Ecological Archives E096-206-A2

Qiang Yu, Kevin Wilcox, Kimberly La Pierre, Alan K. Knapp, Xingguo Han, and Melinda D. Smith. 2015. Stoichiometric homeostasis predicts plant species dominance, temporal stability, and responses to global change. Ecology 96:23282335. http://dx.doi.org/10.1890/14-1897.1

Appendix B. Supplementary tables of statistical analyses.

Table B1. Log-linear regression model statistics and stoichiometric homeostasis coefficients for phosphorus (HP) and N:P (HN:P) for 11 tallgrass prairie vascular plant species. G = grass, S = sedge and F = forb (all other herbaceous species).

Species

Type

 

HP

R²

p value

 

HN:P

R²

p value

Andropogon gerardii

G

 

4.68

0.42

<0.001

 

5.01

0.49

<0.001

Schizachyrium scoparium

G

 

3.81

0.72

<0.001

 

4.37

0.76

<0.001

Aster ericoides

F

 

3.12

0.73

<0.001

 

3.55

0.82

<0.001

Sorghastrum nutans

G

 

3.56

0.57

<0.001

 

4.42

0.48

<0.001

Salvia azurea

F

 

9.60

0.29

=0.003

 

7.48

0.51

<0.001

Solidago missouriensis

F

 

5.08

0.66

<0.001

 

5.09

0.68

<0.001

Dichanthelium oligosanthes

G

 

3.04

0.70

<0.001

 

3.21

0.81

<0.001

Bouteloua curtipendula

G

 

3.55

0.68

<0.001

 

3.39

0.84

<0.001

Ambrosia psilostachya

F

 

6.77

0.58

<0.001

 

5.21

0.61

<0.001

Solidago Canadensis

F

 

3.81

0.32

=0.001

 

-

-

=0.872

Carex meadii

S

 

4.53

0.62

<0.001

 

4.57

0.71

<0.001

 

Table B2. Regression results comparing species’ homeostasis coefficients (H) for nitrogen (HN), for phosphorus (HP) and for N:P (HN:P) with their dominance and stability values.

Dependent variable

H

Intercept

Slope

P

Species Dominance

HN

0.018

2.12

<0.01

    Ln (Dom) ~ H

HP

4.18

-0.17

0.44

HN:P

0.68

1.01

0.50

Species Dominance

HN

-20.52

3.85

<0.01

    Dom ~ H

HP

6.174

-0.405

0.73

 

HN:P

3.752

0.189

0.93

Species Stability

HN

-1.93

0.51

<0.01

    Stab ~ H

HP

1.60

-0.077

0.61

 

HN:P

1.28

0.007

0.48

 

Table B3. Effects of nitrogen additions on species dominance. P values are based on repeated measures ANOVA. G = grass, S = sedge and F = forb.

Species

Type

HN

2003–2006

 

2007–2012

Dominance (%)
in ambient (Mean±SE)

Dominance (%)
with N addition (Mean±SE)

P values

 

Dominance (%)
in ambient (Mean±SE)

Dominance (%)
with N addition (Mean±SE)

P values

Andropogon gerardii

G

9.76

25.0±4.3

25.9±4.4

0.830

 

29.3±2.6

24.5±3.5

0.209

Schizachyrium scoparium

G

8.41

32.3±2.5

20.9±2.7

0.009

 

26.5±4.3

4.7±1.1

<0.001

Aster ericoides

F

6.81

5.1±0.6

8.4±3.1

0.036

 

6±0.6

8.7±0.9

0.113

Sorghastrum nutans

G

6.75

12.8±0.8

18.1±1.9

0.232

 

6.8±1.1

15.3±3.8

0.007

Salvia azurea

F

6.63

0.2±0.1

0±0

0.330

 

0.1±0.1

0±0

0.317

Solidago missouriensis

F

6.28

2.2±0.4

0.6±0.1

0.184

 

2.5±0.4

0.5±0.1

0.105

Dichanthelium oligosanthes

G

5.53

3.2±0.3

4.2±0.7

0.336

 

5.3±0.6

20.1±3.5

<0.001

Bouteloua curtipendula

G

5.49

3.2±0.8

4.4±0.9

0.071

 

4.1±0.5

7.3±1.4

0.111

Ambrosia psilostachya

F

5.34

0.8±0.1

3.3±1.5

0.129

 

0.5±0.3

4.8±2.1

<0.001

Carex meadii

S

4.45

4.3±0.8

4.3±1.4

0.933

 

4.4±0.7

5±0.8

0.641


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