Development of drone-based methodology for inventory and monitoring invasive plants along river banks in Croatia

Monitoring invasive species is required, but ground field-based assessment is often impractical, time-consuming and expensive. In the present paper, we compare standard ground and drone mapping methods to estimate the distribution and abundances of Helianthus tuberosus and Solidago canadensis across a 1.9 km long river bank area in Croatia. We describe beneficial factors and limitations researchers should consider for planning aerial drone surveys. The criteria used include time, precision, cost, and other indicators of the value of each method based on its long term potential. We utilised the Mavic 2 Enterprise Dual model of a drone equipped with an M2ED Visual Camera. Among tested drone modes, the best was the video recording mode at a height of 15 m and speed of 1.2 m/sec, for which we developed a protocol. Obtained data can be useful in adding information on vegetation distribution but also contribute to an effective management plan for invasive species.