Combining forest exploitation and heathland biodiversity: Edges structure drives microclimates quality and reptile abundance in a coniferous plantation

peer reviewedIn Western Europe, natural habitats such as heathlands have been converted into many commercially managed forests, with severe impacts on biodiversity. In dense planted forests, forest edges are often the only suitable areas for ectothermic organisms highly dependent on open habitats for thermoregulation. Surprisingly, the influence of forest edges structure on the thermal quality of microhabitats and reptile species distribution remains poorly understood. In this study, we examined two reptile species and thermal quality of interior forest edges of a coniferous forest in Western France (Brittany). We focused on two hypotheses (i) the vegetation structure of the forest edges drives the thermal quality of the habitat and (ii) structural complexity of the forest edges influences the abundance of two heliothermic reptiles: the common adder (Vipera berus) and the common lizard (Zootoca vivipara). We first deployed temperature sensitive data loggers to quantify thermal conditions along 16 cross-sections of inner forest margins. For each section, 4 temperature loggers were placed at 1, 3, 5 and 7 m from the driveway and we examined the relation to vegetation structure and canopy cover. Second, we carried visual encounter surveys in 55 edges in order to measure the response of two reptiles to the structure of the forest margin along exploitation driveway. Our results show that high local canopy cover decreases microhabitat quality within interior forest edges. We also found that common lizard abundance was significantly influenced by the edge orientation and increased with global canopy openness and ground level vegetation. Adder abundance only increased significantly with the driveway width, suggesting the unmodelled effect of other biotic/abiotic variables. Our study shows that thermal quality of interior edges and driveway characteristics are relevant to support heathland reptile populations. We posit that maintain strips of favourable microhabitats should be an efficient land sharing strategy to combine forestry activities and biodiversity conservation

Evaluer, conserver et restaurer la biodiversité. Des partenariats scientifiques MNHN et entreprises

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Antileishmanial pharmacomodulation in 8-nitroquinolin-2(1H)-one series

International audienceAn antileishmanial pharmacomodulation at position 4 of 8-nitroquinolin-2(1H)-one was conducted by using the Sonogashira and Suzuki-Miyaura coupling reactions. A series of 25 derivatives was tested in vitro on the promastigote stage of Leishmania donovani along with an in vitro cytotoxicity evaluation on the human HepG2 cell line. Only the derivatives bearing a phenyl moiety at position 4 of the quinoline ring displayed interesting biologic profile, when the phenyl moiety was substituted at the para position by a Br or Cl atom, or by a CF3 group. Among them, molecules 17 and 19 were the most selective and were then tested in vitro on the intracellular amastigote stage of both L. donovani and Leishmania infantum, in parallel with complementary in vitro cytotoxicity assays on the macrophage cell lines THP-1 and J774A.1. Molecule 19 showed no activity on the amastigote stages of the parasites and some cytotoxicity on the J774A.1 cell line while molecule 17, less cytotoxic than 19, showed anti-amastigote activity in L. infantum, being 3 times less active than miltefosine but more active and selective than pentamidine. Nevertheless, hit-molecule 17 did not appear as selective as the parent compound. (C) 2015 Elsevier Ltd. All rights reserved

FRIPON: a worldwide network to track incoming meteoroids

Context: Until recently, camera networks designed for monitoring fireballs worldwide were not fully automated, implying that in case of a meteorite fall, the recovery campaign was rarely immediate. This was an important limiting factor as the most fragile – hence precious – meteorites must be recovered rapidly to avoid their alteration. Aims: The Fireball Recovery and InterPlanetary Observation Network (FRIPON) scientific project was designed to overcome this limitation. This network comprises a fully automated camera and radio network deployed over a significant fraction of western Europe and a small fraction of Canada. As of today, it consists of 150 cameras and 25 European radio receivers and covers an area of about 1.5 × 106 km2. Methods: The FRIPON network, fully operational since 2018, has been monitoring meteoroid entries since 2016, thereby allowing the characterization of their dynamical and physical properties. In addition, the level of automation of the network makes it possible to trigger a meteorite recovery campaign only a few hours after it reaches the surface of the Earth. Recovery campaigns are only organized for meteorites with final masses estimated of at least 500 g, which is about one event per year in France. No recovery campaign is organized in the case of smaller final masses on the order of 50 to 100 g, which happens about three times a year; instead, the information is delivered to the local media so that it can reach the inhabitants living in the vicinity of the fall. Results: Nearly 4000 meteoroids have been detected so far and characterized by FRIPON. The distribution of their orbits appears to be bimodal, with a cometary population and a main belt population. Sporadic meteors amount to about 55% of all meteors. A first estimate of the absolute meteoroid flux (mag < –5; meteoroid size ≥~1 cm) amounts to 1250/yr/106 km2. This value is compatible with previous estimates. Finally, the first meteorite was recovered in Italy (Cavezzo, January 2020) thanks to the PRISMA network, a component of the FRIPON science project