Geoscience Reference
In-Depth Information
*
,
*
is the leaf
with the following notations:
ʷ
= z/H,
ˆ
(
ʷ
)=1+
ˈ
(
ʷ
H)/
ˈ
ˈ
'
s water
*
, F=
ρ
gH/
ˈ
*
,
potential, 1/D
1
is a minimum mouth resistance, U=Hr
ks
D
1
d
ʲ
m
L
/
ˈ
G=Hr
ks
ʾ
0
,
ʱ
= a/H,
ʲ
is the leaf index, h=
−
z,
8
<
H
;
wð
H
Þw
;
a
¼
h
; wð
h
Þ
¼
w
; wð
H
Þ
\
w
\
wð
0
Þ;
:
;
wð
0
Þw
0
8.3.5 Modeling the Energy Fluxes in the Atmosphere-Plant-
Soil System
The energy exchange in the system atmosphere-plant-soil (APS) plays an important
role in the formation of climatic processes on every spatial and temporal scale, and
therefore it should be considered in the models of the greenhouse effect that
increases the reliability of the estimates. The appearing problems include the
development of methods in order to measure the energy
fluxes in the air-surface
layer as well as their modeling. A special aspect of these problems concerns the
development of technologies of estimation of energy
fl
fluxes in the APS system on
global scales to take these estimates into account in the global climate systems.
There are well-developed methods of the remote sensing of a wide set of climatic
parameters including energy
fl
fluxes (Krapivin and Kondratyev 2002; Shutko et al.
2010). However, in the remote sounding of the APS system a complicated problem
of an assessment of the screening impact of vegetation over the wavelength regions
used in the monitoring system arises.
Beginning from the 1980s, studies have been carried out on developing a model
of photosynthesis a vegetation bud. Farquhar et al. (1980) showed how a biological
model of the CO
2
assimilation by leaves is connected with fermentative kinetics
and electronic properties of the chloroplast, which made it possible to rather
plausibly describe the process of photosynthesis for the plants of class C. Then Ball
(1988) and Collatz et al. (1990, 1991, 1992), using a model technology and
observation data on the process of the vegetation bud conductivity in photosyn-
thesis, derived a semi-empirical model of the vegetation bud functioning with an
account of changes of the environmental temperature, humidity, CO
2
concentration
in the atmosphere, and intensity of assimilation of the vegetation species itself.
The problem have been also considered on the consequences of the distribution of
the photosynthetic potential of leaves and canopy of plants with respect to
illumination and a criterion has been developed to determine a common potential
corresponding to maximum photosynthetic abilities of the plant in CO
2
assimilation.
Sellers (1985, 1987) developed methods of the vertical integration of leaf can-
opies, models of light scattering and absorption, photosynthesis and conductivity of
fl
Search WWH ::
Custom Search