Political ecology des engrillagements de Sologne - Tentative de défragmentation du paysage écologique, politique et disciplinaire

Quoi de plus naturel qu’une clôture ? Parmi les images d’Epinal qui nous viennent spontanément à l’esprit, le bocage avec ses haies bien ordonnées, évoque une relation apaisée, rationnelle, arcadienne avec une nature nourricière et bienveillante. Pourtant, la prolifération des clôtures en milieu rural depuis un siècle a suscité la curiosité de nombreux chercheurs dans des disciplines variées. Qu’il s’agisse de protéger la nature de dégradations engendrées par les populations humaines - dans le cas d’espaces protégés -, ou à l’inverse de protéger les humains contre des dangers « naturels » - comme dans le cas de la prévention routière, ces clôtures semblent répondre à une nécessité absolue de ségrégation spatiale entre les hommes et la nature : Quoi de moins naturel qu’une clôture ? Vu sous cet angle, le conflit politico-environnemental engendré par la propagation récente des engrillagements forestiers en Sologne reflète assez bien l’ambiguïté de nos perceptions vis-à-vis du caractère naturel ou non de ces clôtures. La Sologne est une région naturelle Française couvrant près de 500 000 hectares délimitée au nord par la vallée de la Loire et au sud par la vallée du Cher. Fruit d’une occupation humaine attestée depuis le XIe siècle, conjuguée à des contraintes écologiques spécifiques, le paysage Solognot est aujourd’hui caractérisé par son couvert boisé important (environ 50% de la surface) et ses populations importantes de grand gibier, qui entretiennent la longue réputation cynégétique de cette région ; la propriété privée y est largement majoritaire (plus de 90% de la surface forestière). En 2012, une agitation médiatique (film, articles de presse, sites internet) cristallisent un conflit environnemental latente, faisant intervenir des éléments écologiques – les effets supposés bénéfiques ou néfastes de ces engrillagements sur la grande faune, mais aussi politiques – la nécessité de réglementer les engrillagements, et culturels - la sauvegarde du « paysage Solognot ». Afin d’analyser ce conflit, une approche interdisciplinaire de type Political Ecology a été menée, mêlant travail d’enquête auprès de la population et étude du fonctionnement écologique des espaces engrillagés. Ces travaux ont montré que les engrillagements modifient la répartition spatiale des cerfs. La recherche d’effets cascades sur les oiseaux forestiers - résultants des surdensités locales de cerfs en espace engrillagé - n’a cependant pas mis en évidence d’effet négatif. A partir des enquêtes, il apparaît que le conflit est pluridimensionnel et que l’aspect écologique – bien réel – ne suffit pas à lui seul pour comprendre l’enjeu de ce débat au sujet des engrillagements. Ces résultats génèrent une réflexion sur la complexité des conflits environnementaux, et la nécessité d’envisager ces conflits sous des angles différents. Cela implique d’utiliser des outils et des approches issues de plusieurs disciplines, mais aussi et surtout de parvenir à mettre en résonance le matériel hétérogène ainsi obtenu, afin de proposer une approche multifacette mais cohérente. Dans ce cas d’étude, les résultats sur les effets cascades se sont par exemple révélés extrêmement marginaux, alors qu’une étude parallèle sur le comportement du sanglier en milieu engrillagé aurait probablement été très pertinente. Cela amène plus largement à réfléchir sur le « cadrage » des problèmes environnementaux, et sur les choix conscients ou non que nous faisons lorsque nous décrivons une situation comme problématique pour « la nature ». Plus généralement, ces résultats incitent à (re)placer le politique au cœur de nos réflexions sur ce qu’est la « nature », y compris dans la façon dont nous écologues posons nos questions de recherches

Overabundant ungulates in French Sologne? Increasing red deer and wild boar pressure may not threaten woodland birds in mature forest stands

Increasing ungulate populations have been considered to drive changes in woodland bird communities in temperate and boreal forests. Ungulates may negatively affect understory-dependent woodland birds either directly or indirectly. For instance ungulates may prey on nests, or they may reduce the availability of nesting sites, foraging resources or cover for understory-dependent bird species. We conducted ungulate pressure, vegetation and bird surveys on 95 plots, in nineteen mature forest stands (9 fenced and 10 unfenced properties) located in the Sologne region (France). In such private forests, ungulate population densities are highly variable; we were therefore able to explore the effects of varying red deer (Cervus elaphus) browsing and wild boar (Sus scrofa) rooting intensity on bird communities. Bayesian Binomial mixture models indicated that ground-nesting birds were more abundant in forests with high observed wild boar rooting intensity. Generally, increasing deer browsing pressure did not have any negative effect on woodland birds in mature forest stands with a developed canopy, and did not result in lower shrub cover. Most previous studies documenting a negative effect of browsing on birds focused on young forest stands where overstory vegetation was scarce. Our results suggest that the impact of ungulate pressure on forest birds may decrease with forest stand age

Dung beetle assemblages, dung removal and secondary seed dispersal: data from a large-scale, multi-site experiment in the Western Palaearctic

By manipulating faeces during feeding and breeding, dung beetles (Coleoptera: Scarabaeidae) fulfil important ecosystem functions in terrestrial ecosystems throughout the world. In a pan-European multi-site experiment (MSE), we estimated the ecosystem functions of dung removal and secondary seed dispersal by differing combinations of dung beetle functional groups. Therefore, we classified dung beetles into five functional groups according to their body size and dung manipulation method: dwellers, large and small tunnelers, and large and small rollers. Furthermore, we set up a dung beetle sampling database containing all sampled dung beetles during the project. By identifying dung beetle specimens to the species level, we obtained a detailed insight into the dung beetle communities at each study location. By establishing experimental plots allowing and inhibiting specific combinations of functional groups in the local dung beetle assemblage from removing dung and seeds, we estimated the role of each group in dung removal and secondary seed dispersal during a 4-week period. We performed all experiments in grazed (semi-)natural grasslands, and used different dung types (cattle, horse, sheep, goat or red deer) to match the herbivore species grazing in close vicinity of each of the study areas. Simultaneously, we sampled dung beetle assemblages by using pitfalls baited with the same dung types as used in the experiments. This data paper documents two datasets collected in the framework of this MSE project. All the experiments took place between 2013 and 2016 at 17 study sites in 10 countries and 11 biogeographic zones. The entire dung beetle sampling dataset was published as a sampling event dataset at GBIF. The dataset includes the sampling results of all 17 study sites, which contain 1,050 sampling events and 4,362 occurrence records of 94 species. The second dataset contains the results of the dung removal and secondary seed dispersal experiments in which we used 11 experimental treatments and the five dung types mentioned above. This experimental results dataset holds all experimental results of the MSE project (11,537 records), and was published in the online data repository Zenodo

The Political Ecology of fencing in the Sologne region in France - An attempt to re-unify the ecological, political and disciplinary landscape

Quoi de plus naturel qu’une clôture ? Parmi les images d’Epinal qui nous viennent spontanément à l’esprit, le bocage avec ses haies bien ordonnées, évoque une relation apaisée, rationnelle, arcadienne avec une nature nourricière et bienveillante. Pourtant, la prolifération des clôtures en milieu rural depuis un siècle a suscité la curiosité de nombreux chercheurs dans des disciplines variées. Qu’il s’agisse de protéger la nature de dégradations engendrées par les populations humaines - dans le cas d’espaces protégés -, ou à l’inverse de protéger les humains contre des dangers « naturels » - comme dans le cas de la prévention routière, ces clôtures semblent répondre à une nécessité absolue de ségrégation spatiale entre les hommes et la nature : Quoi de moins naturel qu’une clôture ? Vu sous cet angle, le conflit politico-environnemental engendré par la propagation récente des engrillagements forestiers en Sologne reflète assez bien l’ambiguïté de nos perceptions vis-à-vis du caractère naturel ou non de ces clôtures. La Sologne est une région naturelle Française couvrant près de 500 000 hectares délimitée au nord par la vallée de la Loire et au sud par la vallée du Cher. Fruit d’une occupation humaine attestée depuis le XIe siècle, conjuguée à des contraintes écologiques spécifiques, le paysage Solognot est aujourd’hui caractérisé par son couvert boisé important (environ 50% de la surface) et ses populations importantes de grand gibier, qui entretiennent la longue réputation cynégétique de cette région ; la propriété privée y est largement majoritaire (plus de 90% de la surface forestière). En 2012, une agitation médiatique (film, articles de presse, sites internet) cristallisent un conflit environnemental latente, faisant intervenir des éléments écologiques – les effets supposés bénéfiques ou néfastes de ces engrillagements sur la grande faune, mais aussi politiques – la nécessité de réglementer les engrillagements, et culturels - la sauvegarde du « paysage Solognot ». Afin d’analyser ce conflit, une approche interdisciplinaire de type Political Ecology a été menée, mêlant travail d’enquête auprès de la population et étude du fonctionnement écologique des espaces engrillagés. Ces travaux ont montré que les engrillagements modifient la répartition spatiale des cerfs. La recherche d’effets cascades sur les oiseaux forestiers - résultants des surdensités locales de cerfs en espace engrillagé - n’a cependant pas mis en évidence d’effet négatif. A partir des enquêtes, il apparaît que le conflit est pluridimensionnel et que l’aspect écologique – bien réel – ne suffit pas à lui seul pour comprendre l’enjeu de ce débat au sujet des engrillagements. Ces résultats génèrent une réflexion sur la complexité des conflits environnementaux, et la nécessité d’envisager ces conflits sous des angles différents. Cela implique d’utiliser des outils et des approches issues de plusieurs disciplines, mais aussi et surtout de parvenir à mettre en résonance le matériel hétérogène ainsi obtenu, afin de proposer une approche multifacette mais cohérente. Dans ce cas d’étude, les résultats sur les effets cascades se sont par exemple révélés extrêmement marginaux, alors qu’une étude parallèle sur le comportement du sanglier en milieu engrillagé aurait probablement été très pertinente. Cela amène plus largement à réfléchir sur le « cadrage » des problèmes environnementaux, et sur les choix conscients ou non que nous faisons lorsque nous décrivons une situation comme problématique pour « la nature ». Plus généralement, ces résultats incitent à (re)placer le politique au cœur de nos réflexions sur ce qu’est la « nature », y compris dans la façon dont nous écologues posons nos questions de recherches.What could be more natural than a fence? Among the traditional images in our collective heritage, a pastoral landscape with well maintained hedges evokes a calm, rational, Arcadian relationship between man and a benevolent, sustaining ature. Yet the century-long proliferation of fences in our rural landscapes has attracted the curiosity of numerous researchers from a variety of disciplines. Whether the goal is to protect nature from the degradations caused by human populations - as in the case of natural protected areas, or inversely, to protect humans from “natural” dangers – as in the case of accident prevention and road safety, fences seem to respond to a primordial necessity to segregate man and nature in space: What could be less natural than a fence? With this in mind, the political/environmental conflict over the recent propagation of forest fences in Sologne reflects quite well the ambiguity of how we perceive such fences – or they “natural” or not? The Sologne is an officially designated “natural region” in France. It extends over nearly 500,000 hectares bordered on the North by the Loire valley and on the South by the Cher valley. The Sologne landscape is the fruit of human occupation, certain since the XI century, combined with specific ecological constraints. Today, Sologne is characterized by extensive forest cover (around 50% of the surface area) and by large populations of big game animals, maintaining the region’s a long history of hunting. Furthermore, land ownership in Sologne is mainly private and more than 90% of the forested area is in private holdings. In 2012, some media excitement (film, newspaper articles, internet sites) crystallized an environmental conflict calling on ecological arguments – the supposed beneficial or detrimental effects of the fencing networks on big game, but also on political arguments – the need to regulate these networks, and on cultural arguments – preserving the Sologne landscape. In order to disentangle the structural lines of this conflict, we applied an interdisciplinary, Political Ecology approach; we combined opinion polls among the inhabitants with the study of ecological functions within the fenced zones. We observed that fences induced modifications of deer habitat use. However, our investigations into a possible cascade effect on forest birds resulting from localized deer over-population in fenced areas revealed no evidence of any negative impact. From our opinion polls, we found that the conflict seems to be multi-dimensional and that the ecological aspect – whose existence is indeed supported by fact – is not sufficient alone to understand what is at stake in this fencing dispute. Our results highlight the complexity of environmental conflicts, and the importance of viewing these conflicts from many different angles. Apprehending this complexity implies using tools and approaches from several different disciplines, but also – and above all – making the heterogeneous results obtained resonate together, in order to propose a coherent, multi-facetted approach. In this study for example, the results obtained for potential cascade effects on birds were extremely marginal, whereas a parallel study on wild boar behavior patterns in an environment with a fencing network would probably have been very pertinent. This leads us to the broader question of the “framework” of environmental problems and to the question of the choices we make – whether consciously or not – when we describe a situation as detrimental to “Nature”. More generally, the results from this study encourage us to put politics (back) into the center of our reflections surrounding the question: What is nature? – and to keep this in mind when we as ecologists define our research hypotheses

Open game fences and their socio-spatial effects: Placing red deer, placing humans, managing territories

Big game populations have been rapidly increasing in temperate and boreal ecosystems worldwide, which has prompted the need to study the socio-ecological issues related to their management. In addition, the use of game-fencing has been spreading in certain rural areas, especially in French Sologne. These two parallel trends raise the issue of the new socio-spatial arrangements developing in rural areas. We set up an in-depth case-study combining stakeholder-interviews and ecological surveys (red deer trails, pellets and bed sites) to understand how game fences may affect both animal and human mobility, and why this may raise human conflicts. The study site was a 17.52 km² fenced landscape comprising a public forest bordered on the north and south by two privately owned fenced lots. Both the interviews and the ecological data indicated that the fences were crossable for red deer. We did not find any fencing effect on the location of red deer trails, though red deer pellet groups were significantly more frequent outside fenced lots. On the other hand, we recorded more bed sites within fenced lots, in accordance with the stakeholders’ statements that fenced lots had a high sheltering value for red deer. This implies that stakeholders have contrasting opportunities to encounter red deer because the fences deter non-owners from trespassing. Although any private owner has the legal right to fence his or her land under French law, our finding calls for more attention to how the fencing is designed, since its effects may impact the surrounding landscape. For instance, fences can allow a single owner to impose game management policies in the areas surrounding his or her estate. &nbsp

Political ecology de l'engrillagement forestier privé en Sologne : quels sont les enjeux socioenvironnementaux au coeur du conflit ?

International audienceWe propose an interdisciplinary approach designed to study the spread of private fencing in the French Sologne as a socio-ecological phenomenon. We conducted two parallel approaches: a study of how fencing may affect spatial use by deer and an interview campaign in order to elucidate which human values were at stake in the fencing debate. To this end we applied a Political ecology approach in order to articulate these two kinds of results. We highlighted two competing discourses regarding hunting-oriented private properties, showing that this contention is based on the replacement of game birds by big game over the past thirty years, which went along with the spread of fencing.Cet article propose une approche interdisciplinaire visant à étudier la dynamique d'engrillagement en Sologne sous ses aspects humains et écologiques. Des travaux ont été menés, relatés par ailleurs dans des manuscrits soumis à des revues d'écologie, afin de décrire le comportement spatial des cerfs de Sologne, en présence de grillages. Un travail d'enquête a également été effectué, portant sur les valeurs associées à l'environnement en Sologne telles qu'elles étaient mises à jour par l'évocation des engrillagements. Nous utilisons ici une approche de type political ecology pour mettre en regard ces deux types de résultats. Nous mettons en évidence deux discours concurrents sur les formes de légitimation des propriétés cynégétiques, dont l'opposition s'articule autour du remplacement du petit gibier par le grand au cours de ces trente dernières années. Nous expliquons le rôle joué par les engrillagements dans cette mise en concurrence

Data from: Epizoochorous dispersal by ungulates depends on fur, grooming and social interactions

The transport phase of the animal-mediated plant dispersal process is critical to dispersal effectiveness as it determines the spatial distribution of the diaspores released and their chance for further recruitment. Assessing this specific phase of the dispersal process generally requires combining diaspore retention times with the associated distances covered. Here, we specifically tested the effect of grooming behavior, interindividual contacts and ungulate fur on diaspore retention times and associated dispersal distances for the hooked diaspores of Xanthium strumarium L. experimentally attached to tamed individuals of three ungulate species. We used a comparative approach based on differing fur quality on different body zones of these three ungulates. During 6-hr sessions, we monitored for grooming and social interactions that may induce intended or inadvertent diaspore detachment. Additionally, we proposed innovative approaches to directly assessing diaspore dispersal distances by red deer in situ. Fat-tailed functions fitted diaspore retention time, highlighting the potential for long-distance dispersal events. The longer the hair, the higher the retention capacity of diaspores in the animal's fur. As predicted, donkey retained diaspores longer than red deer and dwarf goat; and we also confirmed that diaspores attached to the short hair of the head fell off more quickly than did those on the other body zones. Dwarf goat groomed more often than both red deer and donkey, but also when it carried diaspores. Up to 14% of the diaspores detached from animal fur after specific grooming behavior. We observed, in controlled conditions, for the first time and for each ungulate species, interindividual transfers of diaspores, representing 5% of the diaspores attached to animals’ fur. Our results militate for incorporating animal behavior into plant dispersal modeling approaches

Dataset

This dataset comprises 3 sheets : 1) counts and causes of diaspore detachment per animal species 2) paired grooming monitoring data and 3) diaspore retention time and dispersal distance for the 756 monitored diaspores

Atypical hemolytic and uremic syndrome due to C3 mutation in pancreatic islet transplantation: a case report

International audienceBackground: We here report on the first observation of a C3 mutation that is related to atypical hemolytic and uremic syndrome (aHUS), which occurred in a pancreatic islet transplant patient. Immunosuppressive treatments, such as calcineurin inhibitors, have been linked to undesirable effects like nephrotoxicity.Case presentation: A 40-year-old man with brittle diabetes, who was included in the TRIMECO trial, became insulin-independent 2 months after pancreatic islet transplantation. About 15 months after islet transplantation, the patient exhibited acute kidney injury due to aHUS. Despite plasma exchange and eculizumab treatment, the patient developed end-stage renal disease. A genetic workup identified a missense variant (p.R592Q) in the C3 gene. In vitro, this C3 variant had defective Factor I proteolytic activity with membrane proteins as cofactor proteins, which was thus classified as pathogenic. About 1 year after the aHUS episode, kidney transplantation was carried out under the protection of the specific anti-C5 monoclonal antibody eculizumab. The patient had normal kidney function, with preserved pancreatic islet function 4 years later.Conclusions: Pancreatic islet transplantation could have triggered this aHUS episode, but this link needs to be clarified. Although prophylactic eculizumab maintains kidney allograft function, its efficacy still needs to be studied in larger populations