François Malaisse

Edible wild vegetable products in the Zambezian woodland area: A nutritional and ecological approach

Having defined the Zambezian woodland, the edible wild vegetable products occurring in this area are reviewed. As well as 21 cultivated plants, 241 wild species have been listed, of which 184 were sampled and their nutritional value established. These results are discussed. Where available, the collecting period, the type of vegetation in which the species occurs, the Kibemba dialect name and the voucher number of the reference specimen are also given.

Toxicity of some terpenoids of essential oils of Xylopia aethiopica from Cameroon against Sitophilus zeamais Motschulsky

Abstract:  The acute toxicity of essential oils from the whole fruit (EF) or from the fibres of the fruit (FF) of the local aromatic plants Xylopia aethiopica Dunal (Annonaceae) collected in north Cameroon was evaluated on Sitophilus zeamais adults. A concentration of 1 ml of essential oil per 100 g of maize seeds was tested to determine weevil mortality after 24 h of exposure. Under these conditions, the essential oil derived from both EF and FF of X. aethiopica led to 100% mortality. In a second step, proportions of active compounds present in the oil of both EF and FF of X. aethiopica were quantified. The toxicity of the four main compounds was tested against S. zeamais: α‐pinene, β‐pinene, Δ‐3‐carene and terpinen‐4‐ol according to their proportion in the essential oil of the concerned plant part. β‐pinene and terpinen‐4‐ol were responsible for 50% of the mortality at the proportion found in EF and FF essential oils respectively. When mixed, a synergic effect of the compounds was observed that restored the mortality percentage observed for the crude oil. It appears that X. aethiopica essential oil could be a potential source of natural and low‐cost insecticide to control storage pests.

Effect of Site Location and Collecting Period on the Chemical Composition of Hyptis Spicigera Lam. an Insecticidal Essential Oil from North-Cameroon

Abstract Hyptis spicigera essential oils from seven localities in the North-Cameroon (Ngaoundere, Guirvidig, Kodeck, Lara, Toloum, Kaele, Tchecal-baila) were investigated by GC and GC/MS. Results showed differences within harvesting sites and between the different sites of collection but did not revealed clear tendencies in the evolution of the oil composition with regard to the sampling period. The main group of compounds in all the analyzed samples were: α-pinene (11.9%-42.1%), β-pinene + sabinene (6.0%-39.8%) and β-phellandrene + 1,8-cineole (8.8%-27.4%) except in one oil where β-caryophyllene (23.4%) was the principal component. The insecticidal activity of H. spicigera and its principal terpenic components was evaluated against the cowpea weevil Callosobruchus maculatus F., the major cause of damages of cowpea (Vigna unguiculata (L.) Walp) in North Cameroon.

Mycotoxins in Stored Barley (Hordeum vulgare) in Tibet Autonomous Region (People's Republic of China)

Abstract Mycotoxins are naturally occurring toxic chemical compounds produced by fungi infesting agricultural crops both during crop growth and storage. Such secondary metabolites, when ingested, can produce toxic syndromes in humans. This study is the first survey that documents the occurrence of mycotoxins in stored barley in Tibet Autonomous Region [P.R. China]. Twenty-five samples of barley collected from Tibet were analyzed for the presence of aflatoxins, fumonisins, ochratoxins, zearalenone, deoxynivalenol, and T-2 toxin using an easy, sensitive, competitive direct enzyme-linked immunosorbent assay. Ninety-six percent of the samples were contaminated with zearalenone at concentrations ranging from 25 to 270 µg/kg. Seventy-six percent of the samples were contaminated with T-2 toxin at concentrations ranging from 1 to 163 µg/kg. In contrast, deoxynivalenol was observed in only 12% of the samples, with toxin concentrations ranging from 25 to 270 µg/kg. Aflatoxin was observed in only 4% of the contaminated samples.

Rodents of the Miombo woodland area

Rodents contribute greatly to the diet of the populations established in the Zambezian woodland area. Approximately 20 species are eaten, of which 12 were sampled. Having specified their ecology, the authors note their nutritional value and discuss its importance.

Rodents of the Miombo woodland area: A nutritional and ecological approach*Field work was carried out in Shaba Province, Zaire, from December, 1975, through July, 1977. The present note is part of a work which will be presented to obtain the degree of Docteur en Sciences de l'Environment by G. Parent.

Rodents contribute greatly to the diet of the populations established in the Zambezian woodland area. Approximately 20 species are eaten, of which 12 were sampled. Having specified their ecology, the authors note their nutritional value and discuss its importance.

Changes in the Spatial Pattern and Ecological Functionalities of Green Spaces in Lubumbashi (the Democratic Republic of Congo) in Relation With the Degree of Urbanization

An accurate description of spatial urban growth is a prerequisite step in order to implement appropriated policies to improve the ecosystem service performance of green spaces in a city. Such information is, however, absent in Lubumbashi, the second metropolis of the Democratic Republic of Congo, despite its high demographic growth rate and an unplanned spatial urban growth. This study was designed to characterize the spatial pattern of green spaces and the extent of changes driven by the urbanization along the urban–rural gradient using a combination of landscape metrics and floristic plots. Our results revealed that the number of patches was directly proportional to the degree of urbanization of the city, whereas the area of the green spaces and the index of the largest patch showed an inverse relationship with the urbanization degree. Urban green spaces were dominated by attached and roadside spaces that are more equipped and present a higher occurrence of cultivated plants. By contrast, peri-urban green spaces were characterized by buffer zones, fields, abandoned areas, and informal spaces, with an elevated proportion of invasive species and natural vegetation. Moreover, it was found that the number of exotic species increased with the degree of urbanization, reaching values considered a threat to the indigenous flora. The current results underline the need for urgent measures oriented both toward increasing the spatial connectivity between green spaces (e.g., by creating new green spaces planted with indigenous species) while reducing the spread of invasive species in the city.

Using phytostabilisation to conserve threatened endemic species in southeastern Democratic Republic of the Congo

Outcrops in the southeastern Democratic Republic of the Congo (DRC) are recognized as some of the largest copper–cobalt orebodies in the world. They support a unique vegetation with nearly 600 metallophytes that include rare and endemic species. Mineral exploitation has increased considerably in the region since the 1900s, affecting both environmental and public health. Phytostabilisation of polluted areas represents an opportunity to decrease the bioavailability of heavy metals in the highly polluted soils that result from ore extraction. Such a technique has been successfully implemented near Lubumbashi with the grass Microchloa altera. However, long-term maintenance requires a good understanding of interspecific relationships, such as competition and facilitation. This study tested the establishment success of four herbaceous species from the Katangan Copperbelt by assessing the potential role of Microchloa altera as a nurse species. Two annual and two perennial species were sown in an experiment designed to study the influence of soil amendment and vegetation cover on seedling emergence, growth, and survival. These variables were monitored during the vegetation growing season as well as resprouting success for perennials. Microchloa altera showed a distinct effect on the emergence and survival of annual and perennial species and negatively affected the growth of individuals belonging to both groups of species.

Ethnobotanical And Chemical Surveys Of An Edible Wild Legume: Uraria Picta (Jacq.) Dc.

Urariapicta (Jacq.) DC. belongs to the family Leguminosae: Papilionoidae. It is an annual woody erect herb or under‐shrub with edible seeds. In order to evaluate what is known about this species and its seed consumption in Ivory‐Coast, an ethnobotanical investigation was carried out in the department of Séguéla, in the north of the country. The contents of protein and lipid in seeds were analyzed. The ethnobotanical surveys revealed that people belonging to the Malinké ethnic group no longer eat the seeds of Uraria picta. Furthermore, the local knowledge about the species is decreasing from generation to generation. Nevertheless, chemical analyses show that the species is a good source of some nutrients. The protein characteristics of U. picta seeds were compared with several frequently cultivated legumes and cereals. The correlation coefficient calculated for essential amino acids show that U. picta seeds are very close to cultivated legumes (garden pea, horse bean, kidney bean and Bambara groundnut) and slightly close to cultivated cereals (bread wheat, rice, barley). In order to evaluate the nutritional value of protein, the chemical score was calculated. The value obtained, about 87.0%, indicated a great balance of essential amino acids. This value is higher than the chemical score calculated for some other cultivated crops, except Bambara groundnut. The results obtained were also compared with Indian material. This comparison revealed important differences about some amino acid contents. It appears that some variabilitys more or less important exist according to the region concerned. The lipids content of the seeds is low (1.6%), but U. pida oil contains an interesting proportion of essential and long chain fatty acids. It is concluded that, according to the potential nutritional value of its seeds, U. picta should be considered as a source of nutrients that may contribute in the diet of rural people.