Officially called China's Belt and Road Initiative, the project was launched five years ago and aims to include about half the planet -- linking Asia, Europe, Africa, Central and South America.
Yiming Li of the Chinese Academy of Sciences wondered years ago about Beijing's promise that the project would be a "green" initiative.
In particular, what would be the consequences for amphibians, reptiles, birds and mammals?
"Perhaps the focus of the authorities has been more on pests and diseases in agriculture, and invasive species is not a popular topic," he told AFP.
Li and colleagues in China and Britain developed a model overlapping the regions of the world that would be linked by the new routes, based on trade values, and their climates and habitats, in order to predict where 816 types of vertebrates were most likely to be introduced and stick around.
Their study, published Thursday in the journal Current Biology, identifies 14 major hotspots where there is a high risk of invasive species becoming established.
On their map, these hotspots appear on all continents -- from Indonesia, Vietnam, and the Philippines to parts of the Mediterranean to southern Chile and the Caribbean.
In Africa, countries like Algeria, Nigeria and Cameroon -- where the climate is favorable -- are also on the list.
"What we're most concerned about is the six large economic corridors" spanning Asia and Europe, said Li.
Because of the high traffic, "there is a high probability of introduction and local conditions are suitable for the survival of alien species. We refer to these places as invasive hotspots."
A 'wake-up call'
"Invasions are continually happening all over the place," said co-author Tim Blackburn, a professor of invasion biology at University College London.
Europeans exported rats to the Americas. At the start of the 20th century, an Asian fungus wiped out North America's chestnut forests. New Zealand, which was home to no native land mammals before the arrival of man, now has 25 species including rats, mice, hedgehogs and ferrets.
"This will be different, just because of the extent of it, and the volumes of trade potentially involved," Blackburn said.
Like bugs and fungi, rats, frogs, snakes and birds can hitch a ride in trucks, trains, ships and even airplanes.
So can domestic pets, which are then sometimes let go in nature.
Already, a bird called the common myna (Acridotheres tristis), native to Russia and Kazakhstan, has made its way into Xinjiang in northwest China, destroying the nests of local birds.
The American bullfrog (Lithobates catesbeianus) has been eating Chinese amphibians for years -- along with many elsewhere -- and is considered "the most invasive amphibian in the world," said Li.
So what can be done?
Researcher say the solution is biosecurity, including measures such as surveillance of containers, monitoring contents of shipments, instituting quarantines and programs designed to protect biodiversity.
According to Jeffrey Dukes, a professor of forestry and natural resources at Purdue University, the analysis is "interesting" but "it's necessarily pretty coarse in some ways," since it does not go into detail about which invasive species are likely, or where they may end up.
"This paper is great as a wake-up call," added Dukes, who was not involved in the study.
"Invasive species are very hard to eradicate. But if you prevent them, if you prevent the problem from happening in the first place, then you save yourself not just headaches, but you know, dollars and potentially species."