Interannual Variation in Root Production in Grasslands Affected by Artificially Modified Amount of Rainfall

Table 3

The effect of rainfall input and year on the root increment, roots, rhizomes, and total below-ground biomass (TBB): results of repeated measures analysis of variance (ANOVA), using years as repeated measures factor (NS: not significant, *𝑃<0.05, **𝑃<0.01, ***𝑃<0.001; df error = 84).

Effect		Root increment		Rhizomes		Roots		TBB
	df	F	𝑃	F	𝑃	F	𝑃	F	𝑃
Lowland grassland
Rainfall input	2	8.0	**	4.5	*	2.0	NS	2.4	NS
Year	4	12.4	***	0.9	NS	1.9	NS	2.6	*
Interaction	8	1.5	NS	2.1	*	1.8	NS	1.2	NS
Highland grassland
Rainfall input	2	2.5	NS	7.8	**	12.9	***	14.5	***
Year	4	8.8	***	1.7	NS	10.8	***	4.5	**
Interaction	8	1.0	NS	1.6	NS	1.3	NS	0.8	NS
Mountain grassland
Rainfall input	2	9.3	**	1.2	NS	2.7	NS	5.4	NS
Year	4	11.0	***	3.2	*	19.7	***	10.8	***
Interaction	8	1.6	NS	0.1	NS	0.7	NS	0.4	NS