Forest Zone Of Cameroon Research Articles

From alley cropping to rotational fallow: Farmers' involvement in the development of fallow management techniques in the humid forest zone of Cameroon

Alley cropping was introduced in the humid forest zone of Cameroon to increase soil fertility in 1987, but until 1992 the adoption rate had remained low. To better understand the reasons behind this, three types of on farm trials were established from fully researcher controlled to fully farmer controlled. During the evaluation of the technology with farmers a number of modifications were registered (1) Pruning height and frequency: Because of the difficulties to consistently cut back at 30 cm, farmers decided to slash at ground level as they normally do while slashing the natural fallow vegetation. This equally allowed for more flexibility in time of pruning. (2) Cropping intensity and pattern: Initially, alleys were cropped each year. This however had several shortcomings. Having observed the positive impact of incidental fallow period in a farmer's field, it was decided to introduce a fallow phase of at least one year. During the fallow period the plot can be used for fodder production, bee farming and production of stakes. (3) Residue management: Fire went incidentally in a farmer's tree plot after slashing, and the trees were not affected. This gave farmers an alternative way to manage the residue, by controlling the fire, before bringing in other crops such as groundnut and cassava. (4) Agroforestry species: Because Leucaena leucocephala, in spite of it soil fertility restoration potential, rapidly became a noxious weed, farmers have asked for a less invasive species. Calliandra calothyrsus was introduced for this purpose and became a good bee forage. With these modifications, the original alley cropping system has evolved into a rotational tree fallow with higher adoption potential. From about 15 farmers who were testing the technology in 1992, the number increased to 52 in 1996, 120 in 1997 and 236 in 1998.

PRODUCTION AND MARKETING OF SAFOU (DACRYODES EDULIS) IN CAMEROON AND INTERNATIONALLY: MARKET DEVELOPMENT ISSUES

ABSTRACT This paper draws together information from three separate projects on the production of Dacryodes edulis (G.Don) H.J. Lam or ‘safou’ in Cameroon, and its domestic and international trade. The volume of safou fruit commercialised in Cameroon in 1997 was estimated at 11,000 tonnes, equivalent to US$7.5 million. Exports from Central Africa and Nigeria to France, the United Kingdom and Belgium were worth over US$2 million in 1999. A study of nine markets in the humid forest zone of Cameroon in 1999 revealed that women dominate the retail trade while men concentrate on wholesale. For both, safou trade is an important long-term livelihood option. Depending on the market and volume traded, weekly marketing margins can be double the minimum wage. Far from being exploited by traders, producers were found to receive 75% of the consumer price on average. The main constraint to both the domestic and international trade is the high perishability of safou.

Calanoid copepods from the lowland forest zone of Cameroon (West Africa), with the description of a new species of Tropodiaptomus

We illustrate four of the six calanoid copepods currently known from the lowland forest zone of Cameroon. Two are possibly shared with the savannah zone of West Africa. Of interest is a new record from the Korup forest of the recently discovered Camerundiaptomus djamai. A new species, Tropodiaptomus njinei is also described. It is closely related to Tropodiaptomus loveni. The composition of this highly endemic microfauna is discussed. It is suggested that Camerundiaptomus and Thermodiaptomus may share a common origin.

Spatial dynamics of lepidopterous pests on Zea mays (L.) and Pennisetum purpureum (Moench) in the forest zone of Cameroon and their implications for sampling schemes

The most common lepidopterous borers attacking maize and/or the wild host Pennisetum purpureum in the forest zone of Cameroon are the noctuids Busseola fusca (Fuller), Sesamia calamistis (Hampson) and Poeonoma serrata (Hampson), the pyralids Eldana saccharina (Walker) and Mussidia nigrivenella (Ragonot), and Cryptophlebia leucotreta (Tortricidae). The within‐plant distribution on maize and elephant grass was studied for the predominant species B. fusca, and on maize only for E. saccharina to determine the basic sampling unit. On both plant species, B. fusca showed a strong oviposition preference for young plant parts. By contrast, E. saccharina larvae and pupae on maize were only found on older plant parts indicating that it does not oviposit on young plants. No part of the plant strata appeared to be a stable sampling unit and it is recommended to carry out whole plant or whole tiller sampling for maize and grass, respectively. For the development of sampling plans, dispersion was described for all species using Taylor’s power law and a non‐linear model which gives the relationship between the proportion of infested plants [P(I)] and mean density (m). Busseola fusca egg batches as well as diapausing larvae and pupae on maize showed a random distribution whereas all the other cases were aggregated, with B. fusca egg batches on elephant grass exhibiting the lowest and M. nigrivenella on maize the highest aggregation. Optimal sample size/mean density curves were developed for groups of insects with low and high aggregation.

Natural enemies of lepidopterous borers on maize and elephant grass in the forest zone of Cameroon.

The importance, geographical and temporal distributions of parasitoids of lepidopterous borers on maize and elephant grass, Pennisetum purpureum, were assessed during surveys in farmers' fields in six villages and two on-station trials in the forest zone of Cameroon between 1995 and 1996. The borer species encountered were Busseola fusca (Fuller), Sesamia calamistis Hampson, Eldana saccharina Walker on both host plants, and Mussidia nigrivenella Ragonot on maize only. Busseola fusca was the predominant host accounting for 44-57% and 96% on maize and elephant grass, respectively, followed by E. saccharina on maize with 27-39%. Fifteen hymenopterous, two dipterous and one fungal species were found on these stem and cob-borers. Among those were six pupal, six larval, four egg, one larval-pupal parasitoid and four hyperparasitoids. The scelionid parasitoids Telenomus busseolae Gahan and T. isis Polaszek were found on B. fusca eggs in all locations. During the first season, mean egg parasitism was low and ranged between 3.1% and 27% versus 54-87% during the second season. Species belonging to the Tetrastichus atriclavus Waterston complex were recovered from all four borer species. The majority and most common larval and pupal parasitoid species belonged to the ingress-and-sting guild. Larval and pupal parasitism were very erratic and on more than 50% of the sampling occasions no parasitoids were recovered. Parasitoid diversity was higher on elephant grass than maize.

Forest Encounters: Synergy Among Agents of Forest Change in Southern Cameroon

This article investigates how different actors and agents of forest change interact, and whether their interactions have an enhanced impact on forest management or on livelihoods of local villagers. Studies of forest cover change indicate that multiple agents and causes may speed deforestation. We disaggregate and interrogate the conventional polarization of local villagers versus external loggers and show how multiple actors interact in a dynamic context. We investigate these issues through studies of three villages in the Humid Forest Zone of Cameroon in Central Africa. We examine different actors' strategies in the face of external and internal pressures and stimuli. Economic crisis in Cameroon has impacted on local livelihoods as well as logging strategies of timber companies, and this has led to diverse alliances, conflicts, and outcomes. Our study shows that the combined action of local actors has synergistic or enhanced impacts in three ways. First, impacts are enhanced through accelerated extensification of cultivation in forest; second, through increased access to markets; and third, through increased migration to rural areas. These synergistic impacts are brought about by a number of mechanisms, of which the opening of new roads in forest areas is most important. A number of policy measures, including the effective enforcement of the legal mechanisms, clarification of property rights, and creation of spaces or platforms for negotiation between the different actors, are necessary to ameliorate the negative synergistic impacts of their interactions.

Residue management of a planted fallow on an acid soil in Cameroon: crop yields and soil organic matter fractions

A fallow management trial was initiated in March 1990 in Yaounde, Cameroon, with the objective of identifying an efficient method of managing residue derived from a planted fallow of Cajanus cajan. Ten months after establishment, the shrubs were slashed and residues were treated in one of the following ways: burnt, incorporated in the soil, mulched on soil surface or removed. Following that, maize and groundnut were planted. Soil organic matter was fractionated after the residue treatments, and elementary partial budgeting was conducted. After three cycles of fallow and cropping seasons, maize yield was similar, about 3 t ha-1, in all plots except in the residue-removed plots, where it was 1.4 t ha-1. Yield trend of groundnut was also similar. The residue management method did not affect either the nature of fractions or the total content of soil organic matter. The highest net return, US$5945 ha-1 year-1, was obtained from the residue incorporated treatment, whereas the highest return to labour, US$11 per manday-1 was associated with burning of residues. In areas such as the forest zone of Cameroon where labour is a major constraint and climatic conditions allow vigorous vegetation growth, burning appears to be the best method of residues management, at least in the short run.

Paragonimiasis in southwest Cameroon: isolation of microcercous cercariae from land snails caught in a Paragonimus Africanus endemic zone

More than 25 years after the discovery of the 2 main African Paragonimus species, P. africanus and P. uterobilateralis , the snails' first intermediate hosts, which harbour rediae and cercariae as well as these larval stages, remain yet unknown. In the present study, the authors describe microcercous cercariae and rediae with the characteristics of the genus Paragonimus from land snails of the Achatinidae family caught in a forest zone of Cameroon where P. africanus is endemic. The results corroborate Sachs and Cumberlidge's findings in a P. uterobilateralis focus in Liberia and indicate that for both African Paragonimus species, the first intermediate host should probably be land snails rather than fresh water snails.

Stepwise approach to alley cropping technology development and transfer in the forest zone of Cameroon

Two projects on alley cropping research and development have been implemented in the Forest zone of Cameroon (FZC) since 1988. Their goal was to identify the main agricultural constraints in the FZC and to introduce alley cropping in the farming systems to improve soil fertility and crop yields.

Implications of national land legislation and customary land and tree tenure on the adoption of alley farming

Increasing population in the forest zone of Cameroon has led to reduction of fallow periods and to diminution of per capita cropping land area. Alley farming is a promising technology for the zone; however, its large scale adoption depends on host of factors of which an important one is tree and land tenure. For this reason, a study was conducted in 1990 to determine implication of national land legislation and customary land and tree tenure on the adoption of alley farming in the forest zone of Cameroon.