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Mapping artificial drains in peatlands—A national‐scale assessment of Irish raised bogs using sub‐meter aerial imagery and deep learning methods
No full textInternational audiencePeatlands, constituting over half of terrestrial wetland ecosystems across the globe, hold critical ecological significance and are large stores of carbon (C). Irish oceanic raised bogs are a rare peatland ecosystem offering numerous ecosystem services, including C storage, biodiversity support and water regulation. However, they have been degraded over the centuries due to artificial drainage, followed by peat extraction, afforestation and agriculture. This has an overall negative impact on the functioning of peatlands, shifting them from a moderate C sink to a large C source. Recognizing the importance of these ecosystems, efforts are underway for conservation (rewetting and rehabilitation), while accurately accounting for C stock and greenhouse gas (GHG) emissions. However, the implementation of these efforts requires accurate identification and mapping of artificial drainage ditches. This study utilized very high-resolution (25 cm) aerial imagery, and a deep learning (U-Net) approach to map the visible artificial drainage (unobstructed by vegetation or infill) in raised bogs at a national scale. The results show that artificial drainage is widespread, with $ 20 000 km of drains mapped. The overall accuracy of the model was 80% on an independent testing dataset. The data were also used to derive the Frac ditch which was 0.03 (fraction of artificial drainage on industrial peat extraction sites). This is lower than IPCC Tier 1 Frac ditch and can aid in IPCC Tier 2 reporting for Ireland. This is the first study to map drains with diverse sizes and patterns on Irish-raised bogs using optical aerial imagery and deep learning methods. The map will serve as an important baseline dataset for evaluating the artificial drainage ditch conditions. It will prove useful for sustainable management, conservation and refined estimations of GHG emissions. The model's capacity for generalization implies its potential in mapping artificial drains in peatlands at a regional and global scale, thereby enhancing the comprehension of the global effects of artificial drainage ditches on peatlands
Evolutionary diversity impacts tropical forest biomass and productivity through disturbance‐mediated ecological pathways
No full textInternational audienceSignificant research efforts have been made to uncover links between biodiversity and biomass productivity in forest ecosystems. However, the causal link between these two ecosystem components, and the underlying mediation role of disturbance, are yet poorly understood for hyper-diverse tropical forests, because multiple ecological mechanisms are sequentially or simultaneously in play, leading to contradictory results in observational studies. Here, we introduce a novel framework for inferring the expected effects of evolutionary diversity on biomass stocks and productivity within forest ecosystems using observational field data. This framework involves an analytical decomposition of stand biomass into three key components: the number of trees, the mean size of trees and the mean wood density. Through this approach, we can distinguish structure- and compositional-based diversity effects, which likely have distinct ecological origins. We tested this framework in one of the oldest tropical forest experiments, where different levels of silvicultural disturbances were applied in the 1980s, with regular monitoring since then.Our results revealed that disturbance history mediates the effect of evolutionary diversity on forest biomass dynamics and that several Biodiversity Ecosystem Function (BEF) relationships may be hidden behind the composite biomass variable. We specifically found an overall significant negative relationship between evolutionary diversity and biomass productivity soon after disturbances (~5–8 years), mostly via mean tree size, despite a positive evolutionary diversity effect on mean wood density. This result reflects that the productivity of disturbed forests is driven by a few dominant and disturbance-prone species with low wood density and large potential stature, and not by niche complementarity among species. However, these effects rapidly vanished with time, with non-significant overall effect of evolutionary diversity on productivity both ~30 years after disturbance and in the undisturbed plots.Synthesis. By disentangling the effects of evolutionary diversity on the different components of forest biomass, our framework unveiled how evolutionary diversity impacts forest productivity through different ecological mechanisms, and suggests that it plays a major role, albeit mainly negative, only soon after a disturbance
Participatory Video on Groundwater Governance with Youth in the M’zab Valley, Algeria
No full textInternational audienceIn Algeria's M'zab Valley, the skills, knowledge, values, and rules of common resources management for surface and groundwater have been transmitted for centuries. Young people have traditionally learned agricultural and water distribution tasks through oral instruction and field observations from a very young age. However, this intergenerational continuity now faces challenges. Climate change has altered the water cycle, leading to water scarcity that has further disrupted collective organisation. Younger generations have lost interest in their traditional water governance knowledge. Local traditional knowledge holders approached the researchers with a request to involve young people in the management and preservation of common water resources. We responded with a participatory visual approach that integrates different forms of knowledge, including a documentary made by professional researchers and grassroots videos produced by four young scouts in a M'zab oasis community. The participatory video experience enabled the scouts and the other research participants to remember the past, by transmitting traditional ecological knowledge, to document the present, by identifying problems, and to imagine future by pointing at alternative solutions. This experience allowed to bridge different knowledge systems traditional, scientific, and emotional and generations as a contribution to more sustainable common resource governance
Animals as witnesses of major cultural and environmental changes: 8 millennia of sizes and abundance variation in southern France
No full textInternational audienceSouthern France has a long tradition of archaeological research, as well as intensive preventive work over the last 20 years. In this exceptional geographic framework, archaeozoology benefits from a very large and well-contextualised database, but diachronic analyses and socio-economic syntheses become increasingly complicated.As part of the DEMETER project (resp. A. Evin), an exceptional collaboration of archaeozoologists in what are now the Languedoc and Provence regions has enabled the creation of an unprecedented database consisting of species quantification data (NISP) and bone and dental measurements acquired in almost 220 archaeological sites. Long-term changes in stature (Log Size Indexes values) and livestock compositions (relative proportion of Number of Identified Specimens) where studied over the last 8,000 years ago, starting with the Neolithic period in the region. More than 200 000 remains from 225 archaelogical sites were analyzed. The construction of the diachronic trends of size and in abundance of species revealed common trend break episodes that were confronted to paleoenvironmental and paleoclimatic reconstructions. All of these elements have contributed to the identification of five main chronological sequences that retrace the great history of animal morphologies over the last 8 millennia
In vitro protein digestibility of gluten-free pasta made from climate-smart raw matters
No full textInternational audienceTraditionally made from durum wheat semolina (DWS), pasta composition has evolved in recent years, incorporating diverse raw materials such as legumes, wholegrain and/or other nutritious flours. The objective of our study is to go deeper in the development of nutritionally optimized pasta by using climate-smart (CS) crops and assess protein bioacessibility in these new food matrices. It is part of the H2020 Innofood Africa project, bringing together European and African partners to explore CS crops and develop new products for at-risk populations (children and women) suffering from malnutrition or obesity. We have developed optimized pasta made from wholegrain, gluten-free, CS African cereals and legumes. Special attention has been paid on their in vitro protein digestibility and the nature of the released peptides in relation with protein network structure. Four cowpea-based pasta formulations were obtained by linear programming and met the FAO’s nutritional recommendations for one meal for adult women, ensuring adequate levels of protein, fiber, zinc, iron and B9 vitamin. As all optimized formulations combine cowpea with teff and/or amaranth leaf flours, the impact of adding these two flours individually or in combination on the protein network structure, digestibility and peptides released was studied. The comparison with DWS pasta controls, varying in fiber contents from 3.5 to 16 g/100g d.b allowed to highlight the impact of the high fiber content on the protein structure and digestibility.In vitro protein digestibility was assessed using the enzymatic Megazyme kit and the COST Infogest digestion model with control of the degree of proteolysis by monitoring free NH2. At the end of the intestinal phase, the protein digestibility of DWS pasta controls whatever their fiber contents was higher than that of the four cowpea-based pasta with the Megazyme kit, while the results were reversed with the Infogest model. These difference can be explained by distinct gastric and intestinal proteolysis conditions that will be highlighted during the presentation. Despite the lower protein digestibility assessed for cowpea-based pasta, the Megazyme kit revealed PDCAAS two times higher for these matrices compared to DWS controls due to their higher content of essential amino acids. The peptidomic study shows that all cowpea-based pasta have same size of peptides released at the end of intestinal phase (1150 vs 1120 kDa in DWS controls) and highlights that most peptides were derived from cowpea storage proteins such as vicilin (50%) and legumin (15%) differing thus strongly with gliadin and glutenin derived peptides in DWS controls. With the comparison of two reference methods for digestion, this work has pointed out that pasta associating cowpea with amaranth leaf flour provide superior nutritional benefits combined along with high protein digestibility
Managing and Opening Research Data in Life and Environmental Sciences
No full textNational audienceThis training session aims at giving some milestones on open science and how to implement good practices and funder or institutional requirements in a research project
Sources of confusion in global biodiversity trends
No full textInternational audiencePopulations and ecological communities are changing worldwide, and empirical studies exhibit a mixture of either declining or mixed trends. Confusion in global biodiversity trends thus remains while being of major social, political, and scientific importance. Part of this variability may arise from the difficulty to reliably assess global biodiversity trends. Here, we conducted a literature review of studies documenting the temporal dynamics of global biodiversity. We classified the differences among approaches, data and methodology used by the reviewed papers to reveal common findings and sources of discrepancies. We show that reviews and meta-analyses, along with the use of global indicators, are more likely to conclude that trends are declining. On the other hand, the longer the data are available, the more nuanced are the trends they generate. Our results also highlight the lack of studies providing information on the impact of synergistic pressures on a global scale, making it even more difficult to understand the driving factors of the observed changes and how to decide conservation plan accordingly. Finally, we stress the importance of taking into account the sources of confusion identified, as well as the complexity of biodiversity changes, in order to implement effective conservation strategies. In particular, biodiversity dynamics are almost systematically assumed to be linear, while non-linear trends are largely neglected. Clarifying the sources of confusion in global biodiversity trends should strengthen large scale biodiversity monitoring and conservation
Récits de recherche sur l’eau dans un monde interdisciplinaire
No full textInternational audienceEleven original accounts by researchers from various disciplines (sociology, process engineering, water sciences, computer modelling, anthropology, hydrogeology, agronomy, ecology) illustrate in this book concrete ways of practising interdisciplinarity with a view to building committed research on water in society. In an interdisciplinary world, they describe the happy and uncomfortable situations experienced by researchers, and the arrangements made to deal with the unexpected aspects of such practices. The book suggests new ways of working with water, and proposes ways of understanding the relationships that societies have with it, around major issues: pollution, salinisation of groundwater, ecological restoration, technological optimism, in different regions of the world. Beyond the singularity of each story, these accounts highlight the cross-cutting issues of interdisciplinary practice in both individual and collective experiences: the researcher's identity and commitment to society, the aims of research, and reciprocal learning that helps cross disciplinary boundaries. This book is aimed in particular at researchers and students who are undertaking or considering interdisciplinary research.Onze récits originaux de chercheurs de diverses disciplines (sociologie, génie des procédés, sciences de l'eau, modélisation informatique, anthropologie, hydrogéologie, agronomie, écologie) illustrent dans ce livre des manières concrètes de pratiquer l'interdisciplinarité en vue de construire des recherches engagées sur l'eau en société. Dans un monde interdisciplinaire, ils témoignent de situations heureuses ou inconfortables vécues par les chercheurs, et des arrangements déployés pour composer avec les inattendus de telles pratiques. L'ouvrage suggère des façons nouvelles de travailler sur l'eau, et propose de rendre intelligibles les relations que les sociétés entretiennent avec elle, autour de grands enjeux : pollution, salinisation des eaux souterraines, restauration écologique, optimisme technologique, dans différentes régions du monde. Au-delà de la singularité de chaque histoire vécue, ces récits soulignent les enjeux transversaux de la pratique interdisciplinaire à la fois dans les expériences individuelles ou collectives : identité et engagement du chercheur dans la société, finalités de la recherche, ou encore apprentissages réciproques, propices au dépassement des frontières disciplinaires. Ce livre s'adresse notamment aux chercheurs et étudiants qui entreprennent ou envisagent une recherche interdisciplinaire
Can we harmonize the monitoring of plants and pollinators?
No full textMeeting report on the symposium ‘New solutions to monitor plants, pollinators and their interactions in a changing world’, held at Collège de France and Muséum national d'Histoire naturelle, Paris, France, 23–24 May 2024International audienc
Large gradient of susceptibility to esca disease revealed by long-term monitoring of 46 grapevine cultivars in a common garden vineyard
No full textInternational audienceGrapevine (Vitis vinifera L.) is prone to many fungal diseases, including esca, a severe vascular disease threatening the wine sector and for which there is no cost-effective cure. Susceptibility to esca varies between cultivars in different infection conditions. It may therefore be possible to use the genetic diversity of grapevine cultivars to mitigate disease impact. However, the genetic component of esca susceptibility has rarely been investigated in the vineyard, and the specific mechanisms and varietal traits underlying esca susceptibility remain unknown. In this study, we monitored the incidence and severity of esca foliar symptoms and plant dieback (apoplexy and mortality) at plant level for seven years, on 46 cultivars planted in an experimental common garden, to separate the genetic component of esca susceptibility from the effects of environment and cropping practices. We observed a broad gradient of varietal susceptibility, with a mean incidence of 0 to 26 % of vines expressing esca foliar symptoms depending on the variety. This gradient remained similar across years and, unlike the severity of foliar symptoms, the incidence of grapevine dieback was significantly correlated with that of foliar symptoms. We detected a significant but weak and very localised phylogenetic signal for the incidence of esca foliar symptoms in this panel of cultivars. We then explored the relationships between epidemiological metrics and ecophysiological and phenological traits phenotyped on the same plot. Esca disease incidence was negatively correlated with δ 13 C across cultivars, suggesting that varieties with higher water use efficiency are less prone to the expression of esca symptoms on leaves. Moreover, the least vigorous cultivars were among the least susceptible, although this relationship was not significant. By contrast, neither phenological stages nor nitrogen status were significantly predictive of cultivar susceptibility to the disease. Together, these results provide new insight into the potential of genetic resources for use in the sustainable management of grapevine trunk diseases and open up new perspectives for studying the pathological and physiological determinants of their incidence