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Tropical forest degradation from selective logging, fire and edge effects is a major driver of carbon and biodiversity loss1,2,3, with annual rates comparable to those of deforestation4. However, its actual extent and long-term impacts remain uncertain at global tropical scale5. Here we quantify the magnitude and persistence of multiple types of degradation on forest structure by combining satellite remote sensing data on pantropical moist forest cover changes4 with estimates of canopy height and biomass from spaceborne6 light detection and ranging (LiDAR). We estimate that forest height decreases owing to selective logging and fire by 15% and 50%, respectively, with low rates of recovery even after 20 years. Agriculture and road expansion trigger a 20% to 30% reduction in canopy height and biomass at the forest edge, with persistent effects being measurable up to 1.5 km inside the forest. Edge effects encroach on 18% (approximately 206 Mha) of the remaining tropical moist forests, an area more than 200% larger than previously estimated7. Finally, degraded forests with more than 50% canopy loss are significantly more vulnerable to subsequent deforestation. Collectively, our findings call for greater efforts to prevent degradation and protect already degraded forests to meet the conservation pledges made at recent United Nations Climate Change and Biodiversity conferences.

Despite the documented increase in greenhouse gas (GHG) emissions from Southeast Asian peat swamp forest degradation and conversion to oil palm over recent decades, reliable estimates of emissions of nitrous oxide (N2O) and methane (CH4) are lacking. We measured soil fluxes of N2O and CH4 and their environmental controls along a peatland transition from primary forest (PF) to degraded drained forest (DF) to oil palm plantation (OP) over 18 months in Jambi, Sumatra, Indonesia. Sampling was conducted monthly at all sites and more intensively following two fertilization events in the OP. Mean annual emissions of N2O (kg N ha−1 yr−1) were 1.7 ± 0.2 for the PF, 2.3 ± 0.2 for the DF and for the OP 8.1 ± 0.8 without drainage canals (DC) and 7.7 ± 0.7 including DC. High N2O emissions in the OP were driven by peat decomposition, not by N fertilizer addition. Mean CH4 annual fluxes (kg C ha−1 yr−1) were 8.2 ± 1.9 for the PF, 1.9 ± 0.4 for the DF, and 1.6 ± 0.3 for the OP with DC and 1.1 ± 0.2 without. Considering their 20-year global warming potentials (GWP), the combined non-CO2 GHG emission (Mg CO2-equivalent ha−1 yr−1) was 3.3 ± 0.6 for the PF and 1.6 ± 0.2 for the DF. The emission in the OP (3.8 ± 0.3 with or without DC) was similar to the PF because reductions in CH4 emissions offset N2O increases. However, considering 100-year GWP, the combined non-CO2 GHG emission was larger in the OP (3.4 ± 0.3 with DC and 3.5 ± 0.3 without) compared to both the PF and the DF (1.5 ± 0.2 and 1.2 ± 0.1, respectively). The increase in peat N2O emissions associated with the land-use change transition from primary forest to oil palm plantation at our sites provides further evidence of the urgent need to protect tropical peat swamp forests from drainage and conversion.

Tropical peat swamp forests are major global carbon (C) stores highly vulnerable to human intervention. In Peruvian Amazonia, palm swamps, the prevalent peat ecosystem, have been severely degraded through recurrent cutting of Mauritia flexuosa palms for fruit harvesting. While this can transform these C sinks into significant sources, the magnitude of C fluxes in natural and disturbed conditions remains unknown. Here, we estimated emissions from degradation along a gradient comprising undegraded (Intact), moderately degraded (mDeg) and heavily degraded (hDeg) palm swamps. C stock changes above- and below-ground were calculated from biomass inventories and peat C budgets resulting from the balance of C outputs (heterotrophic soil respiration (Rh), dissolved C exports), C inputs (litterfall, root mortality) and soil CH4 emissions. Fluxes spatiotemporal dynamics were monitored (bi)monthly over 1–3 years. The peat budgets (Mg C ha−1 year−1) revealed that medium degradation reduced by 88% the soil sink capacity (from − 1.6 ± 1.3 to − 0.2 ± 0.8 at the Intact and mDeg sites) while high degradation turned the soil into a high source (6.2 ± 0.7 at the hDeg site). Differences stemmed from degradation-induced increased Rh (5.9 ± 0.3, 6.2 ± 0.3, and 9.0 ± 0.3 Mg C ha−1 year−1 at the Intact, mDeg, and hDeg sites) and decreased C inputs (8.3 ± 1.3, 7.1 ± 0.8, and 3.6 ± 0.7 Mg C ha−1 year−1 at the same sites). The large total loss rates (6.4 ± 3.8, 15.7 ± 3.8 Mg C ha−1 year−1 under medium and high degradation), originating predominantly from biomass changes call for sustainable management of these peatlands.

The vast peat deposits in the Peruvian Amazon are crucial to the global climate. Palm swamp, the most extensive regional peatland ecosystem faces different threats, including deforestation and degradation due to felling of the dominant palm Mauritia flexuosa for fruit harvesting. While these activities convert this natural C sink into a source, the distribution of degradation and deforestation in this ecosystem and related C emissions remain unstudied. We used remote sensing data from Landsat, ALOS-PALSAR, and NASA's GEDI spaceborne LiDAR-derived products to map palm swamp degradation and deforestation within a 28 Mha area of the lowland Peruvian Amazon in 1990–2007 and 2007–2018. We combined this information with a regional peat map, C stock density data and peat emission factors to determine (1) peatland C stocks of peat-forming ecosystems (palm swamp, herbaceous swamp, pole forest), and (2) areas of palm swamp peatland degradation and deforestation and associated C emissions. In the 6.9 ± 0.1 Mha of predicted peat-forming ecosystems within the larger 28 Mha study area, 73% overlaid peat (5.1 ± 0.9 Mha) and stored 3.88 ± 0.12 Pg C. Degradation and deforestation in palm swamp peatlands totaled 535,423 ± 8,419 ha over 1990–2018, with a pronounced dominance for degradation (85%). The degradation rate increased 15% from 15,400 ha y−1 (1990–2007) to 17,650 ha y−1 (2007–2018) and the deforestation rate more than doubled from 1,900 ha y−1 to 4,200 ha y−1. Over 1990–2018, emissions from degradation amounted to 26.3 ± 3.5 Tg C and emissions from deforestation were 12.9 ± 0.5 Tg C. The 2007–2018 emission rate from both biomass and peat loss of 1.9 Tg C yr−1 is four times the average biomass loss rate due to gross deforestation in 2010–2019 reported for the hydromorphic Peruvian Amazon. The magnitude of emissions calls for the country to account for deforestation and degradation of peatlands in national reporting.

Due to the lack of studies about the sociocultural dimension of ecosystem services, we analyze in this work the perception of these benefits by family farmers who have agroforestry systems in the northeast of Pará, in the Amazon region. With this objective, we categorize forest restoration strategies based on primary data collection - interviews, semi structured questionnaire, illustrated questionnaire and Likert Scale. Through the relative perception based on the application of Likert scales, we observed that the farmers recognize the benefits provided by agroforest systems and natural landscapes, with high perception of ecosystem services in all the categories present in the Millennium ecosystem evaluation. Furthermore, the higher perceptions of ecosystem services are related to the group of farmers with a smaller area of forest reserve and bigger area of agroforest systems. The result suggests that loss of forest area, at the individual level, probably drives to a higher sense of the benefits of natural systems and thus, the increment in agroforestry systems constitutes an attempt to return to functions and benefits lost through environmental degradation over time. In general, support programs are necessary to strengthen the capacity of agroforestry systems to provide ecosystem services and increase biodiversity conservation.

L'iconographie oasienne est riche et ancienne, mais son usage dans la recherche reste peu explicité. Revenant sur nos terrains de thèse, à Tozeur et Gabès en Tunisie, il s'agit ici d'interroger le rôle de la photo dans la construction de l'imaginaire territorial oasien, et de la recherche sur ces espaces. Matériel de terrain original, la photo dans les oasis constitue une ressource porteuse de discours divers sur le territoire, entre promotion d'un rêve touristique, documentation d'un paysage, ou support de sensibilisation à la dégradation environnementale du milieu. Nous reviendrons notamment sur la réappropriation de l'abondant corpus colonial au service d'une idéalisation des systèmes anciens, puis le processus de constitution d'un corpus " témoin " des dégradations environnementales dans un contexte de dynamisme associatif, et enfin la manière dont la recherche peut mobiliser ce matériel de terrain pour analyser et illustrer la diversité des formes de mise en valeur des territoires.

Cet article questionne le rôle de la production des savoirs sur l'état écologique des milieux dans la gestion et la mise en oeuvre de politiques de surveillance et de protection des ressources en eau utilisées pour la production d'eau potable en Afrique subsaharienne. Sur la base d'une recherche interdisciplinaire réalisée en Côte d'Ivoire et au Sénégal par une équipe comprenant des sociologues et des écologues, l'article montre comment des savoirs experts d'évaluation de la qualité des milieux interagissent avec les jeux d'acteurs, les structures de gestion existantes et les représentations locales de ces mêmes milieux. Nous interrogeons à travers cette approche interdisciplinaire les difficultés d'articulation de la diversité de points de vue sur les ressources en eau, ainsi que les freins, les incertitudes et controverses autour de la production de savoirs et de leur intégration dans des dispositifs de gestion. Nous analysons plus particulièrement les principaux défis pour la mise en place des suivis de l'état écologique des milieux aquatiques, ainsi que les possibles contributions des savoirs experts et locaux à la co-construction d'un diagnostic partagé.

This article portrays the social and spatial invisibility in the case of the Metropolitan Landfill of Jardim Gramacho (MLJG), located in Duque de Caxias (RJ), Brazil. Its objective is to relate the responsible agents for MLJG's social and spatial invisibility process. Specifically, it aims to analyze the effects of its operation on the territory. Based on empirical and documentary analysis, environmental injustices and ‘urban negligence’ were identified by public, private and real estate agents in the entire process of implementation, operation and closure of MLJG. Even with the international repercussion of this extreme case, it was observed that effective solutions to minimize aspects of social exclusion, poverty and contamination have not been implemented until today. Therefore, the contributions of this article demonstrate the omission of the responsible agents for the current situation of environmental degradation, precarity and unhealthy conditions, and warn about the need to develop effective plans for the appropriate reclamation of the area., Este artículo retrata la invisibilidad social y espacial en el caso del Vertedero Metropolitano de Jardim Gramacho (VMJG), ubicado en Duque de Caxias (RJ), Brasil. Su objetivo es relacionar los agentes responsables por el proceso de invisibilidad social y espacial del VMJG. Especificamente, se pretende analizar los efectos de su funcionamiento en el territorio. Con base en análisis empíricos y documentales, fueron identificadas injusticias ambientales y ‘negligencias urbanas’ de agentes públicos, privados y del mercado inmobiliario en todo el proceso de implementación, operación y cierre del VMJG. Aún con la repercusión internacional de este caso extremo, se constató que no han sido implementadas soluciones efectivas para minimizar aspectos de exclusión social, pobreza y contaminación hasta hoy. De esta forma, las contribuciones de este artículo evidencian la omisión de los agentes responsables por la actual situación de degradación ambiental, precariedad e insalubridad, y advierten sobre la necesidad de desarrollar planes eficazes para la recuperación adecuada del área., Cet article dépeint l’invisibilité sociale et spatiale sur le cas de la Décharge Métropolitaine de Jardim Gramacho (DMJG), situé à Duque de Caxias (RJ), Brésil. Il a pour objectif de relier les acteurs responsables du processus d’invisibilité sociale et spatiale de la DMJG. Spécifiquement, il s’agit d’analyser les effets de son fonctionnement sur le territoire. À partir d’analyses empiriques et documentaires, des injustices environnementales et ‘négligences urbanistiques’ ont été identifiées par des acteurs publics, privés et du marché immobilier dans l’ensemble du processus de déploiement, de fonctionnement et de fermeture de la DMJG. Même avec la répercussion internationale de ce cas extrême, il a été constaté que des solutions efficaces pour minimiser les aspects de l'exclusion sociale, de la pauvreté et de la contamination à ce jour-là n'ont pas été mises en oeuvre. Ainsi, les contributions de cet article montrent l’omission des acteurs responsables de la situation actuelle de dégradation de l’environnement, de précarité et d’insalubrité, et avertissent la nécessité d’élaborer des plans efficaces pour la réhabilitation adéquate de la zone., Este artigo retrata a invisibilidade social e espacial no caso do Aterro Metropolitano de Jardim Gramacho (AMJG), localizado em Duque de Caxias (RJ), Brasil. Tem como objetivo relacionar os agentes responsáveis pelo processo de invisibilidade social e espacial do AMJG. Especificamente, pretende-se analisar os efeitos de seu funcionamento no território. A partir de análises empíricas e documentais, foram identificadas injustiças ambientais e ‘negligências urbanísticas’ por parte de agentes públicos, privados e do mercado imobiliário em todo o processo de implantação, funcionamento e encerramento do AMJG. Mesmo com a repercussão internacional deste caso extremo, constatou-se que não foram implementadas soluções efetivas para minimizar aspectos de exclusão social, pobreza e contaminação até hoje. Desta forma, as contribuições deste artigo evidenciam a omissão dos agentes responsáveis pela atual situação de degradação ambiental, precariedade e insalubridade, e alertam sobre a necessidade de desenvolver planos eficazes para a recuperação adequada da área.

Malgré les dommages qu'elle occasionne pour les populations humaines et la biodiversité littorales depuis parfois plusieurs dizaines d'années, l'eutrophisation des milieux marins n'a que très progressivement accédé à une visibilité dans l'espace politique et auprès d'un large public. Due à la production industrielle d'azote réactif et de l'extraction massive de minerai de phosphate, en particulier pour la fertilisation des cultures, cette pollution terrigène majeure est aujourd'hui considérée comme le symptôme le plus manifeste de la perturbation anthropique à grande échelle des cycles biogéochimiques des nutriments. Dans ce contexte, l'ambition de cet article est de rendre compte de l'émergence contrariée de l'eutrophisation côtière comme problème public. Fondé sur une revue systématique de la littérature internationale en sciences sociales et en sciences de la soutenabilité, littérature jusqu'à présent très dispersée, il propose une lecture critique des dynamiques multi-échelles de la surfertilisation des océans. Cette analyse met en évidence trois périodes majeures qui caractérisent l'histoire sociale de l'eutrophisation des milieux marins et examine la façon dont elle a été prise en charge, ou pas, par les autorités publiques. Dans la plupart des cas documentés, l'expérience vécue des populations a rarement suffi à déclencher des politiques publiques régulatrices, le manque d'efficacité de l'action publique étant souvent présenté comme résultant d'antagonismes locaux et d'incertitudes scientifiques persistantes. Si les mobilisations sociales contre l'eutrophisation côtière tendent à se cantonner à des sites emblématiques, les conflits socio-environnementaux directement reliés à des symptômes d'eutrophisation se déploient, en revanche, au sein d'une grande diversité de configurations hydro-sociales, dont nous proposons une typologie.

Background: The control and prevention of vector-borne and zoonotic diseases is often based on the reduction of host or vector populations, involving but not limited to preventative culling and use of insecticides. Yet, destructive interventions such as these have shown several limitations including ineffectiveness on arthropods and negative impacts on ecosystems. An alternative strategy would be to rely on the natural ecosystem functions and their careful management to regulate such diseases. The goal of our work was to evaluate existing scientific evidence on potential links between ecosystem components/functions and 14 vector-borne and zoonotic diseases impacting human health and answer the question: “What evidence exists on the impact of specific ecosystem components and functions on infectious diseases?”. Methods: We searched for scientific articles published in English and French and screened them in a 3-round process (title, abstract and full-text). Articles were retained, without any geographical limitation, if they matched the following eligibility criteria: an exposure/intervention linked to changes in biological communities, habitats, or landscapes; an outcome consisting of any measure of infection in vector, animal or human hosts; and the presence of a comparator, in time and/or in space. The results are presented as a systematic map, followed by a narrative review where the amount of papers allowed for synthesis. Results: Searches in 5 scientific publication databases allowed to retrieve 9723 unique articles, among which 207 were retained after the screening process. The amount of relevant literature was highly variable depending on diseases, and the types of exposures also varied greatly among studies focusing on the same disease. A hundred articles presented in the map were unique in their “disease x exposure” combination and thus not eligible for further narrative description. The remaining 107 articles were organized in 34 “disease x exposure” group

Accurate characterization of tropical moist forest changes is needed to support conservation policies and to quantify their contribution to global carbon fluxes more effectively. We document, at pantropical scale, the extent and changes (degradation, deforestation, and recovery) of these forests over the past three decades. We estimate that 17% of tropical moist forests have disappeared since 1990 with a remaining area of 1071 million hectares in 2019, from which 10% are degraded. Our study underlines the importance of the degradation process in these ecosystems, in particular, as a precursor of deforestation, and in the recent increase in tropical moist forest disturbances (natural and anthropogenic degradation or deforestation). Without a reduction of the present disturbance rates, undisturbed forests will disappear entirely in large tropical humid regions by 2050. Our study suggests that reinforcing actions are needed to prevent the initial degradation that leads to forest clearance in 45% of the cases.

This article deals with the environmental issues south of the Guadalajara Metropolitan Area, in the State of Jalisco, Mexico. Its objective is to foster awareness of the environmental impact facing the inhabitants of this geographical area. A review of books, articles and official reports of the various surface water quality studies done by state authorities, universities and non-governmental organizations was carried out, focused on the El Ahogado creek and dam. In addition, we undertake a socio-spatial projection of the inhabitants which are exposed to contaminants found in surface water: barium, chromium, iron, mercury and zinc. The State has been aware of the environmental degradation for 40 years. This speaks to the re-victimization of the socio-environmental space where the water industry has not been sanctioned, urban sprawl is unregulated and the demands of the population in terms of health have not been met., Cet article montre les problèmes environnementaux dans le sud de la zone métropolitaine de Guadalajara, dans l'État de Jalisco, au Mexique. L'objectif est de connaître les affections environnementales dans lesquelles se trouvent les habitants de ce territoire. Une revue bibliographique et journalistique a été faite des différentes études sur la qualité des eaux de surface réalisées par les autorités de l'État, les universités et les organisations non gouvernementales, en se concentrant sur le ruisseau et le barrage d'El Ahogado. En outre, une projection socio-spatiale a été réalisée sur les habitants qui sont exposés aux contaminants des eaux de surface : baryum, chrome, fer, mercure et zinc. L'État est conscient de la dégradation de l'environnement depuis 40 ans. Cela nous parle d'une re-victimisation de l'espace socio-environnemental : l'industrie n'a pas été sanctionnée, la croissance urbaine est désordonnée et les demandes de santé de la population n'ont pas été satisfaites., Questo articolo mostra i problemi ambientali nel sud dell'area metropolitana di Guadalajara, nello Stato di Jalisco, Messico. L'obiettivo è quello di conoscere le affezioni ambientali in cui si trovano gli abitanti di questo territorio. È stata fatta una rassegna bibliografica e giornalistica dei diversi studi sulla qualità delle acque superficiali effettuati da autorità statali, università e organizzazioni non governative, con particolare attenzione al torrente e alla diga di El Ahogado. Inoltre, è stata effettuata una proiezione socio-spaziale degli abitanti esposti ai contaminanti presenti nelle acque superficiali: bario, cromo, ferro, mercurio e zinco. Lo Stato è consapevole del degrado ambientale da 40 anni. Questo ci parla di una rivittimizzazione dello spazio socioambientale: l'industria non è stata sanzionata, la crescita urbana è disordinata e le esigenze di salute della popolazione non sono state soddisfatte., Este artigo mostra os problemas ambientais no sul da Área Metropolitana de Guadalajara, no Estado de Jalisco, México. O objetivo é conhecer as afetações ambientais em que se encontram os habitantes deste território. Foi feita uma revisão bibliográfica e jornalística dos diferentes estudos de qualidade das águas superficiais realizados por autoridades estatais, universidades e organizações não governamentais, com foco no riacho e na barragem de El Ahogado. Além disso, foi feita uma projeção sócio-espacial dos habitantes que estão expostos a contaminantes na água superficial: bário, cromo, ferro, mercúrio e zinco. O Estado está consciente da degradação ambiental há 40 anos. Isto nos fala de uma revalorização do espaço socioambiental: a indústria não foi sancionada, o crescimento urbano é desordenado e as demandas de saúde da população não foram atendidas., El presente artículo muestra la problemática ambiental al sur de la Zona Metropolitana de Guadalajara, en el Estado de Jalisco, México. El objetivo es conocer las afectaciones ambientales en que se encuentran los habitantes de este territorio. Se realizó una revisión bibliográfica y hemerográfica de los distintos estudios de calidad de agua superficial, efectuados por parte de autoridades estatales, universidades y organizaciones no gubernamentales, enfocados al arroyo y presa El Ahogado. Además, se hizo una proyección socio espacial de los habitantes que están expuestos a los contaminantes en el agua superficial: bario, cromo, hierro, mercurio y zinc. El Estado ha tenido conocimiento de la degradación ambiental desde hace 40 años. Esto nos habla de una re-victimización del espacio socioambiental: la industria no ha sido sancionada, el crecimiento urbano es desordenado y las exigencias de la población en materia de salud no han sido atendidas.

L'ensemble des activités en lien avec l'eau du lac de Guiers au Sénégal a potentiellement des conséquences importantes sur son état écologique. Cet article part du constat que la pollution par les pesticides concentre l'essentiel des débats et des actions entreprises tandis que l'enrichissement en nutriments des eaux du lac (représentant un risque d'eutrophisation) n'est un problème que rarement évoqué. Ce constat conduit les auteurs à s'interroger sur les facteurs sociopolitiques qui conduisent à " l'invisibilisation " de certaines causes de dégradation des milieux aquatiques. En nous appuyant sur une enquête de terrain auprès des gestionnaires et usagers du lac, nous montrons les concurrences entre les différents services administratifs qui conduisent à diverses formes de segmentation des causes de dégradation et à la sélection de l'une d'entre elles. Nous montrons ensuite comment cette formalisation du problème est diffusée et renforcée par la mise en oeuvre de bonnes pratiques agricoles, essentiellement centrées sur la question des produits phytosanitaires et relayées par des acteurs territoriaux. Cette analyse de la construction institutionnelle de l'ignorance est enfin complétée par une étude des représentations que les usagers se font de la dégradation de leur lac, permettant d'identifier les dynamiques sociales, les conflits et les jeux de pouvoir autour de l'appropriation de l'espace et de l'accès à l'eau, qui conduisent à l'invisibilisation du problème de l'eutrophisation.

As a consequence of the impering productive system in the world, climate change is considered as one of the most controversial phenomena because of its environmental, economical, demographic and social effects which cause, in the end, the displacement and migration of population, specially in the Global South. Nowadays, natural disasters and climate change are factors causing the greatest number of migrant people around the globe. Events such as droughts in the Sahel region, the rising sea levels in the Asian South and Southeast and the disappearance of insular states as Kiribati or Tuvalu give testimony of this condition. In this context, the term “climate refugee” arises to tackle and give an answer to those people who are forced to abandon their homes due to environmental deterioration caused by climate change. Nevertheless, this concept poses a series of challenges and difficulties regarding its implementation in international law of refugees. Thus, the aim is to provide an approximation of a collective, the climate refugees, by analyzing their origins and consequences., Conséquence de la mise en péril du système productif mondial, le changement climatique est considéré comme l’un des phénomènes les plus controversés en raison de ses effets environnementaux, économiques, démographiques et sociaux qui entraînent, en fin de compte, le déplacement et la migration des populations, en particulier dans le Sud. De nos jours, les catastrophes naturelles et le changement climatique sont les facteurs qui provoquent le plus grand nombre de migrations dans le monde. Des événements tels que les sécheresses dans la région du Sahel, l’élévation du niveau des mers dans le Sud et le Sud-Est de l’Asie et la disparition d’États insulaires comme Kiribati ou Tuvalu témoignent de cette situation. Dans ce contexte, le terme “réfugié climatique” apparaît pour aborder et donner une réponse à ces personnes qui sont forcées d’abandonner leurs maisons en raison de la détérioration environnementale causée par le changement climatique. Néanmoins, ce concept pose une série de défis et de difficultés quant à sa mise en œuvre dans le droit international des réfugiés. Ainsi, nous avons l’intention de donner une approximation d’un collectif, les réfugiés climatiques, en analysant leurs origines et leurs conséquences., Como consecuencia del sistema productivo que impera en el mundo, el cambio climático se presenta como uno de los fenómenos más controvertidos por sus efectos ambientales, económicos, demográficos y sociales, provocando, en última instancia, el desplazamiento y la migración de la población, especialmente en el Sur global. Actualmente, los desastres naturales y el cambio climático constituyen factores que causan el mayor número de personas migrantes a nivel mundial. Acontecimientos como la sequía en la región del Sahel, el aumento del nivel del mar en el Sur y Sudeste Asiático, y la desaparición de estados insulares, como Kiribati o Tuvalu, dan prueba de ello. En este contexto, el término «refugiado climático» surge para abordar y dar respuesta a las personas que se ven forzadas a abandonar sus hogares por la degradación ambiental, ocasionada por el cambio climático. No obstante, este concepto plantea una serie de desafíos y dificultades, en cuanto a su implementación en el derecho internacional de los refugiados. Así, se pretende dar una aproximación de un colectivo, los refugiados climáticos, analizando sus orígenes y consecuencias.

Potential time lags between human-mediated disturbances and the subsequent responses of ecosystems are critical for planning and implementing conservation and restoration actions. In this context, decoupling between the temporal trajectories of ecosystems structure and functions is particularly critical. Here, we stand out the need to differentiate the temporal trajectories of ecosystem structure and functions to be considered in ecological restoration programs. In cases when ecosystem functions persist after the degradation of the ecosystem structure, and when functions do not recover at the same rate as structure, some kind of ecosystem functioning credits or debts can occur. In other situations, an ongoing loss of the ecosystem function can occur even in the absence of further disturbance. Ecosystem restoration outcomes could be optimized in regions with ecosystem functioning credit, since mitigating the decline in functioning will be more efficient than recovering functions in highly degraded conditions. Ecological restoration programs should not only focus on structure-derived indicators but they should also consider the dynamics of ecosystem functions to guide land-planning decision-making.

Selective logging, fragmentation, and understory fires directly degrade forest structure and composition. However, studies addressing the effects of forest degradation on carbon, water, and energy cycles are scarce. Here, we integrate field observations and high‐resolution remote sensing from airborne lidar to provide realistic initial conditions to the Ecosystem Demography Model (ED‐2.2) and investigate how disturbances from forest degradation affect gross primary production (GPP), evapotranspiration (ET), and sensible heat flux (H). We used forest structural information retrieved from airborne lidar samples (13,500 ha) and calibrated with 817 inventory plots (0.25 ha) across precipitation and degradation gradients in the eastern Amazon as initial conditions to ED‐2.2 model. Our results show that the magnitude and seasonality of fluxes were modulated by changes in forest structure caused by degradation. During the dry season and under typical conditions, severely degraded forests (biomass loss ≥66%) experienced water stress with declines in ET (up to 34%) and GPP (up to 35%) and increases of H (up to 43%) and daily mean ground temperatures (up to 6.5°C) relative to intact forests. In contrast, the relative impact of forest degradation on energy, water, and carbon cycles markedly diminishes under extreme, multiyear droughts, as a consequence of severe stress experienced by intact forests. Our results highlight that the water and energy cycles in the Amazon are driven by not only climate and deforestation but also the past disturbance and changes of forest structure from degradation, suggesting a much broader influence of human land use activities on the tropical ecosystems.

Few longitudinal studies link agricultural biodiversity, land use and food access in rural landscapes. In this paper, we test the hypothesis that, in a context of economic change, cash crop expansion is associated with deforestation, reduced agrobiodiversity and changes in food access. For this purpose, we analysed data collected from the same 53 upland and floodplain mestizo households in Ucayali, Peru, in 2000 and 2015. We found an emerging transition towards less diversified food access coupled with loss of forest cover and reduced agricultural biodiversity. In 2015, diets appeared to rely on fewer food groups, fewer food items, and on products increasingly purchased in the market compared to 2000. Wild fruits and plants were mentioned, but rarely consumed. Agricultural production systems became more specialised with a shift towards commercial crops. Peak deforestation years in the 15-year period appeared linked with incentives for agricultural expansion. Our results suggest an overall trend from diversified productive and “extractive” systems and more diverse food access, towards specialized productive systems, with less diverse food access and stronger market orientation (both in production and consumption). The assumption in the food and agricultural sciences that increased income and market-orientation is linked to improved food security, is challenged by our integrated analyses of food access, agrobiodiversity, land use and forest cover. Our results highlight the importance of longitudinal, multidimensional, systemic analyses, with major implications for land use, food and health policies. The potential risks of parallel homogenisation of diets and agricultural production systems require interdisciplinary research and policies that promote integrated landscape approaches for sustainable and inclusive food systems.

The agricultural sector is the second major source of climate change globally, contributing to anthropogenic Greenhouse Gas (GHG) emissions. In low-to-middle income countries, estimations indicate future increases in agricultural emissions. Climate-Smart Agriculture (CSA) has an express opportunity to transform agriculture across the globe. In Africa, CSA targets focused on resilience building and food security with less emphasis on the GHG mitigation potential. Nevertheless, to make CSA conclusive as an express low emission development strategy in Africa, understanding the mitigation potential in this context is paramount. Through a systematic-narrative review approach conducted on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), the study aimed to identify opportunities to mitigate GHG emissions in Africa. We observed that the distribution of studies that quantitatively assessed the GHG emissions of CSA practices was disproportionate across Africa. For instance, out of twenty studies evaluated, nine were conducted in Southern Africa; three in East Africa, and the rest distributed among Central, Western, and North Africa. Observed in the studies, advanced livestock breeding and feeding, organic nitrogen input, improved pastures and switching land-use practices, all contributed to GHG emission reduction. As limited experimental evidence exist on the GHG mitigation potential for some of the CSA alternatives including agroforestry, rotational farming, improved livestock breed and intensification of ruminants' diet, we recommend further experimental studies into these alternatives in more locations/contexts in Africa. Also, progress on the mitigation pillar is still limited in Africa due to lack of the necessary analytical infrastructure to conduct the needed measurements. We call for urgent investments into laboratory facilities and skills training to improve data collection and quality.

L'article analyse les correspondances et les décalages entre la pensée sur la résilience dans la littérature et la façon dont on traite de résilience en matière de développement et de sécurité alimentaire dans les projets et dans les guides pratiques d'évaluation. Six paradoxes sont soulevés à propos : de la compréhension ou de la mesure de la résilience ; de la résilience en situation de blocage ; du rôle de métaphore mobilisatrice du concept alors que son interprétation prête à controverses ; de son caractère intégrateur alors que son évaluation porte, le plus souvent, sur des composantes dissociées ; de son positionnement par rapport à la vulnérabilité ; et de la pluridisciplinarité propre au concept de résilience. On cherche comment résoudre chaque paradoxe et mieux saisir les liens entre production agricole et sécurité alimentaire des ménages ruraux dans des contextes de pauvreté, de dégradation environnementale et d'aléas multiples. On souligne ainsi ce qui singularise les travaux sur la résilience en termes d'approche et la possibilité d'une contribution originale dans le domaine du développement, avec notamment la prise en compte des points de vue en présence et un éclairage sur les irréversibilités des changements considérés.

La pression humaine sur les villes littorales à travers le développement des infrastructures touristiques et industrielles, l’urbanisation accélérée est un fait généralisé sur toutes les côtes du Monde. L’Algérie n’échappe pas à cette évolution mais suscite une forte inquiétude. Face à cette pression continue, les villes côtières algériennes et particulièrement la ville de Jijel, présentent des déséquilibres qui se manifestent par des formes de dégradation de l’environnement souvent irréversibles, suite à des tempêtes violentes, à des inondations mais aussi des séismes.L’évolution de ces formes de dégradation du littoral compromet tout projet de développement urbain de la ville de Jijel , avec un risque de submersion au droit des zones nouvellement urbanisées comme le quartier de Rabta et la ZET Kotama (ex Casino) où toute forme de dune bordière a disparue.La ville était considérée comme un lieu de sûreté et d’urbanité alors qu’elle apparait aujourd’hui comme un territoire où les risques naturels se sont aggravés et d’autres dangers prolifèrent à cause de dysfonctionnements industriels ou des pathologies des nouvelles sociétés urbaines.Un rapide constat révèle le peu de maîtrise dans la gestion des risques naturels en Algérie où l’information scientifique fait totalement défaut ; on ne peut enrayer ni l’ampleur ni les pertes matérielles et humaines lors des catastrophes naturelles si on ne connaît pas au préalable, les causes et les mécanismes de ces phénomènes.

L'impact des activités humaines sur l'état d'une rivière est le plus souvent évalué réglementairement par le suivi d'indicateurs de la qualité de l'eau. La définition des réseaux de mesures réglementaires est contrainte par des aspects techniques ou pratiques qui font que les diagnostics sont établis sur une base de connaissances limitée. Etudier la relation qu'ont les riverains avec le cours d'eau peut-il servir à améliorer les connaissances scientifiques sur les pressions et l'état de la rivière, et donc à moyen terme à améliorer la définition des actions de contrôle et de restauration ? La réponse à cette question s'appuie sur l'étude du rio Liberia (longueur 30 km, bassin versant 46 km2) au Costa Rica situé dans la région du Pacifique Nord. La rivière traverse, à l'aval, la zone urbaine de Liberia (39000 habitants), représentative des villes dites périphériques du pays. La thèse est basée sur le couplage de deux démarches : (a) la réalisation du diagnostic réglementaire de la qualité de l'eau et la caractérisation des pressions anthropiques sur la rivière ; (b) l'étude de la perception et de la pratique de la rivière par les riverains. Dans un premier temps, quinze campagnes de mesure de la qualité de l'eau ont été effectuées conformément à la réglementation du Costa Rica, sur un réseau de sept stations, le long du rio Liberia, entre 2013 et 2015. Les indicateurs physico-chimique, biologique et bactériologique montrent un gradient amont-aval de l'état de rivière, de peu à très pollué. Ces indicateurs sont peu variables en fonction des conditions hydrologiques -vu par un indice de précipitation antérieur-, mais sont influencés par les pressions anthropiques, vu par les indices d'occupation du sol et d'état de la ripisylve. La qualité de la rivière est fortement dégradée à la traversée de la zone urbaine. Dans un deuxième temps, une enquête a été effectuée en 2016, auprès de 100 habitants et de 32 acteurs économiques riverains. Une cartographie de la rivière, en t

Concerns about ecological degradation and social inequalities have prompted increasing calls for stewardship in the social–ecological systems and sustainability science literature. However, how can the ideals of stewardship be realised in practice? The links between the theory and practice of stewardship are under-developed, and research to support place-based stewardship practice is limited. We therefore bring together complementary perspectives to guide research on place-based stewardship practice in the context of multifunctional landscapes. We unpack and synthesise literature on stewardship, landscapes, and collaboration for natural resource management, and highlight the ways in which the pathways approach can deepen research on collaboration and stewardship practice. We propose landscapes as a suitable level of analysis and action for stewardship. Since all landscapes are multifunctional, we argue that collaboration among multiple stakeholders is a necessary focus of such research. Our analysis reveals that existing theory on collaboration could be deepened by further research into the agency of individual human actors, the complex social–relational dynamics among actors, and the situatedness of actors within the social–ecological context. These factors mediate collaborative processes, and a better understanding of them is needed to support place-based stewardship practice. To this end, the pathways approach offers a waymark to advance research on collaboration, particularly in the complex, contested social–ecological systems that tend to characterize multifunctional landscapes.

While international migration attracts most attention, since the late 1990s, internal and in particular temporary migration flows increased significantly in Senegal. These migratory dynamics, whose modalities have diversified alongside migrants' profiles and trajectories, are the result of the combined effect of population growth and underemployment, of a continuous degradation of the natural environment and of migration policies of OECD countries limiting international mobility. Internal migration largely comes from rural areas. This is indicative of a state of structural crisis that marks the agricultural sector but also reflects the low diversification of the national economy. The migrations flows reshape the national space and illustrate the need for territorial balancing around regional development poles. This rebalancing is necessary in order to avoid the continuation of a concentration of the Senegalese population in the Dakar agglomeration, which poses problems of sustainability of the national growth model. Migration dynamics thus highlight the need for public policies adapted to the challenges and they contribute to the strengthening of the debate.