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Ivorian classified forests have been highly anthropized by cocoa farming. In an attempt to provide guidance to the government on approaches to the restoration of the forest while respecting the aspirations of local populations, permanent plots were set up in the classified forest of Haut-Sassandra, and were monitored and measured for 3 years. This study was intended to analyze the evolution of the vegetation of permanent plots in the classified forest of Haut-Sassandra from 2018 to 2021. The results show that the vegetation evolves with the cessation of some agricultural activities. These plantations are colonized by pioneer species during the first three years of the abandonment of agricultural activities. Mortality rates increased by 477.59% and recruitment rates were reduced by 61.87% in regularly maintained plantations compared to their condition three years ago. However, the plantations with no agricultural activities and those which were not maintained but harvested had the highest recruitment rates of pioneer and heliophilous individuals. In sum, tree species could recolonize the classified forest of Haut-Sassandra if clearing is prohibited in cocoa farms. However, the populations could continue to harvest the pods from the cocoa trees which are already established in the classified forest of Haut-Sassandra.

The classified forest of Haut-Sassandra (CFHS) located in the Center-West of Cote d'Ivoire was infiltrated by the population for agriculture in the 2000s. This forest, initially devoted to timber production before its degradation, is today a vast cocoa-growing area associated with food crops, mainly plantains. The objective of the present study is to assess the overall production of wood, cocoa, and plantain in this state-owned area before (2000) and after its degradation (2019). Processed satellite images covering the CFHS showed an increase in anthropogenic vegetation classes and a decrease in the forest cover class from 2000 to 2019. These transformations resulted in an expansion of cocoa (from 146 t to 18,384 t) and plantain production (from 3,087 t to 187,061 t) at the expense of logging in the CFHS, 16,388 and 3,844 m3 respectively in 2000 and 2019. In addition, there was a loss of about 57% of the expected income from the sale of timber and a 15,912% increase in profits from the sale of agricultural products in 2019 compared to 2000. In such circumstances, it is recommended to implement a sustainable cropping system that will integrate timber production and agricultural production within the same area. Key words: Ecosystem service, timber, cocoa production, plantain, anthropogenic pressure, Cote-d’Ivoire, West Africa.

BackgroundTo facilitate mass distribution of azithromycin, trachoma control programmes use height instead of weight to determine dose for children 6 months to 15 years old. WHO has recommended azithromycin distribution to children 1–11 months old to reduce mortality in high mortality settings under carefully monitored conditions. Weight was used to determine dose in children 1–5 months old in studies of azithromycin distribution for child survival, but a simplified approach using age or height for all aged 1–11 months old could increase programme efficiency in real-world settings.MethodsThis secondary analysis used data from two cluster randomised trials of azithromycin distribution for child mortality in Niger and Burkina Faso. An exhaustive search algorithm was developed to determine the optimal dose for different age groups, using tolerance limits of 10–20 mg/kg for children 1–2 months old and 15–30 mg/kg for children 3–11 months old. Height-based dosing was evaluated against the existing trachoma dosing pole and with a similar exhaustive search.ResultsThe optimal two-tiered age-based approach suggested a dose of 80 mg (2 mL) for children 1–2 months old and 160 mg (4 mL) for children 3–11 months old. Under this schedule, 89%–93% of children would have received doses within tolerance limits in both study populations. Accuracy was 93%–94% with a three-tiered approach, which resulted in doses of 80 mg (2 mL), 120 mg (3 mL) and 160 mg (4 mL) for children 1–2, 3–4 and 5–11 months old, respectively. For children 1–5 months old, the existing height pole would result in 70% of doses within tolerance limits. The optimisation identified height-based dosing options with 95% accuracy, although this would require changes to the existing dosing pole as well as additional training to measure infants lying flat.ConclusionsOverall, an age-based approach with two age tiers resulted in high accuracy while considering both concerns about overdosing in this young population and simplicity of field operations.

Located in the extreme north of Côte d’Ivoire, the Sudanian zone is an area where 95% of the population depends on agricultural activities, particularly rain-fed agriculture. Given the serious threats that climate variability poses to food security and household incomes, it is important to understand the evolution of climate variables and their impacts on crops, perceptions, and adaptation measures taken by farmers. To do this, various statistical analyses were conducted using rainfall and temperature data from 1987 to 2018. These analyses were coupled with a survey of 287 farmers. The results showed a strong variability of precipitation marked by the succession of deficit and surplus periods with a return to wetter conditions since 2008. At the same time, an increase in temperature was observed. These phenomena have been perceived by farmers. Thus, to cope with the adverse effects of climate variability, farmers have developed numerous adaptation strategies that include the use of organic manure, agroforestry, changing planting dates, and introducing new crops, notably cashews.

In Cote d'Ivoire, cassava is widely grown all over the country, and a large variety of varieties is encountered. This diversity is due, on the one hand, to the fact that genotypes respond differently to various soil, climate and biotic factors and, on the other hand, to the continuous exchange of seeds among producers. The objective of this study was to find a limited number of reliable and stable morphological criteria that would allow clones to be identified throughout the cassava chain. The study first consisted of a visit in the experimental station with the aim of identifying all the clones found on the different plots. Twenty clones were randomly selected. Then, cassava descriptors developed by the International Institute of Tropical Agriculture (IITA) were used to identify differences between these clones. The PCA analysis method highlighted seven main criteria: "color of the last branch", "color of the leaf", "color of the petiole", "color of the rib", "number of branches", "profile of the petioles" and " shape of the branches". These criteria made it possible to differentiate eleven clones. Keywords : cassava, clone, criterion, morphology, Cote d’Ivoire

A la faveur de la culture de l’anacarde, savanes et forets des zones Nord de la Cote d’Ivoire sont transformees en de vastes vergers d’anacardiers. Ces travaux visent a analyser les modifications du paysage dans les espaces ruraux au Sud-Ouest du Parc National de Comoe (PNC), patrimoine mondial de l’Unesco. De facon specifique, il s’est agi de : (i) cartographier a partir de trois images satellitaires Landsat acquises respectivement les 29/01/2002, 02/12/2006 et 23/02/2014, l’occupation du sol des espaces ruraux au Sud-Ouest du parc national de Comoe et de (ii) suivre la dynamique des differents types d’occupation du sol de 2002 a 2014. Les resultats ont revele que les surfaces occupees par la culture de l’anacarde dans la zone couverte par cette etude sont passees de 11 743 hectares en 2002 a 29 872 hectares en 2014 (soit plus de 160%), tandis que les surfaces des forets (galeries forestieres et forets denses seches) ont fortement regresse et sont passees de 26 242 hectares en 2002 a 6 133 hectares en 2014 (soit -76%). Si la dynamique actuelle du paysage se poursuit, le PNC risque a moyen terme d’etre objet de convoitise par les populations rurales, ce qui fragiliserait sa preservation et sa conservation. © 2019 International Formulae Group. All rights reserved Mots cles: Vegetation, Culture de l’anacarde, Teledetection, Cartographie, Dynamique du paysage, Cote d’Ivoire English Title: Reach of cashew fields on forests and savannas in a rural environment around the National Park of Comoe English Abstract Owing to the cultivation of cashew nuts, savannas and forests in the northern parts of Cote d'Ivoire are transformed into vast orchards of cashew trees. This work aims to analyze landscape changes in the rural areas in the South-West of the Comoe National Park (CNP) which is known as Unesco World Heritage. Specifically, it consisted of: (i) mapping from three Landsat satellite images acquired respectively on 2002/01/29, 2006/12/02 and 2014/02/23, the land use of the South-West of Comoe National Park, and (ii) monitor the dynamics of different types of land use from 2002 to 2014. The results revealed that the areas covered by the cashew crop in the study zone increased from 11,743 hectares in 2002 to 29,872 hectares in 2014 (ie more than 160%), while forest areas (galleries forest and dry dense forests) declined sharply from 26,242 hectares in 2002 to 6,133 hectares in 2014 (ie -76%). If the current dynamics of the landscape continues, the CNP could be coveted by the rural populations, in the medium term, so that would weaken its preservation and conservation. © 2019 International Formulae Group. All rights reserved Keywords: Vegetation, Cashew crop, Remote sensing, Cartography, Landscape Dynamics, Cote d’Ivoire

To assess the impact of a decade of biennial mass administration of praziquantel on schistosomiasis in school-age children in Burkina Faso.In 2013, in a national assessment based on 22 sentinel sites, 3514 school children aged 7-11 years were checked for Schistosoma haematobium and Schistosoma mansoni infection by the examination of urine and stool samples, respectively. We analysed the observed prevalence and intensity of infections and compared these with the relevant results of earlier surveys in Burkina Faso.S. haematobium was detected in 287/3514 school children (adjusted prevalence: 8.76%, range across sentinel sites: 0.0-56.3%; median: 2.5%). The prevalence of S. haematobium infection was higher in the children from the Centre-Est, Est and Sahel regions than in those from Burkina Faso's other eight regions with sentinel sites (P 0.001). The adjusted arithmetic mean intensity of S. haematobium infection, among all children, was 6.0 eggs per 10 ml urine. Less than 1% of the children in six regions had heavy S. haematobium infections - i.e. at least 50 eggs per 10 ml urine - but such infections were detected in 8.75% (28/320) and 11.56% (37/320) of the children from the Centre-Est and Sahel regions, respectively. Schistosoma mansoni was only detected in two regions and 43 children - i.e. 1 (0.31%) of the 320 from Centre-Sud and 42 (8.75%) of the 480 from Hauts Bassins.By mass use of preventive chemotherapy, Burkina Faso may have eliminated schistosomiasis as a public health problem in eight regions and controlled schistosome-related morbidity in another three regions.Évaluer l'impact d'une décennie de distribution biennale massive de praziquantel sur la schistosomiase chez les enfants d'âge scolaire au Burkina Faso.En 2013, dans le cadre d'une évaluation nationale basée sur 22 postes-sentinelles, un examen des urines et des échantillons des selles ont respectivement été utilisés pour déceler des infections à laLaGrâce à un recours massif à la chimiothérapie préventive, le Burkina Faso a peut-être éradiqué la schistosomiase en tant que problème de santé publique dans huit régions et endigué la morbidité liée à la schistosomiase dans trois autres régions.Evaluar el efecto de una década de administración bienal de praziquantel en masa para la esquistosomiasis en los niños en edad escolar de Burkina Faso.En 2013, en una evaluación nacional basada en 22 sitios centinela, se examinó a 3 514 alumnos de entre 7 y 11 años para saber si estaban infectados porSe encontróGracias al uso masivo de quimioterapia preventiva, Burkina Faso puede haber eliminado la esquistosomiasis como un problema de salud pública en ocho regiones y controlado la morbilidad relacionada con la esquistosomiasis en otras tres regiones.تقييم تأثير توزيع دواء "البرازيكوانتيل" على نطاق عمومي كل سنتين على مدار 10 سنوات في داء البلهارسيا المصاب به الأطفال من سن الدراسة بدولة بوركينا فاصو.في عام 2013، جرى تقييم وطني مستند إلى 22 موقعًا خفريًا، وتم فحص 3514 طفلاً من أطفال المدارس الذين تتراوح أعمارهم من 7 إلى 11 عامًا للكشف عن عدوىتم اكتشاف عدوىلعل النجاح كان حليف بوركينا فاصو في القضاء على داء البلهارسيا كمشكلة صحية عامة في ثماني مناطق عبر استخدام العلاج الكيميائي الوقائي على نطاق عمومي، كما نجحت في ضبط معدل الإصابة بالأمراض المتصلة بعدوى البلهارسيا في ثلاث مناطق أخرى.旨在评估为期十年（两年一次）大规模吡喹酮施用对布基纳法索学龄儿童血吸虫病的影响。.2013 年开展的全国性评估活动对 22 个前哨地区 3514 名 7 至 11 岁学龄儿童分别进行了尿液和粪便采样化验，以检测埃及裂体吸虫和曼氏裂体吸虫感染情况。我们对活动观察到的感染率和感染强度进行了分析，并将其与布基纳法索早期相关调查结果进行比较。.检测发现学龄儿童中埃及裂体吸虫感染比例为 287/3514（调整后感染率为：8.76%；前哨地区感染率范围为：0.0-56.3%；中值为：2.5%)。中东部、东部和萨赫勒大区儿童埃及裂体吸虫感染率高于布基纳法索其他八个前哨地区 (通过大规模施用化学预防疗法，布基纳法索可在八个地区清除血吸虫病这一危害公众健康的问题；同时可在另外三个地区控制与血吸虫有关的疾病感染率。.Оценить влияние массового применения празиквантела, повторяющегося каждые два года в течение десяти лет, на распространенность шистомосоза у детей школьного возраста в Буркина-Фасо.В 2013 году в ходе национальной оценки, проводимой на 22 постах наблюдения, 3514 школьников в возрасте от 7 до 11 лет были проверены на наличие инфекцийБлагодаря массовому применению профилактической химиотерапии в Буркина-Фасо такую проблему здравоохранения, как шистосомоз, можно считать решенной в восьми областях, а в других трех областях осуществляется контроль за заболеваемостью, связанной с шистосомой.

Schistosomiasis is the most important waterborne disease in Sub-Saharan Africa. Transmission is governed by the spatial distribution of specific freshwater snails that act as intermediate hosts and human water contact patterns. In developing countries, such as Burkina Faso it remains a serious health problem, which management face important gaps. The main of theses gaps is the lack of reliable information about prevalence. Then, this study has been undertaken in order to determine the prevalence of schistosomiasis in the Centre and Plateau Central regions in Burkina Faso. A cross-sectional descriptive study was conducted in the Plateau Central and Centre regions of Burkina Faso to assess the status of schistosomiasis and intestinal worms among school age children. 1,455 school-age children were selected to participate to the study. Results shows that prevalence of Schistosoma haematobium in the Plateau Central and Centre regions were 4% and 0.6% respectively, with an overall prevalence of 2.3% (95% CI: 1.5% - 3.1%) in two regions. The following intestinal parasites were found in stools with various prevalence: Schistosoma mansoni 0.1% (95% CI: 0% - 0.3%) and Ancylostoma duodenale 0.1% (95% CI: 0% - 0.2%). The prevalence of urinary schistosomiasis in the Centre and Plateau Central regions had been greatly reduced from the previous level in the published data since the large-scale population treatment initiated in 2004. The study confirmed the success in controlling the disease by preventive chemotherapy. However, the progress toward its elimination requires that the implementation of a monitoring and evaluation system focused on sentinel sites, and aiming at quantifying the impact of treatment, be gradually coupled with a monitoring system to identify any outbreak of residual transmission. © 2016 International Formulae Group. All rights reserved Keywords: Schistosoma soil-transmitted helminths, mass drug administration, Burkina Faso

International audience; The aim of this study is to determine landscape dynamics in the classified forest of Haut-Sassandra (CFHS) during the periods of conflict in Ivory Coast (or Côte d’Ivoire). To achieve this, the land cover of this protected area was determined by classifying satellite images obtained before, during and after the conflicts, and via ground surveys. Metrics of landscape ecology were calculated. A ground campaign for observing the CFHS’s flora and damages incurred was carried out using a sampling of eighteen 500 m-long transects. The results show that forest fragmentation intensified during and after the period of conflicts. Forests covered over 93% of the CFHS’s area before conflicts and under 28% in 2015. The main cause of this deforestation is cacao growing. Anthropic activities caused the loss of 40% of plant species, including some which are endemic in Ivory Coast.

Background Burkina Faso is endemic with soil-transmitted helminth infections. Over a decade of preventive chemotherapy has been implemented through annual lymphatic filariasis (LF) mass drug administration (MDA) for population aged five years and over, biennial treatment of school age children with albendazole together with schistosomiasis MDA and biannual treatment of pre-school age children through Child Health Days. Assessments were conducted to evaluate the current situation and to determine the treatment strategy for the future. Methodology/Principal Findings A cross-sectional assessment was conducted in 22 sentinel sites across the country in 2013. In total, 3,514 school age children (1,748 boys and 1,766 girls) were examined by the Kato-Katz method. Overall, soil-transmitted helminth prevalence was 1.3% (95% CI: 1.0–1.8%) in children examined. Hookworm was the main species detected, with prevalence of 1.2% (95% CI: 0.9–1.6%) and mean egg counts of 2.1 epg (95% CI: 0–4.2 epg). Among regions, the Centre Ouest region had the highest hookworm prevalence of 3.4% (95% CI: 1.9–6.1%) and mean egg counts of 14.9 epg (95% CI: 3.3–26.6 epg). A separate assessment was conducted in the Centre Nord region in 2014 using community-based cluster survey design during an LF transmission assessment survey (TAS). In this assessment, 351 children aged 6–7 years and 345 children aged 10–14 years were examined, with two cases (0.6% (95% CI: 0.2–2.1%)) and seven cases (2.0% (95% CI: 1.0–4.1%)) of hookworm infection was identified respectively. The results using both age groups categorized the region to be 2% to, Author Summary Burkina Faso is a West African country endemic with soil-transmitted helminth infections (STH). Mass treatment with albendazole has been implemented for over a decade in the country through annual mass drug administration (MDA) for lymphatic filariasis for population aged five years and over, biennial treatment of school age children with albendazole together with schistosomiasis MDA, and biannual treatment of pre-school age children through Child Health Days. A sentinel site survey in 2013 showed that STH infection in Burkina Faso was very low at 1.3%. Hookworm was the main species detected, but infection was low and light. An assessment was also conducted with two age groups in Centre Nord region through lymphatic filariasis transmission assessment survey in 2014. The results confirmed the low level of infection with soil-transmitted helminths in the region. Through large-scale preventive chemotherapy, Burkina Faso has effectively controlled STH in school age children in the country. The future STH deworming strategy may focus on consolidating the gain and interrupting the STH transmission in the country.

La forêt classée du Haut-Sassandra considérée comme l’une des forêts classées les mieux protégées de la Côte d’Ivoire connaît aujourd’hui plusieurs intrusions dans ses limites conventionnelles à la faveur de la crise militaro-politique dans le pays, de 2002 à 2011. De nombreux fronts pionniers ont été ouverts et ont entraîné le défrichement de plusieurs milliers d’hectares de forêts naturelles suivi d’installation de cultures de rente notamment le cacaoyer. C’est dans ce conteste que le présent travail tente d’évaluer les surfaces forestières restantes de cette aire protégée anciennement contrôlée par les groupes armées rebelles à l’autorité gouvernementale. De façon spécifique, il s’est agi d’une part de cartographier l’occupation du sol du nord de la forêt classée du Haut-Sassandra et de sa périphérie Nord en 2001 et 2013 et, d’autre part, de suivre la dynamique des différents types d’occupation du sol de 2001 à 2013. À cette fin, deux images satellitaires Spot 4 du 14/12/2001 (scène 190.53) et Spot 5 du 28/12/2013 (scène 192.53) ont été acquises et traitées. Il ressort de ces travaux que les surfaces des forêts denses humides naturelles ont fortement régressé dans la zone d’étude et sont passées de 37749 hectares en 2001 à 7844 hectares en 2013 (soit 79, 22 % de régression). Au contraire, les surfaces des mosaïques jachères-cultures ont fortement augmenté et sont passées de 9910 hectares à plus de 36 374 hectares. Du massif forestier du Nord de la forêt classée du Haut-Sassandra, ne subsiste aujourd’hui que des lambeaux de forêts généralement dégradées., The classified forest of Haut-Sassandra which is considered as the best protected classified forest of Côte d’Ivoire, knows several intrusions in its conventional limits supported by the military political crisis in the country, and which lasted from 2002 till 2011. Several pioneers fronts were opened and entailed the clearing of several thousand hectares of natural forests followed by installation of cash crop in particular the cocoa. In this context, the present work tries to estimate the remaining forest surfaces of this protected area mainly in the North, previously controlled by armed groups rebel to Governement authority. On the one hand, this work aims to map the land use of the North of the classified forest of Haut-Sassandra and its periphery in 2001 and 2013 ; and on the other hand to follow the dynamics of the forest cover and these land use types from 2001 till 2013. To achieve these objectives, two Spot images from Spot 4 of 14/12/2001 (scene 190.53) and Spot 5 of 28/12/2013 (scene 192.53) were acquired and treated. This study revealed that the surfaces of the natural rain forests strongly declined and passed from 37749.06 hectares in 2001 to 7 844.62 hectares in 2013 (that is 79.22 %). On the contrary, the surfaces of mosaics fallows-cultures strongly increased and passed from 9 909.74 hectares to more than 36 374 hectares. Of the forest massif of the North of the classified forest of Haut-Sassandra, it remains only scraps of generally degraded forests today.

One of the two main goals of the Global Programme to Eliminate Lymphatic Filariasis (LF) is to provide care for those suffering from the devastating clinical manifestations of this filarial infection. Among the 120 million infected people worldwide, up to 16 million have lymphoedema. The WHO strategy for managing lymphoedema is based on rigorous skin hygiene, exercise, antibiotics and antifungals when indicated. The aim is to reduce acute attacks of adenolymphangitis and cellulitis responsible for lymphoedema progression and disability. The objective of our study was to assess the effectiveness of home-based lymphoedema management implemented by the national health system of Burkina Faso. Any patient was eligible to participate in the study if suffering from LF-related lymphoedema of a lower limb at any stage, and receiving care as part of the health education and washing project between April 2005 and December 2007. The primary readout was the occurrence of an acute attack in the month preceding the consultation reported by the patient or observed by the care-giver. In all, 1089 patients were enrolled in the study. Before lymphoedema management intervention, 78.1% (95%CI: 75.5–80.5) of the patients had an acute attack in the month preceding the consultation; after four and half months of lymphoedema management, this was reduced to 39.1% (95%CI: 36.2–42.1). A reduction of acute attacks related to the number of consultations or related to the patients’ age and gender was not observed. Our results suggest that the home-based lymphoedema management programme in the primary health care system of Burkina Faso is effective in reducing morbidity due to LF in the short-term (4.5 months). The lymphoedema management requires no additional human resources, but whether its effect can be sustained remains to be seen.

La fragmentation des habitats forestiers, induisant une réduction de I'aire totale et une augmentation du nombre de taches forestières constitue I'une des menaces majeures pour le maintien de la biodiversité. La présente étude menée dans la province orientale de la République Démocratique du Congo s'articule autours de I'hypothèse selon laquelle, dans les zones forestières, la variation de la densité de la population entraîne un changement de la structure du paysage. Nous avons déterminé la classe forestière à partir de la classification d'une image de type Landsat ETM+ datant de 2001. Après avoir subdivisé la zone en 266 cellules de 10 km × 10 km, quatre indices de structures spatiales quantifiant la fragmentation de la forět (classe forět) ont été calculés : le nombre d'îlots de forět (taches de forět), la proportion de couverture forestière, la dominance de la plus grande tache et la dimension fractale. La densité de la population dans chaque cellule a été obtenue à partir des données de I'UNEP de I'année 2000. Les résultats ont montré I'existence de corrélations hautement significatives entre la densité de la population et les indices de fragmentation confirmant ainsi I'influence de la densité de la population sur la dégradation de I'écosystème naturel matérialisée par la fragmentation forestière.

Des travaux anterieurs ont montre que les conflits armes des annees 2000 en Cote d’Ivoire ont entraine une forte anthropisation de la foret classee du Haut-Sassandra situee au Centre-Ouest du pays. L’objectif de la presente etude etait de determiner l’impact de la presence des differentes forces militaires sur la dynamique de cette foret pendant la periode des conflits. La methodologie a consiste en la division de la foret en trois zones, Nord, Centre et Sud, suivant les types de forces presentes pendant la periode des conflits. La dynamique spatiotemporelle de ces zones a ete determinee a partir de la classification supervisee de trois images Landsat datant de 2002, 2006 et 2013. Une matrice de transition, un indice de stabilite et des indices de composition ont servi a analyser les changements intervenus dans les paysages pendant les periodes d’etude. La comparaison des zones a travers les indices indique qu’il n’y a pas de difference significative entre elles. Il apparait ainsi que les trois zones subi la meme dynamique de deforestation pendant la periode de conflits. La presence des forces internationales dans les parties Centre et Sud de la foret classee du Haut-Sassandra n’aurait pas empeche leur infiltration et leur deboisement. Mots cles : forces militaires, dynamique forestiere, anthropisation, fragmentation

In order to enable the development of appropriate landscape management plans, the causes and impacts of fragmentation should be fully understood. A new definition, incorporating the key aspects cited in landscape ecological literature since the 1980s, is proposed in order to shed light on the matter of fragmentation. By means of two case studies in the Democratic Republic of the Congo (Oriental Province) and in North Benin, the key role of anthropogenic activities in landscape fragmentation is evidenced; the spatial dispersion of forest vegetation is linked to population density and land use change. The potential impact of fragmentation on biodiversity is shown by an analysis of forest diversity in Ivory Coast (Tanda region), and by a study of edge effects on two rodent species in the Democratic Republic of the Congo (Kisangani). The chapter is concluded by an study on how planned corridors, assuming a spatial regrouping of existing teak plantations, could contribute to the conservation and management of remaining natural forest patches in the Atlantic Department in Benin.

From an ecological landscape perspective, cultural landscapes can be considered as “anthropized” landscapes, in which patterns and processes are altered by human intervention. The importance of the study of spatial patterns in landscapes is justified by the pattern/process paradigm. The emergent properties of patterns reflect two components: landscape composition, which describes the number of patch types as well as their abundance, and landscape configuration, which refers to the spatial arrangement of the patch types. In this chapter, methods and strategies to analyze spatial pattern and landscape dynamics are discussed, and emphasis is put on the detection and quantification of anthropogenic effects on landscapes. Land mosaics showing anthropogenic effects are characterized by fragmented natural land cover, high frequencies of edge habitat, simple patch geometry, and dominant proportions of anthropogenic patch types. Landscape transformations associated with “anthropization” lead to a disintegration of natural patch types and to a reinforcement of anthropogenic ones. Four techniques to measure anthropogenic effects on pattern are discussed (1) the quantification of the fragmentation of natural habitats and its interpretation in terms of diversity, heterogeneity and entropy, (2) the quantification of edge effects in order to measure the ecological impact of human activity, (3) the determination of patch fractal dimensions to detect pattern simplification, and (4) the determination of the landscape transformation processes responsible for pattern dynamics. At the end of the chapter, a short list of analysis methods and strategies is proposed for detecting and measuring landscape “anthropization.”

Landscape ecology is defined as the study of ecological patterns and processes in their spatial context (Antrop 2001). Landscape ecology is motivated by a need to understand the development and dynamics of pattern in ecological phenomena, the role of disturbance in ecosystems, and characteristic spatial and temporal scales of ecological events (Urban et al. 1987). Many other definitions of landscape ecology can be found in the literature (Turner et al. 2001; Wu and Hobbs 2007). The same observation can be made for the landscape concept (Farina 2000a). Application of the principles of hierarchy theory (Allen and Starr 1982; Urban et al. 1987; Forman 1995; Burel and Baudry 2003; Bogaert and Mahamane 2005) to the biosphere leads to a definition of a landscape as the level of spatial or biological organization situated between the ecosystem level (lower level of organization than the landscape) and the regional level (higher level of organization than the landscape). A landscape can consequently be defined asa cluster of interacting and contiguous ecosystems; several contiguous landscapes will constitute a region.

Situee a proximite de Kinshasa, la province du Bas-Congo (R.D. Congo) est l\'une des principales pourvoyeuses en produits vivriers de cette ville. Par consequent, l\'augmentation de la pression sur les ressources naturelles s\'accentue. L\'analyse diachronique du paysage peut servir a montrer l\'effet des actions anthropiques sur l\'occupation du sol de cette province. La presente etude a pour but la quantification de la dynamique paysagere dans une zone test de cette province entre 1960 et 2005. Elle a permis, grâce a la matrice de transition appuyee par le calcul d\'indices de structure spatiale, de montrer que l\'occupation du sol a profondement change. La matrice du paysage, initialement constituee par les forets secondaires (49,95% du paysage), s\'est degradee au profit des savanes (qui ont conquis 14,23% des forets secondaires) et des jacheres et champs (qui ont conquis 27,23% des forets secondaires). L\'etude a ainsi revele trois processus de transformation du paysage: la savanisation, la fragmentation de l\'ecosysteme forestier et enfin une la formation de foret dense (succession). Ces changements – excepte la succession – sont principalement dus a des perturbations anthropiques. La pression demographique et les pratiques agricoles non durables ont oriente la modification de l\'occupation du sol. Les ecosystemes forestiers ont ete substitues par des ecosystemes anthropises menacant alors la biodiversite de cette zone. Situated nearby Kinshasa, the Bas-Congo province (Democratic Republic of the Congo) is one of the principal providers of food products of this city. Consequently, an increased anthropogenic pressure on natural resources is observed. Analysis of the landscape dynamics can be used to demonstrate the impact of human activities on land cover in this province. The objective of this study is to quantify landscape dynamics between 1960 and 2005 in a test zone situated in the aforementioned province Based on the interpretation of the transition matrix and on the calculation of spatial pattern metrics, a profound change of land cover has been shown. The landscape matrix, initially constituted by secondary forests (49.95% of the landscape), has been degraded and replaced by savannah vegetation (substitution of 14.23% of the secondary forests) and mosaics of fallow land and fields (substitution of 27.23% of the secondary forests). Three spatial processes of land transformation have been identified: creation of savannah, forest degradation or fragmentation, and formation of dense forest (succession). These changes – except succession – are mainly due to anthropogenic disturbance. Demographic pressure and unsustainable agricultural practices have contributed to the change of land cover. Forest ecosystems are substituted by anthropogenic ecosystems which indicates a threat to the biodiversity of this area. Keywords : Landscape dynamics, land cover, anthropogenic pressure, agricultural system, Central Congo Province, biodiversity. Sciences & Nature Vol. 5 (1) 2008: pp. 49-60

Forest fragmentation has a paramount impact on landscape pattern and has therefore been a key focus of landscape ecology. Trends and causes of deforestation are analysed for the Democratic Republic of the Congo, Rwanda and Burundi, and are put in a regional, continental and global perspective. In order to investigate the role of shifting cultivation as a driver of fragmentation, the dynamics of a forest landscape between 1970 and 2005 for a study area in the Bas-Congo province of the Democratic Republic of the Congo were analysed. Using a transition matrix and the identification of the spatial land transformation processes involved, historical data are compared with the current situation based upon field visits and remote sensing imagery. As a consequence of non sustainable shifting agriculture, forest fragmentation is observed, leading to an expansion of savannah, fallow lands and fields which replace secondary forest vegetation and limit forest succession towards primary forest. Since forest ecosystems are known to be the habitat of indicator species only observed in one specific phytogeographic territory, the potential impact of habitat preservation for these species is investigated. A dataset of 310 Acanthaceae species containing 6362 herbarium samples for the Democratic Republic of the Congo, Rwanda and Burundi is analysed and species presence is compared with the phytogeographic theories of Robyns (1948), White (1979,1983) and Ndjele (1988). Study of the spatial distribution and analyses of species habitats reveal the importance of forest preservation to protect these indicator species. Conservation of these habitats should therefore be given priority to avoid loss of genetic resources for future generations. Implications for the management of forested landscapes are discussed, regarding the role of local populations, the application of ecological principles, the conservation of virgin forests, the potential role of forest plantations, and the importance of landscape pattern analysis.

Les communes de Banté-Glazoué-Ouessé (département des Collines) en zone sou- dano-guinéenne du Bénin constituent le domaine des mosaïques de forêts et une des principales pourvoyeuses en produits agricoles et en charbon de bois. Ces mosaïques de forêts sont soumises à de multiples formes de dégradation. Une étude de la dynamique spatio-temporelle basée sur une interprétation des images de types Landsat (MSS 1972, TM 1986 et ETM+ 2006) a été réalisée grâce à l’utili- sation du système d’information géogra- phique et des outils d’écologie du paysage afin d’envisager un programme de restau- ration forestière. Les résultats de cette étude ont permis, grâce à des matrices de transition et des indices de structure spa- tiale, d’évaluer les mutations liées aux pratiques agricoles. Quatre grands pro- cessus de transformation spatiale ont été mis en évidence et quantifiés pour la période de 34 ans (1972 à 2006) retenue pour cette étude : (i) la formation des savanes, (ii) la déforestation, (iii) le déve- loppement des activités agricoles et, enfin,(iv) une restauration forestière. La dyna- mique de la structure spatiale est dominée pendant cette période d’étude par une séquence de création suivie d’agrandis- sement pour les taches des classes de champs-jachères et de plantations arbo- rées ; d’agrégation pour les classes de savanes et de sols nus-agglomérations ; et de suppression pour les taches de forêt.

La dynamique temporelle des forêts d'une zone de transition forêt-savane, située dans le département de Tanda, à l'est de la Côte d'Ivoire, a été déterminée à partir de l'analyse diachronique de deux images satellitaires de type Landsat TM 1986 et Landsat ETM+ 2000, et de missions de vérification sur le terrain. Les résultats indiquent que les surfaces forestières en 2000 couvraient 29 % de la zone d'étude au lieu de 73 % en 1986. Cette régression forestière a été compensée par une augmentation des zones occupées par les savanes. Les forêts denses sont les plus affectées par cette perte d'habitat, leur superficie ayant diminué de 83 % pendant la période d'étude. La dynamique spatiale du paysage, caractérisée par des indices structuraux, a montré un processus de création de taches de savanes par opposition à la suppression de celles des formations boisées. D'une façon générale, la région d'étude a subi une transformation importante liée essentiellement aux activités agricoles et à la pression démographique. (Résumé d'auteur)