Table 3.

Effects of nutrient heterogeneity on the performance (aboveground biomass, belowground biomass, and total plant biomass) of invasive and non-invasive plant species.

Response variable	Initial size	Invasiveness (I)	Nutrient treatment (T)	I*T
Aboveground biomass	23.65 (0.000)	0.00 (0.975)	4.08 (0.043)	5.33 (0.021)
Belowground biomass	4.92 (0.027)	0.28 (0.599)	91.36 (0.000)	2.88 (0.090)
Total biomass	19.27 (0.000)	0.06 (0.811)	35.28 (0.000)	2.35(0.125)

Presented are the results of likelihood-ratio tests [log-likelihood ratio and corresponding p-value (in parentheses)], which we used to test whether invasiveness of species, soil nutrient heterogeneity and their interaction significantly improved the model fit of linear mixed effects models. Significant results are in bold.