Ecological Archives E085-044-A4

Jon Loman. 2004. Density regulation in tadpoles of Rana temporaria: a full pond field experiment. Ecology 85:1611–1618.

Appendix D. ANOVA tables showing effects of density treatment on tadpole performance (density (Table D1), tadpole body length (Table D2), hind leg length (Table D3), metamorph body length (Table D4), and time for metamorphosis (Table D5)) in high and low density sections.


Appendix D1. Effect of density treatment on tadpole density index.

Site
Effect of treatment
Year
Period
Treatment
Treatment ×  year
   
df
F
P
df
F
P
df
F
P
df
F
P
AD17
0.82
5, 125
2.56
0.03
1, 125
0.064
0.80
1, 125
1.12
0.27
5, 125
3.49
0.005
AD17-98
1.14
4, 109
2.95
0.023
1, 109
0.049
0.83
1, 109
0.45
0.50
4, 125
0.22
0.93
HP25
2.79
6, 106
7.71
<0.001
1, 106
4.48
0.037
1, 106
20.92
<0.001
6, 100
0.63
0.71
HP27
1.59
6, 176
11.1
<0.001
1, 176
0.390
0.53
1, 176
15.9
<0.001
6, 176
3.84
0.001
HP27-91
1.74
5, 144
10.5
<0.001
1, 144
0.072
0.79
1, 144
27.5
<0.001
5, 139
22.50
0.034

   Notes: The test is based on log10 tadpole densities. However, the effect of treatment is recalculated from this value to actually give the average density in the intended high density section divided by that in the low density section. The test is a two-way ANOVA. Data for AD17 and HP27 are analyzed either for all available years or excluding a year (1998 and 1991, respectively) that was identified as an outlier with respect to the effect of the density manipulation. Non-significant interactions (in italics) are not included in tests of main effects. P values are shown as given by the non-corrected test, but because three ponds are tested I only consider values <0.05/3 significant.


Appendix D2. Effect of density treatment on tadpole body length.

Site
Effect of treatment
Three-way
Two-way
 
 
Treatment × period
Year
Treatment
Year × treatment
 
 
df
F
P
df
F
P
df
F
P
df
F
P
AD17
0.70
1, 1717
14.23
<0.001
5,776
92.4
<0.001
<0.001
44.9
<0.001
5, 776
7.09
<0.001
AD17-98
0.86
1, 1477
50.9
<0.001
4, 668
115.7
<0.001
1, 668
59.6
<0.001
4, 668
6.50
<0.001
HP25
0.10
1,1150
9.00
0.003
5, 750
61.8
<0.001
1, 750
26.9
<0.001
5, 745
2.86
0.014
HP27
0.10
1, 593
0.44
0.51
4, 301
11.45
<0.001
1, 301
1.33
0.25
4, 297
0.59
0.67
HP27-91
0.00
1, 380
0.12
0.73
3, 195
14.1
<0.001
1, 195
0.005
0.95
3, 192
0.22
0.88

   Notes: The estimated effect of the treatment is computed for the full model, with the interaction and measures the average difference in mm between tadpoles in low and high density sections respectively. The top set of tests is a three-way ANOVA analyzing the effects of year, treatment (high vs. low section density) and period (May, June). Only the effect of the interaction treatment × period is given in the table. The lower part is an account for a two-way ANOVA analyzing the effects of year and treatment. This test is only based on June data. Non-significant interactions (in italics) are not included in tests of main effects.


Appendix D3. Effect of density treatment on tadpole relative hind leg length.

Site
Effect of treatment
Year
Treatment
Year ×  treatment
   
df
F
P
df
F
P
df
F
P
AD17
0.024
5, 771
172.6
<0.001
1, 771
19.5
<0.001
5, 771
3.60
0.003
AD17-98
0.026
4, 663
190.1
<0.001
1, 663
18.0
<0.001
4, 663
3.96
0.003
HP25
0.004
5, 748
57.7
<0.001
1, 748
4.26
0.039
5, 743
1.25
0.28
HP27
-0.010
4, 297
4.59
0.001
1, 297
1.16
0.29
4, 297
2.01
0.64
HP27-91
-0.014
3, 195
1.68
0.17
1, 195
4.36
0.038
3, 192
0.64
0.59

   Notes: The effect of treatment measures the average difference in the development index between low and high density sections. The test results are for a two-way ANOVA analyzing effects of year and treatment (high vs. low section density) on tadpole hind legs. Only June data are included. Non-significant interactions (in italics) are not included in tests of main effects.


Appendix D4. Effect of density treatment on metamorph body length.

Site
Effect of treatment
Year
Treatment
Year ×  treatment
   
df
F
P
df
F
P
df
F
P
AD17
0.008
4, 548
28.6
<0.001
1, 548
0.007
0.93
4, 548
24.9
<0.001
AD17-98
0.32
3, 351
44.6
<0.001
1, 351
10.0
0.002
3, 351
8.87
<0.001
HP25
0.62
3, 307
119.0
<0.001
1, 307
10.4
0.001
3, 307
9.66
<0.001
HP27
0.76
4, 513
201.5
<0.001
1, 513
40.7
<0.001
4, 513
6.83
<0.001
HP27-91
0.58
3, 435
250.9
<0.001
1, 435
49.6
<0.001
3, 435
6.99
<0.001

   Notes: Effect of treatment is the difference measured in millimeters between metamorphs from low density and high density sections. The test is a two-way ANOVA.


Appendix D5. Effect of density treatment on time for metamorphosis.

Site
Effect of treatment
Year
Treatment
Year ×  treatment
   
df
F
P
df
F
P
df
F
P
AD17
-1.7
4, 459
60.5
<0.001
1, 459
2.18
0.14
4,455
1.70
0.15
AD17-98
-0.67
3, 283
60.8
<0.001
1, 283
0.11
0.74
3, 280
0.65
0.60
HP25
1.6
3, 291
168.3
<0.001
1, 291
8.00
0.005
3, 288
1.35
0.26
HP27
2.6
4, 388
19.8
<0.001
1, 388
23.9
<0.001
4,384
1.54
0.19
HP27-91
3.1
3, 329
1.41
0.24
1, 329
24.6
<0.001
3, 326
1.21
0.31

   Notes: Effect of treatment is the average number of days by which metamorphosis was accelerated in low density sections. The test is a two-way ANOVA. Non-significant interactions (in italics) are not included in tests of main effects.


[Back to E085-044]