Table 4. Results from Kruskal-Wallis tests for experiment (seasonal) and treatment (nutrient addition) effects on the phylum distribution of Actinobacteria and Alpha- and Betaproteobacteria.

Phyla	df	χ2	p
Experiment
Actinobacteria	2	31.91	<0.001
Alphaproteobacteria	2	58.95	<0.001
Betaproteobacteria	2	59.06	<0.001
Treatment
Actinobacteria	3	26.50	<0.001
Alphaproteobacteria	3	0.73	ns
Betaproteobacteria	3	5.33	ns