Drones can help monitor forest restoration

Leighton Reid is a postdoctoral fellow in the Center for Conservation and Sustainable Development.

Hexacopter flying over a restoration site. The red, digital camera is visible between the landing bars.

Monitoring restoration projects is important to demonstrate progress and learn what works and what doesn’t, but it can be time consuming and expensive. As such, restoration practitioners around the world are looking to automate tasks like monitoring, and one way this can be done is with unmanned aerial vehicles, or drones.

Over the past two years I’ve worked with a research team in southern Costa Rica to test how well drones can monitor tropical forest restoration. We used hexacopter drones: helicopter-like contraptions with six rotors. Each drone had a consumer-grade digital camera attached to the bottom. We flew the drones over thirteen restoration sites and then used Ecosynth computer software to stitch the images together and create three-dimensional models of the vegetation structure.

Drones accurately estimated forest structure

Drone-based measurements of canopy height closely matched our hard-won field measurements (but with less sweat and insect bites). The drone-based system also detected canopy gaps, predicted fruit-eating bird movements, and estimated above ground biomass. The ability to accurately assess above ground biomass is particularly important; it suggests that drones could be used to monitor carbon accumulation in regenerating forests.

Editors’ choice – a must read

Our research on drones and forest restoration was published this week in the journal Biological Conservation. The editors selected it as the must-read choice of the month, saying:

“The rapidly expanding use of unmanned vehicles to monitor vegetation and other aspects of biodiversity is an exciting development in conservation biology. This article also demonstrates that bird abundance can be estimated using data gathered by UAVs.”

The paper is freely available for download through August 27, 2015 at the publisher’s website.

Researchers Jonathan Dandois and Dana Nadwodny (University of Maryland Baltimore County) launch a drone at a site in Costa Rica [Photo courtesy of Karen Holl].