The unique isolation of the Galapagos Islands has led to the evolution of species found nowhere else on earth. This same isolation makes the Galapagos especially vulnerable to the threat of invasive species. Human assisted introductions have accelerated the rate of invasions from an estimated one new species every 10,000 years to about 10 species a year during the last twenty years. 

The Nature Conservancy recently worked with Ecuador’s Center for Integrated Surveys for Natural Resources by Remote Sensors and other partners on a project to map the islands. Once the team had finished updating the initial cartography, they honed in on invasive plants on 25,000 hectares of five of the main islands where the park was most concerned about the status of invasions. A combination of high resolution satellite images, multi-spectral aerial images and measurements taken in the field were used to map the presence of quinine, guava, blackberry and rose apple.

These four plants are some of the worst invaders on the island, disrupting local species. The roots of quinine, for example, are so strong that they prevent the Galapagos petrel from making its nest in the soil. The study focused in on areas targeted for control efforts and provided a bird’s eye view of the plants’ distribution.  This information is now being used by the Conservancy and their partners to develop effective strategies to control, eradicate and manage these invaders.

Nature picture credits (top to bottom, left to right): © Marcus Koenen (Bartolome Island, Galapagos); © Mitchel A. Woltersdorf(palm frond, Galapagos).