Effects of nitrogen addition and drought on the relationship between nitrogen- and water-use efficiency in a temperate grassland

Ecological Processes

Table 2 Results of two-way ANOVA to test the effects of N addition (N) and drought (D) on WUE_INST, NUE_INST, WUE_LT and NUE_LT for the six studied species

Functional groups	Species	Factors	df	WUE_INST		NUE_INST		WUE_LT		NUE_LT
Functional groups	Species	Factors	df	F	p	F	p	F	p	F	p
Grass	L. chinensis	N	1	1.13	0.307	4.12	0.063	0.22	0.645	38.48	< 0.001
		D	1	3.95	0.068	2.9	0.113	51.94	< 0.001	27.86	< 0.001
		N × D	1	2.08	0.172	3.63	0.079	5.57	0.032	8.78	0.010
	S. baicalensis	N	1	0.59	0.367	3.20	0.103	8.05	0.013	115.54	< 0.001
		D	1	2.37	0.145	47.28	< 0.001	24.60	< 0.001	197.66	< 0.001
		N × D	1	0.03	0.856	0.99	0.342	15.85	< 0.001	38.52	< 0.001
Leguminous forb	T. lanceolata	N	1	1.45	0.250	19.85	0.002	3.54	0.083	7.84	0.013
		D	1	0.01	0.938	27.84	< 0.001	47.52	< 0.001	3.84	0.068
		N × D	1	0.41	0.533	13.53	0.006	0.53	0.526	0.73	0.406
Non-leguminous forb	P. bifurca	N	1	1.17	0.305	0.10	0.755	17.43	< 0.001	24.89	< 0.001
		D	1	1.82	0.207	9.43	0.011	83.49	< 0.001	23.54	< 0.001
		N × D	1	0.46	0.513	3.88	0.074	0.19	0.671	10.09	0.006
	T. squarrosum	N	1	0.01	0.911	5.19	0.049	1.61	0.229	9.58	0.009
		D	1	1.15	0.312	5.33	0.046	57.07	< 0.001	12.95	0.004
		N × D	1	0.10	0.755	1.52	0.248	0.02	0.893	5.99	0.031
	K. centauroide	N	1	0.27	0.614	3.64	0.079	1.44	0.250	114.06	< 0.001
		D	1	2.35	0.149	4.76	0.048	37.64	< 0.001	1.61	0.221
		N × D	1	0.03	0.862	0.45	0.514	0.84	0.375	1.02	0.327