Analysis of long-term fire-related deforestation and cover change dynamics in South American ecosystems

Fire is a major driver of forest change worldwide. In tropical regions, it is primarily used by local populations to clear forested land for human activities such as agriculture and infrastructure development. Here, we use three decades of Landsat-based observations to analyse fire-related forest loss over a broad temporal scale across a major tropical region in South America, spanning more than 2 million km² and encompassing a wide range of ecosystems. This long-term assessment provides a comprehensive view of post-fire forest cover dynamics, with strong potential to capture deforestation trends, forest fate, and the roles of protection status and landscape history. Over the study period, the newly generated medium-resolution dataset of burned area detected a cumulative total of approximately 345 million hectares burned, equivalent to an average annual burned fraction of 5.65%, with pronounced interannual variability and the period between 1999 and 2010 being the most extreme. During the same timeframe, more than 24.5 million hectares of forest were lost, representing nearly one-quarter of the 1990 forest extent, with fires accounting for 26% of this loss. Most of these losses have not recovered over time and were subsequently followed by deforestation, with 99% of affected areas converted to pastures and croplands, while recovery rates have remained negligible. Fragmentation and fire history legacy emerged as critical factors influencing the trajectory of forest loss.