EarthShape - BOFEDAL: Biota's forcing of earth surface dynamics ascertained on land and sea

• Applicants: Dr. Bertil Mächtle; Dr. Karsten Schittek
• Subject Area: Physical Geography ; Palaeontology
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 280528655

One of the main goals of EarthShape is the quantification of biotic processes, which modify the earth shape in the critical zone. Besides monitoring of modern processes and its modelling, the low intensity of some biotic processes in the Atacama Desert needs a period of consideration of at least tens to thousands of years to be measurable. Biotic processes in the (recently hyper-)arid Atacama desert are most prominently controlled by the availability of water. As precipitation was highly variable at these timescales, the modification and volatility of process intensities on the scale of decades to millennia, due to climatic changes, has to be considered in quantitative approaches. Paleoclimatic information on these timescales is strongly recommended. Paleoclimatic archives as peat and mineral sediments offer an insight to past environments based on climatic proxies, e.g. micro-/macrofossils, sediments and its geochemistry. However, highly variable arid land bio-geodynamics prevent the formation of continuous archives, which the EarthShape approach calls for! Therefore, those priority program primary focus areas located in the hyper-arid costal desert of Chile only offer discontinuous records of paleoclimate. Existing gaps in paleoclimatic records need framing and completion by the nearest continuous information, which has to be made available by studying the regional paleoclimatic context. In our project, we aim to study the activity of biota in the coastal area during the mid- to late Holocene (primary focus area Pan de Azucar, 26° S). Paleoclimatic records at these areas are expected to be discontinuous and lack resolution. Hence, the acquisition of undistorted, continuous information will be done by the study of two framing master records: the study of a high Andean peatland (bofedal) and adjacent lake and the study of a marine sediment core (GeoB 7139-2, 30° S off Chile). By this means, we want to fill the unavoidable gaps in coastal sedimentary archives with the help of continuous high-resolution paleoclimatic proxy data to get the best possible assessment of changes in biota-controlled processes and their intensity in north central Chile, where detailed Holocene paleoclimatic information is missing. In summary, this project is integrated in priority program 1803 by providing essential information which was asked for by many groups to reach their individual goals, as stated during the EarthShape workshop 2014 in Potsdam. Therefore, this interdisciplinary project between geoecology, geography/geomorphology and marine geosciences is by itself a cutting-edge integrative collaboration, bringing together terrestrial and marine expertise under the umbrella of EarthShape. Furthermore, immediate linkages to other initiatives are obvious, particularly regarding vegetation dynamics, soil formation, biochemical weathering and stabilization of landscapes most notably in the primary focus area Pan de Azucar.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1803: EarthShape: Earth Surface Shaping by Biota
• International Connection: Chile
• Co-Investigator: Dr. Frank Lamy
• Cooperation Partner: Professor Dr. Antonio Maldonado