Ecological Archives E090-043-A2

Jake M. Alexander, Peter J. Edwards, Myriam Poll, Catherine G. Parks, and Hansjörg Dietz. 2009. Establishment of parallel altitudinal clines in traits of native and introduced forbs. Ecology 90:612–622.

Appendix B. A table showing mixed-effects model summaries for the effect of altitude and region on stem height and capitulum seed mass, for each of eight Asteraceae forbs separately.

TABLE B1. Mixed-effects model (residual maximum-likelihood method) summaries for the effect of altitude and region on stem height and capitulum seed mass, shown for each of eight Asteraceae forbs separately. Only denominator degrees of freedom (df) are given, since all numerator degrees of freedom are 1. When pooling across species, we found a signifcant difference between the relationship of capitulum seed mass and altitude between the native and introduced ranges (Table 2). However, this difference was not apparent at the species level. Therefore for this trait we conducted a power analysis to calculate the sample sizes (n) required to reject the null hypothesis that there were no significant differences between the observed correlations of capitulum seed mass and altitude in each region. Power was taken to be 0.8 with α = 0.05. Values of n > 100 indicate that correlation coefficients were very similar between regions.


 

C. arvanse

C. vulgare

C. intybus

L. serriola

C. canadensis

E. annuus

M. discoidea

Solidago

 

Source

df

F

df

F

df

F

df

F

df

F

df

F

df

F

df

F


Stem height

                               
 

Region (R)

15

11.56**

20

0.24

15

0.09

16

3.36

17

0.45

18

6.32*

18

2.76

17

79.85***

 

Altitude (A)

15

0.68

20

16.64***

15

0.33

16

25.23***

17

7.88*

18

0.005

18

0.003

17

39.81***

 

A × R

15

35.93***

20

0.006

15

0.09

16

9.34**

17

6.81*

18

3.55

18

0.13

17

4.20

Capitulum seed mass

                           
 

Region (R)

13

3.54

18

0.10

14

6.70*

16

3.72

17

1.41

7

8.30*

17

4.10

11

2.68

 

Altitude (A)

13

0.08

18

0.47

14

0.38

16

0.68

17

0.19

7

7.80*

17

16.12***

11

0.37

 

A × R

13

1.24

18

<0.001

14

0.25

16

0.06

17

0.04

7

1.53

17

0.09

11

1.16

 

n

26

>100

>100

41

73

44

>100

29


*P < 0.05; **P < 0.01; ***P < 0.001.


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