Table 2.

Factorial anovas for the effects of CO₂ levels and coral–algal competition on the growth of seaweeds and corals

Source of variation	d.f.	MS	F	P	Conclusion – SNK test
Seaweeds
CO2	3	70.08	2.74	0.046	(300 = 400 = 560) > 1140*
Competition	1	1710.71	66.75	< 0.001	Isolated alga > alga with coral
CO2 × Competition	3	22.86	0.89	0.447	n.s.
Error	133	25.63
Corals
CO2	3	23.021	2.863	0.039	300 = 400 > 560 = 1140
Competition	1	1.963	0.244	0.622	n.s.
CO2 × Competition	3	3.175	0.395	0.757	n.s.
Error	127	8.041

MS, mean square; SNK, Student–Newman–Keuls test; n.s., not significant.

^*We also specifically tested for CO₂ effects on seaweed growth within the isolated seaweed treatment. The results of this test indicated: anova, P= 0.006; SNK: (400 = 560) > 1140, 560 > 300, 400 > (300 = 1140). anova for the effects of CO₂ on seaweed growth within the seaweed-coral treatment was not significant (P= 0.439).