Suchergebnisse

Introduction: The Copper belt of Katanga presents huge resources of Cu and Co-ore. On the copper hills, mineralized rocks outcrop and a specific flora did develop as a response to the high levels of Cu and Co in soil. Soil-vegetation relationships need to be understood in order to elaborate biodiversity conservation programs prior to industrial mining of the copper hills. Literature: This paper reviews knowledge about soil characterization in the copper hills of Katanga and makes proposals for further research about the influence of the very specific chemical conditions of contaminated soils on the vegetation. The focus was put on the geochemical background and the bioavailability of Cu and Co. A lot of progress has been made recently about identification of soil-vegetation relationships. Conclusion: However, the issue of Cu and Co mobility within soil-plant systems is not entirely solved. ; Introduction : L'arc cuprifère du Katanga regorge d'importantes réserves en cuivre et en cobalt dans son sous-sol. En plus de cette ressource, s'ajoute une diversité végétale spécifique aux sols des affleurements métallifères. Le fonctionnement des écosystèmes cupro-cobaltifères est étudié dans le cadre de l'élaboration et la mise en œuvre de programmes de conservation de la biodiversité préalables à l'exploitation minière des collines. Littérature : Cette étude fait un état des connaissances sur les sols de l'arc cuprifère du Katanga et propose des pistes de recherches pouvant contribuer à la connaissance du fonctionnement de ce milieu aux conditions édaphiques inhabituelles. Sont principalement ciblés, le fonds géochimique et la biodisponibilité des éléments. Conclusion : Même si les études actuelles ont permis d'importants progrès dans la connaissance des relations entre propriétés des sols et distribution dans l'espace des communautés végétales, la mobilité du cuivre et du cobalt dans ces systèmes n'est pas encore complètement comprise. ; Peer reviewed

Our study aimed at deepen our understanding of relationships between soil properties and vegetation distribution in metalliferous ecosystems of Tenke-Fungurume in the Democratic Republic of Congo. The first question concerned the differences and similarities between soils of the main vegetation units and four variation factors of soil properties were summarized by multivariate analysis. They were all linked to lithology and significantly contributed to explain the distribution of vegetation units. Our result suggest that the variation of soil properties which is observed within the various vegetation units (rocky steppe savanna, sward, and steppe savannas on slope or on Dembo) should partially be attributed to differences of geochemical composition of rocks between sites but the main source of variability is to be found inside each hill. The soil contamination in Cu and Co originates from rock weathering and besides site effect and topographic distribution of the rocks, the variability of soil properties within one vegetation unit may be due to variability of soil parent material and not only to erosion. The second question dealt with the changes of soil properties at small distances. Metric variation was studied from transects between adjacent vegetation units. Our results showed that the abrupt changes of vegetation units which were clearly identified on the field were all truly explained by the variations of one or more properties linked to lithology. The key point being the Cu bioavailability. ; Peer reviewed