Impact of cutting date on carabids and spiders in a wet meadow

International audienceThe impact of different cutting dates on two dominant groups of ground-dwelling arthropods (carabids and spiders) was assessed. Short-term impacts were assessed by comparing them before and after cutting. Arthropods were collected by pitfall traps located in three plots with different cutting dates between June and August and one uncut control plot. Trapping was performed during a 4-month period in the spring and summer 2011. In total, 26,392 spiders and 12,278 carabids, representing 56 and 82 species respectively, were collected. Overall, the effects of cutting were negative and mostly visible in the long term for carabids, with reduced abundances and species richness in cut plots, and in the short-term for spiders; several parameters (proportion of predators and polyphagous species, and body length) decreased after cutting while remaining stable in the control. Long-term cutting effects revealed almost no differences between plots cut at different dates whereas the short-term effects decreased slightly over time, with respect to the overall phenology of both groups. In conclusion, this study underlines the fact that cutting has drastic effects on ground-dwelling arthropods, and even late dates, which are supposedly positive for other animals like breeding birds, are deleterious for highly diverse and species-rich grassland groups

Changes in soil organic matter driven by shifts in co-dominant plant species in a grassland

International audienceGlobally, grassland soils, if managed properly, are important for the sake of carbon sequestration. The quality and quantity of soil organic carbon is probably influenced by vegetation traits such as composition and plant species. We determined the influence of vegetation composition and co-dominant species on soil organic carbon in two Prangus uloptera stands. The stands situated at close proximity were identified in a Prangos uloptera community in north-western Iran. Both stands shared similar dominant plant species with the same physiographical and climatological characteristics, but differed in their co-dominant plant species. To compare soil organic matter (SOM) parameters, soil samples from each stand were collected from depths of 0-15 cm and 15-30 cm. The results showed that SOM had spatial variation which was probably affected by the plant species. The highest values of total C, Total N, POM-C, POM-N, microaggregates, C in macroaggregates and C in microaggregates in the upper soil layer occurred in the stand with the highest cover of Astragalus microcephalus and Acanthophyllum microcephalum. It is suggested that, in conservation projects based on higher carbon sequestration, the plant species with more incorporation of carbon content into soil should be identified and used more widely

Ecological determinants of meadow community of Coleoptera Scarabaeoidea Laparosticti (Manche, France)

Beetles belonging to the group of Scarabaeoidea Laparosticti represent an important component of grazed meadows, particularly in contributing to their structural biodiversity. They are indeed functioning elements that recycle organic matter coming from herbivore dejections. This study aimed at characterizing the whole assemblage of Coleoptera Scarabaeoidea Laparosticti and at determining respective influence of two main ecological factors, i.e. the type of herbivore (cow or horse) and the type of grazed meadow (meso-hygrophilous or xerophilous), on the distribution (in terms of presence/absence and abundances) of coprophagous beetles. Sampling were carried out in the “Réserve naturelle nationale du Domaine de Beauguillot” (Manche, France) during 2005 by using the standard trapping “Cebo-Superficie-Rejilla”. A total of 12,621 individuals belonging to 26 species were collected. A strong effect of herbivore type was highlighted, as numerous species were found to be exclusively or mainly present in cow dung. The effect of meadow type slightly occurred, being important only in case of statistical interactions with herbivore typeLes Coléoptères Scarabaeoidea Laparosticti forment une composante importante des milieux prairiaux pâturés, à la fois comme éléments constitutifs de leur biodiversité et en tant que maillons essentiels de leur fonctionnement (recyclage de la matière organique issue des fèces d'herbivores). Les objectifs de cette étude furent d'une part de caractériser globalement le peuplement de Coléoptères Scarabaeoidea Laparosticti et d'autre part d'évaluer l'influence de deux facteurs écologiques majeurs, le type d'herbivore présent (vache ou cheval) et le type de prairie pâturée (méso-hygrophile ou xérophile) sur la répartition (en termes de présence/absence et d'abondances) des espèces de Coléoptères coprophages. L'échantillonnage a été mené dans la Réserve naturelle nationale du Domaine de Beauguillot (Manche, France) durant l'année 2005 au moyen du piégeage standard Cebo-Superficie-Rejilla. Au total, 12 621 individus appartenant à 26 espèces ont été récoltés. Nous avons pu mettre en évidence un effet marqué du type d'herbivore, un grand nombre d'espèces étant notamment inféodées ou préférentielles des bouses de vache. L'effet du type de prairie est apparu faiblement, plus fortement dans le cas d'interactions statistiques avec le type d'herbivore

Towards establishment of a centralized spider traits database

A main goal of ecological and evolutionary biology is understanding and predicting interactions between populations and both abiotic and biotic environments, the spatial and temporal variation of these interactions, and the effects on population dynamics and performance. Trait-based approaches can help to model these interactions and generate a comprehensive understanding of ecosystem functioning. A central tool is the collation of databases that include species trait information. Such centralized databases have been set up for a number of organismal groups but is lacking for one of the most important groups of predators in terrestrial ecosystems - spiders. Here we promote the collation of an open spider traits database, integrated into the global Open Traits Network. We explore the current collation of spider data and cover the logistics of setting up a global database, including which traits to include, the source of data, how to input data, database governance, geographic cover, accessibility, quality control and how to make the database sustainable long-term. Finally, we explore the scope of research questions that could be investigated using a global spider traits database.Peer reviewe

An expert-curated global database of online newspaper articles on spiders and spider bites

Mass media plays an important role in the construction and circulation of risk perception associated with animals. Widely feared groups such as spiders frequently end up in the spotlight of traditional and social media. We compiled an expert-curated global database on the online newspaper coverage of human-spider encounters over the past ten years (2010-2020). This database includes information about the location of each human-spider encounter reported in the news article and a quantitative characterisation of the content-location, presence of photographs of spiders and bites, number and type of errors, consultation of experts, and a subjective assessment of sensationalism. In total, we collected 5348 unique news articles from 81 countries in 40 languages. The database refers to 211 identified and unidentified spider species and 2644 unique human-spider encounters (1121 bites and 147 as deadly bites). To facilitate data reuse, we explain the main caveats that need to be made when analysing this database and discuss research ideas and questions that can be explored with it.Peer reviewe

Breton versus British Spiders: Are They So Different?

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Small scale changes in spider diversity and composition between two close elevations in a Neotropical forest

International audienceTropical rainforests are one of the most diverse ecosystems worldwide, yet the mechanisms driving the spatial distribution of their biodiversity remain poorly understood. Here, we tested the effects of elevation, sampling method and their interaction on alpha and beta diversities of spider assemblages between two close elevations in one tropical forest of French Guiana. Through a standardized protocol, both ground- and vegetation-dwelling (up to 2.5-m high) assemblages were sampled at medium and high elevations, during day and night using 3 complementary methods (beating, sweeping, and nocturnal hand collecting). Despite a lower total number of species at high elevation, we found no significant effect of elevation on mean species richness. However, elevation had a significant effect on species composition, notably with less web builders and more ground hunters at higher elevations. In addition, we found a significant effect of sampling methods on both estimated species richness and composition. These results suggest that even slight elevation shape spider assemblages of tropical forests, which probably contributes to the high turn-over and amazing gamma diversity of these ecosystems

Comparison of flooding resistance in salt-marsh (Arctosa fulvolineata and Pardosa proxima) and forest (Pardosa lugubris) spiders (Araneae : Lycosidae).

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Comparison of flooding resistance in salt-marsh (Arctosa fulvolineata and Pardosa proxima) and forest (Pardosa lugubris) spiders (Araneae : Lycosidae).

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Biodiversité et aménagements urbains (réponse des assemblages de carabiques et d araignées dans les haies publiques de Rennes Métropole)

La biodiversité en ville est un nouveau sujet de recherche majeur en écologie pour des raisons qui tiennent à la fois de préoccupations scientifiques, politiques, sociales et éthiques. Ce travail est essentiellement centré sur l'étude des assemblages de carabiques et d'araignées dans des quartiers résidentiels de la Communauté d'agglomération rennaise. Cette étude a éte menée dans des haies urbaines par des pièges d'interception de 2008 a 2010. Un effet barrière semble exister entre le milieu rural et le milieu urbain, en particulier pour les araignées. En effet, les deux modèles sont sensibles et répondent de manière différente aux contraintes liées au milieu urbain et à l'urbanisation, ce qui souligne la complémentarité de ces deux modèles. Cependant, les assemblages observés dans les haies sont relativement semblables entre eux malgré l'hétérogénéité des sites en termes d'âge, d'aménagement et d'entretien. Les nouvelles formes urbaines, en diminuant l'emprise sur le milieu agricole adjacent et en maintenant une biodiversité comparable à celle des formes urbaines conventionnelles, apparaissent comme une alternative intéressante en aménagement urbain. Nos travaux permettent également de guider les différents acteurs locaux de l'aménagement urbain à travers des perspectives d'applications et de recommandations explicites.Biodiversity in the city is a new major research subject in ecology, developed in response to scientific, political, social and ethical concerns. This work focuses mainly on the study of ground beetle and spider assemblages in urban residential neighbourhoods in the urban Community of Rennes. This study was conducted in urban hedgerows using pitfall traps, from 2008 to 2010. A barrier effect seems to exist between rural and urban areas, especially for spiders. Indeed, both models are sensitive and respond differently to stress related to urban conditions and urbanization, which emphasizes the complementarity of these two taxa. However, the assemblages observed in hedgerows are relatively similar despite the heterogeneity of sites in terms of age, management and maintenance. The new urban forms, by reducing the encroachment on the adjacent agricultural areas and maintaining a level of biodiversity comparable to that of the conventional urban forms, appear as an interesting alternative in urban planning. Our study can also guide the various local actors of urban development through application prospects and explicit recommendations.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF