On the Ecology of Mountainous Forests in a Changing Climate: A ...

136 Chapter 5
FORECE
Fagus silvatica
T (°C)
P (mm/yr)
FORC LIM-E/P
FORC LIM-E/P/S
T (°C)
T (°C)
P (mm/yr)
P (mm/yr)
Fig. 5.6: Contour plot of Fagus silvatica biomass [t/ha] as simulated by FORECE (top),
FORCLIM-E/P (bottom left), and FORCLIM-E/P/S (bottom right).
Similar steep gradients as observed with P. excelsa and P. cembra occur with F. silvatica
in the FORECE model (Fig. 5.6): There is an abrupt decline at T l ≈ 5 °C, which is
located in the middle of the upper montane beech-silver fir zone (Fig. 5.1). Again, both
variants of FORCLIM produce smoother and more realistic gradients; specifically, the
species extends down to T l ≈ 4 °C, where the transition between montane and subalpine
forests should occur (Fig. 5.1). Moreover, in FORCLIM F. silvatica extends down to a
precipitation of about 800 mm, which is plausible as well (Fig. 5.6).
Neither FORECE nor FORCLIM are capable of simulating the transition from beech forests
to insubrian and mediterranean forests dominated by oak (Quercus spp.) and chestnut (C.
sativa), which should occur at T l ≈ 10 °C (Fig. 5.6). In both models, Fagus silvatica