The Scottish Forest Service uses drones to protect wildlife from invasive plants that threaten native species. The drones use lidar, a laser technology that allows the scientists to see right through the canopy.
Lidar stands for laser imaging detection and ranging. It is a technology to determine the distance to an object or surface using laser pulses. The Scottish drones use lidar to map the health of the forest floor. The pulses are ‘fired’ at the trees, go straight through the canopy and then hit the ground, after which they are reflected back to the drone. By measuring how long the pulses take over it, a 3D image of the area can be formed.
The aim of the project is to allow scientists to better monitor how the landscape is changing due to factors such as climate change and the advance of invasive plants. Satellites and conventional photographic equipment only see the canopy of a forest from the air; lidar shows what is happening in the vegetation layer beneath all that chlorophyll. The International Space Station also has a lidar system on board to map the problem of large-scale deforestation worldwide.
The BBC News cites the rhododendron as an example of an invasive plant that threatens Scottish wildlife. It was transferred from southern Europe and western Asia to the British Isles in the eighteenth century to bring some more color to the landscape. Later it turned out that the purple rhododendron thrives a little too well in and around the Scottish forests. Due to the high acidity of the soil, the plant has also spread under the canopy at an unprecedented rate, but because the rhododendron carries a fungal disease, the plant is a threat to native vegetation.
With lidar, the spread of these harmful plants can be detected more quickly, so that the forest management service can take measures. The drone project in Scotland is led by the Edinburgh-based company Ecometrica. It has the financial backing of several partners, including the Forestry Commission Scotland, Scottish Orienteering, Woodland Trust, the University of Edinburgh and the UK Science and Technology Facilities Council.