Ulrike Herzschuh
Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Potsdam, Potsdam, Germany, Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany and Institute of Environmental Sciences and Geography, University of Potsdam, 14476 Potsdam, Germany
Author ProfileAbstract
Deciduous larch is a weak competitor when growing in mixed stands with
evergreen taxa but is dominant in many boreal forest areas of Eastern
Siberia. However, it is hypothesized that certain factors such as a
shallow active layer thickness and high fire frequency favor larch
dominance. Our aim is to understand how thermohydrological interactions
between vegetation, permafrost, and atmosphere stabilize the larch
forests and the underlying permafrost in Eastern Siberia. A tailored
version of a one-dimensional land surface model (CryoGrid) is adapted
for the application in vegetated areas and used to reproduce the energy
transfer and thermal regime of permafrost ground in typical boreal larch
stands. In order to simulate the responds of Arctic trees to local
climate and permafrost conditions we have implemented a multilayer
canopy parameterization originally developed for the Community Land
Model (CLM-ml_v0). The coupled model is capable of calculating the full
energy balance above, within and below the canopy including the
radiation budget, the turbulent fluxes and the heat budget of the
permafrost ground under several forcing scenarios. We will present first
results of simulations performed for different study sites in
larch-dominated forests of Eastern Siberia and Mongolia under current
and future climate conditions. Model performance is thoroughly evaluated
based on comprehensive in-situ soil temperature and radiation
measurements at our study sites.