Understorey fire propagation and tree mortality on adjacent areas to an Amazonian deforestation fire

Abstract

Fire characteristics in tropical ecosystems are poorly documented quantitatively in the literature. This paper describes an understorey fire propagating across the edges of a biomass burn of a cleared primary forest. The experiment was carried out in 2001 in the Amazon forest near Alta Floresta, state of Mato Grosso, Brazil, as part of biomass burning experiments conducted in the same area since 1997. The vegetation of a 200 × 200-m2 forested area was clear-cut in early June and burned in late August. The understorey fire that escaped from the main burn was monitored across the four sides of the land clearing area. Flame-front spread varied between 0.14 and 0.35 m min–1. Maximum flame height was about 30 cm and typical flame depth was 10 to 15 cm. Tree mortality was investigated in 2003 in four areas adjacent to the biomass burning experiment. A total of 210 trees were counted in the four areas, 29.5% were dead as a consequence of the understorey fire that had occurred 2 years before. This fire-caused mortality is evidence of the synergistic effect between slash burning, tree mortality and future fire vulnerability on the forest–land clearing interfaces.

Wildfire risk for main vegetation units in a biodiversity hotspot: modeling approach in New Caledonia, South Pacific

“…) to such savannas fire where the damages could be dramatic through understorey fire propagation (e.g., Carvalho et al. ).…”

“…Most of the risk for biodiversity is located around these interfaces between fire-prone vegetation units and vegetation unit having a low tolerance (e.g., Ibanez et al 2013a) to such savannas fire where the damages could be dramatic through understorey fire propagation (e.g., Carvalho et al 2010).…”

“…Indeed, tropical rainforests have a low flammability (Cochrane 2003) but are particularly impacted by wildfires since tropical rainforest species are poorly adapted to fire (Nepstad et al 1999; Barlow and Peres 2008;Carvalho et al 2010;Granzow-de la Cerda et al 2012). Although few data are available in tropical rainforests (but see Balch et al 2011;Brando et al 2012), trees commonly exhibit high postfire mortality rates in these ecosystems (about 40% for large DBH >= 10 cm trees, Barlow and Peres 2008).…”

“…Although few data are available in tropical rainforests (but see Balch et al 2011;Brando et al 2012), trees commonly exhibit high postfire mortality rates in these ecosystems (about 40% for large DBH >= 10 cm trees, Barlow and Peres 2008). This high tree postfire mortality open and fragment these ecosystems favoring the emergence of new fires (Nepstad et al 1999;Carvalho et al 2010;Granzow-de la Cerda et al 2012). Moreover, the recurrence of such fires commonly leads to the conversion of forests in open fire-prone ecosystems such as savannahs (Barlow and Peres 2008).…”

Probability of surface fire spread in Brazilian rainforest fuels from outdoor experimental measurements

“…Major threats to the sustainability of the Amazon forest continue to be the persistent high rates of deforestation, ecosystem degradation and increasing occurrence of forest fires (Malhi et al 2008;Cochrane and Laurance 2008;Alencar et al 2015). Low intensity and slow-moving surface fires are the most common type in moist tropical forests (Cochrane et al 1999;Carvalho et al 2010). Nevertheless, surface fire can be devastating for the ecosystem due to the low resilience of tropical forests.…”