A reconstruction of the El Nino Southern Oscillation signal in Southern and Eastern Africa is being developed. This reconstruc- tion is based on growthring-series of different tree-species of the Miombo Woodland-vegetationtype. The efficiency of this dendrochronological study is increased by a profound site- selection. This selection is conducted through the analysis of satellite-images. A number of problems, frequently occurring in dendrochronological research of tropical species, is examined by accurate monitoring of the phenology of the tree-species. The phenology is examined through monitoring of the cambial activity and through analysis of satellite images.