Nearly Half of Galapagos Island Canopy is Composed of Invasive Plant Species

The Galapagos Islands are heralded as some of the most pristine and biodiverse islands on the planet. Now, though, scientists have revealed that parts of these iconic islands have been overrun by invasive plants from other parts of the world.

"People may be shocked that a place considered so iconic for biodiversity is so overrun with weeds in some areas despite ongoing control effort by National Park rangers, but this is really a global story," said Mandy Trueman, lead author of the new study, in a news release.

In fact, the researchers found that nearly half of the canopy of the vegetation is composed of non-native trees, shrubs and grasses. The scientists also created a map and associated database that detailed the abundance of both introduced and native species over the landscape. This, in particular, could help managers better target conservation efforts.

"These invaders compete with native plants for light and water and can change the environment so that both flora and fauna are affected," said Trueman. "These invasions are one of the factors threatening Galapagos species, many of which occur nowhere else in the world."

Currently, managers are attempting to cull invasive species and replace them with natives. Efforts have actually been somewhat successful so far. In fact, they've resulted in the recovery of some areas of high ecological value, and managers annually manage 400 hectares per year for the worst invaders-blackberry, guava and cedrela.

"The reality is that humans take plants to new places and that can change the nature of those places forever," said Heinke Jager, who is based with the Charles Darwin Foundation in the Galapagos. "Eventually some native species will lose out against the non-native invaders. This is a reality that conservation managers in many parts of the world need to deal with."

The findings are published in the journal NeoBiota.