Mapping the post-fire vegetation recovery by NDVI time series

This study analyzed the state of recovery of the vegetation burnt in the National Park of Torres del Paine by the Olguín fire between December, 2011 and March, 2012. To do this, pre- and post-fire NDVI images were created from a time series of 24 Landsat images (acquired between April, 2009 and 2015). The dynamic of the vegetation recovery was examined by comparing the NDVI values across the time series. The biomass variation of the burnt vegetation was mapped by classifying and comparing pre- and post-fire NDVI images acquired in the same month (October 2009 and 2014). The results indicate that most of the vegetation of the study area (58.61%), corresponding to pre-Andean scrubs, diminished its biomass levels for study period. The pre- and post-fire NDVI class crossing by a confusion matrix showed that the highest and most prevailing pre-fire NDVI classes, mostly corresponding to hydromorphic forests and Andean scrubs, turned into the lowest classes in 2014. The remaining area, comprising Patagonian steppe, reestablished its biomass levels in 2014, mostly exhibiting the same pre-fire NDVI classes. These results may provide guidelines to monitor and manage the regeneration of the vegetation impacted by this fire.