Profile

Polar regions are one of the most sensitive and vulnerable regions on earth. In particular, the long-term interactions between climate, ecosystems and humans in polar continental areas are still poorly understood. Therefore, the research group “Polar Terrestrial Environmental Systems” investigates past climate dynamics, high-latitude vegetation change, arctic lake system dynamics and biodiversity change in high latitudes. As the time-period covered by direct observations is short, the analysis of long-term changes further requires the use of indirect proxy data extracted from environmental archives such as lake sediments. Therefore, proxy development and proxy data synthesis are also a key research interest of the group. Such, a better understanding of the polar continental areas and its interactions with the global earth system can be gained.

Head
Prof. Dr. Ulrike Herzschuh

Assistant
Sigrun Gräning
Phone: +49(331)288-2123

Website
Dr. Boris Biskaborn

Projects

GlacialLegacy

'Glacial legacy on the establishment of evergreen vs summergreen boreal forests'

Ecosystem services of boreal forests are of critical importance for humanity and differ markedly between evergreen and summergreen needle‐leaf forests. GlacialLegacy will address the timely questions “Why is northern Asia dominated by summergreen boreal forests?" and “How will these larch forests change in the future?” with a coherent empirical and modelling approach integrating pollen data synthesis, sedimentary ancient DNA analyses, vegetation & biophysical survey and vegetation modelling.

The hypothesis is that summergreen and evergreen needle‐leaf forests represent alternative quasi‐stable states occurring under similar climates today but which came about because of the different (genetic) characteristics of the northern tree refugia – a legacy of the preceding glacial stage. Once established Asian larch forests stabilised because of their unique vegetation–fire–permafrost–climate system that inhibits the invasion of evergreen taxa. However, the long‐term vegetation trajectory causes the irreversible transition of summergreen into evergreen needle‐leaf forests. This is mainly because larch is a poor competitor compared to evergreen spruce and pine when growing in mixed stands. Asian larch forest would only be able to re‐establish after a new forest‐free glacial stage. As both boreal forest types are only stable across a certain climate range, a future warmer and drier climate may cause their transition into steppe, which is irreversible for Asian larch forests.

Funding: European Research Council Consolidator Grant 2018-2023

Cooperation:

  • Prof. Dr. Luidmila A. Pestryakova (NEFU, University Yakutsk)


Further reading:

Herzschuh, U., Birks, H.J.B., Laepple, T., Andreev, A., Melles, M., & Brigham-Grette, J. (2016). Glacial legacies on interglacial vegetation at the Pliocene-Pleistocene transition in NE Asia. Nature Communications. 7, 1–11. doi:10.1038/ncomms11967, www.nature.com/articles/ncomms11967.pdf

 

 

 

PAST PERMAFROST

Web-based visualisation of past environmental change in permafrost regions

This project brings together stakeholders from the economy, research and educational sectors to shape the future of our scientific goals towards their relevance for the German and international society. The overall objective of PAST PERMAFROST is the development of a web-tool that allows the user to visualize AWI environmental data sets in space and time in permafrost areas (incl. interactive maps of past and present vegetation). The sites can be used to compare the millennial scale climate history in the area to the present thermal state of permafrost. Our vision is to link paleoclimate findings to direct consequences of recent environmental change in the Arctic.

Research focus: Arctic Lake System Dynamics

Contact: Boris Biskaborn, Stuart Vyse

Funding: ESKP - Earth System Knowledge Plattform

Cooperation:

  • Potsdam Institute for Climate Impact Research: Dr. Tobias Geiger
  • Arctic Portal (Iceland): Halldor Johannsson
  • Universität Potsdam: Allgemeiner Studierendenausschuss
  • Deutsches Geoforschungszentrum: Dr. Arne Ramisch

Palaeohydrology of the Gobi Desert

Palaeohydrology of the Gobi Desert

The northern foreland of the Tibetan Plateau with its endorheic basins plays a key role in the geological and palaeoenvironmental development of central Asia. The depositional environment is characterized by aeolian, fluvial, and lacustrine conditions. Sediment supply is also controlled by glacial dynamics and periglacial processes in the mountainous hinterland of the Qilian Shan. The mountains represent important sources for water supply to the agriculture belt of the adjacent Hexi Corridor and the endorheic basins. The sediments in the basins represent sediment repositories for dust transport over Central Asia and northern China and are directly connected with the Chinese Loess Plateau.

Research focus: Arctic Lake System Dynamics

Contact: Georg Schwamborn

Funding: BMBF - Federal Ministry of Education and Research (2011-2014, 2016-2019)

Cooperation:

More details under: www.senckenberg.de/root/index.php

Lake & Sea ice algae

Lake & Sea ice algae

The seasonal extent and properties of arctic ice on land and ocean determine the efficacy of the albedo feedback mechanism causing arctic climate amplification. Various ice types are inhabited by specific ice algae that across taxonomic boundaries share similar mechanisms to survive in these extreme environments. This project explores the potential of sedimentary DNA as a proxy for ice cover changes on millennial time-scales by analysing community functional composition in ice, water column and surface sediment samples, and in marine and lake sediment cores from Fram Strait, Northwest Pacific, Siberia (Samoylov, Central Yakutia) covering the last about 6000 years.

Research focus: High-latitude Biodiversity

Contact: Kathleen Stoof-Leichsenring, Heike Zimmermann

Cooperation:

KoPf-Kohlenstoff im Permafrost

KoPf-Kohlenstoff im Permafrost

The interdisciplinary German-Russian project 'KoPf-Kohlenstoff im Permafrost Kohlenstoffumsatz und Treibhaugasfreisetzung aus tauendem Permafrost Nordostsibiriens unter sich ändernden Umwelt- und Klimabedingungenproject' is funded by the  German Federal Ministry of Education and Research (BMBF). Polar ecosystems on continents are habitats for northern communities and provide indispensable ecosystem services. KoPf will investigate the status, formation, turnover and release of organic carbon in Eastern Siberian permafrost landscapes to gain increased understanding of how permafrost-affected landscapes will respond to global warming and how this response will influence the local, regional and global carbon balance. Rising arctic temperatures will result in increased permafrost thawing, landscape disturbance, vegetation biomass changes and increased fire frequency in taiga and tundra.

Scientists from Russia and Germany work together at different key sites in the Siberian Arctic that are characterised by different disturbance regimes. Key sites are the long-term research sites Lena-Delta and Chukotka with large data collections of subground carbon in permafrost soils and permafrost and a detailled characterisation of the vegetation. Vegetation will be also analysed for Taymyr, Omoloy, and Kolyma regions. This In situ data collection from Russian-German expeditions will be used for upscaling of vegetation, biomass and below and above ground carbon.

The coordination is at the Universität Hamburg, the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (Potsdam Research Unit) and the Arctic and Antarctic Research Institute (St. Petersburg, Russia).

Resaerch focus: High-latitude Vegetation Change

Contact: Ulrike Herzschuh, Birgit Heim

Funding: BMBF - Federal Ministry of Education and Research (2017-2020)

Cooperation:

  • Uni Hamburg (PI): Prof. Pfeiffer, Prof. Kutzbach
  • Helmholtz-Zentrum Potsdam – Deutsches Geoforschungszentrum GFZ, Prof.  Sachs
  • Max-Planck-Institut für Meteorologie Hamburg, Prof. Brovkin
  • Max-Planck-Institut für Biogeochemie, Jena, Dr. Göckede
  • University of Cologne: Prof. Rethmeyer
  • NEFU Yaktusk, Prof. Pestryakova
  • AARI St. Petersburg:  Prof. D. Bolshiyanov
  • Uni St. Petersburg: Prof. I. Fedorova
  • Melnikov Permafrost Institute Yakutsk, Dr. Grigoriev
  • SPbSU Dr. Abakumov
  • RAS/SB Dr. Barsukov

‘Paleolimnological Transect’ (PLOT) project

‘Paleolimnological Transect’ (PLOT) project

 The German-Russian ‘Paleolimnological Transect’ (PLOT) project funded by the German Ministry for Education and Research (BMBF) aims at the investigation of the Late Quaternary climate and environmental history along a more than 6000 km long transect crossing Northern Eurasia, focusing on potentially old lakes i.e. Lake Ladoga, Bolshoye Shuchye, Levinson-Lessing, Taymyr und Emanda.

Within the project, the AWI Potsdam (PI H. Meyer) is responsible for stable isotope geochemistry in the project for climate and environmental research. The lakes are being investigated for stable oxygen isotopes in diatoms derived from lacustrine sediments and for stable water isotopes to reconstruct past climate, environment and hydrology changes. For a quantitative reconstruction, these measured environmental variations are then combined with climate model outputs with explicite isotope diagnostics (AWI Bremerhaven, M Werner).

Research focus: Past Climate Change

Contact: Hanno Meyer, Svetlana Kostrova

Funding: BMBF - Federal Ministry of Education and Research (2015-2019)

Cooperation:

  • University of Cologne: Prof. Dr. Martin Melles (PI), Prof. Dr. B. Wagner
  • University of Kiel. Prof. Dr. S. Krastel
  • AARI St. Petersburg: Dr. G. Fedorov, Prof. D. Bolshiyanov
  • INWP Petrozovodsk: Prof. D. Subetto
  • NEFU Yakutsk: Prof. L. Pestriakova

More details under: www.geologie.uni-koeln.de/2045.html

High-resolution reconstruction of regional climate changes in Antarctica

High-resolution reconstruction of regional climate changes in Antarctica

- Glaciological and isotope-geochemical studies on the Antarctic Peninsula and the West Antarctic Ice Sheet

 

This project aims at investigating the recent and past climate variability of two high-accumulation regions in West Antarctica -  the northern Antarctic Peninsula and the Union Glacier region in the Ellsworth Mountains on the West Antarctic Ice Sheet - and determining potential forcing factors for observed changes. To do so, newly collected firn cores from both regions are used as natural climate archives and analysed in high (sub-annual) resolution for density, stable water isotopes and various chemical parameters. New data on accumulation rates and meteorological parameters (e.g. air temperature) as well as information on moisture source regions and transport paths of precipitating air masses are gained during.

Research Focus: Past Climate Change

Contact: Kirstin Hoffmann, Hanno Meyer

Funding: Elsa-Neumann Scholarship of the state of Berlin for Kirstin Hoffmann (2016-2019)

Cooperation:

  • Department of Geography, Humboldt-University of Berlin, Germany – Prof. Dr. Christoph Schneider
  • Facultad de Ingeniería, Universidad Nacional Andrés Bello (UNAB), Viña del Mar, Chile – Dr. Francisco Fernandoy
  • Trace Chemistry Laboratory, Division of Hydrologic Sciences, Desert Research Institute (DRI), Reno, Nevada, USA – Dr. Joseph R. McConnell
  • Ice Dynamics and Paleoclimate, British Antarctic Survey (BAS), UK – Dr. Elizabeth R. Thomas