High nutrient supply and interspecific belowground competition enhance the relative performance of Picea mariana (Mill). B.S.P seedlings over Picea glauca [Moench] Voss. under elevated CO2

Table 3 Average P_n, E, V_cmax, J_max, leaf N, P, and K concentration (g m²), WUE, NUE, and PUE in black spruce (Sb), and white spruce (Sw) seedlings under different CO₂, belowground competition (BGC), and nutrient supply (N) combinations (n = 6). The seedlings were exposed to two CO₂ concentrations (380 and 720 µmol mol⁻¹) with or without belowground competition (BGC-1 and BGC-0, respectively) at two nutrient levels

CO₂	BGC	N	SP	P_n	V_cmax	J_max	N	P	K	WUE	NUE	PUE
Ambient	BGC-1	High	Sb	7.6	54	71	2.6	0.27	1.4	2.0	2.9	28.2
		High	Sw	6.3	41	56	2.9	0.31	1.4	2.3	2.2	20.2
		Low	Sb	6.8	58	74	2.3	0.25	1.1	4.0	3.0	27.3
		Low	Sw	5.4	28	79	1.9	0.24	0.8	4.8	2.8	22.4
	BGC-0	High	Sb	11.6	81	121	2.7	0.34	1.6	2.5	4.3	34.1
		High	Sw	8.0	50	83	3.5	0.44	1.3	3.6	2.3	18.2
		Low	Sb	6.4	47	93	1.9	0.26	1.4	4.8	3.4	24.7
		Low	Sw	5.9	47	79	3.4	0.43	1.6	2.3	1.7	13.8
Elevated	BGC-1	High	Sb	17.6	77	84	2.8	0.21	1.5	8.9	6.3	83.7
		High	Sw	11.2	48	87	3.6	0.34	1.1	6.2	3.1	32.9
		Low	Sb	15.3	51	110	1.8	0.22	1.0	10.4	8.5	69.5
		Low	Sw	13.5	36	92	2.1	0.24	0.7	5.5	6.4	56.3
	BGC-0	High	Sb	15.4	51	95	2.5	0.29	1.5	5.2	6.2	53.1
		High	Sw	12.7	77	65	3.5	0.37	1.2	5.0	3.6	34.3
		Low	Sb	12.5	44	107	2.8	0.26	1.3	4.4	4.5	48.1
		Low	Sw	11.4	45	85	2.2	0.3	1.0	4.6

ISSN: 1297-966X