Supplemental Table 1. The soil respiration flux (adjusted for the in situ soil temperatures)
and the respired radiocarbon from individual core depth sections collected from Abisko
warming experiment. These values were used to calculate the depth-integrated
radiocarbon values used in the SIAR model.
Cor
Depth
Flux (g C g-1 soil
Δ14C
-2
-1
e
(cm)
C m hr )
1
0-5
14.25
50.35
1
5-15
23.77
81.13
1
15-25
8.99
30.71
1
25-35
3.08
7.87
1
35-42
1.48
-46.50
2
0-5
19.50
35.66
2
5-15
24.71
75.49
2
15-25
8.55
56.74
2
25-35
7.42
17.38
2
35-48
1.20
-38.53
3
0-5
22.34
42.92
3
5-15
18.00
42.03
3
15-25
12.72
101.47
3
25-35
11.50
29.91
3
35-45.5
5.15
9.81
4
0-5
16.41
58.53
4
5-15
21.34
86.48
4
15-25
25.37
87.80
4
25-35
8.17
1.27
4
35-45
3.24
-43.70
4
45-57
0.40
-60.85
5
0-5
11.04
46.65
5
5-15
18.63
60.79
5
15-25
10.13
56.65
5
25-35
4.15
-0.25
5
35-40
0.45
20.18
1
Supplemental Table 2. Soil moisture differences among treatments at Abisko and Healy.
The Abisko data is gravimetric water content (moisture per dry weight in percent)
measured from soil cores (0-5 and 5-15 cm) collected from control and annual long term
warming plots in July 2011. The Healy data is volumetric water content from 0-30 cm
measured continuously with Campbell CS616 reflectometer probes averaged over July
2010 and July 2011. Soil moisture data from Abisko short term warming and Healy long
term warming plots was unavailable. The reported errors are the standard error of the
mean of Abisko soil cores (n=5) or Healy plots (n=12). Capital and lowercase letters not
shared indicate significant differences among treatments for Abisko (p=0.011) and Healy
(p=0.00067), respectively.
Site
Abisko
Healy
Depth (cm)
0-5
5-15
0-30
Control
840 ± 70A
750 ± 40 A
0.54 ± 0.01a
Short warming Long warming
700 ± 10B
660 ± 40B
0.61 ± 0.01b
2
Supplemental Figure 1. The nonlinear relationship used to model ecosystem respiration at
Abisko based on average daily soil temperature. The black circles are the actual values,
the red circles are the predicted values for each plot on each day between July 14 and
July 29, and the black line is the average prediction of all plots. The predicted values
were then multiplied by 24 to get a daily flux and then summed by plot to obtain the total
respiration flux during the sampling period. The pseudo-R2 for this fit is 0.65.
3