VARIATION IN FOREST COVER DUE TO FIRE IN SIERRA DE LA VENTANA, PROVINCE OF BUENOS AIRES, ARGENTINA

Fires are events that occur regularly in the Sierra de la Ventana region, affecting native and exotic herbaceous and exotic arboreal vegetation (mainly Pinus pinaster and Pinus halepensis). Although they are disturbances ecologically adapted to the environment, the advance of exotic vegetation and the perception of the population has modified their frequency and intensity. The objective was to identify the variation in forest cover due to fires in the Arroyo Ventana Basin, Province of Buenos Aires, covering the period 2010-2020. Two large fires were identified: 2013 and 2018. A land use map was developed through supervised classification of satellite images Lansat8 and Sentinel2. Likewise, satellite images were used for the dates before and after the events, processed with the QGIS Madeira 3.4.6 software. Vegetation indices Burned Area Index (IAQ), Normalized Burning Ratio (NBR) and Normalized Difference Vegetation Index (NDVI) were applied. It was obtained that the variation of forest cover does not exceed 30 ha in the studied period (minimum 140ha, maximum 170 ha), although its distribution does change, a spatial variation that corresponds to the burned areas. Abundant regeneration was observed between the years 2013 and 2017. The fires have proven to be controllers of the forest cover, maintaining a stable surface in the period studied. However, this process is a triggering factor for the germination and subsequent establishment of regeneration of Pinus sp.