Comparison of Satellite and Drone-Based Images at Two Spatial Scales to Evaluate Vegetation Regeneration after Post-Fire Treatments in a Mediterranean Forest

• Published in: Applied sciences Vol. 11; no. 12; p. 5423
• Main Authors: Martinez, Jose Luis, Lucas-Borja, Manuel Esteban, Plaza-Alvarez, Pedro Antonio, Denisi, Pietro, Moreno, Miguel Angel, Hernández, David, González-Romero, Javier, Zema, Demetrio Antonio
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.06.2021
• Subjects: Biodiversity; contour-felled log debris; Drones; Feasibility studies; Fieldwork; Forest management; Forests; Hydrology; Land cover; land restoration; Land surveys; Land use; log erosion barrier; Remote sensing; Restoration strategies; Runoff; Satellite imagery; Satellites; Soil conditions; Soil erosion; Soil management; Soil quality; Spatial analysis; Stabilization; Unmanned aerial vehicles; VARI; Vegetation; Vegetation cover; Vegetation growth; Wildfires; Greece; Spain
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app11125423

The evaluation of vegetation cover after post-fire treatments of burned lands is important for forest managers to restore soil quality and plant biodiversity in burned ecosystems. Unfortunately, this evaluation may be time consuming and expensive, requiring much fieldwork for surveys. The use of remote sensing, which makes these evaluation activities quicker and easier, have rarely been carried out in the Mediterranean forests, subjected to wildfire and post-fire stabilization techniques. To fill this gap, this study evaluates the feasibility of satellite (using LANDSAT8 images) and drone surveys to evaluate changes in vegetation cover and composition after wildfire and two hillslope stabilization treatments (log erosion barriers, LEBs, and contour-felled log debris, CFDs) in a forest of Central Eastern Spain. Surveys by drone were able to detect the variability of vegetation cover among burned and unburned areas through the Visible Atmospherically Resistant Index (VARI), but gave unrealistic results when the effectiveness of a post-fire treatment must be evaluated. LANDSAT8 images may be instead misleading to evaluate the changes in land cover after wildfire and post-fire treatments, due to the lack of correlation between VARI and vegetation cover. The spatial analysis has shown that: (i) the post-fire restoration strategy of landscape managers that have prioritized steeper slopes for treatments was successful; (ii) vegetation growth, at least in the experimental conditions, played a limited influence on soil surface conditions, since no significant increases in terrain roughness were detected in treated areas.