Ecological Archives E092-132-A1

Dan F. B. Flynn, Nicholas Mirotchnick, Meha Jain, Matthew I. Palmer, and Shahid Naeem. 2011. Functional and phylogenetic diversity as predictors of biodiversity–ecosystem-function relationships. Ecology 92:1573–1581.

Appendix A. Supporting information for model comparisons.

FIG. A1. Structural equation models tested for combinations of functional diversity (FD), phylogenetic diversity (PD), and functional group richness (FGR) in combination with species richness (S) as predictors of the biodiversity effect on aboveground biomass accumulation (LRmean). Models were constructed to represent the effect of PD, FD, or FGR on the biodiversity effect as functions of S, since the indices used here are inherently dependent on S to some extent. That is, the PD and FD indices used here can only remain flat or increase as a species is added to a community. Model 5 shows one of many alternatives where PD and FD do not depend on S; note that this model is consistently the poorest-fitting of the candidate models (Table 3). These models were chosen to test the degree to which PD and FD predict the biodiversity effect, taking into account the correlations between these metrics and species richness.



FIG. A2. Relationship between PD (based on the molecular phylogeny) and FD (based on leaf %N, mean height at maturity, and N-fixing ability) within species richness levels. For species richnesses greater than 8 for this data set, there is no variation in species composition and thus FD and PD do not vary within a species richness level.



FIG. A3. Residuals of linear models of PD (based on the molecular phylogeny) and FD (N, height, N-fixation) as a function of S. After removing the effect of species richness, a statistically significant (P < 0.001) but quite minor relationship can be found between PD and FD (R2 = 0.024).



FIG. A4. Phylogeny extracted from the angiosperm supertree of Davies et al. (2004), showing variation in trait values for the functional traits used in this study. White boxes indicate no data were available. Major families for the 121 species used in this study are indicated at the right.


TABLE A1. Sources of grassland biodiversity and aboveground biomass production data. "Used polycultures" refers to polycultures for which LRmean could be calculated (1,433 out of 1,593 polycultures).

Study Experiment Total
polycultures
Used
polycultures
BioCON / Reich et al. 2001 +C +N 57 57
BioCON / Reich et al. 2001 +C N 57 57
BioCON / Reich et al. 2001 C +N 58 58
BioCON / Reich et al. 2001 C N 59 59
Biodepth / Spehn et al. 2005 Germany 30 16
Biodepth / Spehn et al. 2005 Greece 6 6
Biodepth / Spehn et al. 2005 Ireland 50 46
Biodepth / Spehn et al. 2005 Portugal 28 23
Biodepth / Spehn et al. 2005 Sheffield 30 30
Biodepth / Spehn et al. 2005 Silwood 32 30
Biodepth / Spehn et al. 2005 Sweden 34 34
Biodepth / Spehn et al. 2005 Switzerland 28 14
Dimitrakopoulos and Schmid 2004 Large pot size 20 20
Dimitrakopoulos and Schmid 2004 Medium pot size 20 20
Dimitrakopoulos and Schmid 2004 Small pot size 20 20
Dukes 2001 - 40 16
Fridley 2002 Amb. nut. 50 50
Fridley 2002 High nut. 49 49
Fridley 2002 Low nut. 47 47
Fridley 2003 High nut./High light 42 42
Fridley 2003 High nut./low light 42 42
Fridley 2003 Low nut./High light 42 42
Fridley 2003 Low nut./low light 42 42
Lanta and Leps 2006 High nut. 58 58
Lanta and Leps 2006 Low nut. 58 58
Naeem et al. 1996 - 330 117
Naeem et al. 1999 - 117 330
Tilman et al. 1996 - 127 6
Tilman et al. 1997 - 148 44

TABLE A2. Summary of the best-fit structural equation models for each of the three subsets of data examined, when using PD values based on the highly-resolved molecular phylogeny which covered most species, or based on the supertree which covered all species. Model M8 includes a correlation between PD and FD, and was the most parsimonious model across all plots when PD was calculated from either phylogeny. Model M3 is identical to M8 except for the correlation between PD and FD.

Using PD from molecular phylogeny (110 species) Using PD from angiosperm supertree (121 species)
All: M8 All: M8
Path Estimate S.E. z P Path Estimate S.E. z P
S → PD 0.920 0.012 77.34 < 0.001 S → PD 0.914 0.011 84.98 < 0.001
S → FD 0.471 0.027 17.60 < 0.001 S → FD 0.627 0.021 30.47 < 0.001
PD → B 0.194 0.034 5.79 < 0.001 PD → B 0.191 0.032 5.98 < 0.001
FD → B 0.096 0.034 2.87 0.004 FD → B 0.141 0.032 4.42 < 0.001
S ↔ S 1.000 0.043 23.31 < 0.001 S ↔ S 1.000 0.037 26.75 < 0.001
B ↔ B 0.935 0.040 23.31 < 0.001 B ↔ B 0.911 0.034 26.75 < 0.001
PD ↔ PD 0.154 0.007 23.28 < 0.001 PD ↔ PD 0.165 0.006 26.72 < 0.001
FD ↔ FD 0.778 0.033 23.30 < 0.001 FD ↔ FD 0.607 0.023 26.75 < 0.001
PD ↔ FD 0.053 0.011 5.02 < 0.001 PD ↔ FD 0.038 0.008 4.52 < 0.001
No legumes: M3 No legumes: M8
Path Estimate S.E. z P Path Estimate S.E. z P
S → PD 0.927 0.016 59.63 < 0.001 S → PD 0.904 0.016 56.80 < 0.001
S → FD 0.718 0.029 24.90 < 0.001 S → FD 0.704 0.026 26.67 < 0.001
PD → B 0.099 0.055 1.79 0.074 PD → B 0.102 0.049 2.07 0.039
FD → B 0.110 0.055 1.98 0.048 FD → B 0.117 0.049 2.37 0.018
S ↔ S 1.000 0.059 17.07 < 0.001 S ↔ S 1.000 0.052 19.05 < 0.001
B ↔ B 0.964 0.056 17.07 < 0.001 B ↔ B 0.959 0.050 19.05 < 0.001
PD ↔ PD 0.141 0.008 17.05 < 0.001 PD ↔ PD 0.184 0.010 19.03 < 0.001
FD ↔ FD 0.485 0.028 17.07 < 0.001 FD ↔ FD 0.505 0.027 19.04 < 0.001
PD ↔ FD 0.042 0.011 3.67 < 0.001  
Fertilized: M3 Fertilized: M3
Path Estimate S.E. z P Path Estimate S.E. z P
S → PD 0.930 0.025 36.82 < 0.001 S → PD 0.914 0.023 39.45 < 0.001
S → FD 0.800 0.041 19.35 < 0.001 S → FD 0.870 0.028 30.76 < 0.001
PD → B 0.187 0.094 1.99 0.047 PD → B 0.159 0.089 1.80 0.072
FD → B 0.233 0.094 2.48 0.013 FD → B 0.201 0.089 2.27 0.023
S ↔ S 1.000 0.097 10.27 < 0.001 S ↔ S 1.000 0.081 12.35 < 0.001
B ↔ B 0.847 0.082 10.27 < 0.001 B ↔ B 0.883 0.072 12.35 < 0.001
PD ↔ PD 0.135 0.013 10.26 < 0.001 PD ↔ PD 0.164 0.013 12.33 < 0.001
FD ↔ FD 0.361 0.035 10.27 < 0.001 FD ↔ FD 0.244 0.020 12.34 < 0.001

LITERATURE CITED

Davies, T. J., T. G. Barraclough, M. W. Chase, P. S. Soltis, D. E. Soltis, and V. Savolainen. 2004. Darwin's abominable mystery: Insights from a supertree of the angiosperms. Proceedings of the National Academy of Sciences of the United States of America 101:1904–1909.


[Back to E092-132]