Table 2.

Bivariate trait comparisons of grassland plants sampled in Inner Mongolia and Tibetan Plateau by phylogenetic generalized least-squares regressions at species level. Measure of phylogenetic correlation, λ. Coefficients and standard errors of log₁₀-transformed traits.

Traits	λ	Inner Mongolia		Tibetan Plateau
		Intercept (± SE)	Slope (± SE)	Intercept (± SE)	Slope (± SE)
Phenolics-UVAC	0.000	−0.74 ± 0.23***	1.74 ± 0.26***	0.34 ± 0.28***	1.00 ± 0.28***
Phenolics-SLA	0.042	−2.03 ± 1.32	1.38 ± 0.64*	0.01 ± 0.88**	0.63 ± 0.42*
Phenolics-N	0.179	2.90 ± 1.07*	−1.49 ± 0.73**	1.51 ± 0.73**	−0.14 ± 0.55
Phenolics-P	0.330	0.43 ± 0.25	1.50 ± 0.62*	1.23 ± 0.07***	0.63 ± 0.33***
Phenolics-N:P	0.135	4.17 ± 0.71***	−2.85 ± 0.58***	2.40 ± 0.45***	−0.90 ± 0.38**

Significance of coefficients (t-tests) indicated: ***P < 0.001; **P < 0.01; *P < 0.05. Significance of Inner Mongolia intercepts and slopes is tested for heterogeneity from zero. Tibetan Plateau intercepts and slopes are tested for heterogeneity from Inner Mongolia intercepts and slopes, respectively.