ABSTRACT
Monitoring forest ecosystems is a complex task that requires data at multiple scales. Unmanned Aerial Vehicle (UAV) systems provide very fine scale, local information, acquired from both passive and active sensors, which can be used to complement the capacity of satellite and aerial remote sensing (RS) and to fill key information gaps. UAV systems constitute a safe, flexible, and relatively low-cost technology for acquisition of frequent and very high spatial resolution data. UAV technologies can bridge the field and RS scales with above canopy perspective, providing data for calibration and validation of RS monitoring systems. UAVs may support forest inventory over small areas when used alone or complement inventory activities at broader scales. Current limitations to the use of UAVs are imposed by battery duration, payload weight, and local regulations, as well as massive data processing capability. In the remaining chapters, we focus on four forestry applications in which UAV technologies contribute to get useful insights for sustainable management. An update of precision inventories of forest stands, assessing growth rates and volume increments near Williams Lake (British Columbia, Canada); characterisation of coniferous regeneration in Quesnel (British Columbia, Canada); monitoring health of Pinus radiata in Fresnedo (León, Spain); and identification of invasive species in Viana do Castelo (Portugal).
