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Abstracts Titles


The forest sector in the Congo basin, scientific challenges and opportunities for assessing carbon sequestration capacity

Neree Onguene Awala (1), J. T. Mbogne (2), E. Banfield (3), M. Apps (4), P. D. Khasa (5)
1) Institute of agricultural research for development (IRAD), B.P. 2123 Yaoundé, Cameroon
2) Université de Yaoundé I, département de Physiologie et de Biologie Végétale
3) Natural Resources Canada, Canadian Forest Service, Edmonton, Alberta, Canada,
T6H 4Z4
4) Centre d’étude de la Forêt, Université Laval, Québec, Canada, G1K 7P4

Abstract. For four decades, the problem of increasing atmospheric carbon dioxide and trend in climate rising has become a global concern. Consequently, numerous initiatives have been taken since the years 1980s in order to reduce anthropogenic emissions of greenhouse gases which are CO2, CH4, and N2O… A long literature study based upon many discussions on experts in the field was undertaken to establish whether at the dawn of the 21st century, the carbon budget of the forestry sector of Congo basin was a sink or a source of CO2 emissions. In general, two approaches are used to account for carbon fluxes and stocks of a sector or an ecosystem: data collection from the field and biomass destruction and an indirect method based on mathematical models using allometric equations. Moreover, the carbon budget of a sector or an ecosystem requires many data obtained with several tools like forest inventories, growth and annual wood yields, volumes of exported forest wood and mono, or specific, regional or pantropical allometric equations. After nearly 8000 years, after the last glaciations, forests of the Congo basin cover today a surface area of 4048378 sq² (about 227 millions of hectares). They have accumulated carbon in nearly 40% in forests, 15% in forestry concessions, 11% in protected areas and 11% in agricultural farms. During the period 1990 to 2000, carbon stocks were reduced by deforestation and forest degradation to 0.17% and 0.09, respectively, resulting in 47000 sq² lost of forest cover, suggesting that the carbon budget of the forestry sector of the Congo basin is an important sink and a large reservoir of 15% of world carbon. However, less than 10 allometric equations have been developed for three forest cover types for Cameroun, Gabon and Democratic republic of Congo. All the same, available data do not allow modeling of regional carbon fluxes and stocks according to Marrakech Accords (2001). This requires first of all starting and actualizing forest inventories in the six regional countries as well to promote training in carbon science and geomatics.
Keywords : Carbon budget – Allometric equations – CO2 – Climate change


The woodlands in the margin of the Congo Basin: what place in REDD +?

Robert Christian Anaba Manib (1)
1) Université de Ngaoundéré, Laboratoire de géomatique

Abstract. Tropical forests are seen placed at the center of attention of the international community for combating and attenuation climate change effects. Thus, REDD + promoted in 2010, following REDD (2008) as consistent response aims enhancement of forest carbon stocks in developing countries through the reduction of emissions by deforestation and forest degradation. Since then, several REDD + have been established in countries of the Congo Basin, and rainforests are the heart, leaving reflected a neglect of other vegetation types, including wooded. This discussion attempts to identify possible place woodland margins of the Congo Basin in REDD +. Project analysis reports made in the context of REDD + in Central Africa, literature on this mechanism, as well as the exploitation of woks in savannas allow us to say that the importance of woodland in the margins of Congo Basin is recognized, but little interest to them is still granted.
Keywords : REDD +, woodlands, climate change, marginal forest, savannas, the Congo basin.


Assessing farmers’ interest in Agroforestry practices around the Mount Cameroon National park (MCNP) in Cameroon

Yolande Ndjuala Njongue (1), Marie Louise Avana Tientcheu (2), Eric Fotsing (3), Patrick Muderhwa Mutabesha (4)
1) University of Dschang, Faculty of Agronomy and agricultural sciences (FASA)
2) University of Dschang, Faculty of Agronomy and agricultural sciences (FASA)
3) University of Dschang, The University Institute of Technology Fotso Victor of Bandjoun
4) University of Kinshasa, Faculty of Agronomic Sciences

Abstract. The purpose of this study was to assess farmer’s interest for Agroforestry practices around Mount Cameroon National Park (MCNP). In the study zone, beneficial activities such as fuel wood collection, timber swaying, beekeeping, NTFP gathering, hunting etc. have been deprived of the people due to the change in status of the Mountain into a national park with restricted access. A way out could be to intensify the already existing traditional practices carried out by the farmers around the MCNP. This study aimed at providing the information on the different agroforestry practices around MCNP, and farmer’s constraints and motivations for managing their agroforestry systems. This study was conducted in 8 villages of the four cluster zones round the park (two villages per cluster). Data were collected by using a structured questionnaire, focus group discussions, and direct field observations. The formal and informal interviews were conducted with 190 households ‘heads randomly selected. Descriptive statistics (percentages) were used to show the representation of each agro forestry practice around the park, a multinomial logistic regression analysis was used to determine the factor which explains the choice of a farmers practice and percentages were used to express the percentage of farmers and the constraints they faced in practicing agroforestry. The results showed that the agroforestry practices around the MCNP are heterogeneous and included Cocoa agro forests (39.625%), Trees on cropland (32.625%), Life fences (61.25%), Coffee agro forests (4%), Home gardens (21.875%), Windbreaks (3.75%) and Bee farming (3.75%). The dominant farming practices include cocoa, trees on cropland and palm plantations. A logistic regression model shows a statistically significant variation on the probability of having a system type in a cluster. (Chi square=147.72, df =3, sig=0.000) since the p value 0.00<0.05. The multinomial regression indicated that the determining factor which explains the difference in practices around the park is the agro ecological condition of the cluster zone that influence the performance of the main crops for each practice rather though farmers are aware of the income generating nature or the revenue diversification sources of the system. The major constraints for the promotion of the existing agroforestry practices include lack of tree seedlings for planting (78%) and lack of technical assistance for improved management of associated species. As a result, a more detailed study on the products and services provided by these practices has to be done in other to clearly assess the contribution of the traditional Agroforestry practices in meeting farmer’s needs.
Keywords : Agroforestry technologies, MCNP cluster zones, motivations, constraints.


Participatory management of resources and reduction of woody degradation in the forest reserves of Zamay and Mayo-Louti (Far-North, Cameroon)

Abel Téwéché (1), Michel Tchotsoua (2)
1) Université de Maroua, Ecole Normale Supérieure
2) Université de Ngaoundéré, Laboratoire de Géomatique

Abstract. Forest reserves in Central Africa in general and Cameroon in particular constitute reservoirs for the conservation of biodiversity. Today, these woodlands are under pressure due to anthropogenic activities and the effects of climate change. In the Mandara Mountains, the regressive dynamics of timber are attributable to agropastoral activities and especially to institutional failures in the management of protected areas. This results in both spatial and biological degradation. The purpose of this contribution is to characterize the process of degradation of the woods in the forest reserves of Zamay and Mayo-Louti; Analyze the texts in force relating to forest reserves; Examine the bottom-up approach to participatory resource management. The methodology consisted of exploiting the topographical maps of 1965; To make surveys of current boundaries as well as plots for a diachronic study of the spatial dynamics of the reserves studied. Also, botanical surveys were carried out inside the plots of 900 m². The results show that the area of ​​the Zamay Forest Reserve has increased from 1000 ha in 1965 to 596 ha in 2014, that of Mayo-Louti: 3500 ha in 1965 and 3144 ha in 2014. This study suggests that in addition to Co-management of resources, local populations assisted by NGOs and the State create agroforestry parks, maintain and maintain existing ones in order to protect the wood resources of protected areas on a sustainable basis.
Keywords : Participatory management, Degradation, Forest reserves, Protected areas, Far-North.


Zephania Nji Fogwe (1)
1) The University of Bamenda, Department of Geography and Planning

Abstract. Topographic variations play central stage in subsistence crop cultivation in regions typified by steep slopes. This study examines varying traits of a topographic landscape as constraints to crop cultivation. Focus is laid on how mountain slope inhabitants have gained indigenous knowledge so that they have impacted terrain variation in a bid to increase output and improve their livelihoods. Using primary and secondary sources through descriptive and inferential statistical techniques, data obtained reveal that the intensity of crop cultivation in the Belo area of the Kom Uplands is slope gradient dependent. Topographic variation becomes the main cause of variation in crop types with rice cultivated at low altitude zones; Irish Potatoes in the mid and higher altitudes, meanwhile maize is throughout the area with variable cropping systems. Cognizant that erosion and inaccessibility are prime constraints to crop cultivation affected stakeholders farmers have resorted to internal (mechanical erosion control strategies and the acceptance of agricultural innovations) and external (through the creation of hollow frontiers in and out of the area) measures as hallmarks in their agricultural and rural development of a difficult topographic terrain.
Keywords : Adaptation, cropping, farmers, slopes, topography, Oku


Socio-economic and ecological implications of Eucalyptus expansion in the Western Highlands of Cameroon: The case of Koutaba

Joseph Youta Happi (1)
1) Université de Yaoundé 1, Département de Géographie

Abstract. In Cameroon, the western highlands are densely populated. Average rural densities vary between 200 and more than 500 inhabitants/km². In this region where natural forests are small, the populations have found the establishment of the genus Eucalyptus a palliative to the lack of wood. Afforestation encroaches on savannas and grazing areas, but provides timber and firewood. The study highlights the consequences of these afforestations on the land use and the purchasing power of the populations. Analyzes of survey data, botanical surveys and image processing reveal that reforestation projects initiated in the last 40 years have established 82 ha of Eucalyptus saligna in Koutaba. This gives a positive evolution of the afforestation rate of 4%.
Keywords : Afforestation, Eucalyptus, forest, savanna, Koutaba.


Education, populations and historical evolution of the carbon sequestration process in the Congo basin

Martin Mbengué Nguimè (1), Florence Anisette Bitanda (2)
1) Université de Ngaoundéré, Département d’Histoire et Centre africain de partage du savoir
2) Université de Ngaoundéré, Département d’Histoire et Centre africain de partage du savoir

Abstract. Anthropogenic activity in and around the Congo basin poses the problems of reduced vegetation cover and the long-term growth of the greenhouse effect and, as a result, challenges people around the world. As a result, the researcher who is sensitive to the depletion of carbon reserves questions, for example, the historical responsibility of subjects educated in the reduction of plants and the growth of the influence of the greenhouse effect in and at the margin of the Congo basin. Here, the answer to this main concern is based on the synthesis of writings, observations and field interviews. It is a page of the social and ecological history, the history of the climate or the environment essential to the control of the climatic evolution of the world starting from the Congo basin and, in particular, of the capacity of this space to sequester carbon in the era of Africanity and European preponderance in Africa. Focusing on educational policies of excessive deforestation of tropical and equatorial West Africa, the social uses of forest tree species in the Congolese square of Africa and educational policies of forest rescue for the purpose of carbon sequestration, it is a contribution to historiography at a time when climate change and its effects are fueling debates around the world.
Keywords : Congo zone in Africa, deforestation oriented education, climatic change, dangers to marking; development of the forest pedagogy.


Agroforestry: a wood energy supply potential of villages bordering the Kahuzi Biega National Park in the Democratic Republic of Congo

Patrick Muderhwa Mutabesha (1), Martin Tchamba Ngankam (2), Claude Kachaka Sudi (2), Yolande Ndjuala Njongue (2), Radar Nishuli (3)
1) Université de Kinshasa, Faculté des sciences agronomiques, RDC
2) Université de Dschang, Faculté d’Agronomie et des sciences agricoles, Cameroun
3) Institut Congolais de la Conservation de la Nature, ICCN, RDC

Abstract. In the deforestation and degradation context, agroforestry is increasingly considered in the tropical zones for its potential contribution to provide fuel wood, consequently biodiversity conservation. This biodiversity is threatened by local populations in search of fuel wood. This study had as aim to find out the tree diversity and the potential of traditionnal agroforestry practices around the Kahuzi Biega National Park in Democratic Republic of Congo, as tool of biodiversity conservation. Near of 80 plots were selected after focus group, according to owner availability, agroforestry practices types, the size of plots and tree diversity. Study were driven between may and august 2016. Results shows that fourteen species belonging to 14 monospecific families were surveyed in these traditional agroforestry practices. Significant differences (p<0,01) were noted between species mean number per village (F=39.039, dl=3). Common species for all villages were composed of Grevillea robusta, Eucalyptus sp, Mangifera indica, Persea americana, Maesopsis eminii and Cupressus lusitanica when differential species, were Citrus sp, Erythrina abyssinica, Polyscias fulva, Pinus patula, Cedrela serrulata, Markhamia lutea and Ficus glumosa. Among the enumerate species, 42,85% are indigenious in the region, notably Podocarpus usambarensis, Ficus glumosa, Polyscias fulva, Markhamia lutea, Erythrina abyssinica, Maesopsis eminii. Results of this study, given a potential, approximatively, of 600kg/ha of charcoal, which could give on sale additionnal income near to 100$US/ha. This confirm that traditionnal agroforestry systems could be seen as a possible approach which contribute to reduce poverty, improve food security and to soustainable management of forests.
Keywords : Agroforestry, Fuelwood, Riparian village, Kahuzi Biega National Parc, Biodiversity, DR Congo.


The environment at the ban of urban dynamics in Sub saharian Africa

Alphonse Yapi-Diahou (1), Oumou Kouyate (2), Gilbert Assi Yassi (3)
1) Professeur, Université Paris 8, France
2) Enseignant-Chercheur, Université Alassane Ouattara, Bouaké, Côte d’Ivoire
3) Maître-assistant, ENS Abidjan, Côte d’Ivoire

Abstract. Controlling and controlling both urbanization and urban growth is a concern depending on whether you are in the North or the South. This contribution analyzes the environmental effects of the dynamics of urbanization and the urban pressure which rages in most of the African contexts south of the Sahara. Using specific examples of shantytowns, agricultural activities, soil and subsoil resource extraction, we show the differences between speeches concerned with the environmental and practices of public authorities. The resulting consequences for the equilibrium of the urban system have been analyzed. The analysis relies mainly on the mobilization of bibliographic materials. We present some examples of sites invested by the population in the form of residential neighborhoods, economic activities or mixed neighborhoods.
Keywords : Sub-Saharan Africa, environment, urbanization, urban growth, precarious settlements.


Urban sprawl and expansion of industrial plantations. The forests of the Wouri’ estuary in the middle

Aristide Yemafouo (1), Roméo Keumo Songong (1), Chrétien Ngouanet (2), Guy Charly Dzalla Ngangue
1) Université de Dschang, Département de Géographie
2) MINRESI, Institut National de Cartographie
3) Université de Douala, Département de Géographie

Abstract. Urbanization and agricultural activities are the main factors of forest degradation in the Congo Basin. The case of the Douala basin where is located the first metropolis in the CEMAC zone is proposed in this study. In the 1960s the Wouri estuary was still dominated by a dense and partially flooded coastal forest. After just a half of a century, it is host to the largest urban agglomeration in Central Africa. The development of Douala is leading to the important changes in land use patterns. The mobilization of satellite imagery has enabled an analysis of these changes to understand the implications on both the degradation of forest and derived urban forms. In 1975, the city had already consumed about 3000 ha of vegetation, 9 052 ha in 1986, then 13429 ha in 2001 and finally 18129 ha in 2016. With an annual rate of population growth around 5%, the anthropization of the Wouri estuary follow three interlinked stages: the littoral forest is firstly degraded through actions of deforestation, then agricultural practices, and finally the urban development operations. The specific mangrove forest equally passes through deforestation before being urbanized while swampy areas evolve into embankments before welcoming the people. The complete disappearance of the natural landscape trend is confirmed and invite decision-makers to refocus development operations on sustainable objectives.
Keywords :  Urban sprawl, Industrial plantations, Forests, Degradation, Douala, Cameroon.