Due to their isolation from mainland civilisation, tropical islands have grown to become rich in biodiversity. However, this isolation has made them particularly vulnerable to the ever-changing world we live in today.
One major issue that these islands are facing is the presence of invasive plant species that are threatening the existence of native populations through competition for resources.
Past attempts to map and monitor the presence of native and non-native vegetation on remote islands have been fraught with challenges. This is likely due to the high cost required to fly aircraft through these zones or to even generate high-quality satellite images. In addition, the rugged and remote terrain makes landing aircraft difficult and dangerous to access by foot.
However, new mapping technologies have been trialled to overcome this issue. A paper published earlier this year documented the findings by researchers using such methods in the Galápagos Islands.
The researchers from the University of San Francisco, Quito in Ecuador and the Galápagos National Park used a combination of Landsat satellite data, high-resolution aerial imagery gained from flying UAVs, and other analytical tools to accurately detect and map native and non-native vagetation.
Although Landsat satellites created a vegetation map of the islands, the use of UAVs was particularly useful in confirming the accuracy of the map and adding detail where satellite imagery was limited.
From their study, the researchers were able to identify which islands and specific areas in the Galápagos archipelago were most affected by invasive plant species. This study has been useful in shaping future conservation efforts on the islands and an effective method that could potentially applied in other locations.
You can learn more about the study at:
Rivas-Torres, G., Benítez, F., Rueda, D., Sevilla, C., & Mena, C. (2018). A methodology for mapping native and invasive vegetation coverage in archipelagos. Progress In Physical Geography: Earth And Environment, 42(1), 83-111. doi: 10.1177/0309133317752278