| 1. |
- Hacala, Axel, et al.
(författare)
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Drivers of taxonomic, functional and phylogenetic diversities in dominant ground-dwelling arthropods of coastal heathlands
- 2021
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 197, s. 511-522
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Tidskriftsartikel (refereegranskat)abstract
- Although functional and phylogenetic diversities are increasingly used in ecology for a variety of purposes, their relationship remains unclear, and this relationship likely differs among taxa, yet most recent studies focused on plants. We hypothesize that communities may be diverse in functional traits due to presence of: many phylogenetic lineages, trait divergence within lineages, many species and random functional variation among species, weak filtering of traits in favorable environments, or strong trait divergence in unfavorable environments. We tested these predictions for taxa showing higher (ants), or lower (spiders, ground beetles) degrees of competition and niche construction, both of which might decouple functional traits from phylogenetic position or from the environment. Studying > 11,000 individuals and 216 species from coastal heathlands, we estimated functional as minimum spanning trees using traits related to the morphology, feeding habits and dispersal, respectively. Relationships between functional and phylogenetic diversities were overall positive and strong. In ants, this relationship disappeared after accounting for taxonomic diversities and environments, whereas in beetles and spiders taxonomic diversity is related to functional diversity only via increasing phylogenetic diversity. Environmental constraints reduced functional diversity in ants, but affected functional diversity only indirectly via phylogenetic diversity (ground beetles) and taxonomic and then phylogenetic diversity (spiders and ground beetles). Results are consistent with phylogenetic conservatism in traits in spiders and ground beetles. In ants, in contrast, traits appear more phylogenetically neutral with any new species potentially representing a new trait state, tentatively suggesting that competition or niche construction might decouple phylogenetics from trait diversity.
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| 2. |
- Lafage, Denis, et al.
(författare)
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Disentangling the influence of local and landscape factors on alpha and beta diversities : opposite response of plants and ground-dwelling arthropods in wet meadows
- 2015
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Ingår i: Ecological research. - : SPRINGER JAPAN KK. - 0912-3814 .- 1440-1703. ; 30:6, s. 1025-1035
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Tidskriftsartikel (refereegranskat)abstract
- A large number of studies have tried to understand the determinants of local species richness, i.e. alpha-diversity. Studies dealing with beta-diversity are considerably less numerous but their number has increased in the recent years. In this study, we assessed the relative importance of local and landscape (i.e. composition and connectivity) variables in explaining alpha- and beta-diversities (species turnover and nestedness) of three highly diverse groups, differing in mobility and dispersal: plants, spiders, and carabids. Sampling took place in 2013, using suction samplers for arthropods and phytosociological relev,s for vegetation, in 77 hay meadows distributed along 200 km of the Loire Valley (France). We found plant alpha-diversity to be driven by local factors, whereas spider and carabid alpha-diversities were mostly determined by landscape factors (by composition and connectivity, respectively). Nestedness was negligible for the three groups. Plant beta-diversity was also mainly influenced by local factors, whereas spider beta-diversity was driven by landscape factors (composition and connectivity, equally). Surprisingly, carabid beta-diversity was mainly influenced by local factors and landscape connectivity. Despite these differences, plant, spider, and carabid beta-diversities were not different, suggesting comparable dispersal abilities and/or a low connectivity at large scale, which is in accordance with the high species turnover observed here. Managing biodiversity in meadows consequently necessitates acting at local and landscape scales, the first targeting plants and the second arthropods.
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| 3. |
- Lafage, Denis, et al.
(författare)
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Relative importance of management and natural flooding on spider, carabid and plant assemblages in extensively used grasslands along the Loire
- 2016
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Ingår i: Basic and Applied Ecology. - : Elsevier. - 1439-1791 .- 1618-0089. ; 17:6, s. 535-545
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Tidskriftsartikel (refereegranskat)abstract
- In Europe, agri-environment schemes (ALS) have been implemented to counteract the effects of agricultural intensification. Studies investigating the role of management improvement induced by AES are quite numerous, but rarely take into account the effect of natural perturbations such as flooding, although severe disturbances are well known to shape community structure, Here we investigated the relative importance of management improvement and flooding to explain community parameters of two dominant arthropod groups and vegetation in alluvial meadows. Sampling took place in 2013, using suction samplers for arthropods and phytosociological releves for vegetation, in 83 meadows distributed along 200 km of the Loire Valley (France). Pair-matched approach (by R-ANOVA) was used to assess overall effects of AES whereas a gradient analysis (GLM) was carried out to assess the impact of AES prescriptions (fertilisation and cutting-date) together with indirect (long-term) and direct (short-term) effects of flooding. No significant effect of AES was found on arthropod and plant assemblages, abundance/productivity or diversity (both alpha and beta), but the number of rare plant species was higher in sites under AES. Prescriptions had little impact on most response variables considered; the only significant impact being the positive effect of high-amounts of fertilisers on spider alpha- and beta-diversities, Conversely, systematic long-term effects of flooding were found on all response variables of spiders, carabids and plants, underlining the key role of this factor in alluvial meadows, Our study demonstrates that maintaining or enhancing hydrological functioning of ecosystems is even more important than regulating both the cutting-dates and the low input of fertilisers for conservation purposes in flooded, already naturally nutrient rich, meadows.
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| 4. |
- Lafage, Denis, et al.
(författare)
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Responses of ground-dwelling spider assemblages to changes in vegetation from wet oligotrophic habitats of Western France
- 2019
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Ingår i: Arthropod-Plant Interactions. - : Springer Netherlands. - 1872-8855 .- 1872-8847. ; 13:4, s. 653-662
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Tidskriftsartikel (refereegranskat)abstract
- While many arthropod species are known to depend, directly or indirectly, on certain plant species or communities, it remains unclear to what extent vegetation shapes spider assemblages. In this study, we tested whether the activity-density, composition, and diversity of ground-dwelling spiders were driven by changes in vegetation structure. Field sampling was conducted using pitfall traps in bogs, heathlands, and grasslands of Brittany (Western France) in 2013. A total of 8576 spider individuals were identified up to the species level (for a total of 141 species), as well as all plant species in more than 300 phytosociological relevés. A generalised linear model showed that spider activity-density was negatively influenced by mean vegetation height and mean Ellenberg value for moisture. Indices of diversity (ɑ, β, and functional diversities) increased with increasing vegetation height and shrub cover. Variables driving spider composition were mean vegetation height, dwarf shrub cover, and low shrub cover (results from a redundancy analysis). Spiders, some of the most abundant arthropod predators, are thus strongly influenced by vegetation structure, including ground-dwelling species. Although later successional states are usually seen as detrimental to local biodiversity in Europe, our results suggest that allowing controlled development of the shrub layer could have a positive impact on the diversity of ground-dwelling spiders.
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| 5. |
- Lafage, Denis, et al.
(författare)
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Short-term resilience of arthropod assemblages after spring flood, with focus on spiders (Arachnida Araneae) and carabids (Coleoptera: Carabidae)
- 2015
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Ingår i: Ecohydrology. - : John Wiley & Sons. - 1936-0584 .- 1936-0592. ; 8:8, s. 1584-1599
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Tidskriftsartikel (refereegranskat)abstract
- Despite the expected increase in extreme flood frequency, the manner in which terrestrial arthropods cope with regular submersion of their habitat remains poorly understood in meadows, especially in temperate floodplains. Here, we studied the recolonization dynamics of arthropods after a severe spring flood in the Loire Valley (France). We carried out analyses at the community (order or family identification level) and species scales, focusing on the assemblages of two dominant and diverse groups: carabids and spiders. Our objectives were the following: (i) to describe the temporal changes in community structure after flooding and (ii) to assess the influence of landscape configuration on recolonization patterns of species and their functional traits. Fieldwork was performed along three sampling transects, by using 75 pitfall traps, in 2012. A total of 14767 arthropods belonging to 87 families were trapped, including 5538 spiders (55 species) and 3396 carabids (66 species). Multivariate analyses discriminated assemblages from flooded and non-flooded habitats and revealed changes over time in arthropod families and species after flood withdrawal. In particular, wolf spiders (Lycosidae) were the first to recolonize, whereas other groups clearly avoided flooded sites. Our results also revealed that short distances to hedgerows, and to a lesser extent, distance to woodlands, favoured the recolonization of large and ground-running spiders. In conclusion, our study shows the short-term resilience of certain groups or stenotopic species to flooding and also the relevance of multi-taxon-based studies. The presence of hedgerows has to be considered carefully in management plans because of their role of refuge during flooding. Copyright (c) 2015 John Wiley & Sons, Ltd.
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| 6. |
- Mammola, Stefano, et al.
(författare)
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Challenges and opportunities of species distribution modelling of terrestrial arthropod predators
- 2021
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Ingår i: Diversity & distributions. - : Wiley-Blackwell Publishing Inc.. - 1366-9516 .- 1472-4642. ; 27:12, s. 2596-2614
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Tidskriftsartikel (refereegranskat)abstract
- Aim Species distribution models (SDMs) have emerged as essential tools in the equipment of many ecologists, useful to explore species distributions in space and time and answering an assortment of questions related to biogeography, climate change biology and conservation biology. Historically, most SDM research concentrated on well-known organisms, especially vertebrates. In recent years, these tools are becoming increasingly important for predicting the distribution of understudied invertebrate taxa. Here, we reviewed the literature published on main terrestrial arthropod predators (ants, ground beetles and spiders) to explore some of the challenges and opportunities of species distribution modelling in mega-diverse arthropod groups. Location Global. Methods Systematic mapping of the literature and bibliometric analysis. Results Most SDM studies of animals to date have focused either on broad samples of vertebrates or on arthropod species that are charismatic (e.g. butterflies) or economically important (e.g. vectors of disease, crop pests and pollinators). We show that the use of SDMs to map the geography of terrestrial arthropod predators is a nascent phenomenon, with a near-exponential growth in the number of studies over the past ten years and still limited collaborative networks among researchers. There is a bias in studies towards charismatic species and geographical areas that hold lower levels of diversity but greater availability of data, such as Europe and North America. Conclusions Arthropods pose particular modelling challenges that add to the ones already present for vertebrates, but they should also offer opportunities for future SDM research as data and new methods are made available. To overcome data limitations, we illustrate the potential of modern data sources and new modelling approaches. We discuss areas of research where SDMs may be combined with dispersal models and increasingly available phylogenetic and functional data to understand evolutionary changes in ranges and range-limiting traits over past and contemporary time-scales.
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| 7. |
- Monsimet, Jeremy, et al.
(författare)
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Biogeographic position and body size jointly set lower thermal limits of wandering spiders
- 2021
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Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; :7, s. 3347-3356
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Tidskriftsartikel (refereegranskat)abstract
- Most species encounter large variations in abiotic conditions along their distribution range. The physiological responses of most terrestrial ectotherms (such as insects and spiders) to clinal gradients of climate, and in particular gradients of temperature, can be the product of both phenotypic plasticity and local adaptation. This study aimed to determine how the biogeographic position of populations and the body size of individuals set the limits of cold (freezing) resistance of Dolomedes fimbriatus. We compared D. fimbriatus to its sister species Dolomedes plantarius under harsher climatic conditions in their distribution range. Using an ad hoc design, we sampled individuals from four populations of Dolomedes fimbriatus originating from contrasting climatic areas (temperate and continental climate) and one population of the sister species D. plantarius from continental climate, and compared their supercooling ability as an indicator of cold resistance. Results for D. fimbriatus indicated that spiders from northern (continental) populations had higher cold resistance than spiders from southern (temperate) populations. Larger spiders had a lower supercooling ability in northern populations. The red-listed and rarest D. plantarius was slightly less cold tolerant than the more common D. fimbriatus, and this might be of importance in a context of climate change that could imply colder overwintering habitats in the north due to reduced snow cover protection. The lowest cold resistance might put D. plantarius at risk of extinction in the future, and this should be considered in conservation plan.
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| 8. |
- Monsimet, Jeremy, et al.
(författare)
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Contrasted propensity for waterborne and airborne dispersal between two closely related semi-aquatic spider species
- 2022
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Ingår i: Insect Conservation and Diversity. - : John Wiley & Sons. - 1752-458X .- 1752-4598. ; 15:6, s. 704-713
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Tidskriftsartikel (refereegranskat)abstract
- Dispersal abilities are important to support metapopulation functioning and species distributions, yet it is rarely accounted for in conservation. Here, we compared the propensity for dispersal between the two fishing spiders present in Europe: the widespread habitat-generalist Dolomedes fimbriatus and the scarcer red-listed Dolomedes plantarius. We experimentally tested for airborne and waterborne dispersal using first instar juveniles sampled in nursery webs, and older juveniles. We estimated the propensity for short and long-distance dispersal of airborne and waterborne behaviours, and we tested the difference between species with generalised linear mixed models. Airborne (ballooning) and waterborne (sailing) behaviours were more frequent for D. fimbriatus than for D. plantarius, indicating a higher propensity of the former for long-distance dispersal. The frequency of rappelling behaviour, and thus the propensity for short-distance dispersal, did not differ between species. However, we found contrasting results for short-distance dispersal on the water, with rowing being more frequent and running less frequent for D. plantarius than for D. fimbriatus. The different propensity for dispersal between the two species might be partly explained by the ecology of D. plantarius, which is known to be more habitat-specialist and more dependent to water bodies than D. fimbriatus. The limited propensity for dispersal of the red-listed D. plantarius is another argument for conserving an interconnected network of wetlands in Fennoscandia. Indeed, increased isolation of populations would be detrimental for species maintenance.
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| 9. |
- Monsimet, Jeremy, et al.
(författare)
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Explicit integration of dispersal-related metrics improves predictions of SDM in predatory arthropods
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Fishing spiders (Dolomedes spp.) make an interesting model to predict the impact of global changes because they are generalist, opportunistic predators, whose distribution is driven mostly by abiotic factors. Yet, the two European species are expected to react differently to forthcoming environmental changes, because of habitat specialization and initial range. We used an original combination of habitat and dispersal data to revisit these predictions under various climatic scenarios. We used the future range of suitable habitat, predicted with habitat variables only, as a base layer to further predict the range or reachable habitat by accounting for both dispersal ability and landscape connectivity. Our results confirm the northward shift in range and indicate that the area of co-occurrences should also increase. However, reachable habitat should expand less than suitable habitat, especially when accounting for landscape connectivity. In addition, the potential range expansion was further limited for the red-listed D. plantarius, which is more of a habitat specialist and has a lower ability to disperse. This study highlights the importance of looking beyond habitat variables to produce more accurate predictions for the future of arthropods populations.
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| 10. |
- Åhlén, David, 1988-
(författare)
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Arthropods in Constructed Wetlands : Ecosystem Processes and Riparian Biodiversity
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Constructed wetlands in the agricultural landscape are known to harbor immense arthropod biodiversity, however, riparian arthropod communities have often been neglected compared to aquatic communities when studying environmental responses. These wetlands are highly productive, but vary in form and composition based on its purpose, which influences the communities that inhabit them. Both biotic and abiotic wetland characteristics are known to drive aquatic arthropod community compositions, whereas knowledge is currently lacking as to the influence from characteristic wetland properties on riparian arthropods.This thesis aimed to shed a light on characteristic wetland drivers on riparian arthropod populations and communities. We explored how chironomid emergence rates and diversities responded to wetland nutrient loads and primary production (Chapter I), and subsequently if trophic cascading relationships could be observed across the aquatic-terrestrial boundary to riparian predator abundances (Chapter II). We also explored how riparian arthropod community compositions responded to wetland hydrologic dynamism, shoreline inclines and vegetation height, and grazing management (Chapter III), and finally how characteristic wetland shoreline properties influenced riparian arthropod diversities and habitat specializations (Chapter IV).In Chapter I we found that emergence rates and diversities of chironomids increased with aquatic chlorophyll concentrations during parts of the season but decreased during others, and that chironomid taxonomic diversity correlated with the aquatic concentration of methane. These findings support previously suggested trade-offs relationship between emerging chironomids and methane. We expanded on these findings in Chapter II, where we found that both primary-and secondary consumer abundances responded to wetland nutrient loads and chlorophyll concentrations, but that this trophic pathway was more complex than from primary producers, through primary consumers to secondary consumers. In Chapter III we found that some riparian arthropods responded to hydrological dynamism, but that surprisingly many groups were unaffected. We also found that many groups responded to shoreline vegetation height, but that responses were group specific. Similarly, in Chapter IV we found that shoreline properties greatly influenced spider, beetle and predatory Diptera diversities in constructed wetlands, and that their habitat specialized species richness varied greatly between groups. Altogether, these findings illustrate the complexity of wetland arthropod ecology, and the need for attention to these previously understudied systems. It also highlights the importance of comprehension regarding constructed biodiversity wetlands if the aim is to improve biodiversity across multiple taxa.
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