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Rising temperatures favour defence-suppressing herbivores
No full textInternational audienceRising temperatures due to climate change are predicted to accelerate the life cycle of arthropod herbivores thereby exacerbating pest formation. Notorious pests like spider mites thrive in areas with high temperatures (32-35 °C), and it is predicted that the size and number of such areas will expand in the coming decades. Higher temperatures can directly accelerate population growth, but also indirectly affect them through changes in the plant's defensive mechanisms. Spider mites have been shown to adapt to plant defences, with natural selection favouring defence-suppressing traits. However, it is not known to what extent suppression is affected by rising temperatures and how this might tie into the rate of adaptation and pest damage. In this study, we investigated the effect of two temperatures (25 °C and 32 °C), on the spider mite-tomato interaction, predicting the influence of rising temperatures on favouring defence-adapted mites. We found that all mite strains caused more plant damage at 32 °C, but temperature did not affect the overall patterns of induction and suppression of defence genes. Although fecundity was higher for all strains at 32 °C, juvenile and adult survival was lower, especially for inducer mites. With these data, we parametrized population models for the two strains over three months, indicating that suppressor mites might displace inducers at the higher temperature, either when it is constant or in the form of heat waves. Our models predict that in areas with higher temperatures, defence-suppressing mites are favoured, which will accelerate and consequently spur pest formation
Pour une géographie laitière de l’amont : une contribution par la traite robotisée
No full textInternational audienceRobotic milking of dairy cows has been growing steadily since the early 2000s. Today, it concerns almost 19% of the milking machines present in the French dairy farms. Despite this growth, the spatial dynamics of the development of the robotic milking market have not yet been studied. Based on interviews with robotic milking suppliers, distributors and farmers, this article analyses the contribution of robotic milking to the production of dairy spaces. The paper explores how dealers adapt to the spatial diversity of dairy production, and how they shape this diversity through their strategies for building a distribution network.La traite robotisée des vaches laitières connaît un développement soutenu depuis le début des années 2000 et représente aujourd’hui 19 % des machines à traite au sein des exploitations françaises. Malgré cet essor, la dynamique spatiale du développement du marché de la traite robotisée n’a jusqu’à présent pas été étudiée. En s’appuyant sur des entretiens avec des distributeurs et des concessionnaires de robots de traite ainsi que des éleveurs, cet article analyse la contribution de la traite robotisée à la fabrique des espaces productifs laitiers. Entre géographie rurale et géographie de firmes, il révèle non seulement comment les concessionnaires s’adaptent à la diversité spatiale de la production laitière, mais aussi comment ils la façonnent à travers des stratégies de construction d’un réseau de distribution des robots de traite
A new stegosaurian dinosaur (Ornithischia: Thyreophora) with a remarkable dermal armour from the Middle Jurassic of North Africa
No full textInternational audienceIn recent years the Middle Atlas of Morocco has become an area of interest for the study of dinosaurs in northern Africa. The Boulahfa locality, near Boulemane, has produced a diverse dinosaur assemblage from the Middle Jurassic of the El Mers Group. Fossil remains of sauropods and thyreophorans, such as ankylosaurs (Spicomellus) and stegosaurs (Adratiklit), have been reported so far in this region. Here, we describe a new partial thyreophoran skeleton found in the gray marls of the El Mers III Formation (Bathonian-? Callovian), which mainly consists of disarticulated dorsal vertebrae and ribs, and associated dermal armour elements. Axial characters (e.g., elongated pedicels of the dorsal neural arches; upturned transverse processes and dorsal ribs with straight axes suggesting a narrow ribcage) indicate that the specimen belongs to a medium to large-sized stegosaur. The dorsal vertebrae show differences with those of Adratiklit, whose material has been found at the same stratigraphic levels. Thyreosaurus atlasicus gen. et sp. nov. is characterized by a remarkable dermal armour, which consists of thick (up to 4 cm) subovate to subrectangular-shaped osteoderms. The asymmetrical texture of their sides, one roughly ornamented with small pits and fiber bundles, the other with a well-marked cross-hatched pattern, is clearly different from that observed to date in other stegosaurs (and ankylosaurs). The bone histology of these osteoderms is reminiscent of that of stegosaurian tail spines. It is interpreted that these osteoderms were arranged in a recumbent position over the body of the animal, instead of an erect position. The holotype corresponds to an adult individual who did not reach its maximum body size (estimated body length 6 m). The phylogenetic analysis suggests that Thyreosaurus is closely related to Dacentrurus within Dacentrurinae. The recent discoveries of Adratiklit and Thyreosaurus provide insight into the early evolution of stegosaurs in the Middle Jurassic of Africa
Night life: Positional behaviors and activity patterns of the Neotropical kinkajou, Potos flavus (Carnivora, Procyonidae)
No full textInternational audienceStudying positional behaviors is important for understanding how animals interact with their immediate environment. This is particularly important in arboreal species since arboreal milieus are primarily characterized by three‐dimensional problems that arboreal species must overcome to efficiently access resources. Similarly, a fundamental aspect of an animal's ecology is its daily activity pattern. This information is important for understanding the basic ecology of animal species and their eco‐evolutionary dynamics. This study sought to understand the habitat use and nocturnal lifestyle of the highly arboreal kinkajou ( Potos flavus ) by documenting variation in positional behaviors and activity patterns using 2223 photographs obtained from 27 camera traps in French Guiana. Data were analyzed using descriptive statistics, Kernel density estimation (KDE), and Gantt charts. Our results indicate that kinkajous show a strictly nocturnal activity pattern beginning from 19:00 h to 05:57 h, with peak active periods between 01:00 h and 02:00 h. The most frequent activities were scanning (48.33%) and traveling (47.13%). Quadrupedal walking (95.43%) was the main locomotor behavior during traveling. However, when crossing gaps between two substrates, kinkajous would either bridge (42.22%), leap (33.33%), or drop (26.67%) across gaps. Inactive periods were characterized by grooming (77.32%) and resting (27.84%) while mostly assuming a sitting (90.67%) or a catlike body curl posture (92.59%), interchangeably. This study highlights the broad array of positional behaviors displayed by kinkajous, further providing information to understand its basic ecology and eco‐evolutionary dynamics
A harmonized database of European forest simulations under climate change
No full textInternational audienceProcess-based forest models combine biological, physical, and chemical process understanding to simulate forest dynamics as an emergent property of the system. As such, they are valuable tools to investigate the effects of climate change on forest ecosystems. Specifically, they allow testing of hypotheses regarding long-term ecosystem dynamics and provide means to assess the impacts of climate scenarios on future forest development. As a consequence, numerous local-scale simulation studies have been conducted over the past decades to assess the impacts of climate change on forests. These studies apply the best available models tailored to local conditions, parameterized and evaluated by local experts. However, this treasure trove of knowledge on climate change responses remains underexplored to date, as a consistent and harmonized dataset of local model simulations is missing.Here, our objectives were (i) to compile existing local simulations on forest development under climate change in Europe in a common database, (ii) to harmonize them to a common suite of output variables, and (iii) to provide a standardized vector of auxiliary environmental variables for each simulated location to aid subsequent investigations. Our dataset of European stand- and landscape-level forest simulations contains over 1.1 million simulation runs representing 135 million simulation years for more than 13,000 unique locations spread across Europe. The data were harmonized to consistently describe forest development in terms of stand structure (dominant height), composition (dominant species, admixed species), and functioning (leaf area index). Auxiliary variables provided include consistent daily climate information (temperature, precipitation, radiation, vapor pressure deficit) as well as information on local site conditions (soil depth, soil physical properties, soil water holding capacity, plant-available nitrogen). The present dataset facilitates analyses across models and locations, with the aim to better harness the valuable information contained in local simulations for large-scale policy support, and for fostering a deeper understanding of the effects of climate change on forest ecosystems in Europe
Recent advances in the study of serpentine plants and ecosystems: Perspectives from the 10th International Conference on Serpentine Ecology, France: Part II
No full textInternational audienceThe 10th International Conference on Serpentine Ecology was held in Nancy, France on June 12–16, 2023. The main goals of the conference were to create a platform for the exchange of ideas and experiences and to promote scientific dialogue among scientists from numerous fields who share expertise in the study of ultramafic habitats worldwide. The proceedings of the conference are being published as two Special Issues of Ecological Research , of which this is the second. In this article, we present the major topics and provide some highlights of the contributions to the 10th International Conference on Serpentine Ecology
Bayesian methods for the assessment of PPR immunity coverage
No full textCase study: Post-vaccinal evaluation in Kano State, Nigeria. Nigeria. Distance training. 1 day
Influence of isolation on the resilience of tank bromeliad ecosystems to drought in a Neotropical rainforest
No full textInternational audienceLittle is known of how Neotropical freshwater ecosystems will respond to future climate scenarios. In Neotropical rainforests, a substantial fraction of the freshwater available to the aquatic fauna is found within phytotelmata, plant-held waters that form aquatic islands in a terrestrial matrix. We hypothesized that phytotelmata in close proximity have higher resilience capacity to severe drought than the isolated ones, under the assumption that immigration from nearby sources promotes faster recovery. We used rainshelters to emulate an extreme drought (67 days without rainfall) in tank-forming bromeliads arranged in patches of 1, 3 or 6 plants in a primary forest of French Guiana. Habitat size was a stronger determinant of invertebrate species richness and biomass per bromeliad than patch size. Larger bromeliad patches attenuated the adverse effect of drought on the biomass of predators, probably because short-range migration within dense patches allowed individuals to find moist refuges. However, the recovery of aquatic communities and ecosystem functions was mostly supported by in situ resistance, and a rescue effect of immigration was weak. Whilst environmental management plans tend to focus on dense networks of connected water bodies, our study shows that efforts should not omit the isolated ones
Étude de la consommation en eau potable et de l’impact de la tarification : retour d’expérience sur la difficulté à mobiliser les données SISPEA
No full textIntervention à distance à la commission du CNIS - Conseil national de l’information statistique dans leur réunion sur « Les statistiques relatives à la ressource en eau »International audienc
