Coexistence of different functional types of indigenous trees of the Munessa Forest, Ethiopia: Carbon, water and nutrient relations

DFG Be 473/39-1

Ecophysiological traits (carbon, water and nutrient relations) allowing for the coexistence of different functional types (life-forms) of indigenous trees in Munessa Forest, Ethiopia is proposed. Above and below ground resource acquisition and utilization by Croton macrostachys (facultative deciduous), Podocarpus falcatus (evergreen gymnosperm) and Prunus africana (broad-leafed evergreen) will be investigated as influenced by site conditions and season. In addition to tree growth and canopy characteristics, photosynthesis, respiration and transpiration at different zones of tree crowns will be recorded. Whole-tree transpiration will be followed using the Granier stem-flux system. Partitioning of soil water among the trees will be assessed using 18O/16/O-signatures of xylem sap and of soil water collected from different depths. Seasonal water use of juvenile and adult trees will be compared and the seasonal patterns of fine root biomass production shall be analyzed. Data on nutrient relations, mycorrhizal networks and silvicultural characteristics of the trees, produced by the other collaborating groups will be integrated to explain the coexistence of the three functional types of trees. It is expected that species-specific requirements and strategies of survival and growth of the investigated tree species can be used for an ecologically sound reforestation program of a mixed forest.