Tuesday, August 4, 2009

PS 28-62: Invasive aliens, disposable income and the gentle pursuit of happiness: socio-economic correlates of biological invasions

Gyan P. Sharma, Department of Conservasion Ecology, Karen Esler, Department of Conservation Ecology, and James N. Blignaut, University of Pretoria.

Abstract

Background/Question/Methods:

We explore the relationships between various socio-economic variables and biological invasions at a global scale using country-level data sets (for 172 countries).  We argue here that the level of economic activity acts as conduit and even driver for both propagule pressure and ecological disturbance, which facilitates the establishment and spread of invasive alien species. Using various country-level socio-economic indicators from public data sources [i.e. the Happy Planet Index (HPI); Satisfaction with Life index (SWL); Human Development Index (HDI) and Gross Domestic Product (GDP)], we correlated the state of economic development as reflected by these indexes with the density of invasive alien species. 

Results/Conclusions:

We found a positive and statistically significant relationship between invasive alien species and the HDI, SWL and GDP.  Additionally, the density of invasive alien species increased significantly with human population density, total geographic area, GDP and HDI.  We also found a positive relationship between the density of invasive alien species and the top ten road networks of the world.  Our data support the hypothesis that economic activities are strongly linked with abundance patterns in populations of invasive alien species.  This provides some insight into developing renewed policies and management strategies for invasives across continents and countries.