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

Parameter sensitivity & model validation 133
Total biomass (FORECE)
t/ha
500
400
300
200
100
12
10
8
6
T (°C)
4
2
0
40
90 140 190 0
P (cm/yr)
Total biomass (E/P)
Total biomass (E/P/S)
t/ha
t/ha
500
600
400
500
300
200
100
400
300
200
100
12
10
8
6
T (°C)
4
2
0
40
0
90 140 190 P (cm/yr)
12
10
8
6
4
T (°C)
2
0
40
0
90 140 190 P (cm/yr)
Fig. 5.3: Total aboveground biomass as simulated by the three models FORECE, FOR-
CLIM-E/P and FORCLIM-E/P/S in a space spanned by the annual precipitation sum (P) and
the annual mean temperature (T).
istic. However, it should be noted that nitrogen availability has been introduced in FOR-
CLIM as a substitute of SOILQ, and that the assumption of a constant supply of nitrogen
(100 kg/ha) in FORCLIM-E/P is equally unrealistic; yet this model does not produce the
anomaly evident from FORECE (Fig 5.3).
The major difference of aboveground biomass between the two FORCLIM variants is that
in FORCLIM-E/P/S nitrogen availability rises above 100 kg/ha at higher temperatures,
and total biomass increases above the level reached by FORCLIM-E/P (Fig. 5.3, cf.
Fig. 5.8).