Appendix C. Nested ANCOVA results testing effects of island type (fox-free or fox-infested), island size (log transformed) and island identity nested within island type on extractable soil phosphorus, δ15N soil, grass and Achillea borealis and graminoid biomass.
Response variable: Extractable soil P
Source |
df |
MS |
F |
P |
Island type |
1 |
2.7 |
18.1 |
0.0009 |
Island size |
1 |
1.9 |
17.7 |
0.0008 |
Island identity(type) |
15 |
0.12 |
7.9 |
0.0001 |
Error |
275 |
4.2 |
Response variable: δ15N soil
Source |
df |
MS |
F |
P |
Island type |
1 |
1891 |
20.6 |
0.0004 |
Island size |
1 |
220 |
3.4 |
0.08 |
Island identity(type) |
15 |
75.9 |
13.7 |
0.0001 |
Error |
272 |
5.5 |
Response variable: δ15N grass
Source |
df |
MS |
F |
P |
Island type |
1 |
2707 |
38.9 |
0.0001 |
Island size |
1 |
449 |
6.9 |
0.02 |
Island identity(type) |
15 |
56.0 |
3.1 |
0.0003 |
Error |
123 |
18.3 |
Response variable: δ15N Achillea borealis
Source |
df |
MS |
F |
P |
Island type |
1 |
293.4 |
6.3 |
0.03 |
Island size |
1 |
0.09 |
0.0 |
0.97 |
Island identity(type) |
15 |
41.7 |
4.7 |
0.0001 |
Error |
88 |
8.8 |
Response variable: graminoid biomass
Source |
df |
MS |
F |
P |
Island type |
1 |
170.5 |
64.7 |
0.0001 |
Island size |
1 |
61.9 |
23.8 |
0.0003 |
Island identity(type) |
15 |
2.6 |
1.1 |
0.36 |
Error |
241 |
2.4 |