Table 1. Summary of mixed effects models for aboveground biomass in August 2008 and 2009 to test for effects of diversity (numbers of initially sown species and functional group richness), management and drought treatments.

	Biomass August 2008					Biomass August 2009
	df	AIC	L ratio	p		AIC	L ratio	p
Nullmodel	11	1882.024				2058.232
Block	14	1885.305	2.719	0.4370		2061.191	3.041	0.3854
Species Richness (log-scale) = SR	15	1843.338	43.967	<0.0001	***	2026.597	36.595	<0.0001	***
Number of Functional Groups = FG	16	1845.331	0.007	0.9336		2026.316	2.280	0.1310
Management	19	1815.300	36.031	<0.0001	***	1941.106	91.210	<0.0001	***
Drought	20	1789.755	27.545	<0.0001	***	1927.831	15.275	0.0001	***
Management×Drought	23	1786.773	8.982	0.0295	*	1930.126	3.705	0.2951
Management×SR	26	1789.410	3.363	0.3390		1935.555	0.572	0.9029
Management×FG	29	1793.380	2.030	0.5662		1937.716	3.838	0.2795
Drought×SR	30	1793.947	1.433	0.2313		1939.645	0.072	0.7890
Drought×FG	31	1794.484	1.463	0.2264		1941.613	0.032	0.8579
SR×FG	32	1795.201	1.283	0.2574		1942.251	1.362	0.2431

Models were fitted by stepwise inclusion of variables and likelihood ratio tests (L ratio) were applied to assess statistical significance of variables (p-values). Significance is given with * = p<0.05. ** = p<0.01. *** = p<0.001; df = degrees of freedom.