CORR IGENDUM

Biodiversity effects on ecosystem functioning change along

environmental stress gradients

Bastian Steudel,1,2* Andy Hector,3 Thomas Friedl,4 Christian L€ofke,5 Maike Lorenz,4 Moritz Wesche4 and Michael Kessler1

1Systematic Botany, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland, 2Biodiversity, Macroecology & Conservation Biogeography Group, Faculty

of Forest Sciences and Forest Ecology, Georg-August-University G€ottingen, B€usgenweg 2, D-37077, G€ottingen, Germany, 3Institute of Evolutionary Biology and

Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland, 4Department of Experimental Phycology and Culture Collection

of Algae (SAG), Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University G€ottingen, Nikolausberger Weg 18, D-37073, G€ottingen, Germany and5Institute of Applied Genetics and Cell Biology (IAGZ), University of Natural Resources and Life Sciences (BOKU), Muthgasse 18, A-1190, Vienna, Austria

*Correspondence: E-mail: bastiansteudel@aol.com

Ecology Letters (2013) 16: 568–569

We regret that two errors were inadvertently introduced in the

paper by Steudel et al. (2012); their correction required changes to

Figs 2, S5 and S8 as well as to Tables 2 and 3:

1) Our erroneous inclusion of stress response intensity (SRI) in the

formula for calculating the relative stress-response buffering effect

(rSRBE) positively biased the slope of the relationship between the

Table 2 Empirical studies used for analyzing relationships between the relative stress-response buffering effect (rSRBE) and stress response intensity (SRI).

Reference Treatment log (aSRBE)

log (aSRBE) without

monocultures rSRBE

rSRBE without

monocultures

Stress response

intensity (SRI)

Allison 2004 Low 1 �0.416 NA 0.920 NA 0.73

Allison 2004 Low 2 �1.050 NA �0.481 NA 0.48

Caldeira et al. 2005 �1.653 NA 1.375 NA 0.84

De Boeck et al. 2008 A �0.916 NA �0.222 NA 0.33

De Boeck et al. 2008 B �1.050 NA �0.291 NA 0.29

De Boeck et al. 2008 C �0.223 NA 0.167 NA 0.40

De Boeck et al. 2008 D �0.844 NA �0.375 NA 0.25

De Boeck et al. 2008 E �0.619 NA �0.213 NA 0.20

De Boeck et al. 2008 F 0.890 NA �0.663 NA 0.17

Downing & Leibold 2010 Macrophyte �0.811 NA �0.089 NA 0.37

Downing & Leibold 2010 Herbivore �0.172 NA 0.470 NA 0.45

Dukes 2002 New 0.513 1.386 0.818 0.065 0.35

Dukes 2002 Established 0.030 0.715 0.109 �0.069 0.33

Goodsell & Underwood 2008 Bungan Head 0.932 NA 0.223 NA 0.21

Goodsell & Underwood 2008 Narrabeen Head 0.560 NA 0.129 NA 0.24

Hughes & Stachowicz 2004 1.887 �0.260 0.196 0.163 0.48

Ji et al. 2009 Grasses 2004 0.194 NA 0.249 NA 0.34

Ji et al. 2009 N-fixers 2004 �1.444 �1.641 �1.327 �0.243 0.50

Ji et al. 2009 N-fixers 2005 �0.007 0.755 1.589 1.316 0.60

Ji et al. 2009 Forbs 2005 0.087 NA 0.371 NA 0.22

Joshi et al. 2000 0.513 �0.065 2.900 0.1 0.71

Langenheder et al. 2012 �0.074 NA 0.042 �0.156 0.14

Lanta et al. 2012 2003 �0.239 NA �0.037 0.053 0.12

Lanta et al. 2012 2004 0.125 NA 0.371 0.432 0.32

Lanta et al. 2012 2005 �1 NA �0.338 �0.256 0.13

Liiri et al. 2002 �0.083 NA 0.933 NA 0.47

Mulder et al. 2001 2.140 NA 0.553 NA 0.34

Nagase & Dunnett 2010 Root �0.827 1.078 0.487 2.079 0.56

Nagase & Dunnett 2010 Shoot 0.000 0.047 0.005 0.212 0.29

Roger et al. 2012 High temperature NA NA �0.725 NA 0.47

Roger et al. 2012 Low salinity NA NA �0.386 NA 0.53

Steudel et al. 2011 Above-ground drought 0.573 0.570 0.270 0.262 0.21

Steudel et al. 2011 Above-ground salt 0.610 0.525 0.284 0.225 0.20

Steudel et al. 2011 Above-ground shade 0.772 0.733 0.543 0.488 0.38

Steudel et al. 2011 Below-ground drought 0.578 0.788 0.785 1.094 0.49

Steudel et al. 2011 Below-ground salt 0.501 0.564 0.495 0.493 0.36

Steudel et al. 2011 Below-ground shade �0.675 0.960 3.018 8.096 0.82

© 2013 Blackwell Publishing Ltd/CNRS

Ecology Letters, (2013) 16: 568–569 doi: 10.1111/ele.12079

relative biodiversity effect of the control treatment (rBEc) and the

predicted slope at high stress intensities. The correct rSRBE is the

difference between the relative biodiversity effect of the stress treat-

ment (rBEs) and the rBEc (rBEs-rBEc). Reanalysis of the corrected

data resulted in a positive relationship between rSRBE and SRI

when the monoculture data are excluded in our mixed models anal-

ysis with literature and our own experimental data combined (Fig. 2,

Table 2, Table 3) and with literature data only (Fig. 2, Table 2).

However, reanalysis of only our experimental data revealed no sig-

nificant relationship (Fig. S5A). With the monoculture data included,

the relationship between rSRBE and SRI was positive for the litera-

ture data alone and in combination with our experimental data (Fig.

S8). Again, reanalysis of our experimental data only revealed no sig-

nificant relationship (Fig. S5B). Addition of three new case studies

to the literature analysis with our experimental data included

(Langenheder et al. 2012, Lanta et al. 2012, Roger et al. 2012) con-

firmed the positive relationship when monoculture data are

excluded from the analysis (Fig. 2) or included in the analysis (Fig.

S8). Thus, despite the miscalculation of the rSRBE in our original

paper, the main conclusion of a positive relationship between

rSRBE and SRI is essentially confirmed by the correct analysis. We

thank Dr. T. Banitz for pointing out the mistake.

2) In the figure of Box 1, the absolute stress-response buffering

effect (aSRBE) was incorrectly defined as aBEc/aBEs instead of

aBEs/aBEc, as was correctly stated in the main text. This typo-

graphical error had no consequences for the reported results or

conclusions.

REFERENCES

Langenheder, S., Bulling, M.T., Prosser, J.I. & Solan, M. (2012). Role of

functionally dominant species in varying environmental regimes: evidence for

the performance-enhancing effect of biodiversity. BMC Ecology, 12, 14.

Lanta, V., Dolezal, J., Zemkova, L. & Leps, J. (2012). Communities of different

plant diversity respond similarly to drought stress: experimental evidence from

field non-weeded and greenhouse conditions. Naturwissenschaften, 99, 473–482.Roger, F., Godhe, A. & Gamfeldt, L. (2012). Genetic diversity and ecosystem

functioning in the face of multiple stressors. PloS One, 7, e45007.

Steudel, B., Hector, A., Friedl, T., L€ofke, C., Lorenz, M., Wesche, M. & Kessler,

M. (2012). Biodiversity effects on ecosystem functioning change along

environmental stress gradients. Ecol. Lett., 15, 1397–1405.

Table 3 Measurements of stress-response buffering effects (SRBE) and stress response intensity (SRI) of our algal experiment.

Salinity or temperature log (aSRBE)

log (aSRBE)

without monocultures rSRBE

rSRBE

without monocultures

Stress response

intensity (SRI)

0.13% 0.488 0.472 0.288 0.356 0.24

0.25% 0.155 0.258 0.148 0.242 0.25

0.50% �0.180 �0.321 0.052 0.002 0.25

1.00% �0.248 �0.183 0.125 0.157 0.39

1.50% �0.847 �1.264 �0.047 �0.174 0.40

2.50% �1.724 �0.816 �0.193 �0.057 0.46

27.5 °C 0.151 0.211 0.178 0.125 0.06

30.0 °C 0.538 0.538 0.536 0.613 0.32

32.5 °C 0.311 0.705 0.631 1.007 0.40

35.0 °C 0.032 �0.280 0.279 0.086 0.45

37.5 °C �1.553 �1.333 �0.022 �0.069 0.65

40.0 °C �1.305 �0.889 0.036 0.307 0.72

Figure 2 Relationships between relative stress-response buffering effect (rSRBE)

calculated without monoculture data and stress response intensity (SRI) derived

from monoculture data. Black dots represent literature data, grey dots data from

our algal experiment. Black triangles represent studies not included in the

published paper. The black line is the regression line of a linear mixed model

including published data only, with ‘study’ treated as random factor

(intercept = �4.24, SE = 1.17, t = �3.63; slope = 10.36, SE = 1.98, t = 5.22;

P = 0.001, n = 6). The grey line is the regression line of a linear mixed model

including published data and those of the present experiment, with ‘study’

treated as random factor (intercept = �1.26, SE = 0.76, t = �1.66,

slope = 4.45, SE = 1.52; t = 2.92, P = 0.009, n = 7). The dashed line is the

regression line of a linear mixed model including all data (published, algae, and

new studies), with ‘study’ treated as random factor (intercept = �1.02,

SE = 0.58, t = �1.94, slope = 2.23, SE = 0.55, t = 4.07, P = 0.0046, n = 9).

© 2013 Blackwell Publishing Ltd/CNRS

Corrigendum Corrigendum 569