Supplementary information
Table S1. Statistics of linear models describing the relationships between the logarithmic
transformation of bacterial production (leucine uptake in pmol L-1 h-1) and community
diversity estimates. Estimates for the active fraction and standing stock are based on the 16S
rRNA and 16S rRNA gene respectively. H: Shannon index, SES: standardized phylogenetic
diversity. Significant relationships are in boldface.
Active
fraction
Standing
stock
Variable
Intercept
Slope
df
F
R2
P value
H
Richness
SES
1.23
1.32
1.12
-0.54
-0.00
0.21
39
39
39
0.60
2.57
10.86
0.02
0.06
0.22
0.44
0.12
<0.01
H
Richness
SES
1.8
1.68
1.04
-0.37
-0.01
0.03
44
44
44
14.01
21.28
0.15
0.24
0.33
0.01
<0.01
<0.01
0.70
Table S2. Permutation test under reduced model for canonical correspondence analysis
(CCA) of community assemblies against environmental conditions (salinity, chlorophyll a,
nitrate, nitrite, ammonium, phosphate and silicate) for the active fraction of the community
and the standing stock.
Chisq df F R2 P value
Active fraction 1.67 8 1.25 0.03 0.001
Standing stock 1.43 8 1.16 0.00 0.021
1.0
Bacterial production
0.0
0.5
1.0
0.5
0.0
Bacterial production
1.5
b
1.5
a
50
75
100
30
Community richness
a
60
90
Community richness
b
Figure S1. Relationship between bacterial production and the community richness for the
active bacteria (a) and the standing stock (b). Bacterial production is measured as the rate of
tritiated-leucine incorporation (pmol L-1 h-1) and plotted following logarithmic transformation.
The black line in panel (b) represents a linear fit to the data (R2=0.33, P<0.01, n=46) and the
grey shading shows the 95% confidence interval.
Figure S2. Relationship between bacterial production and the phylogenetic diversity of active
bacteria without weighting by taxa abundance. Without weighting by taxa, all the rare
bacteria become as important as the abundant ones in the calculations. In theory, if rare taxa
can be find everywhere, the phylogenetic diversity of communities will not vary much when
taxa abundance is not taken into account. We thus argue that in the case of natural marine
bacteria communities, characterized by few abundant taxa and a very large number of rare
taxa, phylogenetic diversity has to be weighted by taxa abundance.
a
b
Figure S3. Differences in bacterial production in relation to similarity between communities.
Differences in bacterial production are calculated as Euclidian distance between each pair of
samples and community similarity as Bray-Curtis (a) or Sorensen (b) index of similarity. The
grey shading shows the 95% confidence interval.
Figure S4. Periodogram obtained by spectral analysis showing the periodicity of community
diversity for the standing stock (DNA) and the active bacteria fraction (RNA). Horizontal
lines show the white noise lines illustrating significance level of 0.01 and 0.05. DNA shows a
significant pattern of diversity with a frequency of 1 year while RNA has no significant
pattern.