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

RENATU : un outil d’évaluation du potentiel écologique d’un site industriel ou urbain pour des utilisateurs non spécialisés

International audienceThe biodiversity strategy of companies is part of their financial and social performance. Urban, Industrial and Linear Transport Infrastructures (UILTI) integrate green spaces. For these, managers are asking for tools to assess and monitor their biodiversity. RENATU is a potential biodiversity indicator. It is composed of several indices that concern ecosystem features. The more complex the environment, the greater the taxonomic diversity. The complexity of the ecological components, measured by the indices, is indicative of the potential for hosting plant and animal species (insects, arthropods, butterflies, birds, mammals, etc.). Atotal of 96 sites were used to test this indicator. The results demonstrate the homogeneity of the ecological indices. An evaluation by means of a user questionnaire was used to confirm its relevance as a potential biodiversity management tool. Such an indicator is part of the corporate social responsibility strategy. It enhances both financial and social performanceLa stratégie de biodiversité des entreprises fait partie de leur performance financière et sociale. Les infrastructures de transport urbaines, industrielles et linéaires (ITUIL) intègrent des espaces verts. Pour ceux- ci, les gestionnaires sont demandeurs d'outils d'évaluation et de suivi de leur biodiversité. RENATU est un indicateur de biodiversité potentielle. Il est composé de plusieurs indices qui concernent les caractéristiques des écosystèmes. Plus l'environnement est complexe, plus la diversité taxonomique est importante. La complexité des composantes écologiques, mesurée par les indices, est révélatrice du potentiel d'accueil des espèces végétales et animales (insectes, arthropodes, papillons, oiseaux, mammifères etc.). Au total, 96 sites ont été utilisés pour tester cet indicateur. Les résultats démontrent l'homogénéité des indices écologiques. Une évaluation par le biais d'un questionnaire adressé aux utilisateurs a permis de confirmer sa pertinence en tant qu'outil potentiel de gestion de la biodiversité. Un tel indicateur s'inscrit dans la stratégie de responsabilité sociale des entreprises. Il permet d'améliorer les performances financières et sociales

‘On Vient de Fusiller un des Nôtres’: A Quantitative Study of Military Executions in the French Army during WW1

Early Access : OCT 2022International audienceThis paper explores the issue of French executions during the Great War in a quantitative perspective. Based on the 'Shot in the First World War' database of the Ministry of Defense, we first provide a statistical portrait of the French soldiers who were sentenced to death by courts-martial or summarily executed. Then, we analyze the temporal distribution of executions using a regression approach. More specifically, we investigate whether the variations in the number of executions over time were related to the intensity of engagements. Finally, focusing on the soldiers' place of birth, we examine the differences across counties (departements) in the execution rate. Our results suggest that the vast majority of the executed soldiers were 'poilus' like the others who found themselves before a firing squad for having committed a fault in a moment of weakness, often after being involved in particularly bloody fighting, and sometimes under the influence of alcohol. Their acts were probably, in most cases, much more driven by survival instinct than by pacifist motives or other political considerations

La biodiversité, nouvel enjeu de la RSE

National audienceCompanies must go beyond a purely instrumental conception of biodiversity management to integrate the interactions between the biodiversity of ecosystems and the singularity of human societies into their corporate social responsibility policies.Les entreprises doivent dépasser une conception purement instrumentale de la gestion de la biodiversité pour intégrer au sein des politiques de responsabilité sociétale d’entreprise les interactions entre biodiversité des écosystèmes et singularisme des sociétés humaines