A new study by Danish researchers examines how invasive plant species are reshaping ecosystems and people’s relationship with nature in the tropics. The researchers found roughly 10,000 alien plant species in the greater tropics – which includes both the tropic and sub-tropic parts of the world. Islands are especially invasion hotspots, and some have more alien plants than native ones.
The term ‘alien plants’ is used because not all non-native plants are a problem. Some have been imported for their usefulness and value and most don’t escape and become invasive with undesirable consequences.
An example of a problem invasive plant in the tropics is lantana, a familiar perennial in American gardens. Wild lantana species are highly invasive, outcompeting and displacing native plants in India, Australia, and Hawaii. It is a huge problem.
Invasive plants in the tropics are especially problematic because the tropics are often the home of very poor people who are highly dependent on ecosystems. The plants not only weaken the ecosystems, but they can also create wildlife conflicts.
The tropics have historically been changed by people for thousands of years, but modern life has accelerated the process resulting in species being exchanged all the time. Climate change is leading to widespread ecosystem degradation and, sometimes, collapse, making them more vulnerable to invasive species.
While many alien species require focused management, others lead to more stable new ecosystems around the world. Alien plants can be, and are often seen only as a threat, but the reality in a changing world is more complex. There are no simple answers.
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Invasive plants are rapidly changing the tropics
Photo, posted December 17, 2016, courtesy of Martín Vicente via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio
