干旱区生态环境知识资源中心

On-station and on-farm experiments are being conducted on climate-plant-soil-water-relationships and on soil fertility and landuse practices in close cooperation with the Kenya Agricultural Research Institute (KARI) and the Marsabit Development Programme (MDP-GTZ). It was found that the phenomenon of 'dwarf shrub encroachment' in the ecoclimatic zones 5 and 6 of Jatzold (1988) was originally caused by high grazing pressure several decades ago. Further degradation of the soils favours the establishment of unpalatable herbs (e.g. Solanum spp.), shrubs, dwarf shrubs (e.g. Indigofera spp.) and annual grasses from neighbouring arid areas. Ecophysiological records and botanical observations on differently degraded plots of Duosperma eremophilum revealed a high correlation between soil quality/level of soil degradation and a Duosperma-Indigofera-Index, which can be used for biomonitoring purposes.