Project aims of the Research Unit 2358
The main objectives of Phase 1
1. To reconstruct the natural and the anthropogenic history especially the onset of the afroalpine Anthropocene in space and time.
2. To determine the drivers and processes of environmental change and to quantify their impacts from the molecular to the landscape scale including abiotic factors (climatic change, geomorphological / geological processes, fire), biotic factors (landscape engineering animals) and the human impact.
3. To determine the magnitude of human induced long-term ecological and evolutionary changes both at a landscape level and on keystone plant and animal species and associated organisms at various trophic levels.
Main Achievements during Phase 1
Early human occupation in alpine ecosystems and use of its resources
• 55 rock-shelters and 13 open-air sites were investigated archeologically
• Through time, distinct occupation events with distinct human adaptation strategies occurred
in the Bale Mountains
• Two sites (#A05 and #A58) cover LSA sequences of 5,000 and 8,000 years, respectively
• Obsidian exploitation in 4,240 m
Asymmetric glaciation and permafrost patterns show steep paleo-climate gradients Local Last Glacial Maximum (45.5 ± 3.6 ka, possible older glaciation, MIS 6)
• Deglaciation shortly after 15.2 ka BP
• 265 km² (23 % of the area > 3,500 m) glaciated at the maximum stage of the last glacial cycle,
on the northern slope and northern part of the plateau
• fossil permafrost boulder stripes show the differences on southern plateau
Exceptionally high endemism testifies for ecological stability in evolutionary time scales
• Hundreds of micro-endemic ground beetle species
• Endemic vertebrates
• Sufficient humidity and warmth and never a complete and extinctive icecap
• At least during MIS 3 not too cold for endemic soil-dwelling rodents
• Two endemic monotypic frogs of the Erica forests in 3200 m, they testify for uninterrupted humidity
in the Ericaceous belt
First isotope-based African highland climate record shows decoupling from arid lowland climates
First continuous high resolution fire record shows fire driven ecosystem during last 15 ka
Charcoal and Black Carbon Holocene records along with other soil proxies show the presence of fire bound to Erica and not to Helichrysum heathlands.
Our way back to Africa: since when foragers changed to cultivation and herding?
The age of the transition from foragers to agro-pastoralists remains unknown. The first archaeological record is young (1,400 AD), yet the pollen record of Garba Guracha Lake shows human indicator pollen since 2 ka BP (P4), presumably of herders. Coprostanol levels are highest since 2 ka BP (P2) but have been rising since 7 ka BP. The floristic analyses of the current settlement vegetation reveals 5 species which are probably archeophytes, introduced with the Neolithic package from the near and middle east.