INVESTIGADORES
SPARACINO Javier
artículos
Título:
A long-term assessment of fire regimes in a Brazilian ecotone between seasonally dry tropical forests and savannah
Autor/es:
ARGIBAY, DAIHANA S.; SPARACINO, JAVIER; ESPINDOLA, GIOVANA M.
Revista:
ECOLOGICAL INDICATORS
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2020 vol. 113
ISSN:
1470-160X
Resumen:
Fire is a recurrent phenomenon in semiarid seasonal ecosystems. The study of the relationship between fire and climate could provide new approaches for understanding fire dynamics in semiarid regions, which could be useful for strategically managing the loss and recovery of natural resources under threat. Here, we evaluated the patterns of fires occurrence in a semiarid Caatinga-Cerrado ecotone in the Northeast Region of Brazil by characterizing their spatiotemporal dynamics associated with climatic conditions. Using a temporal series of 306 Landsat images, we mapped a burned area database at a fine spatial resolution (30 m) from 1999 to 2017 in the Capivara-Confusões Mosaic of protected areas and their surroundings. Fire seasonality was analyzed through climatic seasons, distinguishing between the rainy season (RS), early dry season (EDS), middle dry season (MDS) and late dry season (LDS), by analysis of the daily precipitation of ground-based stations in the area. We created yearly, seasonal and recurrence maps of burned areas to assess fire regimes. The results showed that the 48% of the area was burned during the 19-year long period considered. Serra das Confusões National Park (SCoNP) had 302,644 ha burned, Serra da Capivara National Park (SCaNP) had 2056 ha burned and the ecological corridor had 215,718 ha burned. Most of the burned area was registered during the MDS (36% of the study area), there was almost no burned area in the EDS (<0.01%), while the LDS (7%) and the RS (4%) had similar dimensions burned. The years that burned the most (2001, 2007, 2010, 2012, 2015) were followed by years with considerably less burned area. We identified a multiple-year process, consisting of a climatological year with above-average precipitation and consequent low burned area, followed by a climatological year with below-average precipitation and resulting in large extensions of burned area (periods: 1999–2001, 2008–2010, 2010–2012). Fire recurrence reached a maximum value of ten, with 47% of the area burned presenting some degree of recurrence. SCaNP presented no fire recurrence, while SCoNP had a maximum recurrence parameter of four. Areas with moderate fire recurrence were near roads, settlements or cities. Some recurrently burned areas presented similar shapes, which were associated with topography limiting the spread of the fires. The patterns that we described here constitute the first step toward understanding the fire regimes of the region to establish directions for improving management strategies and orienting policies in the area.