Determining the relationship between invasive alien species density and a country’s socio-economic status

• Main Authors: Gyan P. Sharma, Karen J. Esler, James N. Blignaut
• Format: Article
• Language: English
• Published: Academy of Science of South Africa 2010-04-01
• Series: South African Journal of Science
• Subjects: economic development; gross domestic product; human development index; invasion; management; road network
• Online Access: http://archive.sajs.co.za/index.php/SAJS/article/view/113
• ISSN: 0038-2353; 1996-7489

We explored the relationships between various socio-economic variables and the prevalence and density of invasive alien species (IAS) on a global scale using country-level data sets. We did this by testing the hypothesis that the abundance and distribution of populations of IAS are correlated with various socio-economic indicators, with the direction of causality being that the state of IAS is determined by socio-economic conditions. We found a positive and statistically significant relationship between the prevalence and density of IAS and the human development index (HDI), the satisfaction with life index and the gross domestic product (GDP) among all the countries tested. Additionally, the density of IAS increased significantly with human-population density, total geographic area, GDP and HDI. We also found a positive relationship between the density of IAS and the top 10 road networks of the world. This provides some insight into the development of renewed policies and management strategies for invasive species across both continents and countries. We do caution, however, that the results are likely to be influenced by the sampling factor, whereby affluent countries have more resources to measure and monitor IAS than poorer countries and hence have better records of such, which then indicates a stronger relationship with the level of development.