The relationship between leafy spurge cover and the relative abundance of different functional groups in the single (a–d) and multi-site (e–g) surveys. Shown are the relationship with the proportional cover of exotic graminoids (a, e), native graminoids (b, f), native forbs (c, g) and native shrubs (d). Native shrubs were too rare in the multi-site survey to analyse. For the multi-site survey, points and lines are colour-coded by whether the site was grazed by cattle or treated with herbicide to control leafy spurge as shown in the legend. Plots are partial residual plots and fitted lines show the fitted linear (a, b, d, f) or quadratic (c, e, g) regressions with 95% confidence intervals. All relationships, except for native forbs in the single-site survey, were significant at P < 0.05.