Mexican Coastal Dunes: Recipients and Donors of Alien Flora

The invasion of natural communities by exotic plants, which may turn into invasive or potentially invasive, is one of the most severe known threats to biodiversity, and coastal dunes are among the most affected habitats. Mexico’s coastal dunes are abundant and contain high plant biodiversity but attempts to determine the occurrence and impact of exotic plants are absent. First, we explored the number of invasive plant species found on Mexican coastal dunes. Second, we analyzed if the coastal dune flora native from Mexico acts as a source of invasive species worldwide. We found the relevant spread of exotic plants towards and from Mexico, reaching high percentages: 5% of the coastal dune flora are considered exotic plants; this increases to 8.7% when only plants typical of the coastal dune environment are considered. The Mexican coastal dunes flora is also a relevant source of invasive plants affecting all continents. Furthermore, almost half of the 35 worst worldwide invasive plants (according to the Global Invasive Species Database GISD) grow on Mexican coastal dunes, most native to Mexico and invasive elsewhere. Indeed, the worldwide exchange of coastal dune flora between Mexico and the world seems massive, relevant and highlights the need for worldwide and countrywide management and control strategies.