Table 1. Mixed effects model statistics of the response variable CN ratio with the explanatory variables altitude, treatment, plant guild, sampling time and their interactions.

	numDF	denDF	F-value	P-value
(Intercept)	1	257	1114.37	<0.0001
altitude	1	13	2.11	0.17
plant guild	2	103	107.83	<0.0001
sampling time	2	257	31.46	<0.0001
altitude:plant guild	2	103	20.23	<0.0001
altitude:sampling time	2	257	0.57	0.57
plant guild:sampling time	4	257	38.03	<0.0001
altitude:plant guild:sampling time	4	257	4.53	0.002

The explanatory variable treatment was removed from the model as it was neither significant as single variable nor in the interactions. The final model is presented.