Global Ecology and Conservation (Oct 2023)
Roadsides and gardens facilitate the expansion of non-native clonal succulent plants to wetlands in the coastal fringe of the Atacama Desert
Abstract
Urban habitats such as coastal road verges can host a wide range of non-native plant species, which can increase urban biodiversity but also have the potential to impact natural ecosystems. However, the mechanism through which these novel habitats facilitate alien species establishment/invasion in arid coastal systems is not well known. Here, we assessed the potential of roadsides and gardens to facilitate the spread of non-native clonal succulent species to coastal natural ecosystems. We surveyed urban habitats and rural wetlands located from 18°S to 23°S, in the coastal fringe of the Atacama Desert in northern Chile. Using generalized mixed linear models (GLMMs), we explored the effects of habitat extent and distance to urban sources as the main factors contributing to non-native species propagation. Non-native-to-native species spatial association were also examined. We found the occurrences of Sesuvium portulacastrum were higher in roadsides and gardens located from 18°S to 22°S, followed by Malephora crocea, Carpobrotus edulis and Mesembryanthemum (Aptenia) × vascosilvae. S. portulacastrum, followed by C. edulis and, to a lesser extent, M. × vascosilvae, were recorded in urban and rural crypto-wetlands. Increase in species occurrences with built habitat perimeter and a linear reduction by distance to urban sources were detected. Positive association of S. portulacastrum and M. crocea with the native Heliotropium curassavicum was recorded. These results highlight the importance of the coastal landscape composition (diversity and extent of habitat types) and configuration (distance from built to natural habitats) in the process of non-native plant species’ expansion. Given many coastal ecosystems are already damaged by different human-derived impacts, planting non-native succulents in urban habitats should be carefully managed to balance the services/disservices they provide/provoke to urban and natural habitats.
