GDP, a determining variable in the distribution of invasive species

Writing / Irene Vega

Biological invasions, one of the key drivers of global change, are a threat to local flora and fauna around the world, with severe consequences in diverse areas, such as the food industry or the health of ecosystems. To tackle future biological invasions, it is necessary to identify the regions most susceptible to invasion and to identify the most important variables that determine the distribution of invasive species.

A scientific team, led by Dr. Ignasi Arranz, researcher at the Institute for Global Change Research at the Rey Juan Carlos University (IICG-URJC) and the Department of Biology and Geology, Physics and Inorganic Chemistry at the URJC, has studied global data on the distribution of invasive species from various biological groups. The results of this study work, published in the scientific journal Ecology and Evolution, show that macroeconomic factors such as Gross Domestic Product (GDP) have a greater influence on the development of invasive species compared to other environmental or population variables. “Identifying the most important factors that determine the distribution of invasive species is key because it is closely linked to environmental management and policies,” stresses Dr. Arranz.

To carry out this research, the team collaborated with scientists from the University of Girona and the University of Canberra (Australia). The researchers studied the importance of different economic, population and environmental variables to predict the richness of invasive species worldwide in eight taxonomic groups: amphibians, ants, birds, mammals, vascular plants, reptiles, spiders and freshwater fish. database used, published in 2017 by Dr. W. Dawson of Durham University and collaborators, is open access and has great value for its length and quality.

This work also compares data analysis tools to assess the importance of various factors that determine an event, applicable in other studies to evaluate other factors of global change such as habitat destruction or climate change.

How are invasive species introduced?

The degree of success of an invasive species depends on local environmental conditions, since under ideal conditions the species can become established. Similarly, humans are one of the main agents of dispersion of invasive species, transporting them outside their natural geographic ranges.

The probability of introduction of invasive species also depends on the economic conditions or the human population of a territory. “For example, economic factors associated with the transformation of the landscape explain the distribution of invasive species,” explains the URJC researcher. Developed and developing countries may be more susceptible to the introduction of invasive species due to their industry, international trade, and standards of living. “Our work can allow for improved decision-making to prevent introductions,” concludes Arranz.

Image: Global distribution of macroeconomic variables and human population variables. Grey regions correspond to regions where there is no information. The measures were obtained from the article by Dawson et al. (2017).