Services environnementaux des paysages. Labelliser les paysages ruraux

International audienceLandscapes are designated as heritage sites because they are either outstanding, threatened or neglected. But what about the rural landscapes that provide agricultural products and environmental services? Awarding them a label and rewarding the people who shape them with payments for environmental services (PES) would be a way of recognising their value.Les paysages sont reconnus au titre du patrimoine, parce qu'ils sont remarquables, menacés ou délaissés. Qu'en est-il des paysages ruraux qui fournissent produits agricoles et services environnementaux ? Leur attribuer un label et rémunérer ceux qui les façonnent avec des paiements pour services environnementaux (PSE) permettrait d'en reconnaître la valeur

Le Tréport – Chemins des Granges

Les fouilles réalisées par le Smave au Tréport, Chemin des Granges, font suite au diagnostic positif effectué en juin 2011 par Emmanuel Petit (Inrap), dans le cadre d’un projet de lotissement. Ces recherches préalables avaient révélé « une sépulture à incinération de la fin de La Tène C2/début D1 et un complexe pouvant correspondre à une villa gallo-romaine » (Petit 2011). Les fouilles se sont déroulées de mars à juin 2012, sur une surface de 12 900 m2 correspondant à la moitié orientale du p..

Neuville-lès-Dieppe – Le Val d’Arquet

Ces fouilles font suite au diagnostic effectué en juin 2011 par F. Delahaye (Inrap), dans le cadre d’un projet immobilier. Les recherches avaient révélé, dans un contexte archéologique marqué par l’oppidum de Bracquemont (à 800 m au nord-est), « les traces d’une occupation laténienne matérialisée par deux systèmes d’enclos reconnus partiellement [avec une possible] continuité d’occupation dans les premières décennies de notre ère » (Delahaye 2011, p. 12). L’opération s’est déroulée de novembr..

La parole citoyenne face aux enjeux agroalimentaires et environnementaux : étude sémiotique des États généraux de l’alimentation

Depuis les années 2000, les enjeux sanitaires et environnementaux, ainsi que les préoccupations liées au changement climatique occupent une place importante dans la gestion de la politique agricole (à l’échelle française comme européenne). Ce constat nous conduit à nous intéresser aux États généraux de l’alimentation et particulièrement à la plateforme participative de la consultation citoyenne (ouverte du 20 juillet au 10 novembre 2017). Cette dernière nous paraît être un espace privilégié pour aborder le point de vue de la société civile, ses attentes, ses préoccupations, mais aussi, sa représentation du monde agricole à travers un ensemble de registres de valeurs en circulation. Ainsi, en prenant appui sur la consultation citoyenne, nous nous interrogerons sur les questions suivantes : quelles propositions le panel de citoyen(ne)s retient-il pour répondre à la question « Comment accompagner la transformation de notre agriculture » ? Le climat et la préservation de la biodiversité sont-ils présents, si oui, comment ? Le modèle agricole dominant (l’agriculture dite « conventionnelle ») est-il remis en cause ? Si oui, comment ? Au final, quelle(s) représentation(s) des modèles agricoles les investissements sémantiques que nous relèverons suggèrent-ils ? À partir d’une approche sémiotique, nous tenterons d’apporter des réponses à nos interrogations.Since the 2000s, health and environmental issues, but also the climate change have occupied an important place in the management of agricultural policy (at both the French and European levels). This observation leads us to take an interest in the Food General Assembly and particularly in the participatory platform for citizen (open from July 20 to November 10, 2017). The citizen consultation seems to be a privileged space for approaching the point of view of civil society, its expectations, its concerns, but also its representation of the agricultural world through a set of registers of values in circulation. Thus, based on the citizen consultation, we will question on: what proposals does the citizens' panel retain to answer the question "How to support the transformation of our agriculture"? Are the climate and the preservation of biodiversity present, if so, how? Is the dominant agricultural model (so-called "conventional" agriculture) being in question? and how? In the end, what are the representation(s) of agricultural models from semantic investments? From a semiotic approach, we will try to provide answers to our questions

Optimising and applying RNA based approaches to identify active nitrifiers in coastal sediments

Nitrogen is an essential element for all forms of life on earth. Since the beginning of the industrial revolution, nitrogen has become a major pollutant of marine and coastal ecosystems due to the huge rise in the use of inorganic fertiliser. Like many other nutrients, the transformations of the nitrogen cycle are mainly controlled by the activity of microorganisms. Understanding the factors influencing the activity of microbes involved in the biochemical transformation of nitrogen in the environment is therefore crucial. The aim of this thesis is to establish a robust workflow for the study of microbial activity in coastal sediment using transcriptomics. In particular, this work focuses on nitrification, the aerobic chemo-litho-autotrophic oxidation of ammonia to nitrite carried out by ammonia oxidizing bacteria and archaea (AOB and AOA respectively). The First part of the thesis (Chapter I) will consist of a review of the literature on the nitrogen cycle, with a particular focus on nitrification. A review of the techniques used to measure microbial activity in natural environment will also be presented and the knowledge gap that exist in transcriptomic workflow in environmental microbiology identified alongside current understanding of active nitrifiers in coastal sediments. The second part of the thesis (Chapters II and III) will present the first experimental work package which consists of the optimisation of reverse-transcription (RT)- based protocol for the study of microbial activity via transcriptomics. First, a new technique to evaluate RNA integrity, extracted from environmental samples, based mRNA will be developed and tested in a controlled-RNA degradation experiment. We show that this technique can provide a useful complement to the commercial approaches that evaluate RNA integrity mainly through the 16S/23S rRNA ratio. Then, the effect of the RT protocol itself on RT-Q-PCR and RT-PCR- sequencing results will be evaluated by testing a combination of four different RT enzymes and two priming strategies. We show that the choice of the correct protocol can greatly improve accuracy and precision of RT-based results. The third part (Chapters IV) will present the application of the optimised protocol to study the effects of sedimentary structures (ridge/runnel) on microbial nitrification activity measured via reverse-transcriptase quantitative PCR (RT-Q-PCR) and reverse-transcriptase PCR- sequencing. Here, the work developed in part two to ensure RNA integrity and optimal RT-PCR protocols will be applied to ensure robust and reliable measure of nitrifier mRNA from within coastal sediments to inform ecological understanding of the active organisms and controls of nitrification. The study site chosen was the Montportail-Brouage intertidal mudflat, located along the French Atlantic coast. This site has been shown to display interesting characteristics in term of microbial dynamics, with the sedimentary structures (ridges/runnels) significantly influencing microbial nitrification rates. The hypothesis proposed previously to explain the differences in nitrification rates is that AOB are more abundant in the runnels, where the higher nitrification rates had been measured. Here, we will show that these differences are explained by the presence of low abundance but highly active AOB groups that drive ammonia oxidation. Furthermore, we show the inadequacy of DNA studies as stand alone methods to explore nitrification activity, with a negative correlation between abundance of AOB amoA genes and nitrification rates, due to the presence of a highly abundant but inactive AOB cluster

Differential ratio amplicons (Ramp) for the evaluation of RNA integrity extracted from complex environmental samples

Reliability and reproducibility of transcriptomics‐based studies are dependent on RNA integrity. In microbial ecology, microfluidics‐based techniques, such as the Ribosomal Integrity Number (RIN), targeting rRNA are currently the only approaches to evaluate RNA integrity. However, the relationship between rRNA and mRNA integrity is unknown. Here we present an integrity index, the Ratio Amplicon, Ramp, adapted from human clinical studies, to directly monitor mRNA integrity from complex environmental samples. We show, in a suite of experimental degradations of RNA extracted from sediment, that while the RIN generally reflected the degradation status of RNA the Ramp mapped mRNA degradation better. Furthermore, we examined the effect of degradation on transcript community structure by amplicon sequencing of 16S rRNA, amoA and glnA transcripts. We successfully sequenced transcripts for all three targets even from highly‐degraded RNA samples. While RNA degradation changed the community structure of the mRNA profiles, no changes were observed for the 16S rRNA transcript profiles. Since both RT‐Q‐PCR and sequencing results were obtained, even from highly degraded samples, we strongly recommend evaluating RNA integrity prior to downstream processing to ensure meaningful results. For this both the RIN and Ramp are useful, with the Ramp better evaluating mRNA integrity in this study