Environmental Engineering Reference
In-Depth Information
Chapter 10
P
HOTOSYNTHETIC
C
HARACTERIZATION OF
T
HREE
D
OMINANT
P
LANT
S
PECIES IN THE
S
ALT
M
ARSHES
OF THE
Y
ELLOW
R
IVER
D
ELTA
,
C
HINA
Lihua Zhang
1
, Kun Yan
1
, Liye Chu
2
and Hong-Bo Shao
1,2
1
Key Laboratory of Coastal Environmental Processes
and Ecological Remediation and Key Laboratory of Coastal Biology & Bioresources
Utilization, Yantai Institute of Coastal Zone Research(YIC),
Chinese Academy of Sciences(CAS), Yantai, China
2
Institute for Life Sciences, Qingdao University of Science & Technology (QUST),
Qingdao, China
A
BSTRACT
The diurnal variations of photosynthesis of three dominant species, including
Glycine soja
,
Phragmites australis
and
Cynanchum chinensis
, in Yellow River Delta in
China have been studied under the same natural conditions using a Li-6400 portable
photosynthesis system. The results showed that the curves of diurnal variations of net
photosynthetic rate (
P
N
) of the three plants were different. The diurnal variation of
P
N
on
C. chinensis
was a midday depression pattern and had two peaks. However,
P
N
of
G. soja
and
P. australis
showed single-peak curves. The transpiration rate
(
E
) of
G. soja
was
significantly higher than
P. australis
and
C. chinensis
, both showed single-peak curves.
In general, the diurnal course of stomatal conductance (
g
s
) followed the same pattern of
P
N
. A similar diurnal pattern of intercellular CO
2
concentration (
C
i
), vapor pressure
deficit (VPD) and water use efficiency (WUE) was observed among different species.
VPD showed single-peak curves, while WUE was characterized by double-peak curves,
which was contrary to
C
i
. Linear correlations among photosynthetic variables and key
environmental factors indicate high positive correlations between
P
N
and
E
,
P
N
and PAR,
P
N
and leaf temperature (
T
leaf
),
P
N
and VPD,
P
N
and
g
s
except
C. chinensis
. Negative
correlations among
P
N
and relative humidity (RH),
P
N
and
C
i
were found. The irradiance
Correspondence address: Professor HONG-BO SHAO, Institute for Life Sciences, Qingdao University of Science
& Technology (QUST), Qingdao Shandong 266042, P. R. China;Tel: +86-532-84023984; E-mail:
