53 research outputs found

    Trichostatin A treatment of cloned mouse embryos improves constitutive heterochromatin remodeling as well as developmental potential to term

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    <p>Abstract</p> <p>Background</p> <p>Genome reprogramming in early mouse embryos is associated with nuclear reorganization and particular features such as the peculiar distribution of centromeric and pericentric heterochromatin during the first developmental stage. This zygote-specific heterochromatin organization could be observed both in maternal and paternal pronuclei after natural fertilization as well as in embryonic stem (ES) cell nuclei after nuclear transfer suggesting that this particular type of nuclear organization was essential for embryonic reprogramming and subsequent development.</p> <p>Results</p> <p>Here, we show that remodeling into a zygotic-like organization also occurs after somatic cell nuclear transfer (SCNT), supporting the hypothesis that reorganization of constitutive heterochromatin occurs regardless of the source and differentiation state of the starting material. However, abnormal nuclear remodeling was frequently observed after SCNT, in association with low developmental efficiency. When transient treatment with the histone deacetylase inhibitor trichostatin A (TSA) was tested, we observed improved nuclear remodeling in 1-cell SCNT embryos that correlated with improved rates of embryonic development at subsequent stages.</p> <p>Conclusion</p> <p>Together, the results suggest that proper organization of constitutive heterochromatin in early embryos is involved in the initial developmental steps and might have long term consequences, especially in cloning procedures.</p

    Importance, but not intensity of plant interactions relates to species diversity under the interplay of stress and disturbance

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    The lack of clarity on how the intensity and importance of plant interactions change under the co-occurrence of stress and disturbance strongly impedes assessing the relative importance of plant interactions for species diversity. We addressed this issue in subalpine grasslands of the French Pyrenees. A natural soil moisture gradient further experimentally stretched at both ends was used and a mowing disturbance treatment was applied at each position along the soil moisture gradient. Changes in intensity and importance of plant interactions were assessed by a neighbour removal experiment using four target ecotypes. A structural equation modelling approach was used to assess the relative impact of stress, disturbance, the intensity and importance of plant interactions on diversity at both the neighbourhood and community scales. Without mowing, changes in intensity and importance of plant interactions only diverged in the dry part of the soil moisture gradient. The intensity of plant interactions linearly shifted from competition to facilitation with increasing stress, while the importance followed a hump-shaped relationship. Species diversity components were tightly related to the importance of plant interactions only, both the neighbourhood and community scales. Mowing disturbance strongly reduced the importance of facilitation along the soil moisture gradient, and suppressed the relationship between the importance of plant interactions and diversity components. Together, our results highlight that 1) the importance is the best predictor of variations in species diversity in this subalpine herbaceous system, and 2) that fine-scale processes such as plant interactions can affect the entire plant communities. Finally, our results suggest that high level of constraints due to co-occurring stress and disturbance can inhibit the effects of plant interactions on species diversity, highlighting their potential role in regulating diversity and the maintenance/extinction of plant communities. The co-occurrence of stress (i.e. factors such as drought limiting plant growth, sensu Grime 1973) and disturbance (drastic events such as mowing removing plant biomass) can lead to a rapid loss of diversity. Co-occurring negative effects of stress and disturbance on diversity and ecosystem functioning are specific to severe environments such as alpine grasslands or dry steppes OIKOS How plant interactions change along environmental gradients is an unsolved debate, particularly when both stress and disturbance interact. This lack of clarity explains why the relative impact of plant interactions (intensity and importance) on species diversity has been rarely assessed. Using an experimental approach, we found that the importance of plant interactions highly contributed to variation in species diversity, confirming that neighbourhood scale processes such as plant interactions can affect the entire plant communities. The co-occurrence of stress and disturbance inhibited the effects of plant interactions, highlighting that plant interactions may regulate drops of diversity and the maintenance/ extinction of plant communities. Synthesi

    Tracking kelp-type seaweed fuel in the archaeological record through Raman spectroscopy of charred particles: examples from the Atacama Desert coast

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    The use of seaweed as fuel has been mentioned in ethnographic and historical sources of different coastal regions. Nevertheless, the archaeological record of seaweed burning is still limited to contexts where preservation is exceptional and macroscopic discrimination of charred remains is possible. Here, we evaluate the effectiveness of Raman spectroscopy in discriminating seaweed vs. plant/wood char. Our dataset (N = 92) consists of modern and archaeological seaweed and plant/wood charred remains, including specimens of unknown origin from the Atacama Desert coast, Northern Chile. The charred samples were processed to obtain 13 parameters which were then fed into five supervised machine learning models. The models, built on samples of known origin (seaweed and plant/wood), performed remarkably well in terms of accuracy, kappa, sensitivity, and specificity. The models were used for final predictions on 10 non-identified archaeological charcoals. Our results suggest that Raman spectroscopy combined with machine learning techniques is a robust methodology for discriminating seaweed and plant/wood charred remains in the archaeological record. The predictions on unknown samples confirm that seaweed was used as fuel in a specific funerary ritual in the southern Atacama Desert coast around 5000 cal BP. Furthermore, charred specimens of Lessonia spp. recovered from combustion features in other northern Chile coastal settlements, suggest that seaweed pyrotechnology developed by Atacama Desert coast people is likely a long-term process. As for coastal archaeology, this work encourages new research on seaweed as an alternative/main fuel in coastal deserts and evaluates possible bias for chronologies from coastal archaeological settlements around the globe.The present study was supported by the Universidad de Tarapacá (Chile) through the research grants UTA MAYOR 3754 (2021–2022) – “Uso de algas como combustible en sitios arqueológicos de la costa desértica de Atacama: una aproximación arqueomética” and UTA MAYOR 367122 (2022–2024) – “Estudio multiproxy para el reconocimiento de algas en rasgos de combustión arqueológicos de la costa del Desierto de Atacama” (Universidad de Tarapacá, Chile). D.Z. received financial support from the Arqueología, desiertos costeros y visibilización de recursos naturales Project (PIE 190405, CSIC) and ARVCODA – Arqueología de los Recursos Vegetales en la Costa del Desierto de Atacama project (Fundación PALARQ, CSIC). The studied samples were obtained during archaeological excavations or samplings performed in the following projects: FONDECYT 1151203; FONDECYT POSTDOC 3150664; and Quebrada Blanca Phase 2 (QB2) project – Compañía Minera Teck Quebrada Blanca S.A

    Measuring performance on the Healthcare Access and Quality Index for 195 countries and territories and selected subnational locations: A systematic analysis from the Global Burden of Disease Study 2016

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    Background: A key component of achieving universal health coverage is ensuring that all populations have access to quality health care. Examining where gains have occurred or progress has faltered across and within countries is crucial to guiding decisions and strategies for future improvement. We used the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) to assess personal health-care access and quality with the Healthcare Access and Quality (HAQ) Index for 195 countries and territories, as well as subnational locations in seven countries, from 1990 to 2016. Methods Drawing from established methods and updated estimates from GBD 2016, we used 32 causes from which death should not occur in the presence of effective care to approximate personal health-care access and quality by location and over time. To better isolate potential effects of personal health-care access and quality from underlying risk factor patterns, we risk-standardised cause-specific deaths due to non-cancers by location-year, replacing the local joint exposure of environmental and behavioural risks with the global level of exposure. Supported by the expansion of cancer registry data in GBD 2016, we used mortality-to-incidence ratios for cancers instead of risk-standardised death rates to provide a stronger signal of the effects of personal health care and access on cancer survival. We transformed each cause to a scale of 0-100, with 0 as the first percentile (worst) observed between 1990 and 2016, and 100 as the 99th percentile (best); we set these thresholds at the country level, and then applied them to subnational locations. We applied a principal components analysis to construct the HAQ Index using all scaled cause values, providing an overall score of 0-100 of personal health-care access and quality by location over time. We then compared HAQ Index levels and trends by quintiles on the Socio-demographic Index (SDI), a summary measure of overall development. As derived from the broader GBD study and other data sources, we examined relationships between national HAQ Index scores and potential correlates of performance, such as total health spending per capita. Findings In 2016, HAQ Index performance spanned from a high of 97\ub71 (95% UI 95\ub78-98\ub71) in Iceland, followed by 96\ub76 (94\ub79-97\ub79) in Norway and 96\ub71 (94\ub75-97\ub73) in the Netherlands, to values as low as 18\ub76 (13\ub71-24\ub74) in the Central African Republic, 19\ub70 (14\ub73-23\ub77) in Somalia, and 23\ub74 (20\ub72-26\ub78) in Guinea-Bissau. The pace of progress achieved between 1990 and 2016 varied, with markedly faster improvements occurring between 2000 and 2016 for many countries in sub-Saharan Africa and southeast Asia, whereas several countries in Latin America and elsewhere saw progress stagnate after experiencing considerable advances in the HAQ Index between 1990 and 2000. Striking subnational disparities emerged in personal health-care access and quality, with China and India having particularly large gaps between locations with the highest and lowest scores in 2016. In China, performance ranged from 91\ub75 (89\ub71-93\ub76) in Beijing to 48\ub70 (43\ub74-53\ub72) in Tibet (a 43\ub75-point difference), while India saw a 30\ub78-point disparity, from 64\ub78 (59\ub76-68\ub78) in Goa to 34\ub70 (30\ub73-38\ub71) in Assam. Japan recorded the smallest range in subnational HAQ performance in 2016 (a 4\ub78-point difference), whereas differences between subnational locations with the highest and lowest HAQ Index values were more than two times as high for the USA and three times as high for England. State-level gaps in the HAQ Index in Mexico somewhat narrowed from 1990 to 2016 (from a 20\ub79-point to 17\ub70-point difference), whereas in Brazil, disparities slightly increased across states during this time (a 17\ub72-point to 20\ub74-point difference). Performance on the HAQ Index showed strong linkages to overall development, with high and high-middle SDI countries generally having higher scores and faster gains for non-communicable diseases. Nonetheless, countries across the development spectrum saw substantial gains in some key health service areas from 2000 to 2016, most notably vaccine-preventable diseases. Overall, national performance on the HAQ Index was positively associated with higher levels of total health spending per capita, as well as health systems inputs, but these relationships were quite heterogeneous, particularly among low-to-middle SDI countries. Interpretation GBD 2016 provides a more detailed understanding of past success and current challenges in improving personal health-care access and quality worldwide. Despite substantial gains since 2000, many low-SDI and middle- SDI countries face considerable challenges unless heightened policy action and investments focus on advancing access to and quality of health care across key health services, especially non-communicable diseases. Stagnating or minimal improvements experienced by several low-middle to high-middle SDI countries could reflect the complexities of re-orienting both primary and secondary health-care services beyond the more limited foci of the Millennium Development Goals. Alongside initiatives to strengthen public health programmes, the pursuit of universal health coverage hinges upon improving both access and quality worldwide, and thus requires adopting a more comprehensive view-and subsequent provision-of quality health care for all populations

    Measuring performance on the Healthcare Access and Quality Index for 195 countries and territories and selected subnational locations: A systematic analysis from the Global Burden of Disease Study 2016

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    Copyright © 2018 The Author(s). Published by Elsevier Ltd. Background A key component of achieving universal health coverage is ensuring that all populations have access to quality health care. Examining where gains have occurred or progress has faltered across and within countries is crucial to guiding decisions and strategies for future improvement. We used the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) to assess personal health-care access and quality with the Healthcare Access and Quality (HAQ) Index for 195 countries and territories, as well as subnational locations in seven countries, from 1990 to 2016. Methods Drawing from established methods and updated estimates from GBD 2016, we used 32 causes from which death should not occur in the presence of effective care to approximate personal health-care access and quality by location and over time. To better isolate potential effects of personal health-care access and quality from underlying risk factor patterns, we risk-standardised cause-specific deaths due to non-cancers by location-year, replacing the local joint exposure of environmental and behavioural risks with the global level of exposure. Supported by the expansion of cancer registry data in GBD 2016, we used mortality-to-incidence ratios for cancers instead of risk-standardised death rates to provide a stronger signal of the effects of personal health care and access on cancer survival. We transformed each cause to a scale of 0-100, with 0 as the first percentile (worst) observed between 1990 and 2016, and 100 as the 99th percentile (best); we set these thresholds at the country level, and then applied them to subnational locations. We applied a principal components analysis to construct the HAQ Index using all scaled cause values, providing an overall score of 0-100 of personal health-care access and quality by location over time. We then compared HAQ Index levels and trends by quintiles on the Socio-demographic Index (SDI), a summary measure of overall development. As derived from the broader GBD study and other data sources, we examined relationships between national HAQ Index scores and potential correlates of performance, such as total health spending per capita. Findings In 2016, HAQ Index performance spanned from a high of 97·1 (95% UI 95·8-98·1) in Iceland, followed by 96·6 (94·9-97·9) in Norway and 96·1 (94·5-97·3) in the Netherlands, to values as low as 18·6 (13·1-24·4) in the Central African Republic, 19·0 (14·3-23·7) in Somalia, and 23·4 (20·2-26·8) in Guinea-Bissau. The pace of progress achieved between 1990 and 2016 varied, with markedly faster improvements occurring between 2000 and 2016 for many countries in sub-Saharan Africa and southeast Asia, whereas several countries in Latin America and elsewhere saw progress stagnate after experiencing considerable advances in the HAQ Index between 1990 and 2000. Striking subnational disparities emerged in personal health-care access and quality, with China and India having particularly large gaps between locations with the highest and lowest scores in 2016. In China, performance ranged from 91·5 (89·1-93·6) in Beijing to 48·0 (43·4-53·2) in Tibet (a 43·5-point difference), while India saw a 30·8-point disparity, from 64·8 (59·6-68·8) in Goa to 34·0 (30·3-38·1) in Assam. Japan recorded the smallest range in subnational HAQ performance in 2016 (a 4·8-point difference), whereas differences between subnational locations with the highest and lowest HAQ Index values were more than two times as high for the USA and three times as high for England. State-level gaps in the HAQ Index in Mexico somewhat narrowed from 1990 to 2016 (from a 20·9-point to 17·0-point difference), whereas in Brazil, disparities slightly increased across states during this time (a 17·2-point to 20·4-point difference). Performance on the HAQ Index showed strong linkages to overall development, with high and high-middle SDI countries generally having higher scores and faster gains for non-communicable diseases. Nonetheless, countries across the development spectrum saw substantial gains in some key health service areas from 2000 to 2016, most notably vaccine-preventable diseases. Overall, national performance on the HAQ Index was positively associated with higher levels of total health spending per capita, as well as health systems inputs, but these relationships were quite heterogeneous, particularly among low-to-middle SDI countries. Interpretation GBD 2016 provides a more detailed understanding of past success and current challenges in improving personal health-care access and quality worldwide. Despite substantial gains since 2000, many low-SDI and middle- SDI countries face considerable challenges unless heightened policy action and investments focus on advancing access to and quality of health care across key health services, especially non-communicable diseases. Stagnating or minimal improvements experienced by several low-middle to high-middle SDI countries could reflect the complexities of re-orienting both primary and secondary health-care services beyond the more limited foci of the Millennium Development Goals. Alongside initiatives to strengthen public health programmes, the pursuit of universal health coverage hinges upon improving both access and quality worldwide, and thus requires adopting a more comprehensive view - and subsequent provision - of quality health care for all populations

    Measuring performance on the Healthcare Access and Quality Index for 195 countries and territories and selected subnational locations: a systematic analysis from the Global Burden of Disease Study 2016.

    Get PDF
    BACKGROUND: A key component of achieving universal health coverage is ensuring that all populations have access to quality health care. Examining where gains have occurred or progress has faltered across and within countries is crucial to guiding decisions and strategies for future improvement. We used the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) to assess personal health-care access and quality with the Healthcare Access and Quality (HAQ) Index for 195 countries and territories, as well as subnational locations in seven countries, from 1990 to 2016. METHODS: Drawing from established methods and updated estimates from GBD 2016, we used 32 causes from which death should not occur in the presence of effective care to approximate personal health-care access and quality by location and over time. To better isolate potential effects of personal health-care access and quality from underlying risk factor patterns, we risk-standardised cause-specific deaths due to non-cancers by location-year, replacing the local joint exposure of environmental and behavioural risks with the global level of exposure. Supported by the expansion of cancer registry data in GBD 2016, we used mortality-to-incidence ratios for cancers instead of risk-standardised death rates to provide a stronger signal of the effects of personal health care and access on cancer survival. We transformed each cause to a scale of 0-100, with 0 as the first percentile (worst) observed between 1990 and 2016, and 100 as the 99th percentile (best); we set these thresholds at the country level, and then applied them to subnational locations. We applied a principal components analysis to construct the HAQ Index using all scaled cause values, providing an overall score of 0-100 of personal health-care access and quality by location over time. We then compared HAQ Index levels and trends by quintiles on the Socio-demographic Index (SDI), a summary measure of overall development. As derived from the broader GBD study and other data sources, we examined relationships between national HAQ Index scores and potential correlates of performance, such as total health spending per capita

    The interplay of a climate change-induced drought and management in South European calcareous grasslands

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    Cette thèse avait pour objectif de tester l’effet croisé de la gestion et de sécheresses extrêmes liées au changement climatique sur les interactions biotiques entre plantes, la biodiversité, la composition floristique et le fonctionnement écosystémique de pelouses caractéristiques du sud de l’Europe, en bordure occidentale calcaire du Massif Central français. Des sècheresses printanières et une fauche régulière ont été appliquées expérimentalement suivant un plan factoriel sur deux types de communautés situées, en Dordogne, dans des conditions de sols contrastées: les Mesobromion (pente nulle) et les Xerobromion (pente forte convexe et exposition sud). Les résultats ont validé des modèles théoriques prédisant un effondrement des interactions biotiques à l’extrémité sévère d’un gradient de stress, surtout si le système est soumis à de la perturbation. La réponse des pelouses était très dépendante de la communauté considérée. La sècheresse a diminué la biodiversité et altéré la composition floristique des Xerobromion. Ceci s’explique par la combinaison au sein de cette communauté d’un grand nombre de contraintes (sècheresse expérimentale, stress hydrique dû à l’exposition sud et forte perturbation physique induisant notamment un effondrement de la facilitation et un stress édaphique important). Les Mesobromion étaient plutôt affectés par la fauche qui a augmenté leur biodiversité via une diminution du couvert de graminoides compétitrices. En Europe du sud, et dans un contexte de changement climatique, nous recommandons de maintenir des pratiques de gestion basées sur la perturbation dans les Mesobromion et de se focaliser plutôt sur la conservation d’espèces peu tolérantes à la sècheresse dans les Xerobromion.This PhD aimed at testing the crossed effects of management and extreme droughts linked to climate change on plant biotic interactions, biodiversity, composition and ecosystem functions of extensive grasslands from Southern Europe, at the Western calcareous boundary of the French Central Massif. Extreme spring droughts and a mowing-based management were experimentally applied in a factorial design in the Dordogne department on two communities with contrasted soil conditions: the Mesobromion (null slope) and the Xerobromion (steep convex slope and southern exposure). Our results support theoretical models predicting a collapse of biotic interactions at the severe end of a stress gradient, especially if the system is subject to disturbance. Grassland responses were strongly dependent on local environmental conditions. Drought decreased biodiversity and altered composition in the Xerobromion community. This is explained by the combination of several constraints (experimental drought, water stress due to southern exposition and physical disturbance which induces a collapse of facilitation and an important edaphic stress) in this community. The Mesobromion community was rather affected by mowing, which increased biodiversity through a reduction of competitive graminoids cover. In Southern Europe, and in a climate change context, we recommend maintaining disturbance-based management in the Mesobromion communities and focusing on the conservation of species with a poor tolerance to drought in the Xerobromion communities

    The interplay of a climate change-induced drought and management in South European calcareous grasslands

    No full text
    Cette thèse avait pour objectif de tester l’effet croisé de la gestion et de sécheresses extrêmes liées au changement climatique sur les interactions biotiques entre plantes, la biodiversité, la composition floristique et le fonctionnement écosystémique de pelouses caractéristiques du sud de l’Europe, en bordure occidentale calcaire du Massif Central français. Des sècheresses printanières et une fauche régulière ont été appliquées expérimentalement suivant un plan factoriel sur deux types de communautés situées, en Dordogne, dans des conditions de sols contrastées: les Mesobromion (pente nulle) et les Xerobromion (pente forte convexe et exposition sud). Les résultats ont validé des modèles théoriques prédisant un effondrement des interactions biotiques à l’extrémité sévère d’un gradient de stress, surtout si le système est soumis à de la perturbation. La réponse des pelouses était très dépendante de la communauté considérée. La sècheresse a diminué la biodiversité et altéré la composition floristique des Xerobromion. Ceci s’explique par la combinaison au sein de cette communauté d’un grand nombre de contraintes (sècheresse expérimentale, stress hydrique dû à l’exposition sud et forte perturbation physique induisant notamment un effondrement de la facilitation et un stress édaphique important). Les Mesobromion étaient plutôt affectés par la fauche qui a augmenté leur biodiversité via une diminution du couvert de graminoides compétitrices. En Europe du sud, et dans un contexte de changement climatique, nous recommandons de maintenir des pratiques de gestion basées sur la perturbation dans les Mesobromion et de se focaliser plutôt sur la conservation d’espèces peu tolérantes à la sècheresse dans les Xerobromion.This PhD aimed at testing the crossed effects of management and extreme droughts linked to climate change on plant biotic interactions, biodiversity, composition and ecosystem functions of extensive grasslands from Southern Europe, at the Western calcareous boundary of the French Central Massif. Extreme spring droughts and a mowing-based management were experimentally applied in a factorial design in the Dordogne department on two communities with contrasted soil conditions: the Mesobromion (null slope) and the Xerobromion (steep convex slope and southern exposure). Our results support theoretical models predicting a collapse of biotic interactions at the severe end of a stress gradient, especially if the system is subject to disturbance. Grassland responses were strongly dependent on local environmental conditions. Drought decreased biodiversity and altered composition in the Xerobromion community. This is explained by the combination of several constraints (experimental drought, water stress due to southern exposition and physical disturbance which induces a collapse of facilitation and an important edaphic stress) in this community. The Mesobromion community was rather affected by mowing, which increased biodiversity through a reduction of competitive graminoids cover. In Southern Europe, and in a climate change context, we recommend maintaining disturbance-based management in the Mesobromion communities and focusing on the conservation of species with a poor tolerance to drought in the Xerobromion communities

    The interplay of a climate change-induced drought and management in South European calcareous grasslands

    No full text
    Cette thèse avait pour objectif de tester l’effet croisé de la gestion et de sécheresses extrêmes liées au changement climatique sur les interactions biotiques entre plantes, la biodiversité, la composition floristique et le fonctionnement écosystémique de pelouses caractéristiques du sud de l’Europe, en bordure occidentale calcaire du Massif Central français. Des sècheresses printanières et une fauche régulière ont été appliquées expérimentalement suivant un plan factoriel sur deux types de communautés situées, en Dordogne, dans des conditions de sols contrastées: les Mesobromion (pente nulle) et les Xerobromion (pente forte convexe et exposition sud). Les résultats ont validé des modèles théoriques prédisant un effondrement des interactions biotiques à l’extrémité sévère d’un gradient de stress, surtout si le système est soumis à de la perturbation. La réponse des pelouses était très dépendante de la communauté considérée. La sècheresse a diminué la biodiversité et altéré la composition floristique des Xerobromion. Ceci s’explique par la combinaison au sein de cette communauté d’un grand nombre de contraintes (sècheresse expérimentale, stress hydrique dû à l’exposition sud et forte perturbation physique induisant notamment un effondrement de la facilitation et un stress édaphique important). Les Mesobromion étaient plutôt affectés par la fauche qui a augmenté leur biodiversité via une diminution du couvert de graminoides compétitrices. En Europe du sud, et dans un contexte de changement climatique, nous recommandons de maintenir des pratiques de gestion basées sur la perturbation dans les Mesobromion et de se focaliser plutôt sur la conservation d’espèces peu tolérantes à la sècheresse dans les Xerobromion.This PhD aimed at testing the crossed effects of management and extreme droughts linked to climate change on plant biotic interactions, biodiversity, composition and ecosystem functions of extensive grasslands from Southern Europe, at the Western calcareous boundary of the French Central Massif. Extreme spring droughts and a mowing-based management were experimentally applied in a factorial design in the Dordogne department on two communities with contrasted soil conditions: the Mesobromion (null slope) and the Xerobromion (steep convex slope and southern exposure). Our results support theoretical models predicting a collapse of biotic interactions at the severe end of a stress gradient, especially if the system is subject to disturbance. Grassland responses were strongly dependent on local environmental conditions. Drought decreased biodiversity and altered composition in the Xerobromion community. This is explained by the combination of several constraints (experimental drought, water stress due to southern exposition and physical disturbance which induces a collapse of facilitation and an important edaphic stress) in this community. The Mesobromion community was rather affected by mowing, which increased biodiversity through a reduction of competitive graminoids cover. In Southern Europe, and in a climate change context, we recommend maintaining disturbance-based management in the Mesobromion communities and focusing on the conservation of species with a poor tolerance to drought in the Xerobromion communities
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