Logging activities in mangrove forests: A case study of Douala Cameroon

The Cameroon mangroves are exploited by local communities through fishing, hunting, and especially logging for fuel-wood and charcoal. The changing demographic patterns in the region have increased the need of citizens in the urban centres, which in turn, has accelerated the pressure on the neighbouring forests. The objective of these studies was to assess the impact of local communities on the mangroves’ development. Through an eight point semi-structured questionnaire, 120 mangrove loggers were interviewed in the local markets in Douala. The survey data show that 61% of respondents are permanent workers and do not envisage quitting this mode of employment. The surface area destroyed annually approximates 1000 ha. Species of the genus Rhizophora are mostly exploited, with about 200,000 trees cut down per year. The declared revenues are about 400,000 Euros per year. Further analysis of information from different sources suggests that the total annual income could amount to four millions euros. These estimates show that the mangroves have a significant economic value and require significant improvement in modes of exploitation to include strategies for sustainable management.Key words: Anthropogenic impact, deforestation, Douala-Cameroon, economic value, loggers, mangroves,  Rhizophora

Parasitism of host trees by the Loranthaceae in the region of Douala (Cameroon)

The Loranthaceae constitute the most important parasite plants that cause variable damages: morphological, technological, ecological and socio- economic. These numerous and damaging effects make some parasitic angiosperms true agronomic threats, especially in developing countries. The Loranthaceae is represented in Cameroon by 26 species gathered into 7 genus. The study area includes four sites: a traditional plantation of Cola nitida situated at Penja (70 km Nord of Douala), the main road to Douala airport, one quarter (Logbessou) and Makondo village (80 km East of Douala) in an orchard dominated by Citrus. A total of 2643 individuals of DBH (diameter at breast height) greater or equal to 5 cm were inventoried. 637 individuals were parasitized. Eight known species were identified. Phragmanthera capitata is more frequent and more abundant (76.14%). The infested host trees belong to 16 species gathered into 12 genus and 10 families. The most parasitized host family is Sterculiaceae. The most sensitive host species to the parasitism of Loranthaceae is P. americana (21.51%), followed by C. nitida (17.27%) and Terminalia mantaly (13.65%). Lauraceae is infested by 7 Loranthaceae out of 8 parasites investigated. The consequences of the parasitism of the Loranthaceae demonstrate the need for establishing comprehensive ecosystem management programs.Key words: Host trees, inventory, Loranthaceae, parasites plants

Satellite Sanitary Systems in Kampala, Uganda

Satellite sewage collection and treatment systems have been independently developed and managed in East African cities outside the centrally planned and sewered areas. A satellite approach is a promising provisioning option parallel to public sewerage for middle- and high-income residential areas, endowed institutions, and government facilities. Although the studied satellite systems offer localized solutions that fit the situation of Kampala, better treatment and management arrangements are needed. Such arrangements do not readily conform to centralized or decentralized sanitation paradigms and likely require flexible mixtures of the two into modernized mixtures. In the case of Kampala, such mixtures entail regulation and control by centralized agencies, development and management by decentralized satellite providers, hybrid treatment process, and separation of waste(water) flows.Water ManagementCivil Engineering and Geoscience