Vegetation cover estimation in semi-arid shrublands after prescribed burning: field-ground and drone image comparison

The use of drones for vegetation monitoring allows the acquisition of large amounts of high spatial resolution data in a simple and fast way. In this study, we evaluated the accuracy of vegetation cover estimation by drones in Mediterranean semi-arid shrublands (Sierra de Filabres; Almería; southern Spain) after prescribed burns (2 years). We compared drone-based vegetation cover estimates with those based on traditional vegetation sampling in ninety-six 1 m2 plots. We explored how this accuracy varies in different types of coverage (low-, moderate- and high-cover shrublands, and high-cover alfa grass steppe); as well as with diversity, plant richness, and topographic slope. The coverage estimated using a drone was strongly correlated with that obtained by vegetation sampling (R2 = 0.81). This estimate varied between cover classes, with the error rate being higher in low-cover shrublands, and lower in high-cover alfa grass steppe (normalized RMSE 33% vs. 9%). Diversity and slope did not affect the accuracy of the cover estimates, while errors were larger in plots with greater richness. These results suggest that in semi-arid environments, the drone might underestimate vegetation cover in low-cover shrublands. © 2022 by the authors.This research was funded by Interreg Sudoe Programme, European Regional Development Fund, European-Union, grant number SOE2/P5/E0804; by MICINN through European Regional Development Fund (SUMHAL, LIFEWATCH-2019-09-CSIC-13, POPE 2014-2020); and by Ministry of Science and Innovation (MCIN/AEI/10.13039/501100011033) grant number PID2020-116786RB-C32

Estimación de la cobertura vegetal en matorrales semiáridos mediante el uso de drones tras una quema prescrita. Validación mediante datos de campo

Este trabajo se ha desarrollado en el marco del proyecto Open2preserve (SOE2/P5/E0804) financiado por el Programa Interreg Sudoe. Asimismo ha recibido financiación del MICINN a través del Fondo Europeo de Desarrollo Regional [SUMHAL, LIFEWATCH-2019-09-CSIC-13, POPE 2014-2020]