EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Influence of climate change and CO2 fertilization on vegetation and catchment erosion: A coupled modelling approach

Mirjam Schaller1, Todd Ehlers1, Pascal Hirsch2, Thomas Hickler2,3, Juan-Pabloe Fuentes-Espoz4, Antonio Maldonado5, and Leandro Paulino6
Mirjam Schaller et al.
  • 1Department of Geosciences, University of Tuebingen, Tuebingen, Germany (;
  • 2Senckenberg Biodiversity and Climate Research Centre, Frankfurt am Main, Germany
  • 3Department of Physical Geography, University of Frankfurt, Frankfurt am Main, Germany
  • 4Department of Silviculture and Nature Conservation, University of Chile, Santiago, Chile
  • 5CEAZA, University of La Serena, La Serena, Chile
  • 6Department of Soils and Natural Resources, University of Concepción, Campus Chillán, Chile

The Earth’s surface is shaped by a complex interplay between tectonics, lithology, climate and biota. Previous work has shown that vegetation cover effects on erosion rates are non-linear and depend on the ecosystem investigated. Vegetation cover is not only influenced by climate (via changes in precipitation, temperature and solar radiation) but also by changes in the atmospheric CO2 concentration through a fertilization effect and increased water use efficiency. However, disentangling the influence of variable climate or atmospheric CO2 concentrations on vegetation cover, and hence erosion rates, is difficult. Here we present results from a series of coupled model runs aimed at quantifying the non-linear interactions between these different processes.

We apply a landscape evolution model (Landlab) that is coupled to a dynamic vegetation model (LPJ-GUESS) driven by general circulation model predictions of climate change over the last 21 kyr. Three different scenarios are simulated from the Last Glacial Maximum to present-day: 1) Changing climate and changing atmospheric CO2 concentration; 2) Changing climate but constant atmospheric CO2 concentration; and 3) Constant climate but changing atmospheric CO2 concentration. The simulations are adapted to represent four study areas along the extreme climate and ecological gradient of the Chilean Coastal Cordillera (26 º to 38º S). Results indicate that transients in climate and CO2 from glacial to interglacial conditions induce a ~10-25% temporal change in catchment erosion, and should be detectable with different measurement techniques. In more detail, we find that precipitation changes exert a stronger influence on erosion rates than changing atmospheric CO2 concentrations. However, the relative roles of precipitation vs. plant-physiological CO2 effects on catchment erosion varies with the climate and ecological zone investigated such that the effects of CO2 fertilization on erosion are larger in temperate than arid settings.

How to cite: Schaller, M., Ehlers, T., Hirsch, P., Hickler, T., Fuentes-Espoz, J.-P., Maldonado, A., and Paulino, L.: Influence of climate change and CO2 fertilization on vegetation and catchment erosion: A coupled modelling approach, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-885,, 2022.