Empirical Predictability of Community Responses to Climate Change

Robust predictions of ecosystem responses to climate change are challenging. To achieve such predictions, ecology has extensively relied on the assumption that community states and dynamics are at equilibrium with climate. However, empirical evidence from Quaternary and contemporary data suggest that species communities rarely follow equilibrium dynamics with climate change. This discrepancy between the conceptual foundation of many predictive models and observed community dynamics casts doubts on our ability to successfully predict future community states. Here we used community response diagrams (CRDs) to empirically investigate the occurrence of different classes of disequilibrium responses in plant communities during the Late Quaternary, and bird communities during modern climate warming in North America. We documented a large variability in types of responses including alternate states, suggesting that equilibrium dynamics are not the most common type of response to climate change. Bird responses appeared less predictable to modern climate warming than plant responses to Late Quaternary climate warming. Furthermore, we showed that baseline climate gradients were a strong predictor of disequilibrium states, while ecological factors such as species' traits had a substantial, but inconsistent effect on the deviation from equilibrium. We conclude that (1) complex temporal community dynamics including stochastic responses, lags, and alternate states are common; (2) assuming equilibrium dynamics to predict biodiversity responses to future climate changes may lead to unsuccessful predictions

FROM’MIR : Développer des outils de prédiction et de conseil pour maîtriser la fromageabilité des laits destinés à la fabrication des fromages traditionnels franc-comtois

Ce volume regroupe les textes issus du programme Casdar "Innovation et Partenariat" et "Recherche finalisée et innovation" de 2014. Il a été réalisé sous l’égide du GIS Relance Agronomique.Mid-infrared spectroscopy prediction equations of the cheese-making properties of milk, established inthe Franche-Comté PDO/PGI context, exist for the first time in France. Laboratory curd yield in DryMatter was consistent with the yields observed in mini-manufactures of soft and pressed cookedcheeses and it is the best predicted parameter. Under our conditions, some coagulation properties suchas curd firmness could be estimated. The acidification properties, which heavily depend on themicrobiological component of milk, are poorly estimated. The best prediction performances wereobtained on individual cow milks. The performances were poorer on the scale of bulk milks, herd tankmilk but especially dairy vat milk. The study of variation factors made it possible to highlight theimportant weight of genetics with a high level of heritability and strong effects of the genome regionsinvolved. The quality and quantity of fodder and the distribution of calves were influential in the contextstudied. In this same context, few factors of variation have been identified at the scale of dairy vat milks,as the practices were very much governed by the PDO specifications. At the end of this project, anobservatory, from the quality of the milk to the quality of the cheese, will be set up in Franche Comté.Studies will also be carried out at the national level to consolidate and improve the equations in othercontexts.Des équations MIR (spectrométrie moyen infrarouge) d'estimation de la fromageabilité des laits,établies en contexte AOP/IGP franc-comtois, existent pour la première fois en France. Le rendementlaboratoire extrait sec (ES), cohérent avec les rendements observés en mini-fabrications de fromages àpâte molle et à pâte pressée cuite, est le paramètre le mieux prédit. Dans nos conditions, certainsaspects de l'aptitude à la coagulation enzymatique, comme la fermeté des gels, peuvent être estimés.L’aptitude à l’acidification, dépendant fortement de la composante microbiologique des laits, est quant àelle mal estimée. Les meilleures performances de prédiction sont obtenues sur les laits individuels devaches. Les performances sont moins bonnes à l’échelle des laits de mélange, des laits de troupeauxmais surtout des laits de cuves de fromagerie. L'étude des facteurs de variation a permis de mettre enévidence le poids important de la génétique avec un niveau d’héritabilité élevé et des effets forts desrégions du génome impliquées. La qualité et la quantité de fourrages ainsi que la répartition desvêlages sont influents dans le contexte étudié. Dans ce même contexte, peu de facteurs de variationont été mis en évidence à l’échelle des laits de cuves, les pratiques étant très encadrées par le cahierdes charges AOP. A l’issue de ce projet, un observatoire, depuis la qualité des laits jusqu’à celle desfromages, va être mis en place en Franche Comté. Des études seront aussi mises en œuvre au niveaunational pour permettre notamment une consolidation et une amélioration des équations dans d'autrescontextes

Temporal changes in bird functional diversity across the United States

International audienceGlobal changes are modifying the structure of species assemblages, but the generality of resulting diversity patterns and of their drivers is poorly understood. Any such changes can be detected and explained by comparing temporal trends in taxonomic and functional diversity over broad spatial extents. In this study, we addressed three complementary questions: How did bird taxonomic and functional diversity change over the past 40 years in the conterminous United States? Are these trends non-linear? Can temporal variations in functional diversity be explained by broad-scale changes in climate and vegetation productivity? We quantified changes in taxonomic and functional diversity for 807 bird assemblages over the past four decades (1970-2011) considering a suite of 16 ecological traits for 435 species. We found increases in local bird species richness and taxonomic equitability that plateaued in the early 2000's while total abundance declined over the whole period. Functional richness, the total range of traits in an assemblage, increased due to the rising prevalence of species with atypical life-history strategies and under-represented habitat or trophic preferences. However, these species did not trigger major changes in the functional composition of bird assemblages. Inter-annual variations in climate and primary productivity explained the richness of bird life-history traits in local assemblages, suggesting that these traits are influenced by broad-scale environmental factors, while others respond more to more local drivers. Our results highlight that a comparative analysis of the multiple facets of functional diversity can raise novel insights on processes underlying temporal trends in biodiversity

A strategy to assess the sieving time of curd sampled during cheese manufacture to separate curd from whey

International audienceSampling from the vat during cheesemaking may be necessary to study the impact of curd washing, which affects both whey composition and the curd's aqueous phase. The objective of this work was to develop a sieving protocol of curd-whey samples, ensuring enough time for drainage of the free whey, while limiting the loss of the aqueous phase entrapped in the curd grains. We studied the flow rate and lactose content of whey during sieving. Both measurements showed a two-stage dynamic representation of both aqueous phases, the intersection indicating the transition point between the flow of free and entrapped whey

Deciduous trees increase bat diversity at stand and landscape scales in mosaic pine plantations

Context In heterogeneous landscapes, habitat complementation is a key process underlying the distribution of mobile species able to exploit non-substitutable resources over large home ranges. For instance, insectivorous bats need to forage in a diversity of habitat patches offering varied compositions and structures within forest landscape mosaics to fulfill their life cycle requirements. Objectives We aimed at analyzing the effects of forest structure and composition measured at the stand and landscape scales on bat species richness, abundance and community composition in pine plantation forests of south-western France. Methods We sampled bat communities at different periods of the summer season using automatic ultrasound recorders along a tree composition gradient from pine monocultures to pure oak stands. We analyzed bat species activity (as a proxy for bat abundance) and species richness with linear mixed models. Distance-based constrained ordinations were used to partition the spatio-temporal variation in bat communities. Results Deciduous tree cover increased bat activity and modified community composition at both stand and landscape scales. Changes in bat communities were mostly driven by landscape-scale variables while bat activity responded more to stand-scale predictors. Conclusions The maintenance of deciduous trees at both stand and landscape scales is likely critical for bat communities living in fast-growing conifer plantations, by increasing the availability and diversity of prey and roosting sites. Our study suggests that bats respond to forest composition at both stand and landscape scales in mosaic plantation landscapes, mainly through a resource complementation process

Graph edit distance contest: Results and future challenges

International audienceGraph Distance Contest (GDC) was organized in the context of ICPR 2016. Its main challenge was to inspect and report performances and effectiveness of exact and approximate graph edit distance methods by comparison with a ground truth. This paper presents the context of this competition, the metrics and datasets used for evaluation, and the results obtained by the eight submitted methods. Results are analyzed and discussed in terms of computation time and accuracy. We also highlight the future challenges in graph edit distance regarding both future methods and evaluation metrics. The contest was supported by the Technical Committee on Graph-Based Representations in Pattern Recognition (TC-15) of the International Association of Pattern Recognition (IAPR)

Effet des paramètres d'ambiance dans les locaux d'affinage sur la qualité des fromages en conditions expérimentales au laboratoire et en locaux pilotes

Effet des paramètres d'ambiance dans les locaux d'affinage sur la qualité des fromages en conditions expérimentales au laboratoire et en locaux pilote

FROM’MIR : Développer des outils de prédiction et de conseil pour maîtriser la fromageabilité des laits destinés à la fabrication des fromages traditionnels franc-comtois

Des équations MIR (spectrométrie moyen infrarouge) d'estimation de la fromageabilité des laits, établies en contexte AOP/IGP franc-comtois, existent pour la première fois en France. Le rendement laboratoire extrait sec (ES), cohérent avec les rendements observés en mini-fabrications de fromages à pâte molle et à pâte pressée cuite, est le paramètre le mieux prédit. Dans nos conditions, certains aspects de l'aptitude à la coagulation enzymatique, comme la fermeté des gels, peuvent être estimés. L’aptitude à l’acidification, dépendant fortement de la composante microbiologique des laits, est quant à elle mal estimée. Les meilleures performances de prédiction sont obtenues sur les laits individuels de vaches. Les performances sont moins bonnes à l’échelle des laits de mélange, des laits de troupeaux mais surtout des laits de cuves de fromagerie. L'étude des facteurs de variation a permis de mettre en évidence le poids important de la génétique avec un niveau d’héritabilité élevé et des effets forts des régions du génome impliquées. La qualité et la quantité de fourrages ainsi que la répartition des vêlages sont influents dans le contexte étudié. Dans ce même contexte, peu de facteurs de variation ont été mis en évidence à l’échelle des laits de cuves, les pratiques étant très encadrées par le cahier des charges AOP. A l’issue de ce projet, un observatoire, depuis la qualité des laits jusqu’à celle des fromages, va être mis en place en Franche Comté. Des études seront aussi mises en œuvre au niveau national pour permettre notamment une consolidation et une amélioration des équations dans d'autres contextes.Mid-infrared spectroscopy prediction equations of the cheese-making properties of milk, established in the Franche-Comté PDO/PGI context, exist for the first time in France. Laboratory curd yield in Dry Matter was consistent with the yields observed in mini-manufactures of soft and pressed cooked cheeses and it is the best predicted parameter. Under our conditions, some coagulation properties such as curd firmness could be estimated. The acidification properties, which heavily depend on the microbiological component of milk, are poorly estimated. The best prediction performances were obtained on individual cow milks. The performances were poorer on the scale of bulk milks, herd tank milk but especially dairy vat milk. The study of variation factors made it possible to highlight the important weight of genetics with a high level of heritability and strong effects of the genome regions involved. The quality and quantity of fodder and the distribution of calves were influential in the context studied. In this same context, few factors of variation have been identified at the scale of dairy vat milks, as the practices were very much governed by the PDO specifications. At the end of this project, an observatory, from the quality of the milk to the quality of the cheese, will be set up in Franche Comté. Studies will also be carried out at the national level to consolidate and improve the equations in other contexts