Geoscience Reference
In-Depth Information
8.3.2 Biocoenotic Model
The vegetation cover parameters change during the year depending on the weather
situation (Table
8.4
). The speci
c biomass Qi
i
of the ith type of vegetation at time
t can be parameterized according to the following equation:
@
Q
i
=@
t ¼ R
i
M
i
E
i
;
ð
8
:
1
Þ
where R
i
is the biomass productivity and Mi
i
and E
i
are the biomass losses at the
expense of withdrawal and transpiration, respectively.
The function Mi(φ,
i
(
φ
ˈ
ects the set of natural Mi(φ,
Ni
and anthropogenic Mi(φ,
Ai
processes leading to vegetation biomass losses (Mi
i
=M
Ni
+M
Ai
):
,
,t)re
fl
M
i
ðu; w;
t
Þ
¼
l
i
ð
t
Þ
Q
i
ðu; w;
t
Þ
where
φ
,
ˈ
are the latitude and longitude, respectively.
The
fl
ux E
i
is calculated by the formula:
c
p
e
T
ðÞ
e
a
t
Þ
¼
q
b
c
E
i
ðu; w;
;
c
p
r
c
þ
r
b
ð
Þ
where e
ð
T
c
Þ
is the saturated vapor pressure inside the canopy foliage (in units of
Pa), e
a
is the vapor pressure in the canopy air space (Pa), r
c
is canopy resistance
(sm
−
1
), r
b
is the bulk leaf boundary layer resistance of the canopy (sm
−
1
),
ˁ
is air
density (kg m
−
3
), c
p
is the air speci
c heat (J kg
−
1
K
−
1
) and
ʳ
p
is the psychrometric
constant (Pa K
−
1
).
Table 8.4 Dependence of the annual production R (kg m
−
2
year
−
1
) on the average annual
temperature T
a
and the total annual rainfall W, F(Ta, W)
W (mm/year)
Atmospheric temperature (
°
C), T
a
−
14
−
10
−
6
−
226048260
3,125
3.4
3.5
3.7
3.8
3.9
4.0
2,875
3.2
3.3
3.5
3.6
3.7
3.8
2,625
3.0
3.2
3.3
3.4
3.5
3.6
2,375
2.8
2.9
3.0
3.1
3.2
3.3
2,125
2.5
2.6
2.7
2.9
2.9
3.0
1,875
1.6
2.3
2.3
2.4
2.5
2.6
2.7
1,625
0.4
0.6
1.3
2.0
2.1
2.1
2.2
2.3
2.4
1,375
0.2
0.3
0.4
0.7
1.1
1.7
1.9
1.9
2.1
2.1
2.0
1,125
0.2
0.3
0.3
0.4
0.6
1.0
1.6
1.8
1.9
1.8
1.8
1.7
875
0.2
0.3
0.4
0.5
0.8
0.9
1.5
1.4
1.3
1.3
1.2
1.2
625
0.3
0.3
0.5
0.6
0.9
0.9
0.9
0.8
0.8
0.7
0.7
0.7
375
0.4
0.4
0.5
0.7
0.6
0.6
0.6
0.5
0.5
0.5
0.4
0.4
125
0.1
0.3
0.3
0.2
0.2
0.2
0.2
0.2
0.2
0.1
0.1
0.1
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