Table 1.

The df and P values from the two-way analysis of nighttime variation (N) and drought effects (D) in the C isotope composition of leaf-respired CO₂ (δ¹³C_l), leaf soluble sugars (δ¹³C_{soluble sugar}), leaf starch (δ¹³C_starch) and leaf lipids (δ¹³C_lipid) in Chloris virgata (annual C₄), Hemarthria altissima (perennial C₄) and Leymus chinensis (perennial C₃).

Species		δ13Cl (‰)		δ13Csolublesugar (‰)		δ13Cstarch (‰)		δ13Clipid (‰)
		df	P	df	P	df	P	df	P
Chloris virgata	D	3	<0.001	3	0.158	3	0.001	3	0.002
	N	2	<0.001	2	<0.001	2	0.032	2	0.33
	D × N	6	<0.001	6	0.613	6	0.806	6	0.159
Hemarthria altissima	D	3	<0.001	3	0.003	3	0.005	3	0.391
	N	2	<0.001	2	0.037	2	0.012	2	0.66
	D × N	6	0.014	6	0.674	6	0.952	6	0.953
Leymus chinensis	D	3	<0.001	3	<0.001	3	<0.001	3	0.039
	N	2	<0.001	2	0.002	2	0.026	2	0.98
	D × N	6	0.008	6	0.023	6	0.144	6	0.817