4 Combination of Elevated CO 2 Levels and Soil Contaminants’ Stress ... 81
concentrationCu
)-1 rioe shoots (mg kg
35 30 25 20 15 10 5 0
FA
CE
Ambient
concentrationCu
)-1 rioe shoots (mg kg
FA
CE
Ambient
18 15 12 9 6 3 0
concentrationCu
)-1 rioe shoots (mg kg
FA
CE
Ambien
t
12 10 8 6 4 2 0
concentrationCu
)-1 rioe shoots (mg kg
FA
CE
Ambient
10 8 6 4 2 0
FA
CE
Ambien
t
concentrationCu
)-1 rioe shoots (mg kg
10 8 6 4 2 0
Cu
added to soil (mg kg
-1
)
FA
CE
Ambien
t
concentrationCu
)-1 rioe shoots (mg kg
10 8 6 4 2 0
05
0
400
a de
f
bc
Fig. 4.5
Copper concentrations in tissues of rice plants grown in soil with
0, 50, or 400
mg
kg
−1
Cu, under either ambient CO
levels or elevated CO 2
levels 2
( FACE
).
a Rice shoots at the mid-tillering growth stage of the first rice sowing,
b rice shoots at the panicle-initiation growth stage of the first rice sowing,
c^
rice shoots at grain maturity of the first sowing,
d rice seeds at grain maturity of the first season,
e rice shoots at grain maturity of the second season, and
f rice
seeds at grain maturity of the second season. Values represent means
±^
SD. An asterisk indicates a significant difference between
FACE and ambient conditions
( p
<
0.05).
FACE
free-air CO
enrichment 2