Wild animals are not the only ones becoming invasive to other areas. Certain species of plants have also turned into disruptive new tenants in regions outside their natural habitats.

A team of scientists at the University of Konstanz in Germany discovered that the spread of a number of plant species has caused a significantly negative impact on new areas where they have taken root.

Examples of these are Japan's knotweed, which has destabilized buildings in Europe and North America using its rapidly growing roots, and the Amazon's water hyacinth, which has been found to crowd local plant species in the 50 different countries it has spread to.

These highly invasive plant species have caused billions of dollars in damages as they continue to choke out local vegetation in places that they have invaded.

In a study featured in the journal Nature, the researchers found that 13,168 species of plants, roughly amounting to 3.9 percent of the total number of species in the world, have become naturalized in different parts of the globe as a consequence of human activity.

They noted that the number of invasive plants spreading to other areas will likely continue along with the increase in trade and travel by developing countries such as China.

Konstanz researcher Mark van Kleunen said that countries in North America have had the most number of invasive plants over the years. These were brought to the continent from Europe by the waves of colonists who brought different plants with them on the trip.

Van Kleunen explained that the international numbers were considerably higher compared to previous estimates of one to two percent. Invasive plants can be introduced to other areas deliberately as crops, or they can also be transported accidentally as seeds.

With the continuing trend of globalization and increase in global trade and traffic, the researchers noted that it is highly likely that more invasive plant species will be spread to other regions outside their ranges, where they will take root and become naturalized.

Experts have earlier estimated that invasive species, such as plants, animals and microbes, cause over $1.4 trillion worth of damage to the world economy every year.

A report released in 2012 estimated that China continues to lose around $1.1 billion every year because of damages caused by water hyacinth.

Photo: Challiyil Eswaramangalath Pavithran Vipin | Flickr