [ABSTRACT FROM AUTHOR]

Biodiversity accumulates hierarchically by means of ecological and evolutionary processes and feedbacks. Within ecological communities drift, dispersal, speciation, and selection operate simultaneously to shape patterns of biodiversity. Reconciling the relative importance of these is hindered by current models and inference methods, which tend to focus on a subset of processes and their resulting predictions. Here we introduce massive ecoevolutionary synthesis simulations (MESS), a unified mechanistic model of community assembly, rooted in classic island biogeography theory, which makes temporally explicit joint predictions across three biodiversity data axes: (i) species richness and abundances, (ii) population genetic diversities, and (iii) trait variation in a phylogenetic context. Using simulations we demonstrate that each data axis captures information at different timescales, and that integrating these axes enables discriminating among previously unidentifiable community assembly models. MESS is unique in generating predictions of community‐scale genetic diversity, and in characterizing joint patterns of genetic diversity, abundance, and trait values. MESS unlocks the full potential for investigation of biodiversity processes using multidimensional community data including a genetic component, such as might be produced by contemporary eDNA or metabarcoding studies. We combine MESS with supervised machine learning to fit the parameters of the model to real data and infer processes underlying how biodiversity accumulates, using communities of tropical trees, arthropods, and gastropods as case studies that span a range of data availability scenarios, and spatial and taxonomic scales. [ABSTRACT FROM AUTHOR]

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A dramatic insect decline has been documented on the grasslands and forests of European or North American mainland. Yet, other parts of the world and other ecosystems remain much less studied with unknown patterns.Using a unique time‐series dataset, we investigate recent trends on abundance and richness of arthropods sampled in Azorean native forest over 6 years (2013–2018).We test the hypothesis that biodiversity erosion drivers are changing the diversity and relative species abundance structure (species abundance distribution, SAD) of endemics, native non‐endemics and exotic species over time. We also examine temporal trends in abundance for each individual species.In contrast with mainland studies, we observed no decline in overall arthropod diversity, but a clear increase in the diversity of exotic arthropods and some evidence of a tendency for decreasing abundance for some endemic species. We also document stronger species turnover for exotic species, but no specific changes in the SAD.We argue that many changes, particularly in unique systems such as islands, will be noticed not at the richness but mostly at compositional level. Special attention should be given to exotic species which are known to be one of the major drivers of biodiversity erosion on islands. [ABSTRACT FROM AUTHOR]

The aim of our study was to characterise and compare the richness and composition of endemic, native (non-endemic) and introduced arthropod assemblages of two Azorean Historic Gardens with contrasting plant species composition. We hypothesised that Faial Botanic Garden would hold higher arthropod diversity and abundance of native and endemic arthropod species due to its larger native plant community. Species were collected using several arthropod standardised techniques between April 2017 and June 2018. We used the alpha diversity metrics (Hill series) and the partitioning of total beta diversity (βtotal) into its replacement (βtotal) and richness (βtotal) components, to analyse the adult and total arthropod community. The orders Araneae, Coleoptera and Hemiptera were also studied separately. Our results show that the number of exotic arthropod species exceeds the number of native and/or the endemic species in both gardens, but the arthropod community of Faial Botanic Garden exhibited a higher density of endemic and native species. Despite some minor exceptions, the geographic origins of plant communities largely influenced the arthropod species sampled in each garden. This study improves our knowledge about urban arthropod diversity in the Azores and shows how well-designed urban garden management and planning contribute to the conservation of native and endemic Azorean species. [ABSTRACT FROM AUTHOR]

Background The data, presented here, come from samples collected during three research projects which aimed to assess the impact of land-use type on Arbuscular Mycorrhizal Fungi (AMF) diversity and community composition in pastures of Terceira Island (Azores, Macaronesia, Portugal) and also in the native forest of two Azorean Islands (Terceira and São Miguel; Azores, Macaronesia, Portugal). Both projects contributed to improving the knowledge of AMF community structure at both local and regional scales. New information Little is known on the AMF communities from Azores islands and this study reports the first survey in two Azorean Islands (Terceira and São Miguel). A total of 18,733 glomeromycotan spores were classified at the species level from 244 field soil samples collected in three different habitat types - native forests (dominated by Juniperus brevifolia and Picconia azorica), semi-natural and intensively-managed pastures. Thirty-seven distinct spore morphotypes, representing ten glomeromycotan families, were detected. Species of the family Acaulosporaceae dominated the samples, with 13 species (38% of the taxa), followed by Glomeraceae (6 spp.), Diversisporaceae (4 spp.), Archaeosporaceae (3 spp.), Claroideoglomeraceae (3 spp.), Gigasporaceae (3 spp.), Ambisporaceae and Paraglomeraceae, both with the same number of AMF species (2 spp.), Sacculosporaceae (1 sp.) and Entrophospora (family insertae sedis). Members of the family Acaulosporaceae occurred almost exclusively in the native forests especially associated with the Picconia azorica rhizosphere, while members of Gigasporaceae family showed a high tendency to occupy the semi-natural pastures and the native forests of Picconia azorica. Members of Glomeraceae family were broadly distributed by all types of habitat which confirm the high ecological plasticity of this AMF family to occupy the more diverse habitats. [ABSTRACT FROM AUTHOR]

Oceanic islands have been providing important insights on the structuring of ecological communities and, under the context of the present biodiversity crisis, they are paramount to assess the effects of biological invasions on community assembly. In this study we compare the taxonomic and functional diversity of insect herbivore assemblages associated with the dominant tree species of Azorean native forests and investigate the ecological processes that may have originated current patterns of plant-herbivore associations. Five dominant trees—Erica azorica, Ilex perado subsp. azorica, Juniperus brevifolia, Laurus azorica and Vaccinium cylindraceum—were sampled in the remnants of the native forest of Terceira Island (Azores) using a standardised methodology. The taxonomic and functional diversity of insect herbivore assemblages was assessed using complementary metrics and beta diversity partitioning analysis (species replacement and richness differences) aiming to evaluate the variation in insect herbivore assemblages within and between the study plant species. Sixty two insect species, mostly bugs (Hemiptera) and caterpillars (Lepidoptera), were found in the five study plants with indigenous (endemic and native non-endemic) insects occurring with higher species richness and abundance than introduced ones. Species replacement was the most important component of insect herbivore taxonomic beta diversity while differences in trait richness played a major role on functional beta diversity. The endemic E. azorica stands out from the other study plants by having associated a very distinct insect herbivore assemblage with a particular set of functional attributes, mainly composed by large bodied and long shaped species that feed by chewing. Despite the progressive biotic homogenization witnessed in the Azores during the last few decades, several strong associations between the endemic trees and their indigenous insect herbivores remain. [ABSTRACT FROM AUTHOR]

During the last few centuries oceanic island biodiversity has been drastically modified by human-mediated activities. These changes have led to the increased homogenization of island biota and to a high number of extinctions lending support to the recognition of oceanic islands as major threatspots worldwide. Here, we investigate the impact of habitat changes on the spider and ground beetle assemblages of the native forests of Madeira (Madeira archipelago) and Terceira (Azores archipelago) and evaluate its effects on the relative contribution of rare endemics and introduced species to island biodiversity patterns. We found that the native laurel forest of Madeira supported higher species richness of spiders and ground beetles compared with Terceira, including a much larger proportion of indigenous species, particularly endemics. In Terceira, introduced species are well-represented in both terrestrial arthropod taxa and seem to thrive in native forests as shown by the analysis of species abundance distributions (SAD) and occupancy frequency distributions (OFD). Low abundance range-restricted species in Terceira are mostly introduced species dispersing from neighbouring man-made habitats while in Madeira a large number of true rare endemic species can still be found in the native laurel forest. Further, our comparative analysis shows striking differences in species richness and composition that are due to the geographical and geological particularities of the two islands, but also seem to reflect the differences in the severity of human-mediated impacts between them. The high proportion of introduced species, the virtual absence of rare native species and the finding that the SADs and OFDs of introduced species match the pattern of native species in Terceira suggest the role of man as an important driver of species diversity in oceanic islands and add evidence for an extensive and severe human-induced species loss in the native forests of Terceira. [ABSTRACT FROM AUTHOR]

Aim Higher-elevation areas on islands and continental mountains tend to be separated by longer distances, predicting higher endemism at higher elevations; our study is the first to test the generality of the predicted pattern. We also compare it empirically with contrasting expectations from hypotheses invoking higher speciation with area, temperature and species richness. Location Thirty-two insular and 18 continental elevational gradients from around the world. Methods We compiled entire floras with elevation-specific occurrence information, and calculated the proportion of native species that are endemic ('percent endemism') in 100-m bands, for each of the 50 elevational gradients. Using generalized linear models, we tested the relationships between percent endemism and elevation, isolation, temperature, area and species richness. Results Percent endemism consistently increased monotonically with elevation, globally. This was independent of richness-elevation relationships, which had varying shapes but decreased with elevation at high elevations. The endemism-elevation relationships were consistent with isolation-related predictions, but inconsistent with hypotheses related to area, richness and temperature. Main conclusions Higher per-species speciation rates caused by increasing isolation with elevation are the most plausible and parsimonious explanation for the globally consistent pattern of higher endemism at higher elevations that we identify. We suggest that topography-driven isolation increases speciation rates in mountainous areas, across all elevations and increasingly towards the equator. If so, it represents a mechanism that may contribute to generating latitudinal diversity gradients in a way that is consistent with both present-day and palaeontological evidence. [ABSTRACT FROM AUTHOR]

Species richness on oceanic islands has been related to a series of ecological factors including island size and isolation (i.e. the Equilibrium Model of Island Biogeography, EMIB), habitat diversity, climate (i.e., temperature and precipitation) and more recently island ontogeny (i.e. the General Dynamic Model of oceanic island biogeography, GDM). Here we evaluate the relationship of these factors with the diversity of bryophytes in the Macaronesian region (Azores, Madeira, Canary Islands and Cape Verde). The predictive power of EMIB, habitat diversity, climate and the GDM on total bryophyte richness, as well as moss and liverwort richness (the two dominant bryophyte groups), was evaluated through ordinary least squares regressions. After choosing the best subset of variables using inference statistics, we used partial regression analyses to identify the independent and shared effects of each model. The variables included within each model were similar for mosses and liverworts, with orographic mist layer being one of the most important predictors of richness. Models combining climate with either the GDM or habitat diversity explained most of richness variation (up to 91%). There was a high portion of shared variance between all pairwise combinations of factors in mosses, while in liverworts around half of the variability in species richness was accounted for exclusively by climate. Our results suggest that the effects of climate and habitat are strong and prevalent in this region, while geographical factors have limited influence on Macaronesian bryophyte diversity. Although climate is of great importance for liverwort richness, in mosses its effect is similar to or, at least, indiscernible from the effect of habitat diversity and, strikingly, the effect of island ontogeny. These results indicate that for highly vagile taxa on oceanic islands, the dispersal process may be less important for successful colonization than the availability of suitable ecological conditions during the establishment phase. [ABSTRACT FROM AUTHOR]

It is becoming increasingly apparent that the species abundance distribution of many ecological communities contains multiple modes, a phenomenon that has been largely overlooked. Here, we test for multiple modes in the species abundance distribution using a combination of one, two and three mode Poisson lognormal distributions and an extensive arthropod dataset from the Azores. We consider the abundance distribution of twelve native laurisilva forest fragments and the combination of fragments within five islands, allowing us to detect whether patterns are consistent across scales. An information theoretic approach is employed to determine the best model in each case. To explore the processes driving multimodal abundance distributions we tested various potential mechanisms. We classified species as core if they are present in over half the fragments in our study, and as satellite if they are sampled in fewer than half the fragments. Furthermore, species are classified based on body size, whether they are indigenous (i.e. endemic or native non-endemic) or introduced to the Azores, abundance in land uses other than native forest, and dispersal ability. We find that models incorporating multiple modes perform best for most fragments and islands. A large number of communities are bimodal, comprising a mode of very rare species and a mode of relatively common species. Deconstructing the full assemblages into their constituent subsets reveals that the combination of ecologically different groups of species into a single sample underpins the multimodal pattern. Specifically, the rarer mode prevailingly contains a higher proportion of satellite taxa, introduced species and species that are more adapted to anthropogenic land uses that surround the native forest. [ABSTRACT FROM AUTHOR]

Simple Summary: The vertical structure and the tree species in a forest have a strong influence on the communities of wood-inhabiting beetles. Little is known about how this influence varies between rare and common beetle species. We compared alpha and beta diversity patterns of common and rare species in the canopy of the Leipzig floodplain forest to assess their response to vertical structuring of the canopy and tree species. We assessed rarity firstly by using red list status and secondly based on the abundances of the beetle species. The understory displayed a significantly higher number of common species than the tree canopy. Conversely, the canopy harbored a higher number of rare species. The beetles' beta diversity patterns were predominantly shaped by differences in species composition, not by differences in species richness. Vertical structure had a higher influence on the beetle communities than tree species. Both factors had a higher influence on common than on rare beetle species. Our results indicate that studies carried out in the understory alone do not allow drawing conclusions regarding the biodiversity in the forest canopy, and thus regarding the overall community structure of xylobiont beetles in the canopy. Vertical stratification and host tree species are factors with a high influence on the structure of communities of xylobiont beetles. However, little is known about how this influence varies between common and rare species. Based on estimated species richness, we compared alpha and beta diversity patterns of common and rare species in the canopy of the Leipzig floodplain forest to assess their response to vertical stratification and tree species. We used two measures of rarity: threat level in red lists and abundance based on octaves. The understory displayed a significantly higher number of common species than the canopy strata. Conversely, the canopy strata harbored a higher number of rare species. Turnover was always dominant over richness differences in beta diversity partitions. Using Raup–Crick null models and non-metric multidimensional scaling, we found that the vertical strata accounted for 19% of the overall beta diversity of common species and for 15% of the overall beta diversity of rare species. The tree species accounted for 7% of the overall beta diversity of the common species and 3% of the beta diversity of the rare species. Our results indicate that studies carried out in the understory alone do not allow drawing conclusions regarding the biodiversity in the canopy strata, and thus regarding the overall community structure of xylobiont beetles in the canopy. [ABSTRACT FROM AUTHOR]

Aim We explore the island species-area relationships ( ISARs) of several plant groups differing in dispersal ability. We examine whether: (i) the ISAR slope is higher for less dispersive groups (diminishing from not-wind-dispersed seed plants to wind-dispersed seed plants, pteridophytes and bryophytes); and (ii) the regional richness is higher than that predicted by the ISAR of its constituent islands for groups with lower dispersal ability. Additionally, we relate both patterns to the compositional dissimilarity (beta diversity) between islands. Location The Macaronesian archipelagos of the Azores, Madeira and Canary Islands. Methods ISARs were estimated using the conventional power model. Differences in slopes among taxa were analysed through ANCOVA tests. We assessed the deviation of the total richness of the Macaronesian flora from that predicted by the ISAR and calculated several measures of beta diversity (turnover, nestedness-resultant dissimilarity and nestedness). Analyses were repeated after excluding the two Canarian islands of Lanzarote and Fuerteventura, which have unique climatic and geological conditions in the region. Results All ISAR models were significant except for pteridophytes (for which it was significant when excluding Lanzarote and Fuerteventura). ISAR slopes did not differ among taxa. Regional richness followed ISAR predictions for bryophytes and pteridophytes when Lanzarote and Fuerteventura were excluded, while the total number of Macaronesian seed plants (particularly not-wind-dispersed species) always fell above the ISAR. Turnover was higher in seed plants than in bryophytes and pteridophytes, and the opposite occurred with nestedness. Main conclusions Differences in dispersal ability influence the compositional dissimilarity between these islands, but not the rate of species increase with area. This may be because ISAR slopes are mostly determined by within-island processes of species accumulation, while differences in dispersal generate different between-island patterns. The lack of relationship between the ISAR slope and species replacement or nestedness prevents its use as a proxy for beta diversity. [ABSTRACT FROM AUTHOR]

We study how endemic, native and introduced arthropod species richness, abundance, diversity and community composition vary between four different habitat types (native forest, exotic forest of Cryptomeria japonica, semi-natural pasture and intensive pasture) and how arthropod richness and abundance change with increasing distance from the native forest in adjacent habitat types in Santa Maria Island, the Azores. Arthropods were sampled in four 150 m long transects in each habitat type. Arthropods were identified to species level and classified as Azorean endemic, single-island endemic (SIE), native, or introduced. The native forest had the highest values for species richness of Azorean endemics, SIEs and natives; and also had highest values of Azorean endemic diversity (Fisher's alpha). In contrast, the intensive pasture had the lowest values for endemic and native species richness and diversity, but the highest values of total arthropod abundance and introduced species richness and diversity. Arthropod community composition was significantly different between the four habitat types. In the semi-natural pasture, the number of SIE species decreased with increasing distance from the native forest, and in the exotic forest the abundance of both Azorean endemics and SIEs decreased with increasing distance from the native forest. There is a gradient of decreasing arthropod richness and abundance from the native forest to the intensive pasture. Although this study demonstrates the important role of the native forest in arthropod conservation in the Azores, it also shows that unmanaged exotic forests have provided alternative habitat suitable for some native species of forest specialist arthropods, particularly saproxylic beetles. [ABSTRACT FROM AUTHOR]

Simple Summary: We studied the diversity of arthropods in native forests along a 1000 m elevation gradient on Terceira Island, Azores (Portugal). These forests form an isolated and threatened habitat with unique endemic species. We analysed the change in alpha and beta diversity of arthropod species with elevation and if the diversity of endemic, native non-endemic and introduced species responds differently to elevation. Resident arthropods were sampled using SLAM (Sea, Land and Air Malaise) traps between 2014 and 2018. Spiders (Araneae), beetles (Coleoptera), true bugs (Hemiptera) and barklice (Psocoptera), as well as endemic, native and introduced species, were analysed separately. Total species richness decreases with elevation for all species, Coleoptera and Psocoptera, and particularly so for introduced species, but peaks at mid-high elevation for Araneae and endemic species. These patterns are probably driven by unfavourable climatic conditions at higher elevations while being influenced by human disturbance at lower elevations. Total species diversity along the whole elevation gradient is shaped by this decreasing richness as well as the replacement of species at different elevations. We present an analysis of arthropod diversity patterns in native forest communities along the small elevation gradient (0–1021 m a.s.l.) of Terceira island, Azores (Portugal). We analysed (1) how the alpha diversity of Azorean arthropods responds to increasing elevation and (2) differs between endemic, native non-endemic and introduced (alien) species, and (3) the contributions of species replacement and richness difference to beta diversity. Arthropods were sampled using SLAM traps between 2014 and 2018. We analysed species richness indicators, the Hill series and beta diversity partitioning (species replacement and species richness differences). Selected orders (Araneae, Coleoptera, Hemiptera and Psocoptera) and endemic, native non-endemic and introduced species were analysed separately. Total species richness shows a monotonic decrease with elevation for all species and Coleoptera and Psocoptera, but peaks at mid-high elevation for Araneae and endemic species. Introduced species richness decreases strongly with elevation especially. These patterns are most likely driven by climatic factors but also influenced by human disturbance. Beta diversity is, for most groups, the main component of total (gamma) diversity along the gradient but shows no relation with elevation. It results from a combined effect of richness decrease with elevation and species replacement in groups with many narrow-ranged species. [ABSTRACT FROM AUTHOR]

Islands have been disproportionately affected by the current biodiversity crisis. In island biotas, one of the most recurrent anthropic alterations is species introduction. Invasion of exotic species may represent a major threat for island biotas, because invasive species may change species composition and simplify community dynamics. We investigated diversity patterns of native and introduced species in native and exotic forests of Terceira Island (Azores, Portugal) by using diversity profiles based on Hill numbers. Use of diversity profiles allows for a complete characterization of the community diversity because they combine information on species richness, rarity, and dominance. We found that native forest remnants are crucial for the maintenance of endemic Azorean arthropod diversity. However, we also found that some lowland patches of exotic forests can sustain populations of rare endemic species. Our findings reinforce the importance of the few and small remnants of native forests, which are a pillar to the conservation of Azorean endemic arthropods. However, areas occupied by exotic forests, whether they are large and contiguous or small and isolated, close to native forests, or embedded in a matrix of agriculture activities, can also play a role in the conservation of native species, including endemics. [ABSTRACT FROM AUTHOR]

1. Fifteen species richness estimators (three asymptotic based on species accumulation curves, 11 nonparametric, and one based in the species–area relationship) were compared by examining their performance in estimating the total species richness of epigean arthropods in the Azorean Laurisilva forests. Data obtained with standardized sampling of 78 transects in natural forest remnants of five islands were aggregated in seven different grains (i.e. ways of defining a single sample): islands, natural areas, transects, pairs of traps, traps, database records and individuals to assess the effect of using different sampling units on species richness estimations. 2. Estimated species richness scores depended both on the estimator considered and on the grain size used to aggregate data. However, several estimators (ACE, Chao1, Jackknife1 and 2 and Bootstrap) were precise in spite of grain variations. Weibull and several recent estimators [proposed by Rosenzweig et al. ( Conservation Biology, 2003, 17, 864–874), and Ugland et al. ( Journal of Animal Ecology, 2003, 72, 888–897)] performed poorly. 3. Estimations developed using the smaller grain sizes (pair of traps, traps, records and individuals) presented similar scores in a number of estimators (the above-mentioned plus ICE, Chao2, Michaelis–Menten, Negative Exponential and Clench). The estimations from those four sample sizes were also highly correlated. 4. Contrary to other studies, we conclude that most species richness estimators may be useful in biodiversity studies. Owing to their inherent formulas, several nonparametric and asymptotic estimators present insensitivity to differences in the way the samples are aggregated. Thus, they could be used to compare species richness scores obtained from different sampling strategies. Our results also point out that species richness estimations coming from small grain sizes can be directly compared and other estimators could give more precise results in those cases. We propose a decision framework based on our results and on the literature to assess which estimator should be used to compare species richness scores of different sites, depending on the grain size of the original data, and of the kind of data available (species occurrence or abundance data). [ABSTRACT FROM AUTHOR]

Intensive agricultural practices leading to habitat degradation represent a major threat to pollinators. Diverse management practices are expected to influence wild pollinator abundance and richness on farms, although their effect in perennial crops is still unclear. In this study, we assessed the impact of management on apple (Malus domestica) pollination on an oceanic island, by comparing conventional (with and without herbicide application) and organic apple orchards. Pollinator visitation and pan trap surveys were carried out in six apple orchards in Terceira Island (Azores) and the landscape composition surrounding orchards was characterized. We also quantified fruit set, seed set and apple weight. We found no significant effect of management on insect visitation rates, whereas there was a negative association with increasing surrounding agricultural land. In contrast, management had an effect on species abundance, richness and diversity at the orchard level. Conventional orchards without herbicides showed higher abundance than the rest, but lower richness and diversity than conventional orchards with herbicides. Management had an effect on fruit set, but not on seed set or fruit weight. Our results suggest that management alone is insufficient for the overall improvement of apple pollination on an oceanic island, while landscape composition may play a relevant role. [ABSTRACT FROM AUTHOR]