Chemistry Reference
In-Depth Information
surface (Qleaf) was determined simultaneously with measurements of ecophysiological
variables, using the sensor coupled to the chamber of porometers, always disposed
perpendicularly to incident sunlight on the leaf surface throughout each workday.
Additional data on air temperature and relative air humidity of the specific measurement
days were obtained from an automatic weather station Campbell Scientific Inc. installed at
the study site for each rating scale. This information was used to calculate the vapor
pressure deficit of the atmosphere (VPD), as follows [30]:
VPD
,
es
ea
kPa
(1)
The saturation of vapor pressure (es) was calculated using the following equation:
7.5*
Tar
/ 237.3
Tar
es
0.6108 * 10
,
kPa
(2)
Tar = air temperature, ° C
The partial vapor pressure (ea) was obtained by the following equation:
ea
RH
*
es
/ 100,
kPa
(3)
RH = relative humidity of the place, %.
2.3. Ecophysiological models and Scaling up
Structuring the ecophysiological model in the pot scale
The scaling up of information measured on the pot scale was performed by applying the
ecophysiological model used by [45] in order to simulate the E and Gs according to Qleaf,
VPD and Ψ
pd
considering the hourly time scale of the period of study. Thus, follows the
equation:
E
f
(
,
Qleaf
,
VPD
)
(4)
pd
Gs
f
(
,
Qleaf
,
VPD
)
(5)
pd
The models that relate the E and Gs (dependent variables) and environmental variables
Qleaf VPD (independent variables) will be:
E
*
leaf
²
´*
leaf
(6)
1
1
Gs
*
Qleaf
²
´*
Qleaf
(7)
2
2
E
*
VPD VPD
²
´*
(8)
3
3
Gs
*
lnVPD
´
(9)
4
4
