Species scores on the first two CCA components (explaining 88% and 11% of variance, respectively).

<p>Species scores on the first two CCA components (explaining 88% and 11% of variance, respectively).</p

Ant species collected and percentage of sites occupied per habitat type.

<p>FVS: rainforest on volcano-sedimentary soils (13 sites); FUM: rainforest on ultramafic soils (15); MAQ: maquis shrubland (15); SAV: savanna (11) and GAI: gaiac thicket (2).</p><p>An asterisk indicates an introduced species.</p><p>See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067245#pone.0067245.s003" target="_blank">Table S2</a> for the functional group classification.</p

Relationship between habitat variables and the five most abundant exotic species.

<p>Canonical Correspondence Analysis triplot of the habitat variables in relation to sites [FVS: rainforests on volcano-sedimentary substrate (10); FUM: rainforests on ultramafic substrate (12); MAQ: maquis-shrubland (14); SAV: savannas (11); GAI: gaiac thickets (2)] and exotic species (AG: <i>A. gracilipes</i>; WA: <i>W. auropunctata</i>; BO: <i>B.</i> cf. <i>obscurior</i>; NV: <i>N. vaga</i>; PM: <i>P. megacephala</i>). Proportion explained by each eigenvalues is reported next to the axis label. The right- and upper axes relate to the environmental variables constraints.</p

Contribution of native ants to the dissimilarity between ‘pristine’ rainforest sites and rainforest sites dominated by exotic species, with exotic species excluded from the dataset.

<p>Contributions up to a 70% cumulative cut-off value are indicated, using the SIMPER procedure.</p><p>GM: generalised myrmicinae, FOP: forest opportunists, CG: cryptic generalists.</p

Distribution maps of sampling sites and species collected in New Caledonia.

<p>Location of sampling sites in relation to habitat and substrate type (white areas: volcano-sedimentary V; shaded areas: ultramafic U) (a), and proportional frequency (as measured by occurrence in traps) of native ant species, Dominant Opportunists, and exotic Weedy Opportunists (b).</p

Functional group composition of each habitat type.

<p>Values are proportions of total species records. FVS: rainforest on volcano-sedimentary substrate; FUM: rainforest on ultramafic substrate; MAQ: maquis shrubland; SAV: savanna; GAI: gaiac thicket. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067245#pone.0067245.s003" target="_blank">Table S2</a> for the functional group classification.</p

MDS ordinations of sites using different levels of ant community organisation.

<p>The significant groups identified by CLUSTER analysis are overlaid: (a) at the species level, (b) at the genus level, (c) at the functional group level. Group 1 (incl. 1a, 1b and 1c): ‘pristine’ forest sites; group 2: forest sites dominated by <i>Solenopsis</i> sp. B; group 3: sites dominated by exotic ants (3a: <i>P. megacephala</i>; 3b: <i>A. gracilipes</i>; 3c: <i>B.</i> cf. <i>obscurior</i> and 3d: <i>W. auropunctata</i>). DO: Dominant Opportunists and WO: Weedy Opportunists. Sites are displayed according to habitat type [FVS: rainforest on volcano-sedimentary substrate (13); FUM: rainforest on ultramafic substrate (15); MAQ: maquis shrubland (15); SAV: savanna (11); GAI: gaiac thicket (2)]. Stress values <0.2 indicate a good 2-D summary of the sample relationships.</p

MDS ordination of rainforest sites based on native ants only, at the species level.

<p>The significant difference identified by ANOSIM between invaded and non-invaded sites is indicated by a line. FVS: rainforest on volcano sedimentary substrate; FUM: rainforest on ultramafic substrate. Stress values <0.2 indicate a good 2-D summary of the sample relationships.</p

Relative abundance of the five most abundant exotic species according to habitat type.

<p>Values are proportions of total records of the five species per habitat type (total records in brackets). FVS: rainforest on volcano-sedimentary substrate; FUM: rainforest on ultramafic substrate; MAQ: maquis shrubland; SAV: savanna; GAI: gaiac thicket.</p