Absolute and relative species richness over elevation in m. Blue lines showing glm predicted values with the 95% confidence interval A total species richness of native herbaceous plants over elevation. Glm coefficient = .0003, p-value = .007, 35 degrees of freedom B total species richness of alien herbaceous plants over elevation. Glm coefficient = -2.386e-05, p-value = .92, 36 degrees of freedom C relative species richness of alien herbaceous plants over the elevation. Glm coefficient = -.0009, p-value = .0276, 35 degrees of freedom D relative species richness of alien herbaceous plants, represented by boxplots for each elevation level. They show the median per transect (5 m²), third and first quartile and extreme values.