The multiscale (specially upscalling) prediction of forest structure and forest dynamics is a major challenge, since its spatial variation is poorly known. UAVs (Unmanned Aerial Vehicles) can be particularly useful in this respect, offering for a low cost interesting possibilies to measure forest state (e.g., forest height, gap structure, biomass).
Bird’s eye view of the Hainich National Park, drone RGB composite from a height of 250 meters (credits: Getzin & Wiegand/Biodiversitäts-Exploratorien)
Satellites (www.hgf-eda.de) or airplanes are used to scan forest ecosystems, with multispectral, hyperspectral or LiDAR sensors. Drones have been increasingly used as a new remote sensing platform. In our group, the Quadrocopter Microdrones „md4-1000“ is equipped with a laser (LiDAR) scanner, a hyperspectral scanner, a RGB camera and a Thermal Scanner. The LiDAR data are used to measure the height of individual tree crowns, identify tree species or tree fall gaps. Information on forest structure can help to answer important ecological questions (e.g., disturbance state of forests). Drones can be also used to analyse agricultural ecosystems or savannas.