Ecological Archives E088-063-A3

William F. Morris, Ruth A. Hufbauer, Anurag A. Agrawal, James D. Bever, Victoria A. Borowicz, Gregory S. Gilbert, John L. Maron, Charles E. Mitchell, Ingrid M. Parker, Alison G. Power, Mark E. Torchin, and Diego P. Vázquez. 2007. Direct and interactive effects of enemies and mutualists on plant performance: a meta-analysis. Ecology 88:1021–1029.

Appendix C. Effect sizes using Hedges' d.

TABLE C1. Individual, overall, and interactive effects of enemies and mutualists, and their 95% confidence limits.

Effect

Mean

Lower 95% C.L.

Upper 95% C.L.

Number of studies

P value from test for within-group homogeneity

Individual effect of enemies

-1.36

-1.53

-1.18

186

<0.001

Overall effect of enemies

-2.02

-2.24

-1.81

186

<0.001

Individual effect of mutualists

0.97

0.75

1.19

134

<0.001

Overall effect of mutualists

1.43

1.18

1.69

134

<0.001

Enemy–enemy interaction effect

-0.01

-0.15

0.13

36

0.066

Mutualist–mutualist interaction effect

0.37

-0.21

0.96

10

0.029

Enemy–mutualist interaction effect

0.07

-0.09

0.23

114

<0.001

 

TABLE C2. Individual effects of classes of enemies and mutualists.

Individual Effect

Mean

Lower 95% C.L.

Upper 95% C.L.

Number of comparisons

P value from test for within-group homogeneity

All herbivores

-0.67

-0.83

-0.51

100

<0.001

Aboveground herbivores

-0.40

-0.57

-0.23

53

<0.001

Belowground herbivores

-1.11

-1.41

-0.81

47

<0.001

Leaf chewers

-0.47

-0.70

-0.23

38

<0.001

Seed feeders

-0.14

-0.27

0.00

10

0.303

Root feeders

-0.55

-0.99

-0.10

10

0.048

Nematodes

-1.28

-1.63

-0.93

37

<0.001

All pathogens

-2.81

-3.20

-2.43

84

<0.001

Pathogenic fungi

-3.50

-4.03

-2.97

68

<0.001

Viruses

-0.55

-0.90

-0.20

14

<0.001

Pollinators

0.50

0.31

0.69

16

0.050

AM/EM fungi

1.22

0.87

1.57

80

<0.001

Mutualistic bacteria

0.92

0.53

1.31

32

<0.001

 

TABLE C3: Results of homogeneity tests for comparisons of effects in Table C2.

Comparison:

Qb

df

P

Individual effects of herbivores vs. pathogens

84.55

1

<0.001

Individual effects of aboveground vs. belowground herbivores

17.09

1

<0.001

Individual effects of four classes of herbivores

23.23

3

<0.001

Individual effects of fungal vs. viral pathogens

25.84

1

<0.001

Individual effects of three classes of mutualists

3.81

2

0.149

 

TABLE C4: Comparisons between individual effects for different environments (field vs. greenhouse), different plant growth forms (herbaceous vs. woody), and for crops vs. non-crops; P gives result of a test for within-group homogeneity.

Individual Effect

Mean

Lower 95% C.L.

Upper 95% C.L.

Number of comparisons

P

Herbivores

Field

-0.47

-0.65

-0.28

53

<0.001

Greenhouse

-0.95

-1.23

-0.67

47

<0.001

Herbaceous plants

-0.58

-0.74

-0.41

74

<0.001

Woody plants

-1.00

-1.43

-0.57

26

<0.001

Crops

-1.43

-1.76

-1.09

35

<0.001

Non-crops

-0.37

-0.53

-0.22

65

<0.001

Pathogens

Field

-0.58

-0.91

-0.26

19

<0.001

Greenhouse

-3.68

-4.24

-3.11

65

<0.001

Herbaceous plants

-3.49

-4.05

-2.93

65

<0.001

Woody plants

-1.02

-1.46

-0.57

19

<0.001

Crops

-3.25

-3.70

-2.80

72

<0.001

Non-crops

-0.79

-1.29

-0.30

12

0.002

Mutualists

Field

0.41

0.24

0.58

24

0.024

Greenhouse

1.22

0.92

1.53

110

<0.001

Herbaceous plants

0.88

0.65

1.12

92

<0.001

Woody plants

1.10

0.61

1.58

42

<0.001

Crops

1.24

0.93

1.55

85

<0.001

Non-crops

0.57

0.26

0.87

49

<0.001

Enemy–enemy interactions

Field

0.01

-0.14

0.16

26

0.055

Greenhouse

-0.09

-0.41

0.23

10

0.286

Herbaceous plants

0.08

-0.18

0.34

26

0.018

Woody plants

-0.12

-0.35

0.11

10

0.839

Crops

0.27

-0.23

0.77

11

0.002

Non-crops

-0.03

-0.19

0.13

25

0.706

Enemy–mutualist interactions

Field

-0.05

-0.23

0.14

22

0.998

Greenhouse

0.10

-0.12

0.32

92

<0.001

Herbaceous plants

0.05

-0.14

0.25

88

<0.001

Woody plants

0.10

-0.15

0.35

26

0.712

Crops

0.14

-0.06

0.34

85

0.000

Non-crops

-0.07

-0.33

0.18

29

0.012

 

TABLE C5: Results of homogeneity tests for comparisons in Table C4. All tests have 1 df.

Effect:

Field vs. greenhouse:

Herbaceous vs. woody plants:

Crop plants vs. non-crops

Qb

P

Qb

P

Qb

P

Herbivore individual effects

7.42

0.006

2.19

0.139

36.45

<0.001

Pathogen individual effects

36.56

<0.001

19.23

<0.001

17.31

<0.001

Mutualist individual effects

8.37

0.004

0.23

0.629

6.91

0.009

Enemy–enemy interactions

0.40

0.528

1.07

0.302

0.68

0.409

Enemy–mutualist interactions

0.66

0.418

0.08

0.780

1.55

0.213

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