Table 2.

Short‐term modulations in photosynthetic O₂ and inorganic carbon (C_i) fluxes of Emiliania huxleyi in response to low dissolved inorganic carbon (DIC) and high pH (L_DICH_pH), as well as carbonation (H_DICH_pH), acidification (L_DICL_pH) and the combination (H_DICL_pH)

Acclimation	PFD	Carbonate chemistry	Phot (μmol mg−1 h−1)	Resp(μmol mg−1 h−1)	CO2uptPS(μmol mg−1 h−1)	HCO3 −uptPS(μmol mg−1 h−1)	$f_{{\mathrm{CO}}_2}$
2N LL	180	LDICHpH	217 ± 17	75 ± 7	51 ± 20	147 ± 15	0.26 ± 0.09
		HDICHpH	236 ± 34	63 ± 9	58 ± 19	156 ± 43	0.28 ± 0.11
		LDICLpH	271 ± 63	26 ± 17	221 ± 49	25 ± 29	0.90 ± 0.11
		HDICLpH	345 ± 22	42 ± 8	303 ± 28	11 ± 9	0.96 ± 0.03
	700	LDICHpH	327 ± 5	59 ± 10	59 ± 1	239 ± 1	0.20 ± 0.08
		HDICHpH	355 ± 19	57 ± 20	78 ± 1	245 ± 1	0.24 ± 0.15
		LDICLpH	365 ± 69	27 ± 14	226 ± 1	64 ± 1	0.76 ± 0.23
		HDICLpH	464 ± 48	46 ± 7	393 ± 1	29 ± 1	0.93 ± 0.06
2N HL	180	LDICHpH	181 ± 14	72 ± 21	23 ± 39	141 ± 40	0.14 ± 0.25
		HDICHpH	141 ± 2	65 ± 8	32 ± 17	96 ± 15	0.25 ± 0.13
		LDICLpH	nd	nd	nd	nd	nd
		HDICLpH	124 ± 28	67 ± 3	77 ± 36	35 ± 16	0.67 ± 0.17
	700	LDICHpH	360 ± 30	80 ± 11	56 ± 77	271 ± 68	0.17 ± 0.22
		HDICHpH	307 ± 40	64 ± 17	55 ± 18	224 ± 23	0.19 ± 0.05
		LDICLpH	nd	nd	nd	nd	nd
		HDICLpH	225 ± 32	60 ± 4	93 ± 46	129 ± 18	0.40 ± 0.17
1N LL	180	LDICHpH	147 ± 22	38 ± 8	1 ± 8	131 ± 14	0.00 ± 0.06
		HDICHpH	173 ± 69	29 ± 7	28 ± 26	129 ± 39	0.15 ± 0.10
		LDICLpH	202 ± 29	56 ± 12	58 ± 16	126 ± 19	0.31 ± 0.07
		HDICLpH	185 ± 79	29 ± 3	55 ± 83	113 ± 17	0.24 ± 0.33
	700	LDICHpH	223 ± 32	35 ± 4	−6 ± 8	207 ± 23	−0.03 ± 0.04
		HDICHpH	240 ± 56	29 ± 5	7 ± 21	210 ± 41	0.02 ± 0.09
		LDICLpH	286 ± 23	48 ± 11	26 ± 17	225 ± 25	0.11 ± 0.07
		HDICLpH	273 ± 23	32 ± 4	38 ± 52	210 ± 37	0.14 ± 0.19
1N HL	180	LDICHpH	119 ± 13	69 ± 4	−33 ± 7	141 ± 11	−0.31 ± 0.09
		HDICHpH	113 ± 36	54 ± 8	−12 ± 26	114 ± 6	−0.18 ± 0.30
		LDICLpH	136 ± 19	67 ± 19	0 ± 17	124 ± 24	0.00 ± 0.14
		HDICLpH	148 ± 34	79 ± 20	−20 ± 17	154 ± 44	−0.14 ± 0.10
	700	LDICHpH	246 ± 13	68 ± 8	−38 ± 10	261 ± 6	−0.17 ± 0.05
		HDICHpH	196 ± 33	55 ± 9	−29 ± 24	207 ± 24	−0.18 ± 0.15
		LDICLpH	236 ± 25	56 ± 8	−5 ± 8	208 ± 33	−0.02 ± 0.03
		HDICLpH	274 ± 68	75 ± 9	−23 ± 2	272 ± 60	−0.10 ± 0.03

Chla‐ normalized photosynthetic net O₂ evolution (Phot) and respiration (Resp), photosynthetic net CO₂ uptake (CO₂upt_PS), photosynthetic HCO₃ ⁻ uptake (HCO₃ ⁻upt_PS) and the fraction of overall photosynthetic net C_i uptake that is covered by net CO₂ uptake ($f_{{\mathrm{CO}}_2}$) were measured at low and high photon flux densities (PFD; 180 vs 700 μmol photons m⁻² s⁻¹; n = 3; ± SD).

2N LL/HL, diploid life‐cycle stage acclimated to low light/high light; 1N LL/HL, haploid life‐cycle stage acclimated to low/high light; L_DICH_pH, low DIC/high pH; H_DICH_pH, high DIC/high pH; L_DICL_pH, low DIC/low pH; H_DICL_pH, high DIC/low pH; nd, not determined.