Table 1.
Summary of the difference in percentage cover of the seven native plant species which showed the strongest response in the principal response curve analysis.
Figure 1.
Principal response curves for the foliage invertebrate community.
Figure (A) represents 2007 and figure (B) 2008. The uninvaded plots are expressed as the grey line (y = 0) and the black line is the response of the invertebrate community in the invaded plots, compared to the control (uninvaded), over time. The invertebrates groups on the third axis are ordered in their taxon weight corresponding to the y-axis. Both years are significant at P<0.05. For 2007, the first canonical axis explains 95.1% of the total variation where 10.32% is explained by time and 48.19% by treatment. For 2008, the first canonical axis explains 97.7% of the total variation where 7.06% was explained by time and 30.13% by treatment.
Figure 2.
Total invertebrate abundance over time in invaded and uninvaded plots.
Where figure (A) represents the foliage-dwelling community, (B) the ground-dwelling community and (C) the below-ground invertebrate community. Both the foliage-dwelling and ground-dwelling invertebrate communities had a significantly higher total abundance in uninvaded plots compared to invaded plots (P<0.001), whereas the below-ground invertebrate communities showed no difference.
Table 2.
The taxon weights (bk) and difference in abundance of invertebrate groups from the foliage community.
Table 3.
The taxon weights (bk) and difference in abundance of invertebrates categorised by functional feeding groups.
Figure 3.
The difference between morphospecies richness between invaded and uninvaded plots.
Figure (A) shows Coleoptera morphospecies richness and figure (B) shows Heteroptera morphospecies richness. Both Coleoptera and Heteroptera species richness was significantly higher in the uninvaded plots compared to the invaded plots (P<0.001).
Figure 4.
Principal response curves for the ground-dwelling invertebrate community.
Figure (A) represents 2007 and figure (B) 2008. The uninvaded plots are expressed as the grey line (y = 0) and the black line is the response of the invertebrate community in the invaded plots, compared to the control (uninvaded), over time. The invertebrates groups to the right of the graphic are ordered in their taxon weight corresponding to the y-axis. Both years are significant at P<0.05. For 2007, the first canonical axis explains 82.2% of the total variation where 18.51% was explained by time and 13% by treatment. For 2008, the first canonical axis explains 78.1% of the total variation where 41% was explained by time, and 6.4% by treatment.
Table 4.
The taxon weights (bk) and difference in abundance of invertebrate groups in the ground- and below-ground communities.
Figure 5.
Principal response curves for the below-ground invertebrate community.
Figure (A) represents 2007 and figure (B) 2008. The uninvaded plots are expressed as the grey line (y = 0) and the black line is the response of the invertebrate community in the invaded plots, compared to the control (uninvaded), over time. The invertebrates groups on the third axis are ordered in their taxon weight corresponding to the y-axis. The 2007 data set shows a significant shift in the invertebrate community between the invaded and invaded plots (P<0.05) where the first canonical axis explains 59.91% of the total variation where 12.82% was explained by time and 7.56% by treatment. There was no significant shift in 2008 but the graphic is shown for completeness.
Figure 6.
Biplot of the percentage cover of vegetation and invertebrate abundance for the 2007 foliage-dwelling community.
The total variation explained is 69.55%. Axis 1 explains 63.64% and axis 2 explains 4.27% (P<0.05). Plot labels are: Ara: Araneae, Auc: Auchenorrhyncha, Chr: Chrysomelidae, Coc: Coccinellidae, Cur: Curculionidae, Oed: Oedemeridae, Lyg: Lygaeidae, Mir: Miridae.
Figure 7.
Biplot of the percentage cover of vegetation and invertebrate abundance for the 2007 ground-dwelling community.
The total variation explained is 48.8%. Axis 1 explains 40.4% and axis 2 explains 7.1% (P<0.05). Plot labels are: Aca: Acari, Ara: Araneae, Auc: Auchenorrhyncha, Col: Coleoptera, Coll: Collembola, For: Formicidae, Het: Heteroptera, Iso: Isopoda, Ste: Sternorrhyncha, Thy: Thysanoptera, Ves: Vespoidea.