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Extreme drought periods can change spatial effects on periphytic ostracod metacommunities in river-floodplain ecosystems
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Hydrological regimes are seasonally variable in river-floodplain ecosystems. Thus, since in these environments the local and regional factors change at different temporal scales, factors structuring metacommunities might also differ over time. However, temporal dynamics of metacommunities have rarely been assessed. Here, we investigated the influence of environmental and spatial factors over time on the metacommunity structuring of periphytic ostracods in the river-floodplain system of the Upper Paraná River (Brazil). The spatial factors turned out to be more important than environmental factors, and differences in the percentage of explanation of the factors structuring ostracod metacommunities over time were significant, mainly during extreme drought period. Our results showed that the high spatial influence might be related to the low connectivity amongst environments during such extreme drought period, which can increase dispersal limitation, and consequently can increase the turnover of ostracod species throughout the region, leading to a higher beta-diversity of ostracod metacommunities.
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RBINS Staff Publications 2019
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Urbanization drives cross‐taxon declines in abundance and diversity at multiple spatial scales
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The increasing urbanization process is hypothesized to drastically alter (semi‐)natural environments with a concomitant major decline in species abundance and diversity. Yet, studies on this effect of urbanization, and the spatial scale at which it acts, are at present inconclusive due to the large heterogeneity in taxonomic groups and spatial scales at which this relationship has been investigated among studies. Comprehensive studies analysing this relationship across multiple animal groups and at multiple spatial scales are rare, hampering the assessment of how biodiversity generally responds to urbanization. We studied aquatic (cladocerans), limno‐terrestrial (bdelloid rotifers) and terrestrial (butterflies, ground beetles, ground‐ and web spiders, macro‐moths, orthopterans and snails) invertebrate groups using a hierarchical spatial design, wherein three local‐scale (200 m × 200 m) urbanization levels were repeatedly sampled across three landscape‐scale (3 km × 3 km) urbanization levels. We tested for local and landscape urbanization effects on abundance and species richness of each group, whereby total richness was partitioned into the average richness of local communities and the richness due to variation among local communities. Abundances of the terrestrial active dispersers declined in response to local urbanization, with reductions up to 85% for butterflies, while passive dispersers did not show any clear trend. Species richness also declined with increasing levels of urbanization, but responses were highly heterogeneous among the different groups with respect to the richness component and the spatial scale at which urbanization impacts richness. Depending on the group, species richness declined due to biotic homogenization and/or local species loss. This resulted in an overall decrease in total richness across groups in urban areas. These results provide strong support to the general negative impact of urbanization on abundance and species richness within habitat patches and highlight the importance of considering multiple spatial scales and taxa to assess the impacts of urbanization on biodiversity.
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RBINS Staff Publications 2019
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A juvenile skull from the early Palaeocene of China extends the appearance of crocodyloids in Asia back by 15–20 million years
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The earliest Crocodylia from Asia have been represented so far only by alligatoroids and planocraniids. Although definitive crocodyloids are not known until the late Eocene, it has been hypothesized that Asiatosuchus-like basal crocodyloids originated in Asia before the late Palaeocene. In this paper, we describe a new fossil crocodyloid from the lower Palaeocene of Qianshan Basin, Anhui Province, China. The skull and lower jaw fragment exhibit several characteristics typical of juvenile crocodylians. They also display a combination of features not seen in any other taxon, warranting the erection of a new species and genus, Qianshanosuchus youngi gen. & sp. nov. Its affinities are tested in phylogenetic analyses based on two recent character matrices of Eusuchia. To assess the effect of juvenile characteristics on the outcome of the phylogenetic analyses, juvenile specimens of extant crocodylian taxa are analysed in the same way, showing that the effect of their ontogenetic stage on their placement in the tree is minimal. Our analyses point to a basal crocodyloid position for Q. youngi. With these findings, the presence of Crocodyloidea in Asia is extended to the early Palaeocene, 15–20 Myr earlier than formerly thought. Furthermore, our results corroborate previous hypotheses of a Palaeocene dispersal route of Asiatosuchus-like crocodyloids from Asia into Europe.
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RBINS Staff Publications 2022 OA
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Revival and Revision of the genus Paroplites with description of two new species (Coleoptera, Cerambycidae, Prioninae)
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RBINS Staff Publications 2020
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Les campagnes du territoire Nervien : approches croisées
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RBINS Staff Publications 2017
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« Un manuel de terrain pour standardiser les prélèvements des restes biologiques : une nécessité ou un luxe ? Une année d’expérience belge du point de vue de la carpologie »
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RBINS Staff Publications 2017
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« Les agglomérations nerviennes au Haut Empire : la campagne à la ville ? Les apports de l'Archéobotanique »
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A partir des données carpologiques d'un établissement rural, de quatre villae et de deux agglomérations secondaires du Haut-Empire de la civitas nerviorum, mises en perspective avec les données d'établissements ruraux de la cité ménapienne voisine, le mode d'approvisionnement en céréales de ces centres urbains a pu être appréhendé. La découverte de nombreux résidus de premier battage dans les deux agglomérations fait entrer les établissements agricoles et leurs activités dans la ville, qui gère ainsi une partie de son approvisionnement en céréales. Si les blés vêtus constituent les principales productions céréalières de la cité, les blés panifiables -froment et épeautre- tiennent une plus grande place dans les centres urbains et villae. Ces dernières semblent ainsi tenir un rôle privilégié dans l'approvisionnement des agglomérations. La répartition géographique nord/sud de ces deux taxons, avec le froment au sud et l’épeautre au nord du territoire de la cité, coïncide avec les potentialités agricoles des sols. Le froment, espèce exigeante quant à la qualité des sols, est cultivé sur les terres les plus propices à l'agriculture tandis que l'épeautre est mené dans les terres plus sableuses, à moindre potentialité. Ainsi, l'un des critères majeurs quant au choix des céréales qui approvisionnent les centres urbains tient plus à la possibilité de faire du pain qu'à l'espèce elle même. Celles-ci semblent être sélectionnées, de manière opportuniste, selon des critères agronomiques.
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RBINS Staff Publications 2017
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Etudes carpologiques de sites d’habitats médiévaux de Champagne-Ardenne : état de la question
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L’activité archéologique intense en Champagne-Ardenne a permis la mise au jour de plus de quarante sites d’habitats datés du Moyen Âge. Leur distribution géographique montre une disparité entre le département de l’Aube (10), et plus précisément les environs de la ville de Troyes, très bien documentés avec plus de 20 études carpologiques, le département de la Marne (51) riche d’une quinzaine d’études et les départements de la Haute-Marne (52) et des Ardennes (08), largement sous documentés. Les objectifs de cette compilation de données sont divers : il s’agit dans un premier temps de définir les grandes tendances qui se dégagent concernant l’alimentation au cours du Moyen Âge. Le froment est-il dominant sur l’ensemble de la période médiévale ? Quelles places occupent l’orge vêtue polystique et le seigle ? Une mise en culture de l’avoine peut-elle être mise en évidence ? Dans un second temps, il s’agit de voir si des particularismes régionaux peuvent être mis en évidence : les corpus carpologiques entre la région de Troyes et celle de Reims présentent-ils des différences ? Sont-elles le reflet de particularismes régionaux et/ou de contraintes géographiques ou pédologiques?
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RBINS Staff Publications 2017
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La toute première fois : rythmes et contextes d’apparition d’espèces exogènes ou nouvellement introduites dans certaines régions de France
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RBINS Staff Publications 2017
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Titanodula gen. nov., a new genus of giant Oriental praying mantises (Mantodea: Mantidae: Hierodulinae)
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RBINS Staff Publications 2020
