Supplement of Biogeosciences, 11, 4139–4156, 2014
http://www.biogeosciences.net/11/4139/2014/
doi:10.5194/bg-11-4139-2014-supplement
© Author(s) 2014. CC Attribution 3.0 License.
Supplement of
Effects of heat and drought on carbon and water dynamics in a regenerating semi-arid pine forest: a combined experimental and modeling approach
N. K. Ruehr et al.
Correspondence to: N. K. Ruehr (nadine.ruehr@kit.edu)
SWP = (−0.4 −1.6 / (1 + exp ( (SWC − 0.096) / 0.0184 ) ) )
−0.2
Soil water potential
[MPa]
−0.4
●
●
−0.6
−0.8
●
●
●
−1.0
●
●
●
−1.2
●
−1.4
●
−1.6
−1.8
0.02 0.06 0.10 0.14 0.18 0.22
[m3m−3]
Soil water content
Figure S1: Relationship of soil water potential (SWP) with soil water content (SWC, 10–90 cm depth), described by a sigmoid function (R2 = 0.98), assuming a SWP of −2 MPa at SWC of 0 m3 m-3 (−1.8 MPa was
minimum leaf water potential measured midday).
●
●
●
Heterotrophic respiration
[relative to pre−drought]
1.4
1.2
1.0
0.8
0.6
0.4
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
● ●
●
●
●
●● ● ●●●
● ●●
●
●
●●
●
●●
● ●●●●
● ●
●
●
●●●
●●
●
●
●
●
●
●
●
●●●●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●●
●
●
●
●●
●
●●●
●●
●
●
●●
●
●
●●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●●●
●
●
●●
●●●
●
●
●●
●
●
●
●●
●
●
●
●
●
●
●
●●
●
●
●
●
● ●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
● ●●
●
●
●
● ●●●
●●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
● ●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●●●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●●
●
●
●
●
●●
●
●
●●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●●
● ●●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●●●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●●
●
●●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●●
●●
●
●
●
●
●
●
●●●
●
●
●
●●●
●
●
●
●
●
●
●
●●
●●
●
●
● ●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●● ●
●
●
●
●
●
●
●
●●
● ● ● ●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●
●
● ●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
8–12°C
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
12–16°C
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
16–24°C
0.2
0.00
20–24°C
24–28°C
0.04
0.08
0.12
0.16
0.20
[m3m−3]
Soil water content [0–20 cm]
Figure S2: Heterotrophic respiration (Rh) relative to pre-drought conditions (0.15 < SWC < 0.19) vs. soil water
content of half-hourly measurements during the summer 2011. The relationship of Rh relative to pre-drought
conditions with SWC is described by sigmoid functions (R2 = 0.67–0.75) for 5 different temperature classes.
The sigmoid function for the temperature class 16–24 ◦ C (average soil temperature during summer) used to
describe the drought-sensitivity in the model is: y = 0.2 + 0.8 / ( 1 + exp(− (SWC − 0.07 ) / 0.016) ).
2
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●● ●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●
●
●●
●●
●
●
●
●
●
●
●●
●
●
●●●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
2
●
●
●
●
●
●
●
●
0.2
●
●
(b)
●●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●●●
●
●
●
●
●
●
●
●
●●●
●●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●●
●
●
●
●●●
●
●
●
●
●
●
●
●
●
●
●●
●●
●●
●
●
●
●●
●
●
●
●●
●
●
●●
●●●
●
●●
●●●
●
●
●
●
●
●●
●●●
2
●
● ●
●
●●
●
●●
●
●●●
●
●
●
●
●
●
●
all seasons
dry season
0.1
R = 0.95
RMSE = 0.02
Bias = −2.6
0.1
20
10
R = 0.97
RMSE = 1.72 0
Bias = 1.3
0.2
0
10
[°C]
Soil temp 15 cm
SWC 0−40 cm
[m3m−3]
(a)
20
(d)
0
0.0
1
2
3
●
●
●
●
●●
●●
● ●
●
●
●
●
●
●
● ●●
●
●
●●
● ● ●●
●
●
●
●
●
●●
●
●
●
●
●
●● ●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
● ●
●●●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●●
●
●
●
●
●●
●
●
●
●
●
●
●●
● ●
●
● ●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●
●
●
●
●
●
●
●
●
●
●
●
●
●●●
●
●●●●
●
●
●
●●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●●
●
●
●
●●●
●
●
●●
●
●
●
●
●
●
●
●●
●
●
●
●
●●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
● ●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●●
●
●●
●
●
●
● ●
●
●
●
● ●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●●●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●●
●
●
●
●●
(e)
4
2
0
● ●
R2 = 0.8
RMSE = 0.74
Bias = 10.8
−2
−2
0
2
4
1.0
6
● ●● ●
●
●●●
●●
●
●
●
●
●
●
●
●●●
●
●●●
● ●
●
●
●
●
●●
●●●●
●
●
●●
●
●● ●
●
●●
●
●
●
●
●
●
●●
●●
●
●
●
●
●
●
●
●
●● ●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●●●● ●
2
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
−2
Reco
[g C m−2d−1]
2
1
2
0
0
2
4
6
2.0
(g)
3
4
R = 0.64
RMSE = 0.69 −2
Bias = 3
5
4
0.0
1.5
(f)
●
●
6
0.5
Simulated
0
0.5
R = 0.88
RMSE = 0.3
Bias = 63.2
[mm]
Transpiration
R = 0.6
RMSE = 0.58
Bias = −18
1.0
−NEE
1
1.5
●
●●●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
● ●●
●
●
●
●●
●
●
●
●
●
●
●
●
●●
●
●
● ●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●●
●●
●
●
●●
●
●
●●
●●
●
●
●
●
●
●●
●●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●●
●●
●●
●
●
●
●●
●
●
●●
●
●
●
●
●
●●●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
2
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●●
Rh
2
6
−GPP
[g C m−2d−1]
●
●
●
● ●
●●
●● ●
● ●● ●
●● ●
● ● ●
●
●● ●
●●● ●●
●● ● ●●●●
●
●
●●
●
●●
●●
●●● ● ●
●
●
●
●
●
●● ●
●● ●
●
●
●
●
●
●●
●
●●● ●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●● ●
●
●● ●
●
●
●
●
●
● ●●●●
●●
●●●●
●● ●
●
●
●
●
●●
● ●●●
● ●
●
●
●
●●
●
●
●
●
●
●●
●
●●●●●
●●
●
●●●
●
●
● ●●
●●
●
●●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●
●●
●
●●
●●
●
●●
●
●
●
●●
●
●
●●
●
●
●
●●
●●●●
●●
●
●
●●
●
●●
●
●
●●
●●
●
●
●●● ●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●●●●
●
●
●
●
●
●
●
●●
●
●
●●
●
●
●
● ●●●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●●
●
●
●
●●
●
●
●
●●
●●
●
●
●
●
●
● ●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●●
●
●
●
●
●
●
●
●
●
●
●
●
●
● 2
●
●
●
●●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●●● ●●
●
●
●
●
●
●●
●
●
●
●●
●
●
●
●●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●●
●●●
●
●
● ●
(c)
[g C m−2d−1]
3
[g C m−2d−1]
Evapotranspiration
[mm]
Simulated
●
(h)
●●●
●
●
● ●●
●
●●
●
●●
●
●
●
●●
●●
●
●
●
●
●
● ●●
●●
●
●
●
●●●●
●
●●●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●●
●
●
●●
● ●
●● ●
●●
●●
●●
●
●
●●
●
●●
●
●●
●
●●●
●
●
●●●● ● ●
●
●
●
●
●●
●
●●
●
●
●●
●●
●
●
●
●
●
●
●
●
●●
●
●●●
●●●
●●●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●●
●
●●
●
●
●
●●
●
●
●
●●
●
●
●●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●
●●
●
●
●
●●●●
●
●
●●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●●●
●●
●●
●
●
●
●
●●
●
●
●
●
●
●●
●●
●●●
●
●●●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●●●
●
●
●
●
●●
●
●
●●
●
●●●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●●
●●
●
●
●
●
●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
●
●●
●
●
●
●
●
●
●
2
●
●
●
●
●
●
●
●
●
●
●
●
●
●● ●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●
●
● ●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
●●● ●●
●
●
●
●
●●
●
●
●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●●
●
●
●●
● ●●
●
● ●
●
●
●
● ●●
●
●
●
●●
●●
●●●●
●
●●●
●
●
●
●●●
●●
●●
●
●
●
●
●
● ●●
●
●●
●
●
●
●
●
● ●●
● ●● ●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●●
●
● ●●
●
●
●
●
●
●
●
●
●
●
●
●
●●●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
● ●
● ●
● ●●
●●●
●●
●
●
●
●●
●●
●●
●
●
●
●●●
●●
●●
●
●
●●
●
●●
●●
●
●●
●●
●
●
●
●
●
●●
●●
●
● ●
●
●
●●
●
●●●● ●
●
● 2
●
●
●
●
●
●
●
●
●
●
●
●
●
●●
●
R = 0.79
RMSE = 0.51
Bias = 17.3
1
2
3
4
1.5
1.0
0.5
R = 0.68
RMSE = 0.16
Bias = 5.6
5
0.5
1.0
1.5
2.0
Observed
Figure S3: Relationship between simulated and observed daily averages in 2010 and 2011. The regression between simulated and observed values for all seasons is provided by the solid line, and the R2 , RMSE (root mean
square error) and percent mean bias are given. The dry seasons (July, August and September) are highlighted
with the open circles (see legend), and the ideal one-to-one relationship is depicted by the dotted line.
3
Soil water potential
[MPa]
−0.4
●
●
●
●
−0.6
●●
●
−0.8
●●
−1.0
−1.2
●
watered
control
w100_sim
w30_sim
ctrl_sim
Jun
Jul
●●
Aug
Sep
2011
Figure S4: The dynamics of observed and simulated soil water potential (SWP; i.e. predawn leaf water potential) for control and watered treatment during the summer 2011. The simulation run w100sim equals the
irrigation treatment and the w30sim simulates 30% of the water added. The duration of the watering treatment is highlighted by the gray area. Note the relative good accordance of the field watered treatment with
the w30sim during the irrigation period, and fast declines of observed SWP thereafter. Observed SWP for the
control matched the simulation (ctrlsim ) relatively well, but was overestimated by the model in September.
4