Significance / Abstract
Invasive species are species that are not native to a certain area. When they enter a new area, they can harm the area's environment, plants, and animals. This article is concerned with invasive species' potential to harm global agriculture. The authors of the article aim to determine which countries are hit the hardest by invasive species and which produce the most invasive species threat.
Invasive species cause crop loss, reducing food supplies and agricultural profits. With more countries trading crops with each other in the modern day, invasive species have more chances to travel and cause harm. The researchers in this article measure this harm with a value called invasion threat.
Invasion threat represents the chance that an invasive species arrives and successfully inhabits a new area. For each country they studied, the researchers calculated chance of arrival by examining how often the country imports crops. To calculate how likely a species would thrive in a country, they examined the types of environments each species is most suited for. For each country, they summed up the invasion threat of all species that could be expected to enter it. This gave them an idea of a country's overall threat of invasion. They also examined each country's most important crops and whether they could be hosts for invasive species. All this information was then used to calculate the total amount a country would expect to lose in crops lost to invasion.
The researchers also looked at the invasive species threat that each country generates for the rest of the world. They did this by examining how often each country exports food, as well as measuring the amount / variety of invasive species that live in the country.
Countries that are high agricultural producers also suffer the greatest financial losses from invasive species. These include countries like China, the US, Brazil, and India. However, developing countries suffer the greatest losses relative to the sizes of their economies. These include several countries in sub-Saharan Africa.
China and the U.S. are the greatest sources of invasive species. Countries that are great sources of such species often suffer great losses due to invasion.
It is difficult to find a clear pattern of invasion among countries across the globe. This shows that there are many complex factors that dictate the impact invasive species can have on a country. Countries that import crops at high volumes don't necessarily lose the most due to invasion.
Developing countries are the most impacted by invasive species because their economies are so dependent on agriculture. Many of such countries are in sub-Saharan Africa. Even though richer countries have more agricultural losses overall, agriculture is a much smaller part of their economies.
The US and China are the greatest sources of invasive species in the world. This is because of their extensive trade as well as the high numbers and variety of invasive species in the two countries.
There are several uncertainties in the study that the authors discuss. It is difficult to examine invasion threat in countries that have little to no history of invasion. The study also doesn't account for complex invasion processes. For example, there are processes in which there is a delay between arrival in a new area and invasion. There are also instances of arrivals that aren't followed by invasion. Moreover, it is hard to tell whether a species will affect one area differently than another. However, even when accounting for these uncertainties, the results of the study don't change much.
From all this insight gained, the article calls for the formation of an international body to handle invasive species. Such a body should offer countries info and resources to reduce the spread of invasive species.
This may be the first study to examine global invasive species threat on a country-by-country basis.
Materials and Methods
Data on different invasive species and countries were collected from various databases. Statistical and other mathematical methods were used to draw insight from this data.