The Nature Conservancy has received a $1.1 million grant to protect Hawaii forests from invasive weeds. 

The three-year grant from the Joseph & Vera Long Foundation will support work mapping invasive weeds, controlling the weeds, and sharing data and techniques.

The Nature Conservancy said Wednesday it plans to double the resolution of aerial mapping technologies it uses. This should help it identify even those weeds that have small leaves. 

It plans to map 20,000 acres of forest land across Hawaii, allowing it to detect large-scale changes in forests over long periods. 

The organization also expects to use new methods to kill individual weeds from the air. One idea is to use a compressed air-gun loaded with herbicide-filled paintballs to target specific plants from helicopters.