ONLINE RESOURCE 1 Table S1 Alien species list including plant species traits and factors related to the introduction history (traits) and their occurrence in the forest edge or interior.

Traits Presence Native Introduction Biotic Vegetative Species Life form region pathway dispersal repr. Edge Interior Acacia dealbata Tree Oceania Gardening No Yes No No Acacia melanoxylon Tree Oceania Silviculture No Yes No No Acanthus mollis Geophyte Med Gardening No Yes Yes No Acer negundo Tree Namerica Gardening No No Yes No Agave americana Shrub Namerica Gardening Yes Yes Yes No Ailanthus altissima Tree Easia Gardening No Yes No No Aloe arborescens Tree Safrica Gardening No Yes Yes No Aptenia cordifolia Shrub Safrica Gardening Yes Yes Yes No Araujia sericifera Vine Samerica Gardening No Yes Yes Yes Arundo donax Tree Asia Agriculture No Yes Yes No Canna indica Geophyte Samerica Gardening Yes Yes Yes No Carpobrotus edulis Shrub Safrica Gardening Yes Yes Yes No Celtis australis Tree Med Agriculture Yes No Yes Yes Cortaderia selloana Geophyte Samerica Gardening No No No No Cotoneaster lacteus Tree Easia Gardening Yes No Yes Yes Cotoneaster pannosus Tree Easia Gardening Yes No Yes Yes Cupressus sempervirens Tree Med Gardening No No Yes No Datura innoxia Annual Samerica Unintentionally Yes No Yes No Eriobotrya japonica Tree Easia Gardening Yes No Yes Yes Ficus carica Tree Med Agriculture Yes No Yes No Ipomoea indica Vine America Gardening No Yes Yes No Ipomoea sagittata Vine America Unintentionally No Yes Yes No Iris germanica Geophyte Europe Gardening No Yes Yes Yes Juglans regia Tree Eurasia Agriculture Yes No No Yes Lampranthus multiradiatus Shrub Safrica Gardening No Yes No No Ligustrum japonicum Tree Easia Gardening Yes No Yes Yes Lilium candidum Geophyte Africasia Gardening No Yes Yes No Lonicera japonica Vine Easia Gardening Yes No Yes Yes Mahonia japonica Tree Easia Gardening Yes No Yes Yes Myoporum tenuifolium Tree Oceania Gardening Yes No No Yes Opuntia maxima Tree America Gardening Yes Yes Yes No Oxalis debilis Geophyte Samerica Unintentionally No Yes Yes Yes Parthenocissus inserta Vine Namerica Gardening Yes Yes Yes No Paspalum dilatatum Geophyte Namerica Unintentionally Yes Yes No No Phoenix canariensis Tree Namerica Gardening Yes No Yes Yes Phyllostachys aurea Tree Easia Gardening No Yes Yes No Phytolacca americana Geophyte Namerica Gardening Yes Yes Yes No Pittosporum tobira Tree Easia Gardening Yes No Yes Yes Prunus cerasifera Tree Eurasia Gardening Yes No Yes Yes Prunus domestica Tree Asia Agriculture Yes No Yes Yes Prunus persica Tree Easia Agriculture Yes No Yes No Pyracantha angustifolia Tree Easia Gardening Yes No Yes Yes Pyrus malus Tree Eurasia Agriculture Yes No No Yes Robinia pseudoacacia Tree Namerica Gardening No Yes Yes Yes Senecio angulatus Vine Safrica Gardening No Yes Yes No Senecio mikanioides Vine Safrica Gardening No No Yes No Senecio pterophorus Shrub Safrica Unintentionally No No Yes No Solanum chenopodioides Annual Samerica Unintentionally Yes No Yes Yes Solanum nigrum Annual Eurasia Unintentionally Yes No Yes No Sorghum halepense Geophyte Africasia Unintentionally No Yes Yes Yes Tipuana tipu Tree Samerica Gardening No No No No Tradescantia fluminensis Geophyte Samerica Gardening Yes Yes Yes Yes Vicia faba Annual Asia Agriculture Yes No No Yes Xanthium spinosum Annual Samerica Unintentionally Yes No No No Yucca gloriosa Tree Namerica Gardening Yes Yes Yes No Zantedeschia aethiopica Geophyte Safrica Gardening Yes Yes Yes No Table S2 Pearson’s correlation coefficients between the level of invasion by alien species and landscape variables across buffer distances (250, 500, 1000 and 2000 m) around edge and interior forest plots.

Edge Interior Buffer distances 250 500 1000 2000 250 500 1000 2000 Alien Land use diversity 0.13 0.16 0.15 0.18 0.11 0.04 0.14 0.26 * Urban use 0.03 0.07 0.08 0.14 -0.13 -0.12 0.03 0.05 Agriculture use -0.30 * -0.15 -0.12 -0.18 0.09 0.22 0.2 0.2 Forest use 0.31 ** 0.04 0 0.03 0.1 -0.08 -0.22 -0.21 Native Land use diversity -0.02 -0.14 0 0.06 0 -0.2 -0.18 -0.17 Urban use 0.07 0.17 0.17 0.22 -0.1 -0.01 0.06 -0.02 Agriculture use 0.03 0.06 0.14 0.17 0.1 0.09 0.13 0.16 Forest use -0.18 -0.28 * -0.26 * -0.27 * 0.04 -0.09 -0.14 -0.11 Sorensen Alien Sorensen Native Land use diversity 0.06 -0.09 -0.06 -0.17 -0.02 0.09 0.19 -0.03 Urban use -0.12 0.03 0.07 -0.02 0.09 0.1 0.01 -0.09 Agriculture use 0.1 -0.14 -0.28 * -0.27 * -0.04 0.03 0.09 -0.02 Forest use -0.01 0.1 0.19 0.21 -0.05 -0.15 -0.13 0.04

Significant coefficients: *P>0.05; **P<0.01; ***P<0.001. Table S3: Pearson's correlation coefficients between local and landscape variables (1000 m buffer distance) used for modeling alien species richness for edge and interior forest plots.

Dis As Dista Fore Urban Agricu tur pec nce to st use lture ban t roads use use ce

Edge Aspect - 0.075

Distance to roads - 0.017 0.059

Forest use - 0.059 0.086 0.352**

Urban use - 0.135 0.057 0.014 -0.267*

Agriculture use - 0.013 -0.108 0.348** -0.066 -0.347**

Land use diversity - 0.000 0.055 0.376** 0.064 0.524*** -0.538***

Interior Aspect 0.037

Distance to roads - 0.096 0.059

Forest use - 0.052 0.086 0.352**

Urban use - 0.059 0.057 0.014 -0.267*

Agriculture use - - 0.168 -0.108 0.348** -0.066 -0.347**

Land use diversity - 0.137 0.055 0.376** 0.064 0.524*** -0.538***

Significant coefficients: *P>0.05; **P<0.01; ***P<0.001. Table S4: Relationship between alien species traits and landscape and local variables and alien species traits by Fourth-corner analysis. Only significant relations are shown.

Variable Trait Statisti Value Probability c

Edge type Region Chi2 242.233 0.0014 ** Disturbance Life form F 216.101 0.0392 * Aspect Dispersion F 358.302 0.0422 * Distance to roads Region F 244.238 0.0059 ** Agriculture use Life form F 292.575 0.0102 * Agriculture use Pathway F 686.969 0.0001 *** Agriculture use Reproduction F 115.911 0.0003 *** Agriculture use Dispersion F 534.554 0.0153 * Agriculture use Region F 392.457 0.0001 *** Forest use Pathway F 441.204 0.0034 ** Forest use Region F 171.281 0.0430 * Land use diversity Life form F 247.956 0.0233 *