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BackgroundThe provision of emergency and hospital care has become an integral part of the global vision for universal health coverage. To strengthen secondary care systems, we need to accurately understand the time necessary for populations to reach a hospital. The goal of this study was to develop methods that accurately estimate referral and prehospital time for rural districts in low and middle-income countries. We used these estimates to assess how local geography can limit the impact of a strengthened referral programme in a rural district of Madagascar.MethodsWe developed a database containing: travel speed by foot and motorised vehicles in Ifanadiana district; a full mapping of all roads, footpaths and households; and remotely sensed data on terrain, land cover and climatic characteristics. We used this information to calibrate estimates of referral and prehospital time based on the shortest route algorithms and statistical models of local travel speed. We predict the impact on referral numbers of strategies aimed at reducing referral time for underserved populations via generalised linear mixed models.ResultsAbout 10% of the population lived less than 2 hours from the hospital, and more than half lived over 4 hours away, with variable access depending on climatic conditions. Only the four health centres located near the paved road had referral times to the hospital within 1 hour. Referral time remained the main barrier limiting the number of referrals despite health system strengthening efforts. The addition of two new referral centres is estimated to triple the population living within 2 hours from a centre with better emergency care capacity and nearly double the number of expected referrals.ConclusionThis study demonstrates how adapting geographic accessibility modelling methods to local scales can occur through improving the precision of travel time estimates and pairing them with data on health facility use.

BackgroundThe provision of emergency and hospital care has become an integral part of the global vision for universal health coverage. It is recommended that at least 80% of a country’s population should be within two hours of a facility with essential surgery and anesthetic services. In order to strengthen health systems to achieve this goal, there needs to be an understanding of the time necessary for populations to reach a hospital. The goal of this study was to develop methods that accurately estimate referral and pre-hospital time for rural health districts in LMICs. We used these estimates to assess how the local geography can limit the impact of a strengthened referral program in a rural district of Madagascar.MethodsWe developed a database containing 1) travel speed in a subset of routes by foot and motorized vehicles in Ifanadiana District; 2) a full mapping of all roads, footpaths and households in the district; and 3) remotely sensed data on terrain, land cover and climatic characteristics. We used this information to calibrate estimates of referral and pre-hospital time based on shortest route algorithms and statistical models of local travel speed. We compared these estimates with those from other commonly used methods in geographic accessibility modeling. Finally, we studied the impact of referral time on the evolution of the number of referrals completed by each health center in the district in 2014-2020 via generalized linear mixed models, using model estimates to predict the impact on referral numbers of strategies aimed at reducing referral time for underserved populations.ResultsAbout 10% of the population lived less than two hours from the hospital, and more than half lived over four hours away, with variable access depending on climatic conditions. Only the four health centers (out of 21) located near the paved road had referral times to the hospital within one hour, which contributed over 75% of all 8,464 hospital referrals. Referral time remained the main barrier limiting the number of referrals despite health system strengthening efforts. The addition of two new referral centers is estimated to triple the population living within two hours from a center with higher acute care capacity and nearly double the number of referrals expected.ConclusionThis study demonstrates how adapting geographic accessibility modeling methods to local scales can occur through improving the precision of travel time estimates and pairing them with data on health facility data. Such information can substantially improve the design of a local health system to overcome existing barriers to care and achieve universal health coverage.

International audience; The continental coastal waters of the Eastern Channel, from Normandy to Hauts-de-France, are subject to the major influence of unbalanced nutrient inputs from inflowing rivers. Several episodes of harmful algal blooms (HABs) compromising fishing and shellfish farming activities have been observed at the coast. For a better understanding of how the land-to-sea aquatic continuum functions, the GRAFS-RIVERSTRAHLER river biogeochemical model was implemented to cover the watersheds of 11 rivers flowing into this area (including the Seine) and chained with the ecological marine ECO-MARS3D model, applied to the French Northern coastal zone. Human activities strongly impact on the functioning of coastal ecosystems. Specifically, for these fertile soils of Northern France, intensive agricultural nitrogen (N) deliveries in excess over silica (Si) and phosphorus (P), essentially of diffuse origin, are potentially responsible for coastal eutrophication. Phosphorous is today equally supplied by diffuse and point sources, after a drastic reduction of inputs from wastewater treatment plants since the 2000s, and is better balanced regarding Si, as shown by the indicators of coastal eutrophication potential (P-ICEP versus N-ICEP). However, despite this drastic P reduction, HABs still appear repeatedly. Exploration of several scenarios of agro-food chain reorganization shows that (i) further progress in urban wastewater treatment to fully comply with current European regulations will not result in a significant reduction of nutrient fluxes to the sea, hence including HABs, and (ii) radical structural changes in agriculture, based on generalization of long and diversified organic crop rotations, reconnection of crop and livestock farming and changes in the human diet have the capacity to significantly reduce nutrient flows, coastal eutrophication and HABs.

International audience; The Grafs-Seneque/Riverstrahler model was implemented for the first time on the Loire River for the 2002–2014 period, to explore eutrophication after improvement of wastewater treatments. The model reproduced the interannual levels and seasonal trends of the major water quality variables. Although eutrophication has been impressively reduced in the drainage network, a eutrophication risk still exists at the coast, as shown by the N-ICEP indicator, pointing out an excess of nitrogen over silica and phosphorus. From maximum biomass exceeding 120 μgChla l−1 in the 1980's, we observed decreasing maximum values from 80 to 30 μgChla l−1 during the period studied.Several scenarios were explored. Regarding nutrient point sources, a low wastewater treatment scenario, similar to the situation in the 1980's, was elaborated, representing much greater pollution than the reference period (2002–2014). For diffuse sources, two agricultural scenarios were elaborated for reducing nitrogen, one with a strict application of the agricultural directives and another investigating the impact of radical structural changes in agriculture and the population's diet. Although reduced, a risk of eutrophication would remain, even with the most drastic scenario. In addition, a pristine scenario, with no human activity within the basin, was devised to assess water quality in a natural state. The impact of a change in hydrology on the Loire biogeochemical functioning was also explored according to the effect of climate change by the end of the 21st century. The EROS hydrological model was used to force Riverstrahler, considering the most pessimistic SRES A2 scenario run with the ARPEGE model. Nutrient fluxes all decreased due to a >50% reduction in the average annual discharge, overall reducing the risk of coastal eutrophication, but worsening the water quality status of the river network.The Riverstrahler model could be useful to help water managers contend with future threats in the Loire River, at the scale of its basin and at smaller nested scales.

International audience; The model ECO-MARS3D, successfully applied thus far to coastal ecosystems, has been extended to encompass the Seine estuary up to Poses, at the limit between the river and the estuary. We used updated bathymetric data and thoroughly calibrated the hydrodynamics and the sedimentary dynamics in the turbidity maximum zone (TMZ). Biogeochemical processes related to oxygen were newly implemented, and freshwater phytoplank-ton and zooplankton groups were added to the existing marine groups. The simulations allowed us to evaluate the filter effect of the estuary with regard to the main nutrients (N, P, and Si). Today, this filter role appears quite limited and variable depending on the hydrology. On average, considering three different hydrological years, the estuary was able to retain (at least temporarily) 19 kt N yr −1 , 10 kt Si yr −1 , and 0.7 kt P yr −1 , amounting to −13%, −11%, and −27% of the total N, Si, and P inputs, respectively. Seasonal differences in the filtering capacity (lower in winter than in summer) were similar between wet and dry years. Nutrient retention was higher in the upstream fluvial estuary than in the TMZ, the former being mostly characterized by uptake, the latter by remineralization. At the coastal zone, the dry year showed greater risk of eutrophication. Despite lower discharge and lower nutrient fluxes, inputs were confined into a shallower layer, close to the coastline, where nutrients were concentrated and allowed phytoplankton to thrive. Differences in the N : P : Si ratios (lower P-deficit during dry years) could also underpin the larger proliferations, and notably the larger dinoflagellate blooms during dry years.

International audience; Denitrification in riparian wetlands plays a major role in eliminating nitrate coming from agricultural watershed uplands before they reach river water. A new approach was developed for representing this process in the biogeochemical Riverstrahler model, using a single adjustable parameter representing the potential denitrification rate of wetland soils. Applied to the case of three watersheds with contrasting size, land-use and hydro-climatic regime, namely the Seine and the Loir rivers (France) and the Red River (Vietnam), this new model is able to capture the general level of nitrate concentrations as well as their seasonal variations everywhere over the drainage network. The nitrogen budgets calculated from the results show that riparian denitrification eliminates between 10 and 50% of the diffuse sources of nitrogen into the hydrosystem coming from soil nitrate leaching.

International audience; The Lot river, a major tributary of the downstream Garonne river, the largest river on the Northern side of the Pyrenees Mountains, was intensively studied in the 1970s. A pioneering program called “Lot Rivière Claire” provided a diagnosis of water quality at the scale of the whole watershed and proposed an ambitious program to manage nutrient pollution and eutrophication largely caused by urban wastewater releases. Later on, the implementation of European directives from 1991 to 2000 resulted in the nearly complete treatment of point sources of pollution in spite of a doubling of the basin’s population. At the outlet of the Lot river, ammonium and phosphate contamination which respectively peaked to 1 mg N-NH4 L−1 and 0.3 mg P-PO4 L−1 in the 1980s returned to much lower levels in recent years (0.06 mg N-NH4 L−1 and 0.02 mg P-PO4 L−1), a reduction by a factor 15. However, during this time, nitrate contamination has regularly increased since the 1980s, from 0.5 to 1.2 mg N-NO3 L−1 in average, owing to the intensification of agriculture and livestock farming. Application of the Riverstrahler model allowed us to simulate the water quality of the Lot drainage network for the 2002–2014 period. We showed that, with respect to algal requirements, phosphorus and silica are well balanced, but nitrogen remains largely in excess over phosphorus and silica. This imbalance can be problematic for the ecological status of the water bodies. Using the model, for simulating various scenarios of watershed management, we showed that improvement of urban wastewater treatment would not result in any significant change in the river’s water quality. Even though arable land occupies a rather limited fraction of the watershed area, only the adoption of better farming practices or more radical changes in the agro-food system could reverse the trend of increasing nitrate contamination.

International audience; Nitrate and pesticide contamination of surface and groundwater has become a major problem in intensive farming regions in Europe, with nitrate concentrations reaching values above the standard defined in 2000 by the European Water Framework Directive. In the Seine basin, a major issue is the closure and abandonment of drinking-water wells, which force water managers and drinking-water producers to explore solutions for water resource protection. Organic farming has appeared as a credible alternative to conventional farming, and this study explores the potential of organic farming to reconcile agricultural production and water quality. On the basis of agricultural statistics, survey questionnaires and experimental data, the nitrogen soil surface balance (N-SSB) has been established at the scale of a small 104-km 2 catchment (The Orgeval sub-basin), representative of the intensive cash crop farming in the Seine basin. The N-surplus for arable land in specialized organic cash crop systems has been found to be half that of current conventional systems (15 kg N ha À1 yr À1 versus 30 kg N ha À1 yr À1 , respectively). The N-yield in organic systems is 21% lower than in conventional systems, but total fertilization (mostly symbiotic N fixation) is also 26% lower. Whereas 2–3 years of forage legume (e.g., alfalfa) as a starter crop of the typical 7-to 10-year diversified rotation builds up N soil fertility and helps prevent weeds without pesticides, the existence of an outlet for this fodder production is a limiting factor for the economic sustainability and the environmental benefits of these farming systems. Therefore, we explored the possibility of a reconnection of livestock and crop farming systems in the Orgeval catchment, a traditional dairy farming and Brie cheese production region. We calculated the N-SSB for this type of a reconnected livestock and cropping system and found a value very close to the specialized organic cash crop system with full utilization of fodder production, leading to profitable animal production, essentially as milk in this farm design. This reconnected system is compared with the estimated situation in 1955 before separation of plant and livestock production. Furthermore, the N-SSB values were converted into infiltrating sub-root concentrations and used as a boundary condition to a biogeochemical model. Organic cropping and organic reconnected livestock cropping systems result in a 50% reduction of surface water nitrate concentrations, a surface water quality 20% better than that reconstructed for 1955, with an overall higher protein production.

Forests in Madagascar are rich in wood species and exhibit a remarkable endemism rate. However, forest loss is a major environment al issue mainly driven by land conversion for agricultural purposes, the growing domestic demand in wood products and the illegal trade of precious wood for international markets. Forest sustainable management requires a better knowledge of forest and wood properties and uses as well as specific tools to deal with. Unfortunately, few studies have been done regarding properties of Madagascar timber species. Only 200 out of the 4000 existing species have been described to date in terms of their mechanical, durability and physical properties. Some wood species like Dalbergia sp. (48 species) cannot be identified from log observations. A quick and reliable method to estimate wood properties and tools to ensure traceability for legal timber control purpose are therefore essential to improve the management of Madagascar's forest resources. This paper introduces the SPIRMADBOIS project that aims to contribute to the sustainable forest management, plantations and natural forests alike, by providing tools based on NIR spectroscopy analysis. Specific objectives to use NIR spectroscopy are: to estimate wood properties of one plantation species ( Eucalyptus robusta ), to determine geographical provenances of Eucalyptus robusta from Madagascar using wood and/or leaves samples, to estimate wood properties of 60 natural forest species, to distinguish between rosewood and palissander (both belong to the Dalbergia genus) using wood samples. This paper will present on-going progress focused on NIR spectroscopy. By participating in the "Application of NIR spectroscopy in wood science and technology" workshop, we grasp opportunities to create an efficient network amongst NIR specialists, to exchange experiences and to discuss our preliminary results.

Introduction. Apres recolte, les fruits du litchi (Litchi chinensis Sonn.) perdent rapidement la couleur rouge lumineuse de leur peau. Le brunissement du litchi recolte a ete en grande partie attribue a la degradation rapide, dans la peau, des colorants rouges d'anthocyanine lies a l'oxydation des composes phenoliques par l'oxydase de polyphenol (PPO) et/ou la peroxydase (POD). Une anthocyanase a ete egalement identifiee dans le pericarpe du litchi. Nos travaux ont cherche a caracteriser deux varietes specifiques de litchi differant considerablement quant a leur couleur et a leur brunissement. Materiel et methodes. Les teneurs en anthocyanes, oxydase (PPO) de polyphenol, peroxydase (POD) et anthocyanase du pericarpe de deux cultivars de litchi, Kwai May et Wai Chee, developpes respectivement a l'ile de la Reunion et en Espagne ont ete etudiees. Resultats et discussion. La composition qualitative des anthocyanines preponderantes (3-rutinoside de cyanidol et 3-glucoside de cyanidol) a ete identique pour les deux cultivars etudies, mais, quantitativement, la variete Kwai May a eu une concentration en 3-rutinoside de cyanidol inferieure a celle Wai Chee (64% en moins). Pour les deux cultivars, ce composant a represente plus de 90% des anthocyanines totales. L'activite de la PPO a ete 6 fois plus grande pour la variete Kwai May que pour Way Chee et l'activite de la POD a ete 30 fois plus grande. L'activite de la POD a ete plus grande que celle de la PPO pour les deux varietes. Ces differences aident a expliquer les differents comportements des cultivars pendant les etudes apres recoltes. (Resume d'auteur)

Short rotations of Eucalyptus plantations under coppice regime are extensively managed for wood production in Madagascar. Nevertheless, little is known about their biomass production and partitioning and their potential in terms of carbon sequestration. If above-ground biomass (AGB) can be estimated based on established allometric relations, below-ground (BGB) estimates are much less common. The aim of this work was to develop allometric equations to estimate biomass of these plantations, mainly for the root components. Data from 9 Eucalyptus robusta stands (47–87 years of plantation age, 3–5 years of coppice-shoot age) were collected and analyzed. Biomass of 3 sampled trees per stand was determined destructively. Dry weight of AGB components (leaves, branches and stems) were estimated as a function of basal area of all shoots per stump and dry weight for BGB components (mainly stump, coarse root (CR) and medium root (MR)) were estimated as a function of stump circumference. Biomass was then computed using allometric equations from stand inventory data. Stand biomass ranged from 102 to 130 Mg ha −1 with more than 77% contained in the BGB components. The highest dry weight was allocated in the stump and in the CR (51% and 42% respectively) for BGB parts and in the stem (69%) for AGB part. Allometric relationships developed herein could be applied to other Eucalyptus plantations which present similar stand density and growing conditions; anyhow, more is needed to be investigated in understanding biomass production and partitioning over time for this kind of forest ecosystem.

Geoderma ISI Document Delivery No.: 771EL Times Cited: 4 Cited Reference Count: 88 Razakamanarivo, Ramarson Herintsitohaina Grinand, Clovis Razafindrakoto, Marie Antoinette Bernoux, Martial Albrecht, Alain Departement de Soutien et de Formation des Communautes du Sud-Institution de Recherche pour le Developpement (DSF-IRD); French Government This study was funded by the "Departement de Soutien et de Formation des Communautes du Sud-Institution de Recherche pour le Developpement (DSF-IRD)" and the French Government within the framework of a PhD. We thank local people in the county of Sambaina for their profitable collaboration during field work and all our colleagues from the "Laboratoire des Radioisotopes (LRI)" and the "Ecole Superieure des Sciences Agronomiques-Departement Eaux&-Forets (ESSAgro-Forets)" at the University of Antananarivo and also the "Unite Mixte de Recherche Eco & Sols" of the Research Institute for the Development (IRD) for their technical supports and reliable scientific advices. Finally, I am gratefull to Saint-Andre Laurent and Jourdan Christoph for their help during upstreaming activities relatives to allometry equations. Elsevier science bv Amsterdam; International audience; Recent concerns about global warming have resulted in more concerted studies on quantification and modeling of carbon (C) storage in different ecosystems. The aim of this study was to assess and map the carbon stocks in above (ABG), below-ground (BLG) biomass and soil organic carbon contained in the 30 centimeter top-layer (SOC) in coppices of eucalyptus plantations in the central highlands of Madagascar in an area of 1590 ha. Relationships between C stock and various biophysical (stool or shoot stockings and ages, circumferences) and spatial (elevation, slope, and soil type) factors that may affect C storage within each pool were investigated. Three different modeling techniques were tested and compared for various factor sets: (i) simple linear regression (SLM), (ii) multiple linear (MLM) models and, (iii) boosted regression tree (BRT) models. Weights of the factors in the respective model were analyzed for the three pool-specific models that produced the highest accuracy measurement. A regional spatial prediction of carbon stocks was performed using spatial layers derived from a digital elevation model, remote sensing imagery and expert knowledge. Results showed that BRT had the best predictive capacity for C stocks compared with the linear regression models. Elevation and slope were found to be the most relevant predictors for modeling C stock in each pool, and mainly for the SOC. A factor representing circumferences of stools and their stocking (stools.ha(-1)) largely influenced BLG. Shoot circumference at breast height and shoot age were the best factors for ABG fitting. Accuracy assessment carried out using coefficient of determination (R-2) and ratio of standard deviation to prediction error (RPD) showed satisfactory results, with 0.74 and 1.95 for AGB, 0.85 and 2.59 for BLG, and 0.61 and 1.6 for SOC respectively. Application of the best fitted models with spatial explanatory factors allowed to map and estimate C contained within each pool : 32 +/- 13 Gg C for ABG, 67 +/- 15 Gg C for BLG and, 139 +/- 36 Gg C for SOC (1 Gg=10(9) g). A total of 238 +/- 40 Gg C was obtained for the entire study area by combining the three C maps. Despite their relatively low predictive quality, models and C maps produced herein provided relevant reference values of C storage under plantation ecosystems in Madagascar. This study contributed to the reducing of uncertainty related to C monitoring and baseline definition in managed terrestrial ecosystem.

Les écosystèmes forestiers jouent un grand rôle face au réchauffement climatique grâce aux réservoirs importants de carbone organique (C) de leurs compartiments (aérien, racinaire, litière et sol). En ce qui concerne l'utilisation des terres, les changements d'affectation des terres et la foresterie, des mesures précises des stocks de C dans ces compartiments sont recommandées. Dans ce sens, la capacité de fixation de C des taillis d'eucalyptus (20 à 111 ans) des Hautes Terres centrales malgaches dans ces compartiments a été étudiée, en comparaison avec d'autres modes d'usage des terres (pseudo-steppe, rotation culture/jachère). Des mesures destructives de biomasses et des prélèvements de sols ont été effectués, suivis par le développement d'équations allométriques et des analyses en laboratoire (détermination de la teneur en carbone, étude isotopique). Tous âges confondus, la pratique de taillis d'eucalyptus présente le plus grand stock de C (150,8 ± 25,3 Mg C/ha face à 112 ± 15 et 72,3 ± 9,9 Mg C/hapour la pseudo-steppe et la rotation culture/jachère respectivement). Pour tous les modes d'usage, c'est le compartiment sol qui constitue le principal réservoir de C avec 56% pour l'eucalyptus et plus de 96 % pour les autres modes. Mais ce sont essentiellement la souche et les racines lignifiées qui rendent ces plantations d'eucalyptus plus efficaces que les autres modes d'usage (44 Mg C/ha pour l'eucalyptus face à 2 Mg C/ha) en termes de stockage de C. D'après l'étude isotopique, le C dérivé de l'eucalyptus dans le sol ne domine toutefois qu'en surface, probablement en raison de la gestion en taillis. Cependant, d'autres facteurs, à part la durée de plantation, comme l'altitude et la morphopédologie sont à considérer pour comprendre la dynamique des stocks de C mesurés. (Résumé d'auteur)