Ecosystem functioning in urban grasslands: The role of biodiversity, plant invasions and urbanization
Fig 6
Partial dependence plots for the strongest predictor selected by random forest models for aboveground biomass, intrinsic water use efficiency and 15N enrichment factor.
(A) for the whole plant community (AGBC, iWUEC, Δδ15NC), (B) natives (AGBN, iWUEN, Δδ15NN), (C) aliens (AGBA, iWUEA, Δδ15NA), (D) graminoids (AGBG, iWUEG, Δδ15NG) and (E) forbs (AGBF, iWUEF, Δδ15NF) in the studied grasslands in Berlin in summer 2017. The full description of variables is given in Table 1. Note that a partial dependency plot is used not to confirm the effect size but the association pattern including effect direction, since due to normalization, the ranges of y-axes do not directly correspond to the range of the variable. Plots for AGBG and iWUEF were not computed either because only one predictor was selected or because of lack of explanatory power (see text for more information).