Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Discussion papers
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: reviews and syntheses 20 Mar 2019

Submitted as: reviews and syntheses | 20 Mar 2019

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Biogeosciences (BG).

Reviews and syntheses: How do abiotic and biotic processes respond to climatic variations at the Nam Co catchment (Tibetan Plateau)?

Sten Anslan1, Mina Azizi Rad2,3, Johannes Buckel4, Paula Echeverria Galindo2, Jinlei Kai5,6, Wengang Kang2, Laura Keys7, Philipp Maurischat8, Felix Nieberding2,9, Eike Reinosch10, Handuo Tang5,6, Tuong Vi Tran11, Yuyang Wang5,6, and Antje Schwalb2 Sten Anslan et al.
  • 1Zoological Institute, Technische Universität Braunschweig, Mendelssohnstr. 4, 38106 Braunschweig, Germany
  • 2Institute of Geosystems and Bioindication, Technische Universität Braunschweig, Langer Kamp 19C, 38106 Braunschweig, Germany
  • 3Max Planck Institute for Biogeochemistry, 07745 Jena, Germany
  • 4Institute for Geophysics and Extraterrestrial Physics, Technische Universität Braunschweig, Mendelssohnstraße 3, 38106 Braunschweig, Germany
  • 5Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
  • 6University of Chinese Academy of Sciences, Beijing, China
  • 7Institute for Geography, Friedrich-Schiller-Universität Jena, Löbdergraben 32, 07743 Jena, Germany
  • 8Institute of Soil Science, Leibniz Universität Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany
  • 9GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
  • 10Institute of Geodesy and Photogrammetry, Technische Universität Braunschweig, Bienroder Weg 81, 38106 Braunschweig, Germany
  • 11Institute of Fluid Mechanics and Environmental Physics in Civil Engineering, Leibniz Universität Hannover, Appelstraße 9A, 30167 Hannover, Germany

Abstract. The Tibetan Plateau (TP) is the largest alpine plateau on Earth and plays an important role in global climate dynamics. On the TP, climate change is happening particularly fast, with an increase in air temperature twice the global average. The particular sensitivity of this high mountainous environment allows the observation and tracking of abiotic and biotic feedback mechanisms. Closed lake systems, such as the Nam Co on the central TP represent important natural laboratories for tracking past and recent climatic oscillations, as well as geobiological processes and interactions within their respective catchments. This review gives an interdisciplinary overview of modern and paleoenvironmental changes, focusing on Nam Co as model system. In the catchment area, the steep rise in air temperature forced glaciers to melt, leading to a rise in lake levels and changes in water chemistry. Some studies base their conclusions on inconsistent glacier inventories but an ever-increasing deglaciation and thus higher water availability have persisted over the last decades. The enhanced water availability causes translocation of sediments, nutrients and dissolved organic matter to the lake, as well as higher carbon emissions to the atmosphere. The intensity of grazing has a significant effect on CO2 fluxes, with moderate grazing enhancing belowground allocation of carbon while adversely affecting the C-sink potential through reduction of above- and subsurface biomass at higher grazing intensities. Furthermore, increasing pressure from human activities and livestock grazing are enhancing grassland degradation processes, thus shaping biodiversity patterns in the lake and catchment. The environmental signal provided by taxon-specific analysis (e.g. diatoms and ostracods) in Nam Co have revealed profound climatic fluctuations between warmer/cooler and wetter/drier periods since the late Pleistocene and an increasing input of freshwater and nutrients from the catchment in recent years. Based on the reviewed literature, we outline perspectives to further understand the effects of global warming on geo- and biodiversity and their interplay in the Lake Nam Co, which acts as a case study for potentially TP-wide processes that are currently shaping the earth’s future.

Sten Anslan et al.
Interactive discussion
Status: open (extended)
Status: open (extended)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Sten Anslan et al.
Sten Anslan et al.
Total article views: 292 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
217 73 2 292 1 2
  • HTML: 217
  • PDF: 73
  • XML: 2
  • Total: 292
  • BibTeX: 1
  • EndNote: 2
Views and downloads (calculated since 20 Mar 2019)
Cumulative views and downloads (calculated since 20 Mar 2019)
Viewed (geographical distribution)  
Total article views: 255 (including HTML, PDF, and XML) Thereof 255 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
No saved metrics found.
No discussed metrics found.
Latest update: 16 Sep 2019
Publications Copernicus
Short summary
Due to the high elevation, the Tibetan Plateau (TP) is affected stronger than the global average by climate warming. As a result of increasing air temperature, several environmental processes have accelerated, such as melting glaciers, thawing permafrost and grassland degradation. We review several modern and paleoenvironmental changes forced by climate warming in the model lake system of Nam Co to shape our understanding of global warming effects on the current and future geo-biodiversity.
Due to the high elevation, the Tibetan Plateau (TP) is affected stronger than the global average...