New technique tracks invasive species

VOLCANOES NATIONAL PARK, Hawaii, March 8 (UPI) -- U.S. scientists have applied new measurement techniques from a high-altitude aircraft to track invading plants in Hawaii.

Scientists at the Carnegie Institution and elsewhere said invasive species are changing the rainforest ecology near the Kilauea volcano on the island of Hawaii and are doing so at a surprisingly rapid pace. Therefore the ability to detect and track invasive species quickly is valuable for research and for devising control measures.

"We found chemical fingerprints from the plant leaves and used them to tell which species dominated specific areas," said lead researcher Gregory Asner of the Carnegie Institution. "We employed the recently upgraded NASA Airborne Visible and Infrared Imaging Spectrometer to measure leaf nitrogen and water content from the aircraft, and corroborated the data on the ground. The fingerprints showed where the native dominant tree 'ohia' has been taken over by the invading Canary Islands tree, Myrica faya."

Asner said the technique allowed the scientists to identify areas where Myrica invasion is in its early stages. The aircraft imagery also showed how the forest-canopy chemistry is changing as a result of the invader.

The study is published in this week's early online edition of the Proceedings of the National Academy of Sciences.