Changement climatique

Démarche de connaissance de flux admissibles- Application de GAMELag à l’étang de Campignol : phase II : situation repère et phase III : scénarisation ([2025])

Tue, 20 Jan 2026 10:48:23

de Columba Martínez-Espinosa, Julie Regis, Annie Fiandrino, Laurent Benau, Nicolas Mañas, Anaïs Giraud
Arles : Tour du Valat / Ifremer, [2025], 64

La mission Flux Admissibles a joué un rôle essentiel dans la gestion durable de l’étang de Campignol en fournissant des données scientifiques fiables pour la planification à long terme. L’utilisation du modèle GAMELag permet de simuler divers scénarios de gestion et d'évaluer les conséquences d’un changement climatique. Ce modèle aide à estimer les flux admissibles d’azote et de phosphore, tout en respectant les objectifs écologiques de la Directive Cadre sur l’Eau. Un suivi rigoureux est crucial pour mesurer l’efficacité des actions et ajuster les stratégies de restauration. Les sédiments ne constituent pas une source majeure de nutriments, indiquant que la réduction des apports nutritifs pourrait améliorer rapidement la qualité de l’eau. La gestion doit inclure l’ensemble du bassin versant, favorisant la collaboration entre les acteurs locaux pour une efficacité optimale. Une approche intégrée combinant modélisation et gouvernance est recommandée pour lutter contre l’eutrophisation. Enfin, il est nécessaire de coordonner les efforts à différentes échelles pour protéger durablement les initiatives locales face à la croissance démographique.[résumé rédigé par IA]

Assessing methane emissions and soil carbon stocks in the Camargue coastal wetlands: Management implications for climate change regulation

Wed, 21 Aug 2024 14:29:14

de Maite Martínez-Eixarch, Pere Masqué, Anna Lafratta, Paul Lavery, Samuel Hilaire, Lluís Jornet, Cyrille Thomas, Arnaud Boisnard, Néstor Pérez-Méndez, Carles Alcaraz, et al.
In Science of The Total Environment, 950 (November, 2024), 175224
En ligne : www.sciencedirect.com[...]

Coastal wetlands are crucial in climate change regulation due to their capacity to act as either sinks or sources of carbon, resulting from the balance between greenhouse gas (GHG) emissions, mainly methane (CH4), and soil carbon sequestration. Despite the paramount role of wetlands in climate regulation few studies investigate both aspects. The Camargue is one of the largest wetlands in Europe, yet the ways in which environmental and anthropic factors drive carbon dynamics remain poorly studied. We examined GHG emissions and soil organic carbon (SOC) stocks and accumulation rates in twelve representative wetlands, including two rice fields, to gain insights into the carbon dynamics and how it is influenced by hydrology and salinity. Mean CH4 rates ranged between – 87.0 and 131.0 mg m−2 h−1and the main drivers were water conductivity and redox, water table depth and soil temperature. High emission rates were restricted to freshwater conditions during summer flooding periods whereas they were low in wetlands subjected to summer drought and water conductivity higher than 10 mS cm−1. Nitrous oxide emissions were low, ranging from – 0.5 to 0.9 mg N2O m−2 h−1. The SOC stocks in the upper meter ranged from 17 to 90 Mg OC ha−1. Our research highlights the critical role of low-saline wetlands in carbon budgeting which potentially are large sources of CH4 but also contain the largest SOC stocks in the Camargue. Natural hydroperiods, involving summer drought, can maintain them as carbon sinks, but altered hydrology can transform them into sources. Artificial freshwater supply during summer leads to substantial CH4 emissions, offsetting their SOC accumulation rates. In conclusion, we advocate for readjusting the altered hydrology in marshes and for the search of management compromises to ensure the compatibility of economic and leisure activities with the preservation of the inherent climate-regulating capacity of coastal wetlands.

L'écologie-monde du capitalisme (2024)

Wed, 28 Aug 2024 15:14:34

de Jason W. Moore, Nicolas Vieillescazes
Paris : Éditions Amsterdam, 2024, 1 vol. (272 p.)

Dans le discours scientifique et politique, la révolution industrielle s'est imposée comme le point de départ d'une nouvelle ère géologique, l'Anthropocène. L'invention de la machine à vapeur et l'utilisation massive de combustibles fossiles auraient fait de l'Humanité la principale force transformatrice de la planète. Bien que la réalité de la pollution, du changement climatique, de l'épuisement des ressources soit incontestable, l'espèce humaine est-elle, en tant que telle, la cause de la crise environnementale ? Jason Moore montre qu'il n'en est rien. Si l'on veut comprendre de quoi il retourne, on doit remonter à l'époque de la conquête des Amériques. Alors commence la mise au travail généralisée des êtres humains et non humains, des vivants et des fossiles, sous la houlette des puissances impériales et capitalistes : la « Nature bon marché », appropriable, exploitable et consommable à merci, constitue l'indispensable base de l'accumulation et la matrice de la destruction planétaire. La crise actuelle a débuté il y a cinq siècles, avec l'entrée dans I'« écologie-monde » du capital, le Capitalocène.

La Camargue, un delta face au défi climatique

Mon, 13 Nov 2023 17:02:52

de Jean Jalbert
In Annales des mines - Responsabilité et environnement., 112 (Octobre 2023), 104-107
En ligne : www.annales.org[...]

Le delta du Rhône, comme tous les deltas du monde, est sur la ligne de front des changements climatiques. À la suite de son endiguement consécutif à des inondations majeures à la fin de XIXe siècle, cette vaste plaine deltaïque a été le siège d’un extraordinaire récit de conquête et de maîtrise : digues, pompes et réseaux hydrauliques ont permis de dompter ce pays rétif, de s’affranchir des principales contraintes – inondations, sel, submersions marines – pour enfin « mettre en valeur » ce territoire, y développer une agriculture productive, sécuriser ses habitants. Pourtant cette période de stabilité touche probablement à son terme. Sous les effets puissants du changement climatique, ce territoire rappelle aux humains que la richesse d’un delta vient précisément de sa dynamique, des flux qui le traversent. Flux d’eau douce et de sédiments, flux d’eau salée, flux biologiques, flux humains... Il nous rappelle sa nature profonde : un territoire mouvant, mobile par essence, siège de l’impermanence des choses. Et si la Camargue était un parfait laboratoire pour inventer un nouveau récit, celui de l’adaptation et de la résilience ?

The effectiveness of global protected areas for climate change mitigation

Thu, 15 Jun 2023 16:17:40

de L. Duncanson, M. Liang, V. Leitold, J. Armston, S. M. Krishna Moorthy, R. Dubayah, S. Costedoat, B. J. Enquist, L. Fatoyinbo, S. J. Goetz, et al.
In Nature Communications, 14(1) (March, 2023), 2908
En ligne : www.nature.com[...]

Forests play a critical role in stabilizing Earth’s climate. Establishing protected areas (PAs) represents one approach to forest conservation, but PAs were rarely created to mitigate climate change. The global impact of PAs on the carbon cycle has not previously been quantified due to a lack of accurate global-scale carbon stock maps. Here we used ~412 million lidar samples from NASA’s GEDI mission to estimate a total PA aboveground carbon (C) stock of 61.43 Gt (+/− 0.31), 26% of all mapped terrestrial woody C. Of this total, 9.65 + /− 0.88 Gt of additional carbon was attributed to PA status. These higher C stocks are primarily from avoided emissions from deforestation and degradation in PAs compared to unprotected forests. This total is roughly equivalent to one year of annual global fossil fuel emissions. These results underscore the importance of conservation of high biomass forests for avoiding carbon emissions and preserving future sequestration.

Nature-based Solutions for corporate climate targets: views regarding the corporate use of Nature-based Solutions to meet net-zero goals (2023)

Tue, 13 Feb 2024 13:35:23

de G. Martinez, B. Drion, J. Gladstone, A. Vidal
[S.l.] : IUCN, International Union for Conservation of Nature, 2023, 64
En ligne : portals.iucn.org[...]

Nature-based Solutions (NbS) are activities undertaken to protect, sustainably manage and restore natural and modified ecosystems to simultaneously benefit people and nature. NbS are critical to addressing challenges like climate change, food security, water security, disaster risk, human health, and social and economic development. NbS balances conservation with sustainable development and showcases how nature can benefit societal and human well-being. Therefore, NbS are critical to achieving a low-carbon future while facilitating climate change adaptation and supporting other critical ecosystem functions. This publication outlines the available pathways to include NbS in corporate climate strategies consistent with the NbS definition, principles and Global Standard for NbS™. When correctly implemented, NbS can contribute to climate mitigation and adaptation while offering important benefits for biodiversity and human well-being.

Attribution of the 2020 surge in atmospheric methane by inverse analysis of GOSAT observations

Wed, 4 Jan 2023 11:14:26

de Zhen Qu, Daniel J Jacob, Yuzhong Zhang, Lu Shen, Daniel J Varon, Xiao Lu, Tia Scarpelli, Anthony Bloom, John Worden, Robert J Parker
In Environmental Research Letters, 17(9) (2022)
En ligne : iopscience.iop.org[...]

Atmospheric methane mixing ratio rose by 15 ppbv between 2019 and 2020, the fastest growth rate on record. We conduct a global inverse analysis of 2019–2020 Greenhouse Gases Observing Satellite observations of atmospheric methane to analyze the combination of sources and sinks driving this surge. The imbalance between sources and sinks of atmospheric methane increased by 31 Tg a−1 from 2019 to 2020, representing a 36 Tg a−1 forcing (direct changes in methane emissions and OH concentrations) on the methane budget away from steady state. 86% of the forcing in the base inversion is from increasing emissions (82 ± 18% in the nine-member inversion ensemble), and only 14% is from decrease in tropospheric OH. Half of the increase in emissions is from Africa (15 Tg a−1) and appears to be driven by wetland inundation. There is also a large relative increase in emissions from Canada and Alaska (4.8 Tg a−1, 24%) that could be driven by temperature sensitivity of boreal wetland emissions.

Rewetting global wetlands effectively reduces major greenhouse gas emissions

Thu, 1 Sep 2022 16:20:51

de Junyu Zou, Alan D. Ziegler, Deliang Chen, Gavin McNicol, Philippe Ciais, Xin Jiang, Chunmiao Zheng, Jie Wu, Jin Wu, Ziyu Lin, et al.
In Nature Geoscience, 15(8) (August, 2022), 627-632
En ligne : www.nature.com[...]

Carbon and nitrogen losses from degraded wetlands and methane emissions from flooded wetlands are both important sources of greenhouse gas emissions. However, the net-exchange dependence on hydrothermal conditions and wetland integrity remains unclear. Using a global-scale in situ database on net greenhouse gas exchanges, we show diverse hydrology-influenced emission patterns in CO2, CH4 and N2O. We find that total CO2-equivalent emissions from wetlands are kept to a minimum when the water table is near the surface. By contrast, greenhouse gas exchange rates peak in flooded and drained conditions. By extrapolating the current trajectory of degradation, we estimate that between 2021 and 2100, wetlands could result in greenhouse gas emissions equivalent to around 408 gigatons of CO2. However, rewetting wetlands could reduce these emissions such that the radiative forcing caused by CH4 and N2O is fully compensated by CO2 uptake. As wetland greenhouse gas budgets are highly sensitive to changes in wetland area, the resulting impact on climate from wetlands will depend on the balance between future degradation and restoration. Global in situ observations show greenhouse gas emissions from wetlands are lowest when the water table is near the surface, and therefore rewetting wetlands could substantially reduce future emissions.

Underestimating the Challenges of Avoiding a Ghastly Future

Wed, 27 Jan 2021 10:11:41

de Corey J. A. Bradshaw, Paul R. Ehrlich, Andrew Beattie, Gerardo Ceballos, Eileen Crist, Joan Diamond, Rodolfo Dirzo, Anne H. Ehrlich, John Harte, Mary Ellen Harte, et al.
In Frontiers in Conservation Science, 1 (January, 2021), 615419
En ligne : www.frontiersin.org[...]

We report three major and confronting environmental issues that have received little attention and require urgent action. First, we review the evidence that future environmental conditions will be far more dangerous than currently believed. The scale of the threats to the biosphere and all its lifeforms—including humanity—is in fact so great that it is difﬁcult to grasp for even well-informed experts. Second, we ask what political or economic system, or leadership, is prepared to handle the predicted disasters, or even capable of such action. Third, this dire situation places an extraordinary responsibility on scientists to speak out candidly and accurately when engaging with government, business, and the public. We especially draw attention to the lack of appreciation of the enormous challenges to creating a sustainable future. The added stresses to human health, wealth, and well-being will perversely diminish our political capacity to mitigate the erosion of ecosystem services on which society depends. The science underlying these issues is strong, but awareness is weak. Without fully appreciating and broadcasting the scale of the problems and the enormity of the solutions required, society will fail to achieve even modest sustainability goals.

Dynamics of reedbed vegetation and impacts of management in Lesser Prespa Lake wetlands. Final report and synthesis 2017 - 2021. Report within the LIFE15 NAT/GR/000936 Bird conservation in Lesser Prespa: benefiting local communities and building a climate change resilient ecosystem (2021)

Mon, 4 Oct 2021 17:56:18

de Patrick Grillas, Fane Sakellarakis, Gaëtan Lefebvre, Loic Willm, Hugo Fontes, Clémence Pechinot
Arles (FRA) : Tour du Valat, 2021, 105

During the course of the LIFE Prespa Waterbirds project (2017-2021), and regarding the actions regarding the vegetation management and ecology, the main objectives were:
I. The identification of the spatial occupancy and dynamics of T. angustifolia and P. australis with emphasis given on the understanding of their ecological niches as well as detecting the main driving factor(s) for vegetation change, and II. Monitoring the effects of the management actions (cutting and/or grazing) applied towards the restoration of wet meadow communities along the shoreline of Lesser Prespa.
In this framework the detailed objectives set for our study were further divided in:
Assessing the current dynamics in the reedbeds (Phragmites australis / Typha angustifolia) of Lesser Prespa through drone derived orthophotomosaics.
Synthesis of annual mapping of areas burnt by wildfires during the LIFE Prespa Waterbirds using remote sensing techniques on Sentinel-2 and UAV derived orthophotomosaics.
Identification of the ecological niches of T. angustifolia and P. australis.
Effects of submergence after winter cutting on Phragmites australis.
Spatial and structure dynamics of P. australis and T. angustifolia at their patches interface.
Effects of management (mowing + cutting) on the restoration of wet meadows communities.

Migrant birds and mammals live faster than residents

Fri, 20 Nov 2020 16:38:23

de Andrea Soriano-Redondo, Jorge S. Gutiérrez, Dave Hodgson, Stuart Bearhop
In Nature Communications, 11(1) (November, 2020), 5719
En ligne : www.nature.com[...]

Billions of vertebrates migrate to and from their breeding grounds annually, exhibiting astonishing feats of endurance. Many such movements are energetically costly yet there is little consensus on whether or how such costs might influence schedules of survival and reproduction in migratory animals. Here we provide a global analysis of associations between migratory behaviour and vertebrate life histories. After controlling for latitudinal and evolutionary patterns, we find that migratory birds and mammals have faster paces of life than their non-migratory relatives. Among swimming and walking species, migrants tend to have larger body size, while among flying species, migrants are smaller. We discuss whether pace of life is a determinant, consequence, or adaptive outcome, of migration. Our findings have important implications for the understanding of the migratory phenomenon and will help predict the responses of bird and mammal species to environmental change.

Past and future climate-driven shifts in the distribution of a warm-adapted bird species, the European Roller Coracias garrulus

Fri, 11 Sep 2020 15:07:04

de Orsolya Kiss, Ines Catry, Jesus M. Aviles, Sanja Barisic, Tatiana Kuzmenko, Svilen Cheshmedzhiev, Ana Teresa Marques, Angelo Meschini, Timothée Schwartz, Béla Tokody, et al.
In Bird Study, 67(2) (July, 2020), 1-17
En ligne : www.tandfonline.com[...]

We used MaxEnt for species distribution modelling based on the reconstructed distribution map of the species.
Our results suggest that during glacial periods Rollers persisted in small southern refugia, and then spread and colonized northern latitudes during the mid-Holocene. In the future, our models forecast a shift in climatically suitable range towards northern latitudes and an overall small range contraction (4.5–5.5%). Warmer temperatures will increase climate suitability in northern countries where the species is currently declining or became locally extinct. On the other hand, wide suitable areas under current climatic conditions are predicted to become unsuitable in the future (35–38% by 2050 and 2070, respectively), signiﬁcantly impacting large populations such as those in Romania, Spain, Bulgaria and Hungary. French and Italian populations are identiﬁed to be future key populations for Roller conservation.
Our ﬁndings suggest that future climate changes will likely amplify the impacts of existing threats on the majority of large European Roller populations in Europe.

Forest microclimate dynamics drive plant responses to warming

Mon, 25 May 2020 11:58:57

de Florian Zellweger, Pieter De Frenne, Jonathan Lenoir, Pieter Vangansbeke, Kris Verheyen, Markus Bernhardt-Römermann, Lander Baeten, Radim Hédl, Imre Berki, Jörg Brunet, et al.
In Science, 368(6492) (May, 2020), 772-775
En ligne : science.sciencemag.org[...]

Microclimates are key to understanding how organisms and ecosystems respond to macroclimate change, yet they are frequently neglected when studying biotic responses to global change. Zellweger et al. provide a long-term, continental-scale assessment of the effects of micro- and macroclimate on the community composition of European forests (see the Perspective by Lembrechts and Nijs). They show that changes in forest canopy cover are fundamentally important for driving community responses to climate change. Closed canopies buffer against the effects of macroclimatic change through their cooling effect, slowing shifts in community composition, whereas open canopies tend to accelerate community change through local heating effects.
Climate warming is causing a shift in biological communities in favor of warm-affinity species (i.e., thermophilization). Species responses often lag behind climate warming, but the reasons for such lags remain largely unknown. Here, we analyzed multidecadal understory microclimate dynamics in European forests and show that thermophilization and the climatic lag in forest plant communities are primarily controlled by microclimate. Increasing tree canopy cover reduces warming rates inside forests, but loss of canopy cover leads to increased local heat that exacerbates the disequilibrium between community responses and climate change. Reciprocal effects between plants and microclimates are key to understanding the response of forest biodiversity and functioning to climate and land-use changes.

A How‐to Guide for Coproduction of Actionable Science

Mon, 12 Dec 2016 17:15:31

de Paul Beier, Lara J. Hansen, Lynn Helbrecht, David Behar
In Conservation Letters, e12713 (April, 2020)
En ligne : onlinelibrary.wiley.com[...]

Resource managers often need scientific information to match their decisions (typically short-term and local) to complex, long-term, large-scale challenges such as adaptation to climate change. In such situations, the most reliable route to actionable science is coproduction, whereby managers, policy makers, scientists, and other stakeholders first identify specific decisions to be informed by science, and then jointly define the scope and context of the problem, research questions, methods, and outputs, make scientific inferences, and develop strategies for the appropriate use of science. Here, we present seven recommended practices intended to help scientists, managers, funders and other stakeholders carry out a coproduction project, one recommended practice to ensure that partners learn from attempts at coproduction, and two practices to promote coproduction at a programmatic level. The recommended practices focus research on decisions that need to be made, give priority to processes and outcomes over stand-alone products, and allocate resources to organizations and individuals that engage in coproduction. Although this article focuses on the coproduction of actionable science for climate change adaptation and natural resource management, the approach is relevant to other complex natural-human systems.

Perception et adaptation au changement climatique dans les deltas méditerranéens

Tue, 21 Jan 2020 14:02:10

de Lisa Ernoul, Camille Roumieux, Alain Sandoz
In Géoconfluences, Online (Janvier 2020), 5
En ligne : geoconfluences.ens-lyon.fr[...]

Les deltas méditerranéens sont des espaces dont les milieux dépendent des aménagements anthropiques des fleuves qui les alimentent. En tant que côtes basses à climat méditerranéen, ils sont particulièrement vulnérables aux effets probables des changements climatiques. L'étude de trois deltas (Rhône, Vardar et Gediz) montre que les pratiques de leurs habitants associent adaptation locale et prise de conscience globale, mais aucune adaptation efficace n'est possible sans gestion concertée à plusieurs échelles.

Common ground (2020)

Tue, 13 Oct 2020 18:11:22

de Ludovic Larbodière, Jonathan Davies, Ruth Schmidt, Chris Magero, Alain Vidal, A. Arroyo Schnell, Peter Bucher, Stewart Maginnis, Neil Cox, Olivier Hasinger, et al.
Gland, Switzerland : UICN, 2020, 100
En ligne : portals.iucn.org[...]

Recent major international reports have highlighted the alarming impact of food production systems on climate change, land and biodiversity. This report shows that common ground between the agriculture and conservation sectors for mutually beneficial action exists, and that there is great potential for widespread adoption of sustainable agricultural practices that can meet our needs for food, feed, fibre, and energy. More widely, sustainable agriculture can contribute to food, water security,climate regulation and other objectives, supporting progress towards the Sustainable Development Goals and other international targets for climate change, biodiversity and land degradation.

Organic farming favours bird communities and their resilience to climate change in Mediterranean vineyards

Wed, 18 Sep 2019 14:43:46

de Alex Rollan, Antonio Hernández-Matías, Joan Real
In Agriculture, Ecosystems & Environment, 269 (2019), 107-115
En ligne : www.sciencedirect.com[...]

Farmland birds have suffered notable declines in Europe in recent decades, mainly due to agricultural intensification and climate change. Organic farming, which has been shown to enhance biodiversity, is increasingly being put into practice in European vineyards. Nevertheless, no previous studies have reported significant positive responses in avian communities to organic practices. On the other hand, cover cropping is a common practice in both organic and conventional vineyards and is thought to have positive effects on bird communities and, particularly, on insectivorous species that may help control pests in agroecosystems. In this work, we studied bird communities in Mediterranean vineyards in Catalonia (NE Iberian Peninsula) in both the breeding and wintering seasons, and tested the effects of two common management options – organic vs. conventional farming and herbaceous cover vs. bare soil – on bird communities. In particular, we focused on (a) insectivorous birds that may help control pests and (b) avian species negatively affected by climatic warming whose population fluctuations may reflect the resilience of these bird communities to future climate change. Organic farming had a positive effect on vineyard bird communities and, specifically, increased species richness and overall bird abundance. This farming technique also positively affected the abundance of both insectivorous species and species whose populations are declining due to climate change. The presence of inter-row herbaceous cover between vines also had positive effects on bird community parameters, specifically in spring and in organic vineyards, when herbaceous cover favours species richness and the abundance of insectivorous species. However, further investigations are still needed to better understand the effects of different types of vegetation cover - i.e. plant origin and composition (e.g. sown vs. spontaneous vegetation) and proportion of vegetation cover (full vs. partial vegetation cover) - when employed as tools in wildlife conservation. This work provides useful information regarding bird conservation, which will help mitigate the effects of climate change on bird populations.

Emerging threats and persistent conservation challenges for freshwater biodiversity

Wed, 26 Jun 2019 10:37:54

de Andrea J. Reid, Andrew K. Carlson, Irena F. Creed, Erika J. Eliason, Peter A. Gell, Pieter T. J. Johnson, Karen A. Kidd, Tyson J. MacCormack, Julian D. Olden, Steve J. Ormerod, et al.
In Biological Reviews, 94(3) (June, 2019), 849-873
En ligne : onlinelibrary.wiley.com[...]

In the 12 years since Dudgeon et al. (2006) reviewed major pressures on freshwater ecosystems, the biodiversity crisis in the world’s lakes, reservoirs, rivers, streams and wetlands has deepened. While lakes, reservoirs and rivers cover only 2.3% of the Earth’s surface, these ecosystems host at least 9.5% of the Earth’s described animal species. Furthermore, using the World Wide Fund for Nature’s Living Planet Index, freshwater population declines (83% between 1970 and 2014) continue to outpace contemporaneous declines in marine or terrestrial systems. The Anthropocene has brought multiple new and varied threats that disproportionately impact freshwater systems. We document 12 emerging threats to freshwater biodiversity that are either entirely new since 2006 or have since intensiﬁed: (i) changing climates; (ii) e-commerce and invasions; (iii) infectious diseases; (iv) harmful algal blooms; (v) expanding hydropower; (vi) emerging contaminants; (vii) engineered nanomaterials; (viii) microplastic pollution; (ix) light and noise; (x) freshwater salinisation; (xi) declining calcium; and (xii) cumulative stressors. Effects are evidenced for amphibians, ﬁshes, invertebrates, microbes, plants, turtles and waterbirds, with potential for ecosystem-level changes through bottom-up and top-down processes. In our highly uncertain future, the net effects of these threats raise serious concerns for freshwater ecosystems. However, we also highlight opportunities for conservation gains as a result of novel management tools (e.g. environmental ﬂows, environmental DNA) and speciﬁc conservation-oriented actions (e.g. dam removal, habitat protection policies, managed relocation of species) that have been met with varying levels of success. Moving forward, we advocate hybrid approaches that manage fresh waters as crucial ecosystems for human life support as well as essential hotspots of biodiversity and ecological function. Efforts to reverse global trends in freshwater degradation now depend on bridging an immense gap between the aspirations of conservation biologists and the accelerating rate of species endangerment.

The adaptive capacity of local water basin authorities to climate change: The Thau lagoon basin in France

Thu, 7 Mar 2019 16:01:00

de David Aubin, Cécile Riche, Vincent Vande Water, Isabelle La Jeunesse
In Science of The Total Environment, 651 (February, 2019), 2013-2023
En ligne : www.sciencedirect.com[...]

Climate change exacerbates climate variability, and makes water governance more complex. The French local water management plans (SAGE) developed an integrated approach that relies on a balance between bottom-up and top-down governance. The aim of this article is to question the actual role of the local basin authorities and ask whether they are central in water governance. The Social Network Analysis of the Thau basin shows that the key actors of the SAGE, namely the Rhone-Mediterranean-Corsica Water Agency, the local water agency and the local water commission, are the most powerful actors in the management of the river basin and play a crucial brokerage role in climate change adaptation. Integrated water resource management shifted power from territorial and central authorities to functional and local managers.

Des solutions fondées sur la nature pour s'adapter au changement climatique (2019)

Mon, 25 May 2020 11:59:50

de Observatoire national sur les effets du réchauffement climatique
[S.l.] : Observatoire national sur les effets du réchauffement climatique, 2019, 306
En ligne : www.vie-publique.fr[...]

La France possède déjà de nombreux savoirs et savoir-faire pertinents pour développer une véritable offre de service dans le domaine des Solutions d’adaptation fondées sur la Nature : gestion souple des dunes, modélisation de l’impact de la végétalisation sur le microclimat urbain, modélisation de l’efficacité et du ratio coût/bénéfice des SfN face aux catastrophes naturelles, restauration écologique. Or ces connaissances et compétences se développent dans un contexte politique, juridique et normatif particulier qui peut également être mobilisé, du niveau international au niveau local, dans une perspective de déploiement des Solutions fondées sur la Nature pour l’adaptation au changement climatique. Au niveau national par exemple, un certain nombre d’outils de planification permettent déjà d’intégrer les SfN ou constituent un cadre favorable à leur déploiement. C’est notamment le cas du Plan Biodiversité et du deuxième Plan national d’adaptation au changement climatique (PNACC-2) qui promeuvent tous deux le recours aux SfN pour l’adaptation au changement climatique. Par ailleurs, du fait des multiples bénéfices qu’elles peuvent engendrer, les Solutions fondées sur la Nature pourraient même faciliter la mise en oeuvre d’outils de planification multisectoriels tels que le Schéma régional d’aménagement, de développement durable et d’égalité des territoires (SRADDET), ou de compétences transversales telles que la Gestion des milieux aquatiques et prévention des inondations

La santé face au changement climatique en région Provence-Alpes-Côte d'Azur (2019)

Tue, 17 Dec 2019 10:32:34

de (GREC PACA) Groupe régional d’experts sur le climat en Provence-Alpes-Côte d’Azur
Marseille (13001, France) : AIR, 2019, 48 p.
En ligne : www.grec-sud.fr[...]

Les activités humaines et le changement climatique associé affectent notre santé. Les événements climatiques extrêmes (canicules, sécheresses, inondations…) peuvent fragiliser les organismes, rendre malades, voire provoquer des décès, l’augmentation de la température favorise l’apparition de maladies tropicales, la pollution de l’air altère notre système respiratoire et cardio-vasculaire… Comme les projections climatiques mettent en évidence une hausse de la température ces prochaines décennies variant selon les scénarios socio-économiques, les impacts sur la santé vont s’aggraver. Les risques diffèrent selon les personnes et les territoires. Qu’en est-il en région Provence-Alpes-Côte d’Azur ? Comment faire face au changement climatique ? Un nouveau cahier thématique du GREC-SUD présentant les principaux résultats scientifiques vient de paraître

La nature sous pression : pourquoi la biodiversité disparait ? (2019)

Wed, 17 Jul 2019 15:13:40

de Julien Massetti, Stanislas Wroza, Observatoire national de la biodiversité
[S.l.] : Agence française pour la biodiversité, 2019, 7
En ligne : indicateurs-biodiversite.naturefrance.fr[...]

Ce rapport propose une cartographie inédite des cinq principales pressions qui menacent la biodiversité : l’artificialisation des sols, la surexploitation des ressources, le changement climatique, les pollutions et les espèces exotiques envahissantes. Après le cri d’alarme historique sur le « dangereux déclin de la nature » lancé à l’échelle mondiale par les experts de la plateforme intergouvernementale sur la biodiversité et les services écosystémiques (IPBES) en mai 2019, l’Observatoire de la biodiversité replace ces cinq grandes menaces à l’échelle française.

Projected linear trend in heating (HDD) and cooling degree days (CDD) over the period 1981-2100 under two scenarios (2019)

Wed, 26 Jun 2019 10:39:39

[S.l.] : European Environment Agency, 2019, 7
En ligne : www.eea.europa.eu[...]

These maps show the trend in heating degree days (left) and cooling degree days (right) from 1981-2100 for all EEA member and cooperating countries, based on the median of an ensemble of 11 EURO-CORDEX simulations.

Sortir du pot au noir (2019)

Thu, 2 May 2019 15:08:00

de Mireille Delmas-Marty
Paris : Buchet-Chastel, 2019, 93

La 4e de couv. indique : "L'humanité serait-elle entrée dans le « pot au noir », cette zone au milieu des océans où les vents qui soufflent en sens contraires se neutralisent ou se combattent ? Dans un monde pris dans ces tourbillons, entre paralysie et naufrage, où trouver la boussole qui permettrait d'en sortir ? Pour échapper au désordre, stabiliser l'instable et penser l'imprévisible, il ne suffit pas de placer l'humanité et ses valeurs au centre du monde, comme a tenté de le faire la Déclaration universelle des droits de l'homme en 1948. Il faut réguler les vents autour de principes communs et inventer la boussole d'un humanisme élargi à la planète qui guiderait les humains sur les routes imprévisibles du monde."

Agir pour le climat (2019)

Thu, 2 May 2019 15:07:59

de Valéry Laramée de Tannenberg, Valérie Masson-Delmotte
Paris : Buchet-Chastel, 2019, 140

Depuis plus d'un quart de siècle, diplomates et experts de près de 200 pays réfléchissent aux moyens de ralentir le réchauffement climatique. L'accord de Paris, signé en 2015 à l'issue de la COP 21, en est l'aboutissement le plus visible. Mais, devant la lenteur des avancées et la croissance des émissions de gaz à effet de serre, de nouveaux acteurs interviennent aujourd'hui et modifient les rapports de force : le monde de l'entreprise et de la finance, des collectivités, des ONG, des juristes et des avocats, sans oublier les organisations philanthropiques aux moyens quasi illimités et aux motivations parfois troubles. Ces nouveaux acteurs - non étatiques - se mobilisent aussi bien pour des raisons d'ordre éthique que par intérêt bien compris. Ils disposent d'un formidable potentiel pour infléchir les politiques internationales, et leurs initiatives commencent à donner des résultats concrets.

Ecosystem change and zoonoses in the Anthropocene

Fri, 15 Feb 2019 15:22:01

de Barry J. McMahon, Serge Morand, Jeremy S. Gray
In Zoonoses and Public Health, 65(7) (11/2018), 755-765
En ligne : doi.wiley.com[...]

Changes in land use, animal populations and climate, primarily due to increasing human populations, drive the emergence of zoonoses. Force of infection (FOI), which for these diseases is a measure of the ease with which a pathogen reaches the human population, can change with specific zoonoses and context. Here, we outline three ecosystem categories—domestic, peridomestic and sylvatic, where disease ecology alters the FOI of specific zoonoses. Human intervention is an overriding effect in the emergence of zoonoses; therefore, we need to understand the disease ecology and other influencing factors of pathogens and parasites that are likely to interact differently within ecological and cultural contexts. Planning for One Health and community ecology, such as an ecological impact assessment, is required to prepare and manage the emergence and impact of zoonoses in the Anthropocene.
biodiversity, infectious disease, landscape, one Health /
Avec près de 60% des maladies infectieuses émergentes classées comme zoonotiques, ces pathologies représentent un enjeu croissant de santé publique au niveau mondial. La facilité par laquelle elles se propagent dans la population humaine dépend à la fois de la zoonose et du contexte écologique. Dans un article paru dans la revue scientifique Zoonoses and public health, une équipe de scientifiques illustre la nécessité de prendre en compte les exigences écologiques des agents pathogènes zoonotiques, l’impact des interventions humaines, mais aussi les types d’écosystèmes concernés (urbain, péri-urbain et forestier) pour se préparer à leur émergence et les gérer efficacement.
À l’heure de l’anthropocène, les changements d’usage des terres, les populations animales et le climat entraînent l'apparition de maladies transmises des animaux à l’Homme, autrement appelées zoonoses

Waterbird communities adjust to climate warming according to conservation policy and species protection status

Mon, 24 Sep 2018 10:46:09

de Elie Gaget, Thomas Galewski, Frédéric Jiguet, Isabelle Le Viol
In Biological Conservation, 227 (November, 2018), 205-212
En ligne : www.sciencedirect.com[...]

Climate change is one of the strongest biodiversity threats. Worse still, the impact of multiple anthropic stressors on species dynamics could complicate adaptation to temperature increase. International conservation policies aim to protect ecosystems against anthropic pressures, but their ability to facilitate adaptation to climate change has yet to be assessed. Using wetland bird monitoring surveys, we evaluated the differences at the country scale of community adjustment to temperature increase of wintering waterbird communities (145 species) according to the implementation of the two main western Palearctic international conservation policies (Bern Convention and Birds Directive) in the Mediterranean basin (2786 sites, 22 countries) over a 22-year period. We showed that thermic community composition increases over time in countries which have enforced conservation policies. We found that strictly protected species under the Birds Directive and the Bern Convention contributed more to this community adjustment than the not strictly protected species. The mechanism results from a population increase in protected warm-dwelling species but not from a decline in cold-dwelling species. This study supports the ability of international conservation policies to mitigate the effect of climate change on animal communities./
Nous avons observé que les politiques internationales de conservation jouent un rôle positif dans l’adaptation des oiseaux d’eau au réchauffement climatique. Plus les pays du bassin méditerranéen ont des mesures de conservation fortes, plus les changements au sein des communautés d’oiseaux reflètent un meilleur ajustement au réchauffement climatique. Dans le détail, les espèces strictement protégées par la Directive Oiseaux et la Convention de Berne ont un meilleur ajustement de leur distribution que les espèces non strictement protégées.

The Second Warning to Humanity–Providing a Context for Wetland Management and Policy

Thu, 16 Aug 2018 15:24:49

de C. M. Finlayson, Gillian T. Davies, William R. Moomaw, G. L. Chmura, Susan M. Natali, J. E. Perry, N. Roulet, Ariana E. Sutton-Grier
In Wetlands, https://doi.org/10.1007/s13157-018-1064 (July 2018), 1–5

The Second Warning to Humanity provides a clarion call for wetland researchers and practitioners given the loss and degradation of wetlands, the declining availability of fresh water, and the likely consequences of climate change. A coordinated response and approach to policies has the potential to prevent further degradation and support resilient wetlands that can provide a range of ecosystem services, including buffering wetlands from climate impacts, and avoiding major climate amplification from temperature-induced release of additional carbon dioxide and methane while addressing the causes and consequences of global climate change. The Warning to Humanity also provides an opportunity for organisations such as the Society of Wetland Scientists to raise the profile of wetlands and to initiate a discussion on how to respond and change direction from the destructive development trajectory that led to wetland loss and degradation. It also provides a signal for a reappraisal of the effectiveness of the implementation of the Ramsar Convention on Wetlands as an international mechanism for ensuring the sustainability of wetlands. KW
Climate change Ramsar convention Wetlands Second warning to humanity

Global change effects on land management in the Mediterranean region

Mon, 23 Apr 2018 13:49:00

de Žiga Malek, Peter H Verburg, Ilse R. Geijzendorffer, Alberte Bondeau, Wolfgang Cramer
In Global Environmental Change, 50 (05/2018), 238-254
En ligne : linkinghub.elsevier.com[...]

The Mediterranean region faces signiﬁcant challenges to supply its growing population with food and living space. The region’s potential to do so in the future is even more uncertain in the light of global change eﬀects. Climate change will impact water availability in the region, which is already limited and often used at unsustainable rates. To investigate the eﬀects of global change and explore alternative development pathways of Mediterranean land use, we simulated two future scenarios with diﬀerent land, water and biodiversity management transitions. We adopted a land systems approach, where land use and land cover are combined with data on land management, irrigation and livestock density, taking into account the characteristics of Mediterranean multifunctional landscapes, speciﬁc agricultural products, such as permanent crops, and irrigation water demands. Future land system changes were explored using the CLUMondo model for diﬀerent development pathways of the region. We constrained the withdrawal of irrigation water based on existing freshwater resources. In a ‘growth’ scenario, we simulated a hypothetical future without consideration of environmental constraints and where food production and urban expansion are main priorities. The ‘sustainability’ scenario represents a future where limited water resources are extracted in a sustainable way and where areas of high biodiversity value are protected. The growth scenario projected signiﬁcant intensiﬁcation of land management, and loss of agro-silvo-pastoral mosaic systems. To achieve this, we calculate that the region would need to increase water withdrawal for irrigation signiﬁcantly, resulting in increased pressure on freshwater resources. The sustainability scenario presents a way of increasing food production and at the same time improving the state of water resources, wetlands and traditional landscapes. Achieving this future would require improvements of yields of rain-fed systems and eﬃciencies of irrigated systems. The results indicate that coordinated environmental policy together with appropriate market access are needed to steer the regions land management towards a more sustainable future while ensuring food production.

Wetlands In a Changing Climate: Science, Policy and Management

Wed, 18 Apr 2018 11:52:23

de William R. Moomaw, G. L. Chmura, Gillian T. Davies, C. M. Finlayson, B. A. Middleton, Susan M. Natali, J. E. Perry, N. Roulet, Ariana E. Sutton-Grier
In Wetlands, Online (April 2018), 1-23
En ligne : link.springer.com[...]

Part 1 of this review synthesizes recent research on status and climate vulnerability of freshwater and saltwater wetlands, and their contribution to addressing climate change (carbon cycle, adaptation, resilience). Peatlands and vegetated coastal wetlands are among the most carbon rich sinks on the planet sequestering approximately as much carbon as do global forest ecosystems. Estimates of the consequences of rising temperature on current wetland carbon storage and future carbon sequestration potential are summarized. We also demonstrate the need to prevent drying of wetlands and thawing of permafrost by disturbances and rising temperatures to protect wetland carbon stores and climate adaptation/resiliency ecosystem services. Preventing further wetland loss is found to be important in limiting future emissions to meet climate goals, but is seldom considered. In Part 2, the paper explores the policy and management realm from international to national, subnational and local levels to identify strategies and policies reflecting an integrated understanding of both wetland and climate change science. Specific recommendations are made to capture synergies between wetlands and carbon cycle management, adaptation and resiliency to further enable researchers, policy makers and practitioners to protect wetland carbon and climate adaptation/resiliency ecosystem services.

The status of Mediterranean coastal wetlands (2018)

Wed, 25 Sep 2019 10:25:33

de Observatoire des zones humides méditerranéennes, Pôle-relais lagunes méditerranéennes, UNEP/MAP Plan Bleu
[S.l.] : MedWet, 2018, 27

In the frame of the MAVA project “A Campaign on Coastal wetlands”, this report aims to provide a state of the art assessment of the available knowledge about Mediterranean coastal wetlands. It is not a full systematic synthesis of available literature, but rather a compilation of available data and knowledge with the partners of the MedWet Initiative and MAVA projects (2018-2022) complemented by cherry-picked results available in the literature. Where possible, detailed information for Albania, Italy, Montenegro, and Tunisia is provided, as they are countries of particular interest for this MAVA project.
This report can therefore serve as a source of inspiration and information for authorities and decision makers at national and European level when they are involved in negotiations with impacts on Mediterranean coastal wetlands. In addition, it can be used by active voices in social media, such as the private (business) sector, the general public, the media, and consultants.
This report contributes to the four key topics:
- Ecosystem processes
- Recreation/tourism/cultural aspects
- Water provision and regulation
- Climate change

2ème colloque national science et société pour l'adaptation des territoires aux changements climatiques (2018)

Wed, 3 Jul 2019 11:47:35

de Aurore Aubail, Antoine Nicault, Philippe Rossello, Laure Thierry de Ville d’Avray
Marseille, France : GREC-SUD, 2018, 89
En ligne : www.grec-sud.fr[...]

Représentant le conseil scientifique, les intervenants ont positionné le colloque au cœur des grands enjeux internationaux, nationaux et locaux liés au changement climatique.
Pour répondre aux enjeux climatiques, la première nécessité mise en avant par le GIEC est la médiation entre sciences, sociétés et politiques. Le GIEC, à l'échelle internationale, et ses équivalents à l'échelle régionale (comme le GREC-SUD en Provence-Alpes-Côte d’Azur ou AcclimaTerra en Nouvelle-Aquitaine), répondent en partie à ce besoin, mais le décalage entre les trois sphères reste grand.
La deuxième nécessité mise en évidence est la réflexion et l'action multi-échelles : échelle globale pour la mise en place de mesures de réduction des émissions de GES, échelle régionale pour la mise en place de mesures d'adaptation correspondant aux contextes locaux, en s'appuyant sur la force de l'attachement régional pour mobiliser les acteurs. Du côté de la communauté scientifique, la baisse de moyens accordés à la recherche par le Ministère de l'Enseignement supérieur, de la Recherche et de l'Innovation, doit encourager les scientifiques à se mobiliser à travers des organisations plus locales. Par ailleurs, les acteurs locaux ont un rôle décisif à jouer pour guider la transformation profonde des modes de vie des sociétés, nécessaire pour limiter les effets du changement climatique et s'y adapter.

Le littoral héraultais face au changement climatique (2018)

Mon, 27 May 2019 10:50:03

de Louise André, Clémence Poitevin, Bérénice Rigal, Léna Tyack
Champs-sur-Marne (12 Avenue Blaise Pascal, 77420, France) : Ecole d'architecture de la ville et des territoires à Marne-la-Vallée, 2018

Les zones humides méditerranéennes, enjeux et perspectives 2 : Solutions pour des zones humides méditerranéennes durables (2018)

Tue, 13 Nov 2018 10:35:17

de Observatoire des zones humides méditerranéennes
Arles : Tour du Valat, 2018, 16p,16 factsheets, ill.
En ligne : tourduvalat.org[...]

Ce nouveau rapport actualise la situation des zones humides méditerranéennes depuis 2012, année de publication du rapport "Mediterranean Wetlands Outlook", qui a été la première évaluation régionale fondée sur des indicateurs de l’état des zones humides et des problèmes auxquels elles font face.
Ce rapport, comprenant 16 fiches d’indicateurs, fournit un appui régional aux résultats du premier rapport de la Convention de Ramsar intitulé "Perspectives mondiales pour les zones humides (GWO) : État mondial des zones humides et de leurs services à l’humanité",

Mediterranean Wetlands Outlook 2: Solutions for sustainable Mediterranean Wetlands (2018)

Thu, 27 Sep 2018 10:40:07

de Mediterranean Wetlands Observatory
Arles : Tour du Valat, 2018, 16p,16 factsheets, ill.
En ligne : tourduvalat.org[...]

This report updates the situation for Mediterranean wetlands since 2012, the year of publication of "The Mediterranean Wetlands Outlook", which was the first regional indicator-based assessment of the status of wetlands and the challenges that they face.
The 2018 report, through its 16 indicator factsheets, provides regional support to the findings of the Ramsar Convention’s first Global Wetland Outlook (GWO): the State of the World’s Wetlands

Plant community patterns in Moroccan temporary ponds along latitudinal and anthropogenic disturbance gradients

Tue, 29 Aug 2017 15:57:17

de Mohammed El Madihi, Laïla Rhazi, Maarten Van den Broeck, Mouhssine Rhazi, Aline Waterkeyn, Er-riyahi Saber, Siham Bouahim, Moustapha Arahou, Abdelmajid Zouahri, Anis Guelmami, et al.
In Plant Ecology & Diversity, 10(1) (2017-07-24), 1-19
En ligne : www.tandfonline.com[...]

Background: Temporary ponds, an abundant habitat in the Maghreb region and notably in Morocco, have a high conservation value. However, they are mainly known from the north of the country.
Aims: The aim of this work was to characterise the vegetation of Moroccan temporary ponds along a combined gradient of latitude and anthropogenic pressure.
Methods: Eighty-five ponds distributed along a north–south gradient of 750 km were sampled. For each pond, all vegetation was surveyed (flooded and dry parts) and the local abiotic characteristics were measured during two successive hydrological cycles. The prevailing anthropogenic pressures were also identified and were attributed an impact score.
Results: Eighty-one characteristic pond species (including 17 rare species) were recorded, with several new distribution data in the southern part of the latitudinal gradient. Plant communities were related to climatic and anthropogenic factors, but mostly to local factors, such as maximum water depth and soil pH. The northern ponds (wettest macroclimate) were rich in characteristic species and rare species, while the southern (driest macroclimate) ponds were more species poor.
Conclusions: In addition to the direct impact of increasing human activity, a further reduction of the floristic richness of temporary ponds is expected due to climatic changes. This is particularly the case for characteristic species which have a high conservation value.

Identifying trends and associated uncertainties in potential rice production under climate change in Mediterranean areas

Fri, 12 May 2017 11:53:03

de Simone Bregaglio, Laure Hossard, Giovanni Cappelli, Remi Resmond, Stefano Bocchi, Jean-Marc Barbier, Françoise Ruget, Sylvestre Delmotte
In Agricultural and Forest Meteorology, 237–238 (May, 2017), 219-232
En ligne : www.sciencedirect.com[...]

The future of global rice productions in top producing countries is undermined by the impact of climate change threatening food security in the near future. In those European Mediterranean areas where rice is cultivated, this peculiar cropping system plays a crucial role in terms of sociocultural and ecological issues, and the climate change impact is still scarcely investigated. In this study, we explored the future trends of potential rice yields in the region considering the multiple sources of uncertainty associated with climate and yield predictions. Two rice crop models (STICS and WARM) were calibrated using 20 field experiments carried out in two main European rice producing areas − i.e., the Italian Lomellina and the French Camargue. These models were then applied under a range of climate change scenarios in 2030 and 2070 time frames, considering projections from the combination of four General Circulation Models and two extreme Representative CO2 Concentration Pathways (RCP 2.6 and 8.5). We compared the simulated yield levels with no adaptation, and designed adaptation strategies based on the anticipation of sowing date and the adoption of varieties with longer crop cycle. Our results showed that with no adaptation yields would decrease on average by 8% in 2030 and 12% in 2070 in Camargue and Lomellina. Future simulated yields in the two areas were lower than in the baseline in 67% (Camargue) and 84% (Lomellina) of the cases. The implementation of both adaptation strategies proved to be effective in reversing the situation, leading to an average yield increase of 28% and 25% in 2030 and 2070, respectively. The associated probability of lower yields than in current conditions was 24% in the two sites. Despite the uncertainty in predictions, mainly related to site, GCM and RCP, our findings indicate that the European rice sector has the potential to enhance current production levels in a changing climate, if longer cycle varieties will be grown in Mediterranean rice areas.

Les messagers: ce que les oiseaux nous disent des menaces provoquées par le changement climatique, et les solutions pour la nature et les hommes (2017)

Thu, 31 Jan 2019 14:06:13

de Birdlife International, National Audubon society (États-Unis)
Rochefort : LPO, 2017, 41
En ligne : www.birdlife.org[...]

Manifestations des changements climatiques et leurs impacts en Méditerranée (2017)

Mon, 22 Oct 2018 16:52:37

de Abdelkarim Daoud, Salem Dahech
Aix-en-Provence, France : Presses Universitaires de Provence, 2017, 71 (Méditerranée : revue géographique des pays méditerranéens. Méditerranée : revue géographique des pays méditerranéens ; 28)

Les changements climatiques, champ de recherches pluridisciplinaire, ont fortement retenu l’attention des géographes au cours des dernières années. La Méditerranée est considérée par l’IPCC comme l’un des espaces géographiques où les manifestations des changements climatiques et de leurs impacts sur les écosystèmes, sur l’Homme et ses activités sont des plus sensibles. L’évolution du climat et du niveau de la mer en particulier y sont importants. C’est également un espace anciennement anthropisé qui connait aujourd’hui un accroissement important de sa population sur la bande littorale. Ces fortes densités humaines, impactent tout autant le patrimoine naturel que culturel, les aménagements ont des répercussions économiques et sociales majeures et diversifiées. Mais peut-on distinguer ce qui relève de l’action du climat, de sa variabilité - qu’elle soit naturelle ou lié au changement climatique d’origine humaine - de celle qui relève de la susceptibilité et de la vulnérabilité (aménagements humains, imperméabilisation des sols...) ?

- Manifestations des changements climatiques et leurs impacts en Méditerranée
- Conditions atmosphériques des précipitations intenses dans le Bassin méditerranéen : variabilité contemporaine et future (1979-2100)
- Les « médicanes » : perturbations atmosphériques déterminant des déluges en Méditerranée
- Réchauffement climatique en ville et ses répercussions énergétiques; Cas de l’agglomération de Sfax (centre-est de la Tunisie)
- Evolution of salty surfaces on the Kerkennah archipelago between 1963 and 2010
- Le déclin de la biodiversité marine dans la baie de Monastir et ses conséquences sociales. Quels changements après la révolution ?
- Élaboration collective et recommandations des parties prenantes face à un scénario de tempête en 2030 sur le lido de Sète
- La plaine de Crau (Ouest de la Provence. Un avenir incertain dans un contexte de changement climatique

L’évolution de l’occupation du sol au sein des sites Ramsar de France métropolitaine en 1975- 2005. Volet II : Pistes d’interprétation (2017)

Fri, 1 Dec 2017 15:16:52

de Christian Perennou
Arles : Tour du Valat, 2017, 45 p.
En ligne : tourduvalat.org[...]

En 2016, un premier rapport dans le cadre de l’Observatoire des Milieux humides/ ONB analysait les changements d’occupation du sol intervenus entre 1975 et 2005 au sein de 32 sites Ramsar de France métropolitaine, à partir de l’analyse d’images satellitaires. Divers changements étaient alors mis en avant et quantifiés, comme la perte en zones humides naturelles et la forte progression des zones humides artificielles.

Ce 2e rapport complète le précédent, en proposant des pistes d’interprétation pour ces changements : quels sont les mécanismes, les causes profondes ? Il se base pour cela tant sur la bibliographie existante (notamment l’Enquête décennale à dires d’experts « Zones Humides»), que sur une enquête spécifique menée en 2016-17 auprès des gestionnaires de ces sites Ramsar

Les ressources en eau et le changement climatique en Provence-Alpes-Côte d’Azur: Cahier thématique du groupe de travail « Ressources en eau » (2017)

Mon, 13 Nov 2017 15:19:54

de Groupe régional d’experts sur le climat en Provence-Alpes-Côte d’Azur
Marseille, France : A.I.R. Climat, 2017, 51
En ligne : www.gesteau.fr[...]

Comment raisonner le partage de l’eau face aux multiples besoins (eau potable, irrigation, énergie…) et enjeux écologiques, dans un contexte de changements climatiques ? Un nouveau guide en ligne du Groupe régional d’experts sur le climat en PACA, dresse un panorama des conséquences attendues sur les ressources en eau de la région et leurs usages, et identifie des pistes d’adaptation en appui aux élus et gestionnaires.
Diminution de la couverture neigeuse et de l’eau stockée dans les glaciers, modification des précipitations, altération de la qualité́ des eaux… les changements du climat et leurs impacts sur les ressources en eau seront potentiellement source de conflits d’usage. En Provence-Alpes-Côte d’Azur, les aménagements réalisés dès les années 1960, tel que le barrage de Serre-Ponçon sur la Durance, ont permis de sécuriser l’accès aux ressources en eau inégalement disponibles sur le territoire (importantes au nord et limitées en basse Provence). Cependant, des tensions persistent notamment en période estivale où les pressions sont accrues en raison d’une forte demande et d’épisodes de sécheresse, caractéristiques du climat méditerranéen.
Pour mieux anticiper ces évolutions et accompagner les acteurs du territoire dans l’élaboration de mesures d’adaptation, 38 chercheurs et ingénieurs interdisciplinaires du GREC PACA proposent, dans un 5ème cahier thématique en ligne, un bilan des connaissances concernant les effets des changements climatiques sur les ressources en eau. Destiné aux élus, ingénieurs, gestionnaires de collectivités locales, d’espaces protégés, et à toute personne intéressée par le sujet, il permet d’appréhender facilement :
- Le devenir des eaux de surface (température des cours d’eau, évolutions de l’humidité du sol et des sécheresses…) et des eaux souterraines sous l’influence des changements climatiques
- La variabilité historique des ressources en eau
- La vulnérabilité des écosystèmes aquatiques
- Les conséquences possibles sur les usages (agriculture, production électrique…)
Des solutions institutionnelles envisagées sur le territoire de la Durance soumis à une forte pression, et des pistes d’adaptation issues de nouveaux concepts et projets de recherche, comme l’utilisation de ressources non conventionnelles (eaux pluviales ou réutilisation des eaux usées traitées ), sont aussi présentées pour aider à la prise de décision.

La mer et le littoral de Provence-Alpes-Côte d'Azur face au changement climatique (2017)

Mon, 18 Sep 2017 13:20:47

de (GREC PACA) Groupe régional d’experts sur le climat en Provence-Alpes-Côte d’Azur
Marseille (13001, France) : AIR, 2017, 47 p.
En ligne : www.grec-sud.fr[...]

Le Groupe régional d’experts sur le climat en Provence-Alpes-Côte d’Azur (GREC-PACA), animé par AIR Climat, publie son 3ème cahier thématique qui porte sur les impacts du changement climatique sur la mer et le littoral.
39 contributeurs ont rédigé cette synthèse des connaissances scientifiques à destination des décideurs et gestionnaires des territoires, mais aussi du public désireux de mieux comprendre les enjeux. Cette publication propose des pistes d’adaptation à l’échelle régionale et locale, tout en précisant les axes de recherche de demain.
Dans quelle mesure le climat change-t-il sur le littoral de la région Provence-Alpes-Côte d’Azur et en mer Méditerranée ? Quels sont les impacts sur l’érosion des côtes, la circulation des courants, le niveau et l’acidité de la mer ? Quelle est la vulnérabilité du littoral face au changement climatique et aux activités anthropiques ? Quels sont les moyens d’observations et de surveillance aujourd’hui ? Pour apporter des éléments de réponses, des scientifiques font un état des lieux des connaissances.
Le milieu marin et sa biodiversité sont influencés par l’évolution du climat. Sur la côte méditerranéenne de la région Provence-Alpes-Côte d’Azur, des facteurs, comme, par exemple, la hausse de la température de l’eau, la dégradation de la qualité de l’eau, la surpêche, les aménagements côtiers ou l’eutrophisation, bouleversent la biodiversité (destruction d’habitats, prolifération de microalgues, décalages phénologiques).
Pour limiter les effets du changement climatique, les décideurs et gestionnaires ont à leur disposition des outils et solutions pour aménager et gérer leur territoire ou repenser les espaces publics et privés, cependant, appliquer des stratégies d’atténuation ou d’adaptation, mettre en œuvre des politiques en faveur des énergies marines renouvelables, de la protection des biens et des personnes, de la régulation des ressources halieutiques soulèvent des questions complexes auxquelles les chercheurs s’efforcent de répondre. La dernière partie de cette étude aborde la problématique du changement climatique sur un plan plus politique, juridique, social et économique.

The role of waterbirds in the dispersal of aquatic alien and invasive species

Wed, 9 Nov 2016 14:05:15

de Chevonne Reynolds, Nelson A. F. Miranda, Graeme S. Cumming
In Diversity and Distributions, 21(7) (juillet 1, 2015), 744-754
En ligne : onlinelibrary.wiley.com[...]

Aim

To review existing literature on the ability of waterbirds to spread aquatic alien and invasive species, and to assess the relevance of bird-mediated dispersal for the conservation of freshwater ecosystems.

Location

Global.

Methods

Literature Review.

Results

A systematic review of the literature revealed that quantitative studies investigating dispersal of alien organisms by waterbirds are rare (n = 14). Most studies citing waterbird dispersal rely on anecdotes or inferences from morphological dispersal syndromes. However, evidence from each stage of dispersal (i.e. emigration, transport and immigration) shows that waterbirds can carry alien plants and invertebrates internally and externally; transport them between water bodies at a variety of spatial scales; and deposit viable propagules in sites suited to aquatic invasive species.

Main conclusions

Our review suggests that waterbirds can and do act as important dispersal vectors for freshwater invasive species. Further experimental and field based research on the numbers and viability of moved alien propagules, and the roles of different species in the bird community, is needed. Furthermore, consideration of the spatially explicit manner in which birds move is imperative to understanding invasive spread. Populations of alien aquatic species in seemingly isolated wetlands can no longer be considered contained if they are able to be spread through waterbird-mediated dispersal, and containment measures must recognize such opportunities for further spread. Changing waterbird movement patterns, driven by climate and land use change, further add to the challenge of managing invasive species and offers an interesting opportunity for future research. The study of waterbird-mediated dispersal of aquatic alien invasive species provides insights not only into species invasions, but more generally into movement ecology, population ecology and biogeography.

Hindcasting Historical Breeding Conditions for an Endangered Salamander in Ephemeral Wetlands of the Southeastern USA: Implications of Climate Change

Wed, 9 Nov 2016 14:04:56

de Houston C. Chandler, Andrew L. Rypel, Yan Jiao, Carola A. Haas, Thomas A. Gorman
In PLOS ONE, 11(2) (24 févr. 2016), e0150169
En ligne : journals.plos.org[...]

The hydroperiod of ephemeral wetlands is often the most important characteristic determining amphibian breeding success, especially for species with long development times. In mesic and wet pine flatwoods of the southeastern United States, ephemeral wetlands were a common landscape feature. Reticulated flatwoods salamanders ( Ambystoma bishopi ), a federally endangered species, depend exclusively on ephemeral wetlands and require at least 11 weeks to successfully metamorphose into terrestrial adults. We empirically modeled hydroperiod of 17 A . bishopi breeding wetlands by combining downscaled historical climate-model data with a recent 9-year record (2006–2014) of observed water levels. Empirical models were subsequently used to reconstruct wetland hydrologic conditions from 1896–2014 using the downscaled historical climate datasets. Reconstructed hydroperiods for the 17 wetlands were highly variable through time but were frequently unfavorable for A . bishopi reproduction (e.g., only 61% of years, using a conservative estimate of development time [12 weeks], were conducive to larval development and metamorphosis). Using change-point analysis, we identified significant shifts in average hydroperiod over the last century in all 17 wetlands. Mean hydroperiods were shorter in recent years than at any other point since 1896, and thus less suitable for A . bishopi reproduction. We suggest that climate change will continue to impact the reproductive success of flatwoods salamanders and other ephemeral wetland breeders by reducing the number of years these wetlands have suitable hydroperiods. Consequently, we emphasize the importance of conservation and management for mitigating other forms of habitat degradation, especially maintenance of high quality breeding sites where reproduction can occur during appropriate environmental conditions.

Linking azolla filiculoides invasion to increased winter temperatures in the doñana marshland (Sw spain)

Wed, 9 Nov 2016 14:04:42

de José L. Espinar, Ricardo Díaz-Delgado, Miguel A. Bravo, Montserrat Vilà
In Aquatic Invasions, 10 (2015)
En ligne : digital.csic.es[...]

© 2015 The Author(s). Unravelling how a multiplicity of global change factors might influence the expansion of alien plants is a major goal of invasion biology. We explored the association of climatic conditions (i.e. annual rainfall and average minimum temperature during the coldest months) and water quality (orthophosphate, nitrate concentrations and electrical conductivity), with blooms of the invasive fern Azolla filiculoides Lam. in the Doñana marshland (SW Spain), one of the most extensive wetlands in Europe. Azolla was first detected in Doñana in 2001. Its annual cover has been quantified since then through remote sensing. In the last decade there has been a considerable increase of orthophosphate and yearly fluctuations of nitrate. The first orthophosphate increase coincided with the presence of Azolla in Doñana. Since then, there has been a positive relationship between inter-annual variation in Azolla cover and minimum temperature during the coldest months. Our study shows that the Doñana marshland is facing rapid eutrophication and invasion by Azolla, most notably in years with high temperatures during the winter.

When Common Birds Became Rare: Historical Records Shed Light on Long-Term Responses of Bird Communities to Global Change in the Largest Wetland of France

Wed, 16 Nov 2016 17:07:30

de Thomas Galewski, Vincent Devictor
In PLOS ONE, 11 (Nov. 2016), 1-18
En ligne : journals.plos.org[...]

Many species have suffered large population declines due to the anthropogenic influence on ecosystems. Understanding historical population trends is essential for informing best efforts to preserve species. We propose a new method to reconstruct the past structure of a regional species pool, based on historical naturalist literature. Qualitative information collected from annotated checklists and reports can be relevant to identify major long-term community changes. We reviewed ornithological literature on the Camargue, the largest wetland in France. We reconstructed the entire breeding bird community from 1830 to 2009 and translated historical data into semi-quantitative data. This data permitted a calculation of a Community Commonness Index to measure the average level of abundance of species in a community. The Community Specialization and Community Temperature Indices were used to evaluate the potential long-term impact of land-use and climate changes on the composition of the regional bird species pool. We found a decrease in average abundance and specialization between 1950 and 1989, suggesting that changes in land-use negatively impacted the structure and composition of the local bird community by reducing species abundance and removing habitat-specialists (e.g. Southern Grey Shrike, Greater Short-toed Lark). These results are likely to be linked with a major loss of natural habitats in the Camargue between 1942 and 1984 when natural areas and traditional farmland were converted into intensive cultivated lands. We also found fluctuations among species with high versus low temperature preference. However, long-term effects of climate change on the bird community might be blurred by the impact of land-use changes. Overall, our results contrast with those obtained from well-monitored colonial waterbirds showing long-term increases. Our results plead for a more regular use of historical naturalist data when examining long-term changes in species communities as they allow the establishment of an older temporal point of reference and consideration of species not covered by traditional monitoring schemes. / où l’on présente l’intérêt de la littérature « grise » naturaliste (livres, compte-rendus, rapports de voyage…) pour retracer les variations démographiques historiques d’une population, d’une espèce ou d’une communauté d’espèces.

Ici on s’est intéressé à la communauté d’oiseaux nicheurs de Camargue que l’on a pu reconstruire depuis le début du 19ème siècle jusqu’à nos jours. Il a été possible de coder de manière semi-quantitative l’abondance de toutes les espèces à différents pas de temps. En utilisant cette méthodologie, on observe que la communauté a beaucoup évolué dans le temps avec notamment une diminution de l’abondance spécifique et une perte de spécialisation. En d’autres termes, si 2 espèces sur 3 pouvaient être qualifiées de communes au 19ème siècle, ce n’est plus le cas que pour 1 espèce sur 3 aujourd’hui. La diminution a principalement affecté les espèces spécialistes des milieux agricoles et pâturés (ex : Alouettes, Perdrix rouge, Chevêche, Petit-duc, Tourterelle des bois, Linotte et beaucoup d’autres) tandis que les oiseaux utilisant les milieux humides ont mieux résisté. Ce déclin s’est produit dans les années 1950-1980 à une époque où on enregistre une très forte perte de milieux naturels et semi-naturels en Camargue (pelouses et sansouires en premier lieu) ainsi qu’un changement majeur de l’agriculture camarguaise qui délaisse l’élevage extensif au profit d’une céréaliculture intensive. Cette étude met en évidence un déclin important des oiseaux des milieux agricoles bien antérieur et supérieur au déclin observé depuis 20 ans à travers les programmes de science citoyenne

Phenological asynchrony in plant-butterfly interactions associated with climate: a community-wide perspective

Wed, 9 Nov 2016 14:05:35

de Isabel Donoso, Constanti Stefanescu, Alejandro Martinez-Abrain, Anna Traveset
In Oikos, 125(10) (October 2016), 1434-1444
En ligne : onlinelibrary.wiley.com[...]

Although much information has been accumulated on the effects of climate change on particular species worldwide, research aimed at assessing how such change influences biotic interactions from a community-wide perspective is still in its infancy. We contribute to filling in this gap by analyzing a 17-year (1996-2012) dataset that includes records of flower-visitation interactions between 12 butterfly species and 17 plant species in a coastal wetland area in northeastern Iberian Peninsula. We assessed the extent to which temporal asynchronies between plants and adult butterflies are influenced by different climatic variables that affect both plant and insect phenologies. Temperature and degree of aridity at various monthly summaries were used as predictors of the plant-butterfly phenological asynchrony. We identified the seasonal window with the greatest effect on asynchronies for two butterfly generations (spring and summer), and assessed whether the magnitude of asynchrony is associated with the level of butterfly specialization. We used generalized linear mixed models considering a total of 39 plant-butterfly interactions. Average asynchrony was higher in the spring generation and dry conditions during winter lead to decreased temporal overlap with flowers in this butterfly generation, whereas dry conditions in the spring lead to decreased temporal overlap in the summer butterfly generation. The magnitude of the effect was consistently small at the community level (all interactions pooled). Moreover, no clear climatic trend over the study time frame was detected. Finally, specialized and generalized butterflies in their resource use as adults were similarly vulnerable to asynchronies, in contrast to previous predictions of greater mutualistic disruptions in species with narrower niches. We conclude that a least in the Mediterranean region, phenological asynchronies might be more affected by aridity level than by temperature itself, and thus the former can be a key climatic trait to make better predictions in this region.

Impacts of climate change on the hydrology of two Natura 2000 sites in Northern Greece

Wed, 9 Nov 2016 14:05:34

de Ch Doulgeris, D. Papadimos, J. Kapsomenakis
In Regional Environmental Change, 16(7) (2016/10/01), 1941-1950
En ligne : link.springer.com[...]

Greece is included among the most vulnerable regions of Europe by climate change on account of higher temperature and reduced rainfall in areas already facing water scarcity. With respect to wetland systems, many ephemeral ones are expected to disappear and several permanent to shrink due to climate change. As regards two specific wetlands of Greece, the change in hydroperiod of Cheimaditida and Kerkini lakes due to climate change was studied. Lakes’ water balance was simulated using historical climate data and the emission scenarios Α1Β for the period 2020–2050 and Α1Β and Α2 for the period 2070–2100. Future climate scenarios, based on emission scenarios A1B and A2, were provided in the context of the study of Climate Change Impacts Study Committee. The surface area of Lake Cheimaditida will undergo a substantial decrease, initially by 20 % during the period 2020–2050 and later until 37 % during the period 2070–2100. In Lake Kerkini, the surface area will decrease, initially by 5 % during the period 2020–2050 and later until 14 % during the period 2070–2100. Climate change is anticipated to impact the hydroperiod of the two wetlands, and the sustainable water management is essential to prevent the wetland’s biodiversity loss.

Lessons from the construction of a climate change adaptation plan: A Broads wetland case study

Wed, 9 Nov 2016 14:05:33

de R Kerry Turner, Maria Giovanna Palmieri, Tiziana Luisetti
In Integrated Environmental Assessment and Management, 12(4) (October 2016), 719-725
En ligne : onlinelibrary.wiley.com[...]

The dynamic nature of environmental change in coastal areas means that a flexible “learning by doing” management strategy has a number of advantages. This article lays out the principles of such a strategy and then assesses an actual planning and management process focused on climate change consequences for the Broads wetland on the East coast of England. The management strategy focused on the concept of ecosystem services (stocks and flows) provided by the coastal wetland and the threats and opportunities posed to the area by sea level rise and other climate change impacts. The analysis explores the process by which an adaptive management plan has been formulated and coproduced by a combination of centralized (vertical) and stakeholder social network (horizontal) arrangements. The process values where feasible the ecosystem services under threat and prioritizes response actions. Coastal management needs a careful balance between strategic requirements imposed at a national scale and local schemes that affect regional and/or local communities and social networks. These networks aided by electronic media have allowed groups to engage more rapidly and effectively with policy proposals. However, successful deliberation is conditioned by a range of context specific factors, including the type of social networks present and their relative competitive and/or complementary characteristics. The history of consultation and dialogue between official agencies and stakeholders also plays a part in contemporary deliberation processes and the success of their outcomes. Among the issues highlighted are the multiple dimensions of nature's value; the difficulty of quantifying some ecosystem service changes, especially for cultural services; and the problem of “stakeholder fatigue” complicating engagement arrangements. Integr Environ Assess Manag 2016;12:719–725. © 2016 SETAC

Water and energy fluxes during summer in an arid-zone passerine bird

Mon, 17 Oct 2016 16:01:22

de Ben Smit, Andrew E. McKechnie
In Ibis, 158(4) (October 2016), 774-786
En ligne : onlinelibrary.wiley.com[...]

Endothermic animals resident in hot, arid terrestrial environments are likely to face a trade-off between their ability to obtain water and elevated thermoregulatory water requirements. We assessed whether daily water flux (DWF) is higher on hot days, reflecting increases in evaporative cooling demands, in an arid-zone bird that obtains its water through food intake. We obtained measurements of DWF (partitioned into water influx and efflux rates) in 71 White-browed Sparrow-Weavers Plocepasser mahali at a desert site and a semi-desert site, during summer in the Kalahari Desert of southern Africa. We found no evidence that DWF varied with maximum daily air temperature (Tair, range = 27.6–39.2 °C). Instead, DWF was lower during dry periods than in the wet season at the semi-desert site. Furthermore, birds showed deficits in water balance (water influx/water efflux) during the dry periods at both sites. Our data show that DWF is low in a non-drinking bird that obtains its water through food, and that demands for evaporative water loss on very hot days (maximum Tair of 40–44 °C) may exceed water intake rates during hot and dry periods. Species that do not have opportunities to drink will experience strong trade-offs between thermoregulation, hydration state and activity levels as temperatures increase.

Projected wetland densities under climate change: habitat loss but little geographic shift in conservation strategy

Wed, 9 Nov 2016 14:05:30

de Helen R. Sofaer, Susan K. Skagen, Joseph J. Barsugli, Benjamin S. Rashford, Gordon C. Reese, Jennifer A. Hoeting, Andrew W. Wood, Barry R. Noon
In Ecological Applications, 26(6) (September 2016), 1677-1692
En ligne : onlinelibrary.wiley.com[...]

Climate change poses major challenges for conservation and management because it alters the area, quality, and spatial distribution of habitat for natural populations. To assess species’ vulnerability to climate change and target ongoing conservation investments, researchers and managers often consider the effects of projected changes in climate and land use on future habitat availability and quality and the uncertainty associated with these projections. Here, we draw on tools from hydrology and climate science to project the impact of climate change on the density of wetlands in the Prairie Pothole Region of the USA, a critical area for breeding waterfowl and other wetland-dependent species. We evaluate the potential for a trade-off in the value of conservation investments under current and future climatic conditions and consider the joint effects of climate and land use. We use an integrated set of hydrological and climatological projections that provide physically based measures of water balance under historical and projected future climatic conditions. In addition, we use historical projections derived from ten general circulation models (GCMs) as a baseline from which to assess climate change impacts, rather than historical climate data. This method isolates the impact of greenhouse gas emissions and ensures that modeling errors are incorporated into the baseline rather than attributed to climate change. Our work shows that, on average, densities of wetlands (here defined as wetland basins holding water) are projected to decline across the U.S. Prairie Pothole Region, but that GCMs differ in both the magnitude and the direction of projected impacts. However, we found little evidence for a shift in the locations expected to provide the highest wetland densities under current vs. projected climatic conditions. This result was robust to the inclusion of projected changes in land use under climate change. We suggest that targeting conservation towards wetland complexes containing both small and relatively large wetland basins, which is an ongoing conservation strategy, may also act to hedge against uncertainty in the effects of climate change.

Proline and glycine betaine accumulation in two succulent halophytes under natural and experimental conditions

Wed, 9 Nov 2016 14:04:39

de L. L. Pardo-Domènech, A. Tifrea, M. N. Grigore, M. Boscaiu, O. Vicente
In Plant Biosystems, 150(5) (September 2016), 904-915
En ligne : dx.doi.org[...]

Proline (Pro) and glycine betaine (GB) contents were determined in two Mediterranean halophytes, Plantago crassifolia and Inula crithmoides, to assess their possible role in salt tolerance of both taxa. Plant material was collected in a littoral salt marsh under different environmental conditions, and from plants subjected to salt treatments in a growth chamber. Relative growth inhibition by NaCl indicated that I. crithmoides is more salt-tolerant than P. crassifolia, in agreement with the distribution of the two species in nature. Field and laboratory data confirmed GB as the major osmolyte responsible for osmotic adjustment in I. crithmoides, but with only a minor role – if any – as “osmoprotectant” in the salt tolerance of P. crassifolia. Under natural conditions, Pro contents were very low in both taxa, but increased to levels high enough to contribute significantly to osmotic balance when plants were artificially treated with 450–600 mM NaCl – higher salt concentrations than those they would normally encounter in their natural habitats. These data suggest that halophytes possess built-in mechanisms, such as accumulation of additional osmolytes, to rapidly adapt to increasing salinity levels in their natural ecosystems; for example, those expected to be caused by climate change in salt marshes in the Mediterranean region.

Ecophysiological response of native and invasive Spartina species to extreme temperature events in Mediterranean marshes

Wed, 9 Nov 2016 14:05:16

de B. Duarte, J. C. Marques, I. Caçador
In Biological Invasions, 18(8) (2016/08/01), 2189-2205
En ligne : link.springer.com[...]

The recent IPCC WG2 5th Assessment Report (IPCC 2014), notes an increase in the frequency and duration of extreme climatic events, especially for the Mediterranean region. Together with climate change, the invasion of natural communities by non-indigenous species (NIS) constitutes a serious threat to biodiversity. One of these NIS is the American Spartina patens, now present in Western European marshes. The present study aims to understand the biochemical and photochemical responses of S. patens compared with S. maritima under extreme temperature events. Under normal and extreme heat conditions, S. patens had a higher photosynthetic efficiency (α), compared with cold wave events, where the native S. maritima was far more efficient. This reduced photosynthetic efficiency was mostly due to a decrease in the connectivity between photosystem II (PSII) antennae. This was accompanied by severe damage to the oxygen-evolving complex of PSII. On the other hand, S. patens oxygen evolving complexes (OECs) seem to be temperature insensitive. The light absorption capacity was maintained due to a higher net rate of reaction centre (RC) closure as a counteractive measure of the reduced number of RC, especially in S. maritima. The loss of connectivity between PSII antennae and damage in OECs under heat stress leads to a severe reduction in the maximum yield for photochemistry enhanced by the low probability of each absorbed quanta to produce electronic work. However, while S. maritima presents high energy losses under heat stress, S. patens developed efficient quenching mechanisms under thermal stress, through auroxanthin. In S. patens, cold wave-treated individuals also displayed a very active line of enzymatic defences for reactive oxygen species scavenging. In fact, only cold treated individuals of this species presented higher activities of anti-oxidant enzymes, revealing some degree of adaptation to this new environment. In contrast, in S. maritima the exposure to extreme heat periods led, in most cases, to a decrease in the enzymatic defences, leaving the cell prone to oxidative damage. In summary, S. patens appears to have a higher fitness for the incoming climatic scenarios, being more tolerant to heat stress, while S. maritima will have its photobiological fitness decreased. This will impose a shift in the salt marsh biodiversity, favouring the non-indigenous S. patens expansion.

Long-term changes in the migration phenology of UK breeding birds detected by large-scale citizen science recording schemes

Mon, 17 Oct 2016 16:03:16

de Stuart E. Newson, Nick J. Moran, Andy J. Musgrove, James W. Pearce-Higgins, Simon Gillings, Philip W. Atkinson, Ryan Miller, Mark J. Grantham, Stephen R. Baillie
In Ibis, 158(3) (July 2016), 481-495
En ligne : onlinelibrary.wiley.com[...]

The timing of migration is one of the key life-history parameters of migratory birds. It is expected to be under strong selection, to be sensitive to changing environmental conditions and to have implications for population dynamics. However, most phenological studies do not describe arrival and departure phenologies for a species in a way that is robust to potential biases, or that can be clearly related to breeding populations. This hampers our ability to understand more fully how climate change may affect species’ migratory strategies, their life histories and ultimately their population dynamics. Using generalized additive models (GAMs) and extensive large-scale data collected in the UK over a 40-year period, we present standardized measures of migration phenology for common migratory birds, and examine how the phenology of bird migration has changed in the UK since the 1960s. Arrival dates for 11 of 14 common migrants became significantly earlier, with six species advancing their arrival by more than 10 days. These comprised two species, Blackcap Sylvia atricapilla and Chiffchaff Phylloscopus collybita, which winter closest to Britain in southern Europe and the arid northern zone of Africa, Common Redstart Phoenicurus phoenicurus, which winters in the arid zone, and three hirundines (Sand Martin Riparia riparia, House Martin Delichon urbicum and Barn Swallow Hirundo rustica), which winter in different parts of Africa. Concurrently, departure dates became significantly later for four of the 14 species and included species that winter in southern Europe (Blackcap and Chiffchaff) and in humid zones of Africa (Garden Warbler Sylvia borin and Whinchat Saxicola rubetra). Common Swift Apus apus was the exception in departing significantly earlier. The net result of earlier arrival and later departure for most species was that length of stay has become significantly longer for nine of the 14 species. Species that have advanced their timing of arrival showed the most positive trends in abundance, in accordance with previous studies. Related in part to earlier arrival and the relationship above, we also show that species extending their stay in Great Britain have shown the most positive trends. Further applications of our modelling approach will provide opportunities for more robust tests of relationships between phenological change and population dynamics than have been possible previously.

Halophytes as a source of salt tolerance genes and mechanisms: a case study for the Salt Lake area, Turkey

Wed, 9 Nov 2016 14:05:35

de Ceyda Ozfidan-Konakci, Baris Uzilday, Rengin Ozgur, Evren Yildiztugay, A. Hediye Sekmen, Ismail Turkan
In Functional Plant Biology, 43(7) (2016/07/13), 575-589
En ligne : www.publish.csiro.au[...]

The worst case scenario of global climate change predicts both drought and salinity would be the first environmental factors restricting agriculture and natural ecosystems, causing decreased crop yields and plant growth that would directly affect human population in the next decades. Therefore, it is vital to understand the biology of plants that are already adapted to these extreme conditions. In this sense, extremophiles such as the halophytes offer valuable genetic information for understanding plant salinity tolerance and to improve the stress tolerance of crop plants. Turkey has ecological importance for its rich biodiversity with up to 3700 endemic plants. Salt Lake (Lake Tuz) in Central Anatolia, one of the largest hypersaline lakes in the world, is surrounded by salty marshes, with one of the most diverse floras in Turkey, where arid and semiarid areas have increased due to low rainfall and high evaporation during the summer season. Consequently, the Salt Lake region has a large number of halophytic, xerophytic and xero-halophytic plants. One good example is Eutrema parvulum (Schrenk) Al-Shehbaz & Warwick, which originates from the Salt Lake region, can tolerate up to 600 mM NaCl. In recent years, the full genome of E. parvulum was published and it has been accepted as a model halophyte due to its close relationship (sequence identity in range of 90%) with Arabidopsis thaliana (L. Heynh.). In this context, this review will focus on tolerance mechanisms involving hormone signalling, accumulation of compatible solutes, ion transporters, antioxidant defence systems, reactive oxygen species (ROS) signalling mechanism of some lesser-known extremophiles growing in the Salt Lake region. In addition, current progress on studies conducted with E. parvulum will be evaluated to shed a light on future prospects for improved crop tolerance.

Adaptation services of floodplains and wetlands under transformational climate change

Wed, 9 Nov 2016 14:05:14

de Matthew J. Colloff, Sandra Lavorel, Russell M. Wise, Michael Dunlop, Ian C. Overton, Kristen J. Williams
In Ecological Applications, 26(4) (June 2016), 1003-1017
En ligne : onlinelibrary.wiley.com[...]

Adaptation services are the ecosystem processes and services that benefit people by increasing their ability to adapt to change. Benefits may accrue from existing but newly used services where ecosystems persist or from novel services supplied following ecosystem transformation. Ecosystem properties that enable persistence or transformation are important adaptation services because they support future options. The adaptation services approach can be applied to decisions on trade-offs between currently valued services and benefits from maintaining future options. For example, ecosystem functions and services of floodplains depend on river flows. In those regions of the world where climate change projections are for hotter, drier conditions, floods will be less frequent and floodplains will either persist, though with modified structure and function, or transform to terrestrial (flood-independent) ecosystems. Many currently valued ecosystem services will reduce in supply or become unavailable, but new options are provided by adaptation services. We present a case study from the Murray–Darling Basin, Australia, for operationalizing the adaptation services concept for floodplains and wetlands. We found large changes in flow and flood regimes are likely under a scenario of +1.6°C by 2030, even with additional water restored to rivers under the proposed Murray–Darling Basin Plan. We predict major changes to floodplain ecosystems, including contraction of riparian forests and woodlands and expansion of terrestrial, drought-tolerant vegetation communities. Examples of adaptation services under this scenario include substitution of irrigated agriculture with dryland cropping and floodplain grazing; mitigation of damage from rarer, extreme floods; and increased tourism, recreational, and cultural values derived from fewer, smaller wetlands that can be maintained with environmental flows. Management for adaptation services will require decisions on where intervention can enable ecosystem persistence and where transformation is inevitable. New ways of managing water that include consideration of the increasing importance of adaptation services requires major changes to decision-making that better account for landscape heterogeneity and large-scale change rather than attempting to maintain ecosystems in fixed states.

Can constructed wetlands treat wastewater for reuse in agriculture? Review of guidelines and examples in South Europe

Wed, 9 Nov 2016 14:05:10

de Stevo Lavrnić, Maurizio L. Mancini
In Water Science and Technology, 73(11) (May 2016), 2616-2626
En ligne : wst.iwaponline.com[...]

South Europe is one of the areas negatively affected by climate change. Issues with water shortage are already visible, and are likely to increase. Since agriculture is the biggest freshwater consumer, it is important to find new water sources that could mitigate the climate change impact. In order to overcome problems and protect the environment, a better approach towards wastewater management is needed. That includes an increase in the volume of wastewater that is treated and a paradigm shift towards a more sustainable system where wastewater is actually considered as a resource. This study evaluates the potential of constructed wetlands (CWs) to treat domestic wastewater and produce effluent that will be suitable for reuse in agriculture. In South Europe, four countries (Greece, Italy, Portugal and Spain) have national standards that regulate wastewater reuse in agriculture. Wastewater treatment plants (WWTPs) that are based on CWs in these four countries were analysed and their effluents compared with the quality needed for reuse. In general, it was found that CWs have trouble reaching the strictest standards, especially regarding microbiological parameters. However, their effluents are found to be suitable for reuse in areas that do not require water of the highest quality.

Les effets du changement climatique sur l’agriculture et la forêt en PACA (2016)

Thu, 5 Jan 2017 17:11:17

de (GREC PACA) Groupe régional d’experts sur le climat en Provence-Alpes-Côte d’Azur
Marseille (13001, France) : AIR, 2016, 40 p.
En ligne : www.grec-sud.fr[...]

Le Groupe régional d’experts sur le climat en Provence-Alpes-Côte d’Azur (GREC-PACA), animé par AIR Climat, publie son 2ème cahier thématique portant sur les effets du changement climatique sur l’agriculture et la forêt.Près de 40 chercheurs et ingénieurs ont rédigé cette synthèse des connaissances scientifiques à destination des décideurs et gestionnaires des territoires. Cette publication permet d’évaluer les conséquences du changement climatique à l’échelle régionale et locale, et propose des solutions pour l’adaptation et l’atténuation

The Mediterranean Region under Climate Change (2016)

Wed, 16 Nov 2016 17:07:42

de (AllEnvi) French National Alliance for Environmental Research
French National Alliance for Environmental Research. Paris : IRD Editions, 2016, 736
En ligne : books.openedition.org[...]

This book has been published to coincide with the 22nd Conference of Parties to the United Nations Framework Convention on Climate Change (COP22) in Marrakesh. It is the outcome of work by academic researchers on both sides of the Mediterranean and provides a scientific review of the mechanisms of climate change and its impacts on the environment, the economy, health and Mediterranean societies. It will also be valuable in developing responses that draw on “scientific evidence” to address the issues of adaptation, resource conservation, solutions and risk prevention. Reflecting the full complexity of the Mediterranean environment, the book is a major scientific contribution to the climate issue, where various scientific considerations converge to break down the boundaries between disciplines.

Beyond just sea-level rise: considering macroclimatic drivers within coastal wetland vulnerability assessments to climate change

Wed, 9 Nov 2016 14:05:34

de Michael J. Osland, Nicholas M. Enwright, Richard H. Day, Christopher A. Gabler, Camille L. Stagg, James B. Grace
In Global Change Biology, 22(1) (January 2016), 1-11
En ligne : onlinelibrary.wiley.com[...]

Due to their position at the land-sea interface, coastal wetlands are vulnerable to many aspects of climate change. However, climate change vulnerability assessments for coastal wetlands generally focus solely on sea-level rise without considering the effects of other facets of climate change. Across the globe and in all ecosystems, macroclimatic drivers (e.g., temperature and rainfall regimes) greatly influence ecosystem structure and function. Macroclimatic drivers have been the focus of climate change-related threat evaluations for terrestrial ecosystems, but largely ignored for coastal wetlands. In some coastal wetlands, changing macroclimatic conditions are expected to result in foundation plant species replacement, which would affect the supply of certain ecosystem goods and services and could affect ecosystem resilience. As examples, we highlight several ecological transition zones where small changes in macroclimatic conditions would result in comparatively large changes in coastal wetland ecosystem structure and function. Our intent in this communication is not to minimize the importance of sea-level rise. Rather, our overarching aim is to illustrate the need to also consider macroclimatic drivers within vulnerability assessments for coastal wetlands.

The impact of human pressure on landscape patterns and plant species richness in Mediterranean coastal dunes

Wed, 9 Nov 2016 14:04:47

de M. Malavasi, R. Santoro, M. Cutini, A. T. R. Acosta, M. Laura Carranza
In Plant Biosystems, 150(1) (January 2016), 73-82
En ligne : dx.doi.org[...]

We analyze the spatial patterns of natural dune cover patches and their plant richness, comparing coastal sites with different levels of human pressure in central Italy. We created a detailed land cover map of dune sites. The spatial pattern of natural dune cover types was characterized by computing a set of patch-based metrics. To quantify patch plant richness, we used 16 m2 vegetation plots, randomly distributed on coastal dune cover types. For each patch, the richness of the entire pool of species and of three guilds (i.e., typical dune, ruderal, and alien species) was considered. We compared different levels of human pressure on coastal dunes focusing on pattern metrics and floristic information by using the nonparametric Kruskal–Wallis test. In sites with high human pressure, we have observed a general simplification in the natural dune spatial pattern and a decline of plant richness but with a specific response for each cover type. Alien and ruderal species presented low richness in all patches. In coastal dunes, the harsh ecological conditions and the strong sea–inland gradient shape the distribution of human activities and control the number of ruderal species. The approach effectively describes fragmentation and biodiversity in dune ecosystems.

Trade and habitat change virtually eliminate the Grey Parrot Psittacus erithacus from Ghana

Mon, 17 Oct 2016 16:03:18

de Nathaniel N. D. Annorbah, Nigel J. Collar, Stuart J. Marsden
In Ibis, 158(1) (January 2016), 82-91
En ligne : onlinelibrary.wiley.com[...]

The heavily traded Grey Parrot Psittacus erithacus is believed to have undergone rapid population decline, yet there are almost no quantitative data on abundance changes over time from anywhere within its huge range. We reviewed the species’ historical abundance across Ghana, undertook targeted searches during 3- to 5-day visits to 42 100-km2 cells across the country's forest zone, repeated counts at 22 parrot roosts first performed two decades ago and gauged around 900 people's perceptions of the decline and its causes. In over 150 days of fieldwork, just 32 groups (maximum group size = 12) were recorded in 10 cells. Encounter rates averaged 0.15 individuals per hour of targeted search, around 15 times lower than those recorded in the early 1990s. No active roosts were found, and only 18 individuals were recorded in three roost areas that each harboured 700–1200 birds two decades ago. Interviewees stressed the importance of very tall trees of commercially important species such as Terminalia superba and Ceiba pentandra for nesting and roosting, and believed that the felling of large trees on farmland (42% of responses) and trapping for trade (37%) were the two main causes of decline. Ghana has lost 90–99% of its Grey Parrots since 1992, a time when the population had presumably already been seriously reduced by two decades of extremely heavy trade. There is no evidence that, away from one or two localities, declines are less severe anywhere else within the West African range of P. erithacus, or across the entire range of the recently split Timneh Parrot Psittacus timneh.

Quelle occupation du sol au sein des sites Ramsar de France métropolitaine ? Rétrospective 1975- 2005 (2016)

Wed, 5 Oct 2016 16:03:24

de Christian Perennou, Anis Guelmami
Arles : Tour du Valat, 2016, 37 p.

Dans le cadre de l’Observatoire National des milieux humides, la Tour du Valat (Observatoire des zones humides méditerranéennes) avec l’aide de l’Association Ramsar-France, a étudié l’évolution de l’occupation du sol dans 32 de ces sites métropolitains (désignés avant 2015) entre 1975, 1990 et 2005, à partir d’images satellites. Utilisant la méthodologie du projet GlobWetland-II (mené en partenariat avec l’Agence Spatiale Européenne, Jena Optronik et le Secrétariat Ramsar), elle a permis d’analyser l’évolution des grandes classes d’habitats, en particulier des milieux humides (naturels et artificiels) ; d’analyser le niveau de pression agricole et urbain sur les sites Ramsar métropolitains de France ; et d’établir des cartes d’occupation du sol simplifiée des 32 sites. Optimisée pour une échelle globale, la méthode permet de mettre en évidence des tendances à l’échelle de l’ensemble des sites.
Il s’agit du premier essai de déclinaison nationale d’une démarche de suivi à partir d‘images satellitaires, appliquée en 2009-14 à l’échelle du bassin méditerranéen.

Principaux résultats :
- Globalement, en 30 ans, les milieux humides naturels ont régressé de 6%, et les milieux humides artificiels progressé de 38% dans les sites Ramsar métropolitains. Les milieux naturels terrestres ont aussi régressé. Ces changements sous-estiment probablement ceux ayant affecté les zones humides de France en général, souvent mois bien protégées/valorisées que les sites Ramsar.
- Marais & lagunes, forêts inondables et prairies humides sont les milieux humides qui ont le plus régressé entre 1975 et 2005.
- A l’inverse, lacs et étangs artificiels ont fortement progressé.
- Les milieux urbanisés ont fortement progressé entre 1975 et 2005 (+ 39%), tant dans les sites Ramsar métropolitains que dans leurs proches alentours.
- En revanche l’agriculture a stagné : +2% à +4 % dans les sites, -2% à -3% dans les alentours.
- Le littoral méditerranéen apparaît comme le plus concerné par la progression tant de l’agriculture que des milieux urbains.

Caractérisation de la vulnérabilité des zones humides de Provence-Alpes-Côtes d’Azur au changement climatique : le cas des zones humides alluviales. (2016)

Fri, 30 Sep 2016 17:22:15

de Sophie Guingand
[S.l.] : Université de Liège, 2016, 75 p.

Fifty percents of wetlands have disappeared or have been altered for agricultural uses. Climate change makes this habitat type one of the most vulnerable of the world. With the objective to characterize wetlands vulnerability to climate changes, with a particular attention to Mediterranean wetlands, the Agence de l’Eau and the Région PACA have launch the Regional Action Plan on Climate Change and water resources (PRACC). The methodology used to characterize this vulnerability is based on physical and hydrological criteria (lithology, distance to the river, relation between seepage and water flow) and also with biological criteria (species richness, presence of threatened species, species’ sensibility to climate change). Those criteria have been translated in indicators allowing comparisons between wetlands and a hierarchical treatment of those habitats. This methodology and the resulting preliminary results obtained from amphibian’s data and for the alluvial wetlands only, will be extended to the overall PACA wetland network, and with other flora and fauna taxa. / Alors que plus de 50 % des zones humides en France ont disparu ou ont été utilisées dans un but agricole, le contexte du changement climatique fait de ces milieux un des habitats les plus vulnérables au monde. Afin de caractériser la vulnérabilité des zones humides aux changements climatiques, avec une attention particulière portée sur les zones humides méditerranéennes, l’Agence de l’Eau et la Région PACA ont mis en place le PRACC. La méthodologie adoptée pour caractériser cette vulnérabilité se base alors sur des critères physiques, hydrologiques (relation débit-nappe, distance au cours d’eau, lithologie) et biologiques (richesse spécifique, présence d’espèces menacées, sensibilité des espèces au changement climatique). Ces critères sont alors traduits en indices permettant une quantification et la comparaison de la vulnérabilité des zones. Le cadrage méthodologique et les résultats préliminaires présentés à partir du cortège d’amphibiens sur les zones humides alluviales, est voué à s’appliquer sur l’ensemble des zones humides actuellement recensé en PACA, et s’appliquera dans la suite de l’étude à d’autres cortèges floro-faunistiques.

Climat et changement climatique en région Provence-Alpes-Côte d'Azur (2016)

Wed, 8 Jun 2016 17:27:39

de (GREC PACA) Groupe régional d’experts sur le climat en Provence-Alpes-Côte d’Azur
Marseille (13001, France) : AIR, 2016, 40 p.
En ligne : www.grec-sud.fr[...]

Cette publication revient sur les caractéristiques du climat de la région Provence-Alpes-Côte d’Azur. Elle replace les bouleversements actuels et futurs dans un contexte de changement climatique à long terme, grâce aux acquis de la paléoclimatologie. La synthèse des principales connaissances apporte des éléments de compréhension afin de mieux cerner la problématique du climat et du changement climatique qu’il soit dû à la variabilité naturelle ou aux activités humaines. Les moyens de surveillance météorologique et climatique, les outils et techniques de spatialisation et de modélisation qui permettent de fournir des indicateurs aux services techniques, mais aussi au grand public, sont présentés. L’approche locale, avec des exemples concrets, est privilégiée afin d’accompagner les décideurs et gestionnaires locaux.

Tracking global change in ecosystem area:The Wetland Extent Trends index

Thu, 21 Apr 2016 17:51:47

de M.J.R. Dixon, J. Loh, N.C. Davidson, C. Beltrame, R. Freeman, M. Walpole
In Biological Conservation, 193 (January 2016), 27-35
En ligne : linkinghub.elsevier.com[...]

We present a method for estimating broad trends in ecosystem area based on incomplete and heterogeneous data, developing a proof-of-concept for the first indicator of change in area of natural wetland, the Wetland Extent Trends (WET) index. We use a variation of the Living Planet Index method, which is used for measuring global trends in wild vertebrate species abundance. The analysis is based on a database containing 1100 wetland extent time-series records and the method identifies and addresses ecological and biogeographic biases in the dataset. Globally, the natural WET index, excluding human-made wetlands, declined by about 30% on average between 1970 and 2008. Declines varied between regions from about 50% in Europe to about 17% in Oceania over the same period. The WET index fills an important gap in the ecosystem coverage of global biodiversity indicators and can track changes related to a number of current international policy objectives. The same method could be applied to other datasets to create indicators for other ecosystems with incomplete global data.