Invasive alien species (IAS) are a primary threat to global biodiversity, economies and human health1. The threat of invasion at any given location has been shown to increase with the rate at which IAS propagules are introduced and the degree of disturbances that promote IAS establishment. Currently, the highest numbers of IAS in the world, the strongest IAS management efforts and the greatest knowledge about the extent of invasions are found in economically developed countries, that is, those with a high Human Development Index (HDI). However, the geographical patterns of future invasions is likely to be substantially different from that of today.
As a consequence IAS are often perceived as a "first world" problem. Increasing globalization, especially imports of pets and plants, has have caused much of the biological invasions in the past. However, in the future air travel will be responsible for biological invasions of Africa and Asia. This will be exacerbated by climate change, and intensifying agriculture, which make it easier for invasive species to become established.
A group of researchers from the UK and the US have now shown that these invasions are also threatening the last remaining biodiversity strongholds in the world's most fragile economies. They conducted a global, spatial analysis of the terrestrial threat from IAS in light of twenty-first century globalization and environmental change, and evaluated national capacities to prevent and manage species invasions.
As it turns out one sixth of the global land surface is highly vulnerable to invasion, including substantial areas in developing nations and areas with diverse species of birds and plants. The study shows that rich nations become accustomed to the nuisance of invasive alien species, and are increasingly taking protective action but poorer economies have little power to regulate imports but at the same time are crucially reliant on international trade.
In the coming years, the negative impacts associated with the introduction of harmful species will likely be exacerbated by other global stressors, such as climate change, landscape degradation and pollution. Developed and developing countries -- especially the latter -- may lack the operational infrastructure to prevent and deal with harmful introductions.
The researchers hope that their findings will lead to governments and NGOs improving schemes to warn communities of the threats of biological invasion and provide solutions.
Uniting data on the causes of introduction and establishment can improve early-warning and eradication schemes. Most countries have limited capacity to act against invasions. In particular, we reveal a clear need for proactive invasion strategies in areas with high poverty levels, high biodiversity and low historical levels of invasion.