1 Department of Horticultural Sciences, Institute of Crop Science and Resource Conservation, University of Bonn, 53121 Bonn, Germany. luedeling@uni-bonn.de.
2 Department of Economics of Sustainable Land Use and Bioeconomy and Center for Development Research, Institute for Food and Resource Economics, University of Bonn, 53115 Bonn, Germany.
3 Department of Soil Science and Soil Ecology, Institute of Crop Science and Resource Conservation, University of Bonn, 53115 Bonn, Germany.
4 Department of Horticultural Sciences, Institute of Crop Science and Resource Conservation, University of Bonn, 53121 Bonn, Germany.
5 World Agroforestry Centre, Gigiri, Nairobi, Kenya.
6 World Agroforestry Centre, Kinshasa, Democratic Republic of Congo.