Abstract
Globalisation has resulted in the movement of organisms outside their natural range, often with negative ecological and economic consequences. As cities are hubs of anthropogenic activities, with both highly transformed and disturbed environments, these areas are often the first point of entry for alien species. We compiled a global database of cities with more than one million inhabitants that data had on alien species occurrence. We then identified the most prominent pathways of introduction and vectors of spread of alien species in these cities. Most species were intentionally introduced to cities and were released or escaped from confinement. The majority of alien species then spread within cities through natural means (primarily unaided dispersal). Pathway prominence varied across the taxonomic groups of alien species: the most prominent pathway for plants and vertebrates was the escape pathway; for invertebrates the stowaway and contaminant pathways were most likely to facilitate introductions. For some organisms, pathway prominence varied with the geographical and climatic characteristics of the city. The characteristics of the cities also influenced the prominence of vectors of spread for alien species. Preventing the natural spread of alien species within cities, and into adjacent natural environments will be, at best, difficult. To prevent invasions, both the intentional and unintentional introduction of potentially harmful alien species to cities must be prevented. The pathways of introduction and vectors of spread identified here should be prioritised for management.
Similar content being viewed by others
References
Bacon SJ, Bacher S, Aebi A (2012) Gaps in border controls are related to quarantine alien insect invasions in Europe. PLoS ONE 7:e47689
Blackburn TM, Pyšek P, Bacher S, Carlton JT, Duncan RP, Jarošik V, Wilson JRU, Richardson DM (2011) A proposed unified framework for biological invasions. Trends Ecol Evol 26:333–339
Blackie RR, Sunderland TC (2015) Mapping landscape guidelines and principles to the Aichi targets. CIFOR 123:1–4
Brown R (2006) Exotic pets invade United States ecosystems: legislative failure and a proposed solution. Indiana Law J 81:713–731
Burt JW, Muir AA, Piovia-Scott J, Veblen KE, Chang AL, Grossman JD, Weiskel HW (2007) Preventing horticultural introductions of invasive plants: potential efficacy of voluntary initiatives. Biol Invasions 9:909–923
Cope RC, Ross VJ, Wittmann TA, Prowse TAA, Cassey P (2016) Intergrative analysis of the physical transport network into Australia. PLoS ONE 11:e0148831
Crawley M (2007) The R book. Wiley, Chichester
Cronin K, Kaplan H, Gaertner M, Irlich I, Hoffman TM (2017) Aliens in the nursery: assessing the attitudes of nursery managers to invasive species regulations. Biol Invasions 19:925–937
Dehnen-Schmutz K, Touza J, Perrings C, Williamson M (2007) The horticultural trade and ornamental plant invasions in Britain. Conserv Biol 21:224–231
Demographia (2014) Demographia world urban areas (built-up urban areas or world agglomerations) 10th annual edition. http://www.demographia.com/. Accessed 23 Aug 2015
Drew J, Anderson N, Andow D (2010) Conundrums of a complex vector for invasive species control: a detailed examination of the horticultural industry. Biol Invasions 12:2837–2851
ESRI (2006) ArcGIS 9.3. Environmental Research Systems Institute, Inc, Redlands, CA
Essl F, Bacher S, Blackburn TM, Booy O et al (2015) Crossing frontiers in tackling pathways of biological invasions. Bioscience 65:769–782
Faulkner KT, Robertson MP, Rouget M, Wilson JRU (2016a) Understanding and managing the introduction pathways of alien taxa: South Africa as a case study. Biol Invasions 18:73–87
Faulkner KT, Robertson MP, Rouget M, Wilson JRU (2016b) Border control for stowaway alien species should be prioritised based on variations in establishment debt. J Environ Manage 180:301–309
Ficetola GF, Thuiller W, Padoa-Schioppa E (2009) From introduction to the establishment of alien species: bioclimatic differences between presence and reproduction localities in the slider turtle. Divers Distrib 15:108–116
Gallardo B, Aldridge DC (2013) The ‘dirty dozen’: socio-economic factors amplify the invasion potential of 12 high-risk aquatic invasive species in Great Britain and Ireland. J Appl Ecol 50:757–766
GBIF (2016) Global Biodiversity Information Facility. http://www.gbif.org/. Accessed 01 Dec 2016
GISD (2016) Global Invasive Species Database. Invasive Species Specialist Group (ISSG) of the IUCN Species Survival Commission. http://www.issg.org/database. Accessed 9 June 2016
Gotzek D, Axen HJ, Suarez AV, Helms Cahan S, Shoemaker D (2015) Global invasion history of the tropical fire ant: a stowaway on the first global trade routes. Mol Ecol 24:374–388
GRIIS (2016) Global Register of Introduced and Invasive Species. http://www.griis.org/. Accessed 15 Nov 2016
Hansen MJ, Clevenger AP (2005) The influence of disturbance and habitat on the presence of non-native plant species along transport corridors. Biol Conserv 125:249–259
Hulme PE (2006) Beyond control: wider implications for the management of biological invasions. J Appl Ecol 43:835–847
Hulme PE (2015) Invasion pathways at a crossroads: policy and research challenges for managing alien species introductions. J Appl Ecol 52:1418–1424
Hulme PE, Bacher S, Kenis M et al (2008) Grasping at the routes of biological invasions: a framework for integrating pathways into policy. J Appl Ecol 45:403–414
Katsanevakis S, Zenetos A, Belchior C, Cardoso A-C (2013) Invading European seas: assessing pathways of introduction of marine aliens. Ocean Coast Manage 76:64–74
Kenis M, Auger-Rozenberg M-A, Roques A et al (2009) Ecological effects of invasive alien insects. Biol Invasions 11:21–45
Kölzsch A, Blasius B (2011) Indications of marine bioinvasion from network theory. Eur Phys J B 84:601–612
Kottek M, Grieser J, Beck C, Rudolf B, Rubel F (2006) World Map of the Köppen–Geiger climate classification updated. Meteorol Z 15:259–263
Kraus F (2007) Using pathway analysis to inform prevention strategies for alien reptiles and amphibians. Manag Vertebr Invasive Species 21:94–103
Kumschick S, Richardson DM (2013) Species-based risk assessments for biological invasions: advances and challenges. Divers Distrib 19:1095–1105
Leung B, Springborn MR, Turner JA, Brockerhoff EG (2014) Pathway-level risk analysis: the net present value of an invasive species policy in the US. Front Ecol Environ 12:273–279
McGeoch MA, Genovesi P, Bellingham PJ, Costello MJ, McGrannachan C, Sheppard A (2016) Prioritizing species, pathways, and sites to achieve conservation targets for biological invasions. Biol Invasions 18:299–314
McLean P, Gallien L, Wilson JRU, Gaertner M, Richardson DM (2017) Small urban centres as launching sites for plant invasions in natural areas: insights from South Africa. Biol Invasions. doi:10.1007/s10530-017-1600-4
Mohri M, Rostamizadeh A, Talwalkar A (2012) The foundations of machine learning. The MIT Press, Cambridge
Novoa A, Le Roux JJ, Robertson MP et al (2015) Introduced and invasive cactus species: a global review. AoB Plants 7:plu078. doi:10.1093/aobpla/plu078
Pergl J, Pyšek P, Bacher S et al (2017) Troublling travellers: are economically harmful alien species associated with particular introduction pathways? NeoBiota 32:1–20
Pimentel D, McNair S, Janecka J et al (2001) Economic and environmental threats of alien plant, animal and microbe invasions. Agric Ecosyst Environ 84:1–20
Puth LM, Post DM (2005) Studying invasions: have we missed the boat? Ecol Lett 8:715–721
Pyšek P, Richardson DM (2010) Invasive species, environmental change and management, and health. Annu Rev Environ Resour 35:25–55
R Core Team (2015) R: a language and environment for statistical computing. r foundation for statistical computing. Vienna, Austria. http://www.R-project.org/
Reaser JK, Meyerson LA, Von Holle B (2008) Saving camels from straws: how propagule pressure-based prevention policies can reduce the risk of biological invasion. Biol Invasions 10:1085–1098
Richardson DM, Pyšek P, Rejmánek M et al (2000) Naturalization and invasion of alien plants: concepts and definitions. Divers Distrib 6:93–107
Richardson DM, Pyšek P, Carlton JT (2010) A compendium of essential concepts and terminology in invasion ecology. In: Richardson DM (ed) Fifty years of invasion ecology: the legacy of Charles Elton. Wiley, Oxford. doi:10.1002/9781444329988.ch30
Saul W-C, Roy HE, Booy O, Carnevali L, Chen H-J, Genovesi P, Harrower CA, Hulme PE, Pagad S, Pergl J, Jeschke JM (2016) Assessing patterns in introduction pathways of alien species by linking major invasion databases. J Appl Ecol 54:657–669
Scalera R, Genovesi P, Booy O et al. (2016) Technical report: progress towards pathways prioritization in compliance to Aichi Target 9. Information documented presented at SBSTTA 20 UNEP/CBD/SBSTTA/20/INF/5, the twentieth meeting of the CBD’s Subsidiary Body on Scientific, Technical and Technological Advice, Montreal, Canada, 25–30 April 2016
Schrader G, Unger J-G (2003) Plant quarantine as a measure against invasive alien species: the framework of the International Plant Protection Convention and the plant health regulations in the European Union. Biol Invasions 5:357–364
Therneau T, Atkinson B, Ripley B (2015) Rpart: recursive partitioning and regression trees. R package version 4.1.10. https://CRAN.R-project.org/package=rpart
United Nations, Department of Economic and Social Affairs, Population Division (2014) World urbanization prospects: the 2014 revision, CD-ROM edition. https://esa.un.org/unpd/wup/cd-rom/. Accessed 23 Aug 2015
Van Wilgen NJ, Richardson DM, Baard EHW (2008) Alien reptiles and amphibians in South Africa: towards a pragmatic management strategy. S Afr J Sci 104:13–20
Van Wilgen NJ, Wilson JRU, Elith J et al (2010) Alien invaders and reptile traders: what drivers the live animal trade in South Africa? Anim Conserv 13(Suppl 1):24–32
Vila M, Basnou C, Pyšek P, Josefsson M et al (2010) How well do we understand the impacts of alien species on ecosystem services? A pan-European, cross-taxa assessment. Front Ecol Environ 8:135–144
Visser V, Wilson JRU, Fish L, Brown C, Cook GD, Richardson DM (2016) Much more give than take: South Africa as a major donor but infrequent recipient of invasive non-native grasses. Glob Ecol Biogeogr 25:679–692
von der Lippe M, Kowarik I (2008) Do cities export biodiversity? Traffic as dispersal vector across urban-rural gradients. Divers Distrib 14:18–25
Wilson JRU, Dormontt EE, Prentis PJ et al (2009) Something in the way you move: dispersal pathways affect invasion success. Trends Ecol Evol 24:136–144
Woodford DJ, Richardson DM, MacIsaac HJ et al (2016) Confronting the wicked problem of managing biological invasions. NeoBiota 31:63–68
Acknowledgements
This research was funded by the South African National Department of Environmental Affairs through its funding of the South African National Biodiversity Institute’s Invasive Species Programme. An early version of this paper was presented at a workshop on “Non-native species in urban environments: Patterns, processes, impacts and challenges” that was hosted and co-funded by the DST-NRF Centre of Excellence for Invasion Biology in Stellenbosch in November 2016. Many participants at the workshop provided useful comments and suggestions which improved the paper. We thank The Global Invasive Species Database for the provision of data, Desika Moodley and Osadolor Ebhuoma for their technical assistance, and two anonymous reviewers for their comments and suggestions.
Author information
Authors and Affiliations
Corresponding author
Additional information
Guest Editors: Mirijam Gaertner, John R.U. Wilson, Marc W. Cadotte, J. Scott MacIvor, Rafael D. Zenni and David M. Richardson/Urban Invasions.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Padayachee, A.L., Irlich, U.M., Faulkner, K.T. et al. How do invasive species travel to and through urban environments?. Biol Invasions 19, 3557–3570 (2017). https://doi.org/10.1007/s10530-017-1596-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10530-017-1596-9