Large time behavior of solutions of viscous Hamilton-Jacobi Equations with superquadratic Hamiltonian

We study the long-time behavior of the unique viscosity solution $u$ of the viscous Hamilton-Jacobi Equation $u_t-\Delta u + |Du|^m = f\hbox{in }\Omega\times (0,+\infty)$ with inhomogeneous Dirichlet boundary conditions, where $\Omega$ is a bounded domain of $\mathbb{R}^N$. We mainly focus on the superquadratic case ($m>2$) and consider the Dirichlet conditions in the generalized viscosity sense. Under rather natural assumptions on $f,$ the initial and boundary data, we connect the problem studied to its associated stationary generalized Dirichlet problem on one hand and to a stationary problem with a state constraint boundary condition on the other hand

Human Elephant Conflict in the Waza-Logone Region of Northern Cameroon: An Assessment of Management Effectiveness

An investigation into the current level of humanelephant conflicts in the Waza Logone region was carried out during the 2005 rainy season to assess the effectiveness of conflict management. This was done by talking mainly to wildlife authorities, the local agricultural service, the local communities and consulting sequential reports from the nearest enumerators. The number of villages affected was declining in the dry season compared to the rainy season crop raiding. However, general pattern indicates a decline in the number of villages impacted by elephants since the 1992 to 1993 surveys, but comparatively more damaging as shown by the estimated costs. Therefore, the improve in ecological management of the Waza National Park and its elephant population has had a positive impact in the number of villages crop raided but has not definitely resolved the conflicts between man and elephant. Other approaches are needed to buttress the effort been undertaken in the region to date

Aerial survey of Elephants (Loxodonta africana africana), other large mammals and human activities in Waza National Park, Cameroon

Total aerial count of elephants, other large mammals and human activities in Waza National Park was conducted between 21st and 23rd February 2007. Total counts of elephants and other wildlife species were done and livestock numbers were estimated. A Cessna 206 Stationair six-seater aircraft fitted with GPS was used in navigation, recording survey paths and waypoints. A total of three different herds of 180 and 66 in the park along with a further 250 migrating elephant population towards Kalamaloue National Park were counted. The herds in the park were aggregated around central part of the park along watering point. The consideration of the number of the migrating herd then put the total Waza ecosystem elephant population at 496 individuals. The total number of carcasses recorded was 7 giving a carcass ratio of 2.85%. About 21,002 heads of livestock and over 50 farmlands and human settlement were estimated in the zone abutting the park. This signifies a high level of human pressures at the periphery and thus a high potential for loss of range for the elephants and illegal killing

Les gorilles du Parc National de Lobéké (Cameroun): interactions avec les populations locales et implications pour la conservation

La connaissance des interactions entre les populations locales et le gorille est nécessaire pour l’élaboration des stratégies de conservation durable dans une aire protégée. L’insuffisance d’informations de base sur ces interactions a motivé la présente étude autour du Parc National de Lobéké (PNL). Des entretiens et des enquêtes ont été menés auprès des  ménages, des gestionnaires de parc et des associations villageoises dans quatre sites autour du parc. Le résultat des enquêtes indique que le gorille est une source importante de revenus à travers le tourisme, les emplois locaux et des réalisations des opérateurs économiques. Cependant, ces retombées sont disparates selon les sites et restent d’ailleurs négligeables auprès des populations. D’autre part, le gorille génère les conflits, puisqu’il détruit les champs des riverains et est braconné par les populations. Les pertes en cultures sont rapportées par plus de 59% des ménages selon le site et sur près de 30% des superficies cultivées. Ainsi, les stratégies de redistribution des retombées et de résolution des conflits doivent tenir compte des spécificités de chaque site autour du parc. Il est recommandé de sensibiliser les populations à installer leur champ dans un périmètre où elles maîtrisent le contrôle.Mots clés: Gorille, Tri-National de la Sangha, conflit Homme-gorille, gouvernance

Analysis of Cameroon’s forestry sector: Implication for sustainable management

Cameroon forestry sector has undergone profound institutional and legislative reforms for the past decades. Consequently, the objective of this paper is to examine the activities of Cameroon administration focused on the strategies for sustainable management of the forestry sector. The target population for achieving this objective constituted members of the forest administrative personnel. Primary data resulted from structured questionnaire and interview of key persons, secondary data resulted from consultation of annual reports and adequate literatures. Result revealed a drastic drop in labour force in all the categories; technical incompetence of more than 81% of the personnel notably with respect to the accomplishment of certain tasks; majority of the respondents agreed with the following: decision making process did not give room for everybody’s opinion; decisions taken, did not reach every level; no quality interaction between superior staff and subordinates and hardworking staffs were rarely usually rewarded. Nevertheless, most of the respondents revealed that the impact of decentralization in the forestry sector and the contribution to the national economy are positive. Consequently, decision makers of the forestry sector should consider the development of human capacity as a priority in view of personnel motivation of the sector, to better accomplish assigned tasks.Keywords: Forest administration, motivation, devolution of responsibilities, bureaucrac

Elephants and their interactions with people and vegetation in the Waza-Logone region, Cameroon

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Caracterização e cartografia da vegetação da região do Chipindo Província da Huíla - Angola

Angola tem escassez de estudos de biodiversidade e a flora é mal conhecida. Neste trabalho estudou-se a vegetação no município de Chipindo, província da Huíla, sudoeste de Angola, inserido no bioma Sudano-Zambeziaco, coberto essencialmente por florestas ou florestas de Miombo. Foram realizados inventários de campo em 79 parcelas de 1.000 m2, distribuição aleatório-estratificada, pelo município de Chipindo em concordância com as manchas do mapa de vegetação. Calcularam-se índices de diversidade e, com análise de imagens de satélite, determinou-se a variação dos parâmetros fenológicos “Doy start green”, Amplitude, “Green duration” e Total Integral, ao longo do ano. A vegetação do Chipindo é bastante diversificada e apresenta três formações, todas do grupo Miombo: floresta aberta de Brachystegia floribunda, floresta de Brachystegia boehmii e floresta de Julbernardia paniculata e Brachystegia spiciformis. São formações jovens, com predominância de árvores com 30-80 cm de perímetro à altura do peito, que ocorrem em solos ferralíticos e paraferraliticos. Os principais fatores de degradação são a agricultura, fogo e aumento da população; Abstract: Characterization and cartography of vegetation in the Chipindo region of Huíla province - Angola Angola has a great lack of biodiversity studies and knowledge on vegetation is particularly scarce. In this work we studied the vegetation in the municipality of Chipindo, province of Huíla, southwest Angola, inserted in the Sudano-Zambeziaco biome, mainly covered by Miombo forests. Field surveys were carried out in 79 plots of 1,000 square meters, random-stratified distributed throughout the municipality of Chipindo in concordance with patches of vegetation map. Diversity indexes were calculated and, with satellite images, the variation of the phenological parameters "Doy start green", Amplitude, "Green duration" and Total Integral were determined throughout the year. Vegetation of Chipindo has great diversity and presents three formations, all of the group Miombo: open forest of Brachystegia floribunda, forest of Brachystegia boehmii and forest of Julbernardia paniculata. They are young formations, with predominance of trees with 30-80 cm of perimeter at breast height, that occur in ferralitic and paraferralitic soils. The main degradation threats are agriculture, fire and population increase

Status of blue duiker (Cephalophus monticola) in the Lebialem-Mone- Banyang-Mbo landscape, South-West Cameroon

A survey of blue duikers (Cephalophus monticola) in the Lebialem-Mone-Banyang-Mbo (LMBM) landscape was conducted during the period of May to September 2012 with the aim of establishing a database for the enhancement of sustainable management of Wildlife population. The line transect method (Tsi, 2011) was used for data collection. Results revealed an encounter rate of 12.8 indexes per km, a density of 2.56 per km2 and estimate of 1162 blue duikers in the entire landscape. The findings also showed that there is currently a high level of bush meat harvesting and a tragic forest transformation due to uncontrolled anthropogenic activities in the landscape. In comparison with the findings of Walhert in Korupt national park, the estimated density in the LMBM landscape was considered relatively high for a non protected area. It was concluded that this high population of blue duikers against a background of intense anthropogenic activities is indicative; It is strong evident that LMBM landscape serves as a natural wildlife corridor, linking it many surrounding protected areas. There the gazetment of the proposed Bechati- Mone wildlife corridor situated in the LMBM landscape will go a long way to enhance effective wildlife conservation in the region.Keywords: Conservation status, blue duiker, encounter rate, anthropogenic activities, sustainable management, wildlife corridor