Distance to suburban/wildland border interacts with habitat type for structuring exotic plant communities in a natural area surrounding a metropolitan area in central Chile

Abstract

Background: The explosive growth of urbanisation in Mediterranean ecosystems in Chile has favoured the rapid expansion of exotic plant species, yet factors driving these invasion patterns in adjacent natural areas remain poorly assessed.

Aims: To assess how distance to a suburban/wildland border, habitat type, site-scale disturbance and woody plant cover of native species influences the diversity of exotic species in a natural area surrounding the city of Santiago, Chile.

Methods: Three watersheds were chosen, and the diversity of exotic species was assessed in 36 100-m-long transects, equally distributed over two distance categories and three habitats. For each transect, we measured woody plant cover of native species and frequency of rabbit faeces as a measure of competitive exclusion and site-scale disturbance, respectively.

Results: Species diversity decreased as the distance from the suburban/wildland border increased, and it was found to be higher in north-facing habitats compared to south-facing and alluvial habitats. Neither native woody plant cover nor frequency of rabbit faeces had an effect on species diversity.

Conclusions: The current pattern of exotic plant species in this natural area is mainly influenced by the distance to suburban border and habitat type. An adequate management of conditions favouring exotic species in suburban/wildland border may prevent the spread of these into natural areas next to urban settings.

Keywords:

• Andean piedmont
• exotic species
• Mediterranean region
• propagule source
• Santiago de Chile
• urbanisation

Acknowledgements

We thank two anonymous reviewers who improved the paper with cogent comments and criticisms.

Additional information

Funding

This work was supported by The Chilean Ministry of Economy, Development and Tourism ICM P05–002 and CONICYT (Comisión nacional de investigación científica y tecnológica) under the Becas-Chile Program and FONDAP (Fondo de Financiamiento de Centros de Investigación en Áreas Prioritarias) [15110020].

Notes on contributors

Darío Moreira-Arce

Darío Moreira-Arce is a Ph.D. student. He has worked on invasion ecology in plants and birds. He is currently studying the impact of human-dominated landscapes on wildlife.

Francisco de la Barrera

Francisco de la Barrera is a researcher. He studies the biodiversity in natural and urban ecosystems, their spatial distribution and the associated ecosystem services they provide.

Ramiro O. Bustamante

Ramiro O. Bustamante is an associate scientist at the Institute of Ecology and Biodiversity and an associate professor at the University of Chile. His research interest includes plant ecology and the role of plant functional traits and biotic interactions to understand plant regeneration patterns and processes.