Abstract
Abstract. To assess the damage produced by wildfires on forest ecosystems is a critical task for their subsequent management and ecological restoration. Satellite-based optical images provide reliable ex-ante and ex-post data about vegetation state, making them suitable for the aforementioned purpose. In this study we assessed the damage produced on two forested lands by the series of wildfires occurred in central Chile during summer 2017. Arithmetic differences from pre- and post-fire NDVI (normalized difference vegetation index), NDWI (normalized difference water index) and NBR (normalized burnt ratio) were retrieved from a Sentinel-2 image set embracing four near-anniversary summer dates: 2016 (ex-ante), 2017, 2018 and 2019 (ex-post). The nine index-derived differences resulting were correlated to CBI (composite burn index) data collected in the field during summer 2019, and a model constructed by a stepwise regression was formulated. Results show that planted forests exhibited a somewhat smaller biomass recovery than native ones, in part due to their post-fire clearing and preparation, deriving in a smaller tree cover. CBI poorly performed because its calculation includes low vegetation strata largely recovered at the time of the field data collection. However, when overstory field data were used alone correlations noticeably increased (r = 0.66–0.74). This was because during the field campaign this stratum was still appreciably damaged, thus better matching with the data provided by the indices-derived differences, intrinsically more representative of uppermost vegetation layers. The burn damage was mapped on both study areas employing the best performing regression model, based on NDWI2016-2019, NDWI2016-2017, NBR2016-2018 and NBR2016-2017 differences (adjusted R2 = 0.72, p < 0.005, root mean square error = 0.38). The use of approaches like this one in other areas of central Chile, where wildfires are increasing their frequency and intensity, might contribute to better lead post-fire management and restoration actions on their damaged forest ecosystems.
Highlights
Wildfires may produce severe disturbances on forest ecosystems, among these: biodiversity destruction, habitat fragmentation, soil erosion and sterilization, water and atmosphere degradation and carbon dioxide release (Chuvieco, 1999)
To assess and monitoring the calcination severity and biomass recovery progression of a burnt forest ecosystem is a key task to orientate long- and short-term site-specific post-fire actions of management and ecological restoration. In this regard, satellitebased optical remote sensing stands out as a cost-efficient tool for capturing and analysing data sensitive to the effects produced by wildfires on any vegetation land cover
The capabilities offered by optical images to retrieve vegetation state variables related to disturbances like wildfires is widely documented in the scientific literature, where subtractions between ex-ante and ex-post spectral vegetation indices have been routinely used as fire damage proxies (Chuvieco et al, 2002; Key and Benson, 2006; Escuin et al, 2008; Sever et al, 2012, Ryu et al, 2018)
Summary
Wildfires may produce severe disturbances on forest ecosystems, among these: biodiversity destruction, habitat fragmentation, soil erosion and sterilization, water and atmosphere degradation and carbon dioxide release (Chuvieco, 1999). To assess and monitoring the calcination severity and biomass recovery progression of a burnt forest ecosystem is a key task to orientate long- and short-term site-specific post-fire actions of management and ecological restoration In this regard, satellitebased optical remote sensing stands out as a cost-efficient tool for capturing and analysing data sensitive to the effects produced by wildfires on any vegetation land cover. The capabilities offered by optical images to retrieve vegetation state variables related to disturbances like wildfires is widely documented in the scientific literature, where subtractions between ex-ante and ex-post spectral vegetation indices have been routinely used as fire damage proxies (Chuvieco et al, 2002; Key and Benson, 2006; Escuin et al, 2008; Sever et al, 2012, Ryu et al, 2018).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
