Heat and water exchange processes in larch dominated permafrost ecosystems

Supervisors: Dr. Moritz Langer (AWI), PD Dr. Julia Boike (AWI), Prof. Dr. Ulrike Herzschuh (AWI)and Dr. Stefan Kruse (AWI)

Project Outline:

The distribution and condition of permafrost, is directly linked to the snow and vegetation cover, topography, water bodies, the geothermal heat flux and the air temperature. Therefore, the prediction of permafrost sensitivity to a warming climate is highly complex with many uncertainties. Moreover, climate change has a direct impact on the water, heat and nutrient budget of boreal ecosystems. The boreal forests of Siberia are expected to expand to the North under warming climatic conditions. Extensive ecosystem changes such as a change in composition, density and distribution of Arctic vegetation are already reported all over the Arctic and Sub-Arctic. These changes and transitions trigger multiple feedback mechanisms of different magnitudes. The numerous interactions and inter-dependencies of the atmosphere, the larch dominated vegetation, and the permafrost ground in Eastern Siberia make predictions and interpretations of the current and future state highly challenging. In a multi-proxy and multidisciplinary approach the climate-vegetation-soil interactions in permafrost-dominated areas are studied over a large transect of Eastern Siberia. I co-develop a numerical model of physical processes in permafrost landscapes by coupling a multilayer forest canopy model. The developed model simulates boreal landscapes with to further understand the interactions between the biosphere, atmosphere and cryosphere. Accordingly, one major aspect of my work consists of the collection and employment of large measurement datasets for the parameterization and validation of the modeled interactions. In two field campaigns, we generated a great variety of validation points from in-situ measurements in remote boreal areas of Eastern Siberia, which are now used for model validation.


Stuenzi, S. M., Boike, J., Cable, W., Herzschuh, U., Kruse, S., Pestryakova, L. A., Schneider Von Deimling, T., Westermann, S., Zakharov, E. S., Langer, M. (2021). Variability of the surface energy balance in permafrost-underlain boreal forest. Biogeosciences, 18, 343–365. https://doi.org/10.5194/bg-18-343-2021

Stuenzi, S. M., Boike, J., Gädeke, A., Herzschuh, U., Kruse, S., Pestryakova, L. A., Westermann, S., Langer, M., (2021). Sensitivity of ecosystem-protected permafrost under changing boreal forest structures. Environmental Research Letters, 16(8), 084045. https://doi.org/10.1088/1748-9326/AC153D

Stuenzi, S. M., Schaepman-Strub, G.(2020). Vegetation Trajectories and Shortwave Radiative Forcing following Boreal Forest Disturbance in Eastern Siberia, Journal of Geophysical Research: Biogeosciences 125, e2019JG005395. https://10.5194/10.1029/2019JG005395.