Holocene hyrax dung deposits in the afroalpine belt of the Bale Mountains (Ethiopia) and their palaeoclimatic implication

Abstract

The results of pollen analysis and radiocarbon dating are presented for two hyrax dung deposits from rock shelters found in the Afroalpine zone of the Bale Mountains (South-Central Ethiopia). Deposits accumulated from about 15,000 to 1500 (cal) years BP and from 7000 (cal) years BP till nowadays, respectively. Pollen spectra of the initial stages of deposit development (up to 15,000 (cal) years BP) correlate with unfavourable conditions in the Late Glacial Maximum. The African Humid Period (AHP) (15,000–5000 (cal) years BP) is registered in this palaeoecological record as well as the Younger Dryas event (about 12,500 (cal) years BP). Upward shift of Afromontane forest belt and expansion of ericoid communities at high altitudes were characteristic of the Pleistocene/Holocene transition (about 10,000 (cal) years BP). The AHP which continues around 10,000 (cal) years BP after Younger Dryas, was interrupted by a dry episode around 8200 (cal) years BP. Principal aridisation trend during the last 5000 years was observed. Presumably the first traces of human activities in this area can be shown for up about 2500 (cal) years BP.