Promoting Climate-Friendly Diets: What Should We Tell Consumers in Demark, Finland and France?

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The Quadruple Squeeze: Defining the safe operating space for freshwater use to achieve a triply green revolution in the Anthropocene

Humanity has entered a new phase of sustainability challenges, the Anthropocene, in which human development has reached a scale where it affects vital planetary processes. Under the pressure from a quadruple squeeze—from population and development pressures, the anthropogenic climate crisis, the anthropogenic ecosystem crisis, and the risk of deleterious tipping points in the Earth system—the degrees of freedom for sustainable human exploitation of planet Earth are severely restrained. It is in this reality that a new green revolution in world food production needs to occur, to attain food security and human development over the coming decades. Global freshwater resources are, and will increasingly be, a fundamental limiting factor in feeding the world. Current water vulnerabilities in the regions in most need of large agricultural productivity improvements are projected to increase under the pressure from global environmental change. The sustainability challenge for world agriculture has to be set within the new global sustainability context. We present new proposed sustainability criteria for world agriculture, where world food production systems are transformed in order to allow humanity to stay within the safe operating space of planetary boundaries. In order to secure global resilience and thereby raise the chances of planet Earth to remain in the current desired state, conducive for human development on the long-term, these planetary boundaries need to be respected. This calls for a triply green revolution, which not only more than doubles food production in many regions of the world, but which also is environmentally sustainable, and invests in the untapped opportunities to use green water in rainfed agriculture as a key source of future productivity enhancement. To achieve such a global transformation of agriculture, there is a need for more innovative options for water interventions at the landscape scale, accounting for both green and blue water, as well as a new focus on cross-scale interactions, feed-backs and risks for unwanted regime shifts in the agro-ecological landscape

Enhancing Nutrient Use Efficiencies in Rainfed Systems

Successful and sustained crop production to feed burgeoning population in rainfed areas, facing soil fertility-related degradation through low and imbalanced amounts of nutrients, requires regular nutrient inputs through biological, organic or inorganic sources of fertilizers. Intensification of fertilizer (all forms) use has given rise to concerns about efficiency of nutrient use, primarily driven by economic and environmental considerations. Inefficient nutrient use is a key factor pushing up the cost of cultivation and pulling down the profitability in farming while putting at stake the sustainability of rainfed farming systems. Nutrient use efficiency implies more produce per unit of nutrient applied; therefore, any soil-water-crop management practices that promote crop productivity at same level of fertilizer use are expected to enhance nutrient use efficiency. Pervasive nutrient depletion and imbalances in rainfed soils are primarily responsible for decreasing yields and declining response to applied macronutrient fertilizers. Studies have indicated soil test-based balanced fertilization an important driver for enhancing yields and improving nutrient use efficiency in terms of uptake, utilization and use efficiency for grain yield and harvest index indicating improved grain nutritional quality. Recycling of on-farm wastes is a big opportunity to cut use and cost of chemical fertilizers while getting higher yield levels at same macronutrient levels. Best management practices like adoption of high-yielding and nutrient-efficient cultivars, landform management for soil structure and health, checking pathways of nutrient losses or reversing nutrient losses through management at watershed scale and other holistic crop management practices have great scope to result in enhancing nutrient and resource use efficiency through higher yields. The best practices have been found to promote soil organic carbon storage that is critical for optimum soil processes and improve soil health and enhance nutrient use efficiency for sustainable intensification in the rainfed systems

Approche comparative des communautés piscicoles des plans d'eau

The objective of this thesis was to investigate fish community patterns in the lakes of France and northeast USA in order to infer the underlying processes. This was achieved using a macroecological approach. Fish communities displayed patterns of addition and replacement of species along environmental gradients related to the lakes' local features and geographic location. The structuring role of biotic interactions was not demonstrated. Human-mediated species introductions clearly perturb the relation of local vs. regional species richnesses. Land use in the lakes' catchments appears to modify guild community structure. The response of community structure along gradients of temperature and lake size displayed convergence between the lakes of France and northeast USA, thereby indicating that that the availability of spawning substrates exerts a strong constraint on local communities. These results allow inferring the potential effect of global warming on lake fish communities. Complementary studies of assembly rules and metacommunity processes should be fruitful for both basic and applied ecology.L'objectif de cette thèse est de préciser les patrons de variabilité des communautés piscicoles entre les plans d'eau en vue de contribuer à la compréhension des mécanismes qui en sont responsables, qu'ils soient naturels ou conséquences des activités de l'Homme. Cette approche macroécologique des peuplements en France et dans le nord-est des Etats-Unis a montré des patrons d'addition et de remplacement d'espèces en fonction des caractéristiques abiotiques locales et de la position géographique des plans d'eau. Le rôle structurant des interactions biotiques est moins évident. Les introductions d'espèces modifient radicalement la relation entre richesses locales et régionales alors que l'occupation agricole et urbaine des bassins versants entraîne des modifications de la structure en guildes des communautés. La convergence observée dans la réponse des communautés aux conditions climatiques et à la taille du plan d'eau montre que la disponibilité des habitats de reproduction exerce une contrainte forte sur les communautés locales et autorise quelques inférences sur les conséquences du changement climatique global. L'étude des règles d'assemblage et une réflexion relative au fonctionnement de métacommunautés à l'échelle des bassins versants offrent des perspectives sur les plans scientifique et appliqués

Approche typologique des peuplements piscicoles lacustres Français. II. Structuration des communautés dans les plans d'eau d'altitude inférieure à 1500m

National audienceFew research has been carried out on French lacustrine fish communities. In a first part, we presented the results obtained by analysing fish communities in natural lakes and reservoirs located over 1500m in altitude (ARGILLIER et al., 2002b). The present article follows a similar analytical approach but deals with lowland sites.Both natural and man-made lakes display a fish gradient ranging from pikeperch, followed by perch, pike and roach, then gudgeon, rainbow trout and brown trout. The distinction between the fish communities of natural lakes and reservoirs relies upon the abundance of several species. Whitefish and arctic charr are lake dwellers whereas the abundances of black bullhead, French nase and barbel are maximum in reservoirs. The fish communities can be related to the location of the sites in their catchment. Some results suggest that the physical features of littoral habitats could contribute to explain the observed communities. Further works should take into consideration complementary descriptors of both fish communities and environmental features.En France, les communautés piscicoles lacustres ont fait l'objet de peu de travaux de recherche. Dans une première partie, nous avons présenté les résultats d'analyses des peuplements et des facteurs structurant ces peuplements dans les plans d'eau d'altitude supérieure à 1 500 m (ARGILLIER et al., 2002b). Les résultats d'une démarche analogue menée sur les réservoirs et les lacs naturels de plaine sont exposés ici. Que le milieu soit naturel ou artificiel, on observe une même succession des espèces caractéristiques des communautés le long d'un gradient amont-aval. Ainsi, au sandre succèdent la perche, le brochet et le gardon, puis le goujon et les truites. La distinction entre les communautés des lacs naturels et des réservoirs se fait sur l'abondance de quelques espèces. Le corégone et l'omble chevalier sont plus abondants dans les lacs naturels que dans les retenues alors que l'inverse est observé pour le poisson-chat, le toxostome ou le barbeau fluviatile. Dans les lacs naturels, la nature des habitats littoraux semble expliquer certaines associations d'espèces. La prise en compte de nouveaux descripteurs des communautés et du milieu est envisagée pour la poursuite des analyses