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In Niger, literature from the years 1990–2020 shows a rapid regression in the surface areas of forest, an abundant regeneration of trees in some cultivated areas, and a sharp increase in the consumption of wood energy in cities and the countryside, with this wood increasingly coming from parklands. This study, carried out in 2015–2019 on the outskirts of Niamey, aimed to assess the economic benefits for households of parkland fuelwood production and the ecological state of the parklands. Surveys were carried out among 90 farmers to assess the contribution of fuelwood to their household income. Semi-structured interviews with focus groups were conducted in 3 villages to determine farmers' strategies and practices. The inventory of the trees in the parklands was carried out in 3 villages (5000 ha per village). Most rural households have an income diversification strategy to cope with the vagaries of agricultural production. Among these revenues, the sale of fuelwood occupies on average a small place (4 to 10%). To explain their reduced use of assisted natural regeneration (ANR) for the restoration of parklands, farmers point to the difficulty in exploiting wood pruned from their trees due to conflicts of use with livestock herders, taxes and fines from environmental services agencies. Trees and shrubs in parklands have a low diversity (24 species) and low density (5–8 trees/ha). The low density of young trees indicates that during the past decade, there have been fewer efforts to enrich parklands compared to the 1980s, when ANR projects were first implemented. The 3 parklands studied are in the process of becoming severely degraded because dead old trees are no longer replaced through ANR. The Economic importance of fuelwod in family resources is not a sufficient trigger factor for farmers to restore their parklands but could support village's interest for sustainable management of natural forests. These results should serve to alert public authorities and aid organizations that research and development actions must be launched to reverse this deterioration trend in parklands.

In West Africa, household energy transition has so far mainly been synonymous with the conversion from woodfuel to LPG. This paper analyses the failure of 30 years of household energy transition policies in Mali by combining two major frameworks: Multi-Level Perspective (MLP) and Social Practice Theory (SPT). Based on empirical field studies undertaken in Bamako since 1985 and on literature review, two historical narratives are presented, one focusing on the dynamics of the dominant woodfuel regime and the other on changes in cooking practices. The MLP analysis showed that all elements seemed aligned for destabilization of the dominant regime, yet the woodfuel regime has resisted and is maintained. The SPT analysis showed that the stability of cooking, eating and fuel purchasing practices did not converge towards and even opposed the transition to LPG. This paper shows that the MLP and SPT frameworks offer complementary perspectives for understanding transitions in developing countries. It concludes that the definition and implementation of energy policies need to integrate an analysis of daily practices and should consider that energy transition is not synonymous with the replacement of one fuel by another, but with new opportunities to diversify ways of cooking.

This study aims to investigate the contribution of nigral dopaminergic (DA) cell loss, repeated exposure to DA medication and the combination of both to the development of neuropsychiatric symptoms observed in Parkinson’s disease (PD). A bilateral 6-OHDA lesion of the substantia nigra pars compacta (SNc) was performed in rats. A set of animals was repeatedly administered with L -dopa (20 mg/kg/day) and benserazide (5 mg/kg/day) over 10 days starting from day 11 post-lesion. Behavioural testing was performed in week 3 post-lesion: novel object recognition (NOR), elevated plus maze (EPM) social interaction (SI) tests, and amphetamine-induced hyperlocomotion (AIH). Immunohistochemical analysis revealed a significant partial lesion (48%) in 6-OHDA versus sham rats. This lesion was not associated with motor impairment. However, lesioned rats displayed a significant deficit in the NOR, which was reversed by acute treatment with l -dopa/benserazide (12.5 mg/kg and 15 mg/kg respectively). Lesioned rats also displayed a deficit in the EPM which was not reversed by acute treatment with l -dopa. No difference was observed in the SI test or in the AIH assay. In all assays, no effect of chronic l -dopa exposure was observed. This study provides new insights into the neuropathophysiology associated with neuropsychiatric symptoms of PD. Our data strongly emphasises a not previously clearly identified critical role in cognition for the SNc. The results suggest that DA pathways were less directly involved in lesion-induced anxiety-like behaviour. We did not report any effect of chronic l -dopa exposure in the context of partial nigral cell loss.

Background: Nausea and vomiting are common side effects of cancer therapies thereby seriously affecting the quality of life of patients. Therefore, the prevention or treatment of chemotherapy-induced nausea and vomiting has become an important part of the comprehensive treatment of cancer. Several 5-HT3 receptor antagonists have been developed in the treatment of nausea and vomiting using mainly the oral route of administration (which is not convenient due to vomiting) or the intravenous route. In this study we tested whether ocular administration of the 5-HT3 receptor antagonist palonosetron (eye drops) could prevent nausea and vomiting associated with intravenous cisplatin injection in dogs. Methods: Six adult male Beagle dogs (10-13 kg) were included in a randomized crossover study. This study was carried out in AAALAC facilities in strict accordance with the European and French animal welfare regulations for animal use in experimentation. Dogs were administered 18 mg/m2 cisplatin intravenously over a 20-min period, followed 45 min later by ocular administration (eye drops, 200µL/eye) of either placebo (2% povidone in saline) or palonosetron (30 or 120 µg/kg). The number of vomits and nausea associated behaviours, scored on a visual analogue scale (VAS), were recorded every 15 min for 7 h following cisplatin administration. Blood samples were collected to measure plasma levels of palonosetron. Results: The placebo treated group vomited an average number of 10.2±2.1 times (range 5-17) over the 7-h period following cisplatin infusion. Ocular administration of palonosetron at 30 μg/kg in cisplatin-treated dogs very strongly and significantly decreased vomiting episodes, with only 1 vomiting episode in 2 dogs overall (p Conclusions: This study demonstrates for the first time that palonosetron administered via ocular route produces a rapid clear-cut anti-emetic and anti-nausea effect in conscious dogs exposed to cisplatin. This finding points out the tremendous interest of this novel and convenient route of administration which could help improving the quality of life of patients. Citation Format: Sandra Nourry, Minja Hyttila-Hopponen, Pierre Montagne, Lasse Saloranta, Sari Pappinen, Jouko Levijoki, Christophe Drieu La Rochelle. Ocular drops of palonosetron reduce chemotherapy-induced acute nausea and vomiting in the dog [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 593.

Whichever the type of combustion installation, liquid fuels burned in gas turbines tend to generate particulate matter (PM) emissions, which consist in soot only or in ash plus soot, according to their ash-free or ash-forming character. Standard diffusion flame combustion systems are known as “universal” combustors, capable to burn both ash-free (naphtha, light and heavy distillates) and ash-forming (crude and heavy) fuels. In contrast, DLN systems are designed to burn gaseous fuels and light distillates. PMs in the range of a few parts per million represent a solid micropollutant, the measurement and abatement of which creates specific technical challenges. In order to fully characterize soot emission and investigate their reduction, GE has undertaken a multi-year investigation program covering (i) an exploratory engineering study starting from the EN13284-1 standard and (ii) the testing of a number of inorganic oxidation catalysts used in the form of fuel additives (“soot inhibitors”). In this framework, a joint work involving GE and Electricity Authority of Cyprus has been conducted in the first half of 2017 and a full-scale test plan has been performed at the Vasilikos power plant in Cyprus, involving a Frame 6F.03 DLN2.6 that burns light distillate oil and is equipped with a DeNOx water injection system. Four types of soot inhibitor additives: cerium (IV) and (III), iron (III) and (II) were tested. This paper reviews the results of this field test and compares them with data previously acquired at other power plants featuring different liquid fuels and combustion systems. Its goal is to provide the gas turbine community with a better understanding of PM emissions and their abatement using various soot inhibitor candidates, in function of liquid fuel type and combustion system.

International audience; The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated nonhuman primate (NHP) has been described as the most translatable model for experimental reproduction of L-dopa-induced dyskinesia (LID). However, from a drug discovery perspective, the risk associated with investment in this type of model is high due to the time and cost. The 6-hydroxydopamine (6-OHDA) rat dyskinesia model is recommended for testing compounds but relies on onerous, and nonstandard behavioral rating scales. We sought to develop a simplified and sensitive method aiming at assessing LID in the rat. The purpose was to validate a reliable tool providing earlier insight into the antidyskinetic potential of compounds in a time/cost-effective manner before further investigation in NHP models. Unilaterally 6-OHDA-lesioned rats were administered L-dopa (20 mg/kg) and benserazide (5 mg/kg) daily for 3 weeks starting 4 weeks postlesion, then coadministered with amantadine (20–30–40 mg/kg). An adapted rating scale was used to score LID frequency and a severity coefficient was applied depending on the features of the observed behavior. A gradual increase (about 3-fold) in LID score was observed over the 3 weeks of L-dopa treatment. The rating scale was sensitive enough to highlight a dose-dependent amantadine-mediated decrease (about 2.2-fold) in LID score. We validated a simplified method, able to reflect different levels of severity in the assessment of LID and, thus, provide a reliable tool for drug discovery.

Gas turbines burn a large variety of gaseous fuels under elevated pressure and temperature conditions. During transient operations like maintenance, start-ups or fuel transfers, variable gas/air mixtures flow through the gas piping system and can cause damages in case of ignition. In order to properly control this risk of explosion and ensure safe operation, it is of the essence to have a good knowledge of the flammability limits of the gas mixtures involved, and to be in position to define safe inerting conditions every time it is required. While well-established methods are available in the engineering science to calculate flammability limits of fuel/air mixtures, no systematic methodology exists — to the authors’ knowledge — for the prediction of the Lower and Upper Flammability Limits (UFL-LFL) of gaseous blends containing variable amounts of inert components and over a large temperature and pressure range. The purpose of this study was then the evaluation of the LFL and UFL of multi-component fuels in air, in function of pressure, temperature and the concentrations of the most frequently used inerting gases, namely: nitrogen, carbon dioxide and steam. Different prediction criteria proposed in the literature were tested and eventually an original methodology based on the adiabatic flame temperature (Tad) was adopted as criterion and extended to gas mixtures and to high temperatures and pressures. Flame temperatures of different blends were calculated for different initial conditions assuming the access to the chemical equilibrium. Minimum temperature criteria corresponding to the Tad values reached at the LFL and UFL equivalence ratios were deduced from experimental data for each individual combustible molecule. It has been then possible to evaluate the minimum Tad values which ensure flame propagation of fuel blends on the lean and rich sides and to deduce the flammability limits. These calculations were repeated while adding various contents of the three selected inert gases. The methodology was validated by comparison against experimental data when available. The method proves to be simple, accurate, easy to use and applicable to large ranges of pressure, temperature and fuel compositions and to various diluents. The results confirm and quantify some well-known trends of flammability limits, e.g. their widening with increasing initial temperature and pressure, with a stronger effect on UFL than on LFL. The impact of the nature of the inerting gas was also successfully simulated for variable initial conditions and fuel compositions.

Le transfert contractuel de la gestion locale des ressources renouvelables et la decentralisation se situent dans des registres distincts. Ils s'influencent reciproquement et conditionnent les rapports entre communes et communautes locales. Trois elements cles influencent la gouvernance locale des ressources dans un contexte de decentralisation : la domanialite, la fiscalite (fiscalite forestiere et/ou fiscalite communale) et le controle (controle forestier et controle communal) sur les ressources renouvelables.

International audience; Except in diesel engine applications, auto-ignition is an unwanted event from a general safety and reliability standpoint. It is especially undesirable in the premixing process involved in most low NOx combustion technologies. Therefore, in addition to auto-ignition temperature, auto-ignition delay (AID) is a key data for the design of modern combustors including gas turbine ones. The authors have investigated the detailed kinetic mechanisms leading to auto-ignition and established practical AID correlations involving the fuel composition, its temperature, pressure and equivalence ratio. The correlations brought about during this program offer a good reconciliation between calculated and experimental AID through a wide range of fuel composition, initial temperature and pressure. Validations were mainly done against data acquired with experimental setups consisting in shock tubes and rapid compression machines. The auto-ignition delay times of methane, pure light alkanes and various blends representative of several natural gas and process-derived fuels have been reviewed. For each fuel mixture, this study procures a simple equation linking the auto-ignition delay time to the temperature, pressure and equivalence ratio. As a direct application of this work, the authors have evaluated the risk of auto ignition in the premixing zone of a combustor characterized by a residence time and an associated probability density function. The results of this simulation stress the key role of larger hydrocarbon in the risk of flashback events.

Des le debut du xxe siecle, la legislation forestiere coloniale a Madagascar a, par la mise en place d’une politique repressive, voulu contraindre les populations a respecter une nature exceptionnelle. Cette politique n’a pas empeche sa degradation. En 1990, une nouvelle politique forestiere a ete initiee pour redonner aux populations locales un role majeur dans sa protection. Nous presentons l’evolution historique qui a conduit Madagascar dans une situation ou la mise en œuvre de cette nouvelle politique reste inachevee mais demeure a nos yeux la seule possible a ce jour.

Heavy duty gas turbines are very flexible combustion tools that accommodate a wide variety of gaseous and liquid fuels ranging from natural gas to heavy oils, including syngas, LPG, petrochemical streams (propene, butane…), hydrogen-rich refinery by-products; naphtha; ethanol, biodiesel, aromatic gasoline and gasoil, etc. The contemporaneous quest for an increasing panel of primary energies leads manufacturers and operators to explore an ever larger segment of unconventional power generation fuels. In this moving context, there is a need to fully characterize the combustion features of these novel fuels in the specific pressure, temperature and equivalence ratio conditions of gas turbine combustors using e.g. methane as reference molecule and to cover the safety aspects of their utilization. A numerical investigation of the combustion of a representative cluster of alternative fuels has been performed in the gas phase, namely two natural gas fuels of different compositions, including some ethane, a process gas with a high content of butene, oxygenated compounds including methanol, ethanol, and DME (dimethyl ether). Sub-mechanisms have specifically been developed to include the reactions of C4 species. Major combustion parameters, such as auto-ignition temperature (AIT), ignition delay times (AID), laminar burning velocities of premixed flames, adiabatic flame temperatures, and CO and NOx emissions have then been investigated. Finally, the data have been compared with those calculated for methane flames. These simulations show that the behaviors of alternative fuels markedly differ from that of conventional ones. Especially, DME and the process gases appear to be highly reactive with significant impacts on the auto-ignition temperature and flame speed data, which justifies burner design studies within premixed combustion schemes and proper safety considerations. The behaviors of alcohols (especially methanol) display some commonalities with those of conventional fuels. In contrast, DME and process gas fuels develop substantially different flame temperature and NOx generation rates than methane. Resorting to lean premix conditions is likely to achieve lower NOx emission performances. This review of gas turbine fuels shows for instance that the use of methanol as a gas turbine fuel is possible with very limited combustor modifications.

In the 1980s, tropical forest-management principles underwent a shift toward approaches giving greater responsibilities to rural people. One argument for such a shift were the long-term relations established between rural people and their natural resources. In Madagascar, a new law was drawn up in 1996 (Gelose law), which sought to integrate rural people into forest management. A gap was observed between the changes foreseen by the projects implementing the Gelose law and the actual changes. In this article, we use the concept of the social-ecological system (SES) to analyze that gap. The differences existing between the planned changes set by the Gelose contract in the village of Ambatoloaka (northwest of Madagascar) and the practices observed in 2010 were conceptualized as a gap between two SESs. The first SES is the targeted one (i.e., a virtual one); it corresponds to the designed Gelose contract. The second SES is the observed one. It is characterized by the heterogeneity of forest users and uses, which have several impacts on forest management, and by very dynamic social and ecological systems. The observed SES has been reshaped contingent on the constraints and opportunities offered by the Gelose contract as well as on other ecological and social components. The consequences and opportunities that such an SES reshaping would offer to improve the implementation of the Gelose law are discussed. The main reasons explaining the gap between the two SESs are as follows: (1) the clash between static and homogeneous perceptions in the targeted SES and the dynamics and heterogeneity that characterize the observed SES; and (2) the focus on one specific use of forest ecosystems (i.e., charcoal-making) in the targeted SES. Forest management in the observed SES depends on several uses of forest ecosystems.

Forest management policies in tropical countries have undergone a paradigm shift in the 1980s. International environmental policies have recommended redirecting natural resource management from state control to approaches giving responsibilities to local people. In Niger, forest cooperatives and firewood rural markets characterized the transition in forest policies toward the integration of rural people in forest management. Forest management principles have been progressively adapted to the social and ecological context, since the establishment of the first cooperatives in 1986. Changes in forest policies concerned two fronts: forest management governance and forest management technical instruments. In this paper, the impact of governance and technical instruments on forest management is studied in two types of firewood rural markets found in Niger. Both rural markets have been designed to bring about a governance shift in favour of rural people. In one type of rural market, rigorous technical instruments were added, consisting in a rotational system among several plots to be harvested in the forest. This paper shows that in the implementation of rural markets, the shift is mainly on governance of forest management, and not so much on technical instruments. The general management principles remain based on scientific knowledge and are not enforced by rural people. These principles have been shown to be inappropriate with regard to Sahelian people’s representation of space, but because they are scientific, they cannot be questioned. The study suggests that sustainable forest management will be better served by interesting rural people in the rural markets, and thereby promoting their appropriation of forest resources, than by defining rigorous technical rules.

Preservation et valorisation durable des forets sont percues par l’administration forestiere, comme des objectifs antagonistes, donc a appliquer a des massifs distincts. L’impossibilite de les concilier sur un meme massif n’a ete demontree nulle part et les populations riveraines ou forestieres ne trouvent, le plus souvent, leur place ni dans le premier, ni dans le second. L’exploitation des forets par concession a des operateurs reste artisanale et est realisee sans amenagements forestiers. En 1996 et 1997, les textes renovant la legislation malgache autorisant une gestion locale communautaire des ressources renouvelables et particulierement forestieres ouvrirent une alternative contradictoire avec l’option d’exclusion de l’homme des espaces naturels telle qu’elle etait arretee depuis les annees 1930. Pour les ONG de conservation, les « pressions anthropiques » sont la principale cause de degradation environnementale. Ces deux options concurrentes coexistent depuis quinze ans : la preservation est portee au niveau de l’Etat alors que la gestion communautaire, transferee contractuellement, repond souvent a une demande de la societe rurale locale. La politique « vision - Durban » de 2003 debouchant sur la creation de nouvelles aires protegees (NAP) sembla marquer la victoire de la preservation et sonner le glas de la gestion locale des ressources. Mais la realite est plus complexe. Le processus de creation de NAP dans deux sites comparables, les « corridors forestiers » de Fandriana – Vondrozo et d’Ankeniheny – Zahamena, semble deja et pourrait accorder une place importante a la gestion communautaire. La question « preservation et/ou gestion communautaire et valorisation forestiere durable ? » rebondit. Les experiences des transferts de gestion depuis 2000 dans ces massifs forestiers apportent d’utiles jalons pour choisir des combinaisons entre preservation et valorisation durable d’une part, et entre gestion communautaire et gestion administrative en regie des exploitations forestieres par des operateurs, d’autre part. La comparaison de ces deux corridors, d’ecologie et de sociologie similaires, mais geres differemment par ailleurs, fournit les materiaux de ce bilan. La forte demande sociale rurale conduit, y compris pour les ONG de preservation, a passer par le transfert de gestion aux communautes locales. Sans valorisation, ceux-ci ne fonctionnent que le temps des interventions de leur mise en place. Les contrats visant la valorisation forestiere durable demandent plus de temps mais surtout necessitent un appui plus long et continu lie a l’instauration de plans d’amenagement, a la prise en compte de trames foncieres, au montage d’accords inter‑lignagers pour les zones de foncier flou ou litigieux. La gestion communautaire n’est pas une fin en soi, l’objectif etant de concilier conservation de la biodiversite forestiere et developpement des populations residentes ou riveraines que preservation et exclusion ne peuvent assurer durablement. Les transferts de gestion « durables » debouchent sur de nouvelles questions posees a l’administration forestiere dans le contexte de la decentralisation : controle et fiscalite des produits forestiers, prise en compte des savoirs et des formes d’appropriation sociale de l’espace forestier, mais aussi suivi environnemental accordant autant d’interet aux zones exploitees qu’aux zones de preservation.

A Madagascar, la gestion locale des ressources renouvelables plonge ses racines au plus profond de l'histoire. La politique coloniale exclusive de gestion répressive administrative de ces ressources est un intermède séculaire clos par la loi 96-025 instituant la gestion locale des ressources renouvelables. Une continuité existe entre la gestion locale au temps de la royauté et celle instituée à la suite de l'atelier international d'Antsirabe en mai 1995. La référence commune aux valeurs coutumières de la société malgache favorise le développement du transfert de gestion et concrétise la réappropriation par les communautés de la légitimité de leur gestion des ressources.La Loi 96-025 résulte de travaux convergents combinés avec une demande sociale vigoureuse des communautés qui ont trouvé l'occasion de s'exprimer lors de l'atelier international d'Antsirabe. Ses concepteurs pensaient qu’il existe des capacités locales de gestion durable des ressources renouvelables sur la majorité du territoire de Madagascar. Elle fut conçue comme une loi cadre d'application souple à l'ensemble des ressources renouvelables, des forêts aux ressources marines, sur tout le territoire de Madagascar avec la mise en oeuvre d'une politique nationale sur plusieurs décennies.Le transfert de gestion s’est heurté à une obstruction efficace de certaines ONG de conservation de l’environnement concurrentes des populations rurales pour l’accès aux ressources de ce hot spot mondial de la biodiversité. Le développement des transferts de gestion a été obscurci, retardé, parfois dévoyé, mais néanmoins se poursuit de façon inexorable jusqu’à présent.L’inefficacité de la préservation par des aires protégées est révélée de façon particulièrement impitoyable lors des crises politiques où l’autorité de l’Etat chancelle. L’alternative de transferts de gestion de conservation tentée par les ONG de conservation ne supprime pas les exploitations illicites. Le recours aux paiements pour services environnementaux ne résout pas ce problème. La pérennité de ces paiements reste encore aléatoire et chaque interruption se traduit par des dégradations volontaires de la biodiversité.La création de nouvelles aires protégées issues du congrès de Durban pose encore la question de la place accordée aux populations locales et celle d’une encore improbable synthèse entre gestion communautaire, gestion durable, lutte contre la pauvreté et conservation de la biodiversité.Madagascar ne pourra pas indéfiniment repousser un choix politique clair entre préservation et gestion communautaire durable, entre préservation et développement local durable. Une part trop importante de sa population rurale vit en situation d’extrême pauvreté et dépend directement pour sa survie des ressources renouvelables de sa biodiversité. Retarder ce choix c’est assurer de nouvelles dégradations plus ou moins irréversibles d’un patrimoine naturel inestimable., In Madagascar community-based natural resource management pre-dates the colonial episode. The colonial approach to resource management was repressive and exclusive and, as such, it came to an end when Law 96-025 was passed, granting local communities the legal right to manage natural resources. Thus, at least in terms of resource management, there is continuity between the days preceding colonization and what followed the 1995 international workshop held in Antsirabe. What binds these two periods together is a shared reference to Malagasy customary values which are compatible with decentralized resource management. Among other things these fundamental values restore legitimacy to the transfer of rights and responsibilities inherent in resource management.The 96-025 law results from social pressures on the part of communities whose representatives were given the opportunity to voice their demands in the 1995 Antsirabe workshop. Given that those who drafted this particular law knew that local management capacities existed throughout the territory, the legal text was designed as a legal framework for the management of renewable natural resources, including forests and marine resources, for the entire country. It informed a national policy of decentralization to be carried out over a period of several decades.Since this policy’s implementation, a number of conservation NGOs determined to limit resource access in this biodiversity hotspot have tried to block the process. Despite deliberate attempts to delay and even derail it, the process has, however, been unstoppable.Protected areas have not guaranteed biodiversity conservation. This is evident where and when political crises have turned attention away from rural areas. Nor have conservation-oriented management contracts stopped illegal logging. The same is true of conservationpayments. These payments' sustainability remains questionable and each lapse in funding has been met with voluntary acts of aggression against biodiversityFollowing the 2003 Durban declaration calling or the expansion of the protected area network, the question of local communities’ role in resource management must, once again, be raised. Such an initiative jeopardizes the chance of successfully reconciling the multiple goals of decentralized resource management, sustainable resource management, fighting poverty and conserving biodiversity.It is imperative that Madagascar choose between nature preservation and participatory sustainable management and between naturepreservation and sustainable local development. Too large a share of its population lives in extreme poverty and depends on natural resources for survival. The longer decision makers delay the choice, the greater the chance of witnessing irreversible environmental damage in a place where biological wealth is inestimable.

Les stratégies d'énergie domestique ont été mises en oeuvre à grande échelle au Niger puis au Mali à partir des années 1990. Avec plus d'une décennie de recul, il est possible de dresser un bilan comparatif de la mise en oeuvre de ces stratégies au Niger et au Mali. Ce bilan fait apparaître, audelà des similitudes, des différences fondamentales. L'article se focalise sur les résultats en termes d'aménagement forestier et de gestion durable des ressources ligneuses. Si le bilan est largement positif au Niger, il n'en est pas de même au Mali. Les modalités de la fiscalité forestière et du contrôle forestier expliquent ces différences. Le Niger et le Mali sont donc maintenant confrontés à leurs propres nouveaux défis qui s'avèrent différents. Le Niger doit assurer la généralisation de la gestion forestière par les marchés ruraux. Quant au Mali, il doit reprendre à la base la réforme de la réglementation et de la fiscalité forestières dans le cadre de la décentralisation. (Résumé d'auteur)

An advanced version of the box-type solar cooker is presented: a fixed cooking vessel in good thermal contact with a conductive absorber plate is set into the glazing; the results are improved thermal performance, easier access to the cooking vessel and less frequent maintenance due to protection of all absorbing and reflecting surfaces. Outdoor tests show that 5 L of water per sq m of opening surface can be brought to full boiling in less than one hour. A finite element simulation model of the advanced box cooker is presented. It is shown that the most decisive parameters are absorber-to-pot heat transfer and absorber conductivity. Field tests in Ethiopia and India are under way, local production in India has started.

Les auteurs dressent une retrospective de la mise en oeuvre de la politique environnementale et forestiere 1990-2013 qui repose sur quatre lois, a savoir la Charte de l’environnement (loi 90-033 du 21 decembre 1990), la GELOSE (loi 96-025 du 30 septembre 1996), la loi forestiere (loi 97-017 du 8 aout 1997) et le Code des Aires protegees (loi 2001-005 du 11 fevrier 2003). Vingt ans apres l’adoption de la Nouvelle Politique Forestiere, un bilan est possible. Ces textes ont connu un debut d’application avec un bilan decevant dans un contexte surtout marque par une extension de la superficie des aires protegees. Dans le meme temps, des evolutions importantes et positives sont apparues. Avec la decentralisation, l’.e.tat de droit s’est construit quotidiennement au niveau des communes a travers les guichets fonciers, les contrats de transferts de gestion et les experiences positives de controle forestier decentralise. Ont egalement ete realisees des experiences concluantes de valorisation economique des ressources forestieres exploitees dans le cadre des transferts de gestion : bois d’oeuvre, bois energie, raphia, huiles essentielles. Il est donc possible, en novembre 2013, d’envisager de facon realiste une relance vigoureuse de la politique forestiere en tenant compte des invariants comme les faibles effectifs de l’administration et la modicite des financements exterieurs aleatoires. Il est d’abord necessaire de repondre aux urgences : decrets a publier et a appliquer ; mise en oeuvre systematique des avantages economiques prevus pour les communautes de base signataires des contrats de transfert de gestion. . . . ; securisation des espaces communs sous contrats de transfert de gestion. Il faut enfin et surtout faire de la valorisation conservatoire des ressources des produits forestiers ligneux et non ligneux le moteur du developpement local. This paper presents a retrospective on the implementation of Malagasy environmental and forest policy between 1990 and 2013 on the basis of four laws, namely the Environmental Charter (Law 90-033 of 21 December 1990), GELOSE (Law 95-025 of 30 September 1996), the Forest Law (Law 97-017 of 8 August 1997) and the Protected Areas Code (Law 2001-005 of 11 February 2003). Twenty years after the adoption of the new forest policy, an assessment is possible. These texts have started to be applied but with disappointing results, primarily centered on the increase of protected area coverage. Nevertheless, important and positive changes have occurred. With decentralization, the reach of the law has increased day by day in communes through land offices, management transfer contracts, and positive experiences of decentralized forest control. Successful experiences of the economic valorization of forest resources (such as timber, fuelwood, raphia palm and essential oils), have also been gained within management transfers. It is therefore possible, in December 2013, to realistically envisage a strong revival of forest policy, even accounting for permanent constraints such as the weakness of the forest administration and the uncertainty of external funding. It is first necessary to respond to urgent needs; to publish and apply un-finalized decrees, to systematically establish the economic benefits anticipated for the community signatories of management transfer contracts, and to secure common property areas within management transfers. Most importantly, the sustainable economic valorization of woody and non - woody forest products should be used as a tool for local development.

Dès son introduction à Madagascar, Eucalyp- tus robusta a été retenu comme espèce de reboisement pour sa remarquable capacité d'adaptation. L’extension de sa plantation par les populations rurales a abouti à la créa- tion d’un massif de près de 140 000 hectares autour d’Antananarivo. Son bois est devenu la principale source d’énergie utilisée par les ménages urbains et ruraux malgaches. Mais aujourd’hui, la production durable de cette ressource est gravement menacée. Le marché déficitaire et la pauvreté des populations rurales amènent les propriétaires forestiers à exploiter leurs taillis avec des rotations de plus en plus courtes, parfois inférieures à 2 ans. Cette surexploitation induit un gaspil- lage des éléments minéraux qui ne sont pas compensés par des apports extérieurs de nutriments. La production de charbon de bois se poursuit à partir de meules tradition- nelles dont le rendement pondéral n’est que de 10 % environ. Le doublement de ce rende- ment par des méthodes simples permettrait pourtant de diminuer les superficies de forêt exploitées chaque année. À 6 ans, l’accrois- sement moyen annuel en volume commercial bois fort sur écorce des taillis anciens est de 18,8 m3/ha/an. Les meilleures provenances importées récemment permettent de doubler le volume moyen individuel des arbres à 9 ans. Des vergers à graines ont été plantés avec plusieurs provenances de l’aire natu- relle pour créer des variétés composites. Cependant, des fécondations préférentielles intra-provenances et des pollutions par le pollen extérieur affectent fortement la qualité des variétés produites. Pour l’extension du massif d’eucalyptus, les populations rurales continuent à utiliser des graines locales ou planter des sauvageons. Ces plantations en robusta devront continuer à produire du bois malgré les modifications biotiques et abiotiques déjà constatés à Madagascar. Face à ces changements, les technologies modernes peuvent aider la recherche fores- tière à proposer un système durable de pro- duction de bois énergie autour des grands centres urbains. Cela aurait pour effet de maintenir un revenu régulier participant à la survie des populations rurales.

Regularly patterned vegetation in arid ecosystems has been well documented in diverse regions of the world including northern Mexico (Montana 1992), Sudan (Wickens and Collier 1971), South Africa (van der Meulen and Morris 1979), and Jordan (White 1969). Such patterning has been attributed primarily to endogenous landscape processes, particularly those relating to redistribution of rainfall (Boaler and Hodge 1962; White 1971; Cornet, Delhoume, and Montana 1988; Greene 1992; Stafford Smith and Pickup 1993; Ludwig, Tongway and Marsden 1994; Ludwig and Tongway 1995; Thiery, d’Herbes, and Valentin 1995; Tongway and Ludwig 1995; Dunkerley 1997).

Une recherche documentaire a permis de reconstituer l'historique de l'introduction du genre Eucalyptus à Madagascar entre 1857 et 1889, et cela bien avant l'organisation des services forestiers de l'État. Plusieurs acteurs de différents pays ont procédé aux introductions de diverses espèces d'eucalyptus ; mais, à cette époque, l'identification des provenances d'origine des graines n'était jamais mentionnée. Ces introductions avaient notamment pour objectif d'assainir les régions humides infestées par le paludisme, de stabiliser les talus des routes, et de disposer d'arbres ornementaux et d'alignement pour les villes. Par la suite, les premiers boisements ont servi à délimiter les propriétés foncières, produire du bois dans la région centrale de l'Imerina et du Betsileo dépourvue de végétation ligneuse, puis, un peu plus tard, à assurer la production de combustible pour les locomotives à vapeur. Ces espèces fructifiant rapidement dans les conditions écologiques de Madagascar, la récolte de graines sur place fut donc possible dès 1895 pour mener à bien les premiers reboisements programmés par le Service des eaux et forêts. Il en résulte aujourd'hui un massif de près de 150 000 hectares menacé par le changement climatique et principalement par l'augmentation de la sécheresse qui aura un impact sur la productivité des boisements d'eucalyptus, et par conséquent sur les ressources et revenus des paysans des Hautes Terres de Madagascar. Ces eucalyptus ayant une origine inconnue détiennent une variabilité génétique probablement étroite. Aussi le développement de recherches apparaît-il nécessaire pour tester des hypothèses d'évolution de caractères favorisés par des facteurs exogènes. (Résumé d'auteur)

Forests are ubiquitous in the Democratic Republic of Congo; they touch the cultural and economic life of most of the population and have enormous global environmental significance. After years of conflicts and mismanagement, reconstruction is key to improving living conditions and consolidating peace. At the same time, better roads and trade bring risks—threatening forests and biodiversity by facilitating logging, land conversion, and the seizure of forest rights by vested interests. Anticipating these threats, in 2002, the transitional government started a Priority Reform Agenda. This report analyses the soundness of this Agenda, the progress achieved to date, and the priorities for the future. It emphasises the nature of forests as a public good; and the importance of the rule of law, transparency and public participation in managing natural resources. It highlights the multiplicity of claims on forests; calls for multipurpose participatory land-use planning; and emphasises the need to secure traditional user rights. Beyond the risks, the return of peace to the DRC also offers a unique opportunity to take a fresh look at the second-largest rainforest in the world, and to implement innovative strategies that give priority to the environment and to local people.

Les paiements pour services environnementaux (PSE) sont aujourd'hui largement considérés comme un instrument économique majeur de la lutte contre la déforestation. Les projets d'application, de même que les critiques développées autour de cet outil, apparaissent de plus en plus nombreux dans le monde entier, mettant en lumière de fortes divergences quant ê son utilisation et aux objectifs qu'il poursuit. Cet article présente les résultats de l'étude préliminaire à la mise en place d'un système de PSE sur la commune rurale de Didy, dans l'Est malgache. Une part importante de ce territoire est occupée par le corridor forestier d'Ankeniheny-Zahamena, "hot spot" de la biodiversité mondiale, dont l'un des facteurs de dégradation majeur est la pratique traditionnelle de la riziculture sur brûlis, le "tavy". Après avoir présenté les éléments nécessaires à. la compréhension du contexte et des enjeux techniques, cet article s'attache à déterminer le potentiel d'un système de PSE comme financement d'un développement durable par l'amélioration des pratiques agricoles.

Andaingo est une zone rurale forestière et rizicole située à environ 200 km de la capitale, Antananarivo. La localité est un chef-lieu de commune rurale qui a une forte chance d'accélérer son développement avec l'appui de l'électrification rurale à. partir de biomasse. Cet écrit rassemble les potentialités de l'espèce Eucalyptus robusta adoptée dans la région pour produire du charbon de bois et du bois de chauffe autour d'Andaingo. En effet, dans le cadre de la production d'électricité rurale décentralisée, le projet GESFORCOM a estimé - à bon escient - que le bois produit par cette espèce pourra être utilisé de manière durable pour alimenter la chaudière d'une centrale électrique à. biomasse installée au chef-lieu de la commune rurale. Cette unité ayant une durée de vie de plus de 25 ans, qu'en sera-t-il de l'avenir des formations forestières face à. l'approvisionnement en biomasse de cette centrale? Avec une rotation de coupe de 4 ans, la «possibilité» des peuplements traités en taillis est de 59,2 hectares par an. Cette possibilité est définie comme le maximum de surface d'exploitation de bois de taillis pouvant être exploité annuellement si on voulait préserver «durablement» ces taillis autour d'Andaingo. Ce qui permettrait d'assurer entre 1,2 et 1,8 tonne par jour de bois sec à l'air (à 12% d'humidité) utilisable comme bois-énergie d'eucalyptus (à comparer avec une tonne de bois par jour correspondant aux besoins énergétiques de la centrale).

En Afrique, et en particulier dans les pays du Sahel, de nombreux discours et projets opérationnels visent à promouvoir une gestion décentralisée des ressources naturelles renouvelables. Cet article montre que, malgré l'accent mis à juste titre dans les démarches actuelles sur les règles, les instances et la négociation, la question des conditions d'une gestion décentralisée des ressources renouvelables n'a guère été suffisamment prise au sérieux, et en particulier celles liée à l'action collective.