Developing long-term monitoring of natural areas for a Unesco world heritage site: study case of la Reunion

La Réunion island, in the Mascarenes, has been recognized as a World Heritage site for its Piton, Cirques and Remparts since 2010. The site, coinciding with the core zone of La Réunion National Park, represents 100000 ha, equivalent to 40 % of the island. These dramatic landscapes of rugged terrain, impressive escarpments, forested gorges are dominated by three cliff-rimmed cirques and two volcanoes ― a dormant massif forming the highest peak, Piton des Neiges (3069 m), and in the eastern part of the island lies the very active volcano, the Piton de la Fournaise (2632 m). The island harbours a wide variety of natural habitats (tropical montane cloud forests, subalpine shrublands, lowland forests, dry forest…), now all remnant in the Mascarene archipelago, that host high levels of endemism for both flora and fauna. Thereby, La Réunion is the most significant contributor towards conservation of terrestrial biodiversity in the Mascarene islands. The Divines project (FEDER) aims at developing innovative methods for characterizing and monitoring terrestrial biodiversity in the long term for conservation managers to ensure the protection of this world heritage site. In this poster, a description of the goals, actions and preliminary results of the DIVINES project will be described from gene to ecosystem levels

A 20‐million‐year Early Jurassic cyclostratigraphic record and its implications for the chaotic inner Solar System and sea‐level changes

International audienceWe present high-resolution (every 2 cm) magnetic susceptibility (MS) data from the Sancerre-Couy drill core (Paris Basin), spanning the latest Sinemurian to the earliest Aalenian (Early Jurassic). This record allows to build a 20-million-year cyclostratigraphic interval using the stable 405 kyr (g2–g5) orbital eccentricity cycle and to focus on long-period cyclicities and their potential implications for the chaotic diffusion in the inner Solar System and sea-level changes. Time series analysis indicates evidence of two long-period cyclicities of 1.6 and 3.4 Myr. These Early Jurassic cyclicities likely correspond to the Cenozoic orbital cyclicities of 2.4 Myr (g4–g3) and 4.7 Myr eccentricity terms. Shortening of eccentricity terms during the Early Jurassic is potentially related to the chaotic orbital motion of the inner planets expressed in the resonant argument θ = 2(g4–g3) − (s4–s3). The 1.6 Myr (g4–g3) cycle matches the third-order eustatic sequences, whereas the 3.4 Myr cycle has no equivalent in the reference eustatic chart. These cycles of several million years are superimposed a cyclicity of ca. 7.5 Myr, which may correspond to the eccentricity term of 9.5 Myr, previously detected in the Cenozoic. Such cyclicity matches the global, ‘shorter’ second-order sea-level sequences and is strongly documented in the sedimentological and mineralogical proxy data, hence supporting the potential key role of orbitally paced climate and sea-level changes at this timescale

Innover pour nourrir la ville : comment un intermédiaire de la grande distribution renouvelle la pratique des circuits courts (O’Tera dans le Nord-Pas-de-Calais)

International audienceL’article analyse l’émergence d’un nouvel acteur sur le marché des circuits courts alimentaires, à partir d’une étude de cas sur les magasins O’Tera. Ces « supermarchés des circuits courts », parce qu’ils constituent un maillon d’un nouveau type au sein des systèmes alimentaires, ont suscité l’intérêt et parfois la méfiance. Innovateur par l’application des techniques de la grande distribution et les procédés de commercialisation, ambitieux en termes de réseau et de maîtrise du marché, O’Tera réécrit les relations marchandes entre la ville et l’agriculture. Quels sont les liens que cet intermédiaire tisse avec ses partenaires agricoles ? Est-ce un accélérateur des processus d’ancrage des exploitations agricoles dans le territoire, ou au contraire un prédateur absorbant la valeur créée par le désir des consommateurs pour une relocalisation alimentaire ? L’étude s’articule autour de trois thèmes principaux : le concept marchand innovant, l’interface producteurs-consommateurs et les trajectoires, stratégies et débouchés des agriculteurs-partenaires. Elle révèle la forte croissance de la clientèle, la qualité de la relation agriculteurs/entreprise et une augmentation des volumes vendus à des prix plus rémunérateurs pour les producteurs. Ce modèle hybride apparaît comme une nouvelle source de développement pour des exploitations fonctionnant en mode projet

L’entrée de la grande distribution dans le marché des circuits courts : vers un modèle « hybride » ?: Le cas des magasins O’Tera dans la métropole lilloise

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Trace elements in coralline algae as a new proxy for seawater chemistry and metal pollution

International audienceThe abundances of some macronutrients, and trace elements (K, Al, P, V, Mn, Co, Ni, Cu, Zn, Rb, Sr, Mo, Cs, Ba, Pb, Th, U, Y and REE) were determined in a series of coralline algae (Lithothamnion corallioides) samples (n = 101) collected alive in the Bay of Brest and the Iroise Sea (Western Brittany, NW France), in order to assess the potential of these algae as archives of seawater chemistry and potential metal pollution. REE and Y (REY) patterns are similar in shape to those of local seawater, exhibiting similar La, Ce and Y anomalies, but with abundances ranging between 4 and 5 orders of magnitude higher than seawater values. Variations in La anomalies (La/La* = 1.29-2.08), Y anomalies (Y/Ho = 38.6-55.8), and heavy rare earth enrichments (Prsn/Ersn = 0.22-0.52) are consistent with mixing of seawater with rivers flowing into the Bay of Brest. The behavior of other trace elements, such as Al and Cs, also reflects this mixing. Other parameters and processes can control the abundances of the other elements measured. For example, the presence of organic matter in studied samples controls the abundances of K and Rb. The abundances of base metals (e.g., Co, Ni, Cu) are highly sensitive to the various pollutants present in the Bay of Brest. In particular, the Pb content of coralline algae clearly reflects the pollution caused by mining of a nearby Pb deposit from the 18th to the early 20th century. Our results demonstrate the potential of coralline algae not only for tracing water masses, but also for studying metal pollution

National inventory of geological heritage in France: methodology, content and uses

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National inventory of geological heritage in France: methodology, content and uses

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