Managing fires in a changing world: Fuel and weather determine fire behavior and safety in the neotropical savannas

Ana Carla Dos Santos; Samuel da Rocha Montenegro; Maxmiller Cardoso Ferreira; Ana Carolina Sena Barradas; Isabel Belloni Schmidt

doi:10.1016/j.jenvman.2021.112508

Managing fires in a changing world: Fuel and weather determine fire behavior and safety in the neotropical savannas

J Environ Manage. 2021 Jul 1:289:112508. doi: 10.1016/j.jenvman.2021.112508. Epub 2021 Apr 5.

Authors

Ana Carla Dos Santos¹, Samuel da Rocha Montenegro², Maxmiller Cardoso Ferreira³, Ana Carolina Sena Barradas⁴, Isabel Belloni Schmidt⁵

Affiliations

¹ Departamento de Ecologia, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Brasília, DF, CEP 70910-900, Brazil; PEQUI - Pesquisa e Conservação do Cerrado. SRTVN Qd. 701, Ed. Brasília Rádio Center, Sala 3030, Brasília, DF, CEP: 70719-900, Brazil. Electronic address: gs.anacarla@gmail.com.
² Departamento de Ecologia, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Brasília, DF, CEP 70910-900, Brazil. Electronic address: samuelrmonte@gmail.com.
³ Departamento de Ecologia, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Brasília, DF, CEP 70910-900, Brazil. Electronic address: maxmiller.bio@gmail.com.
⁴ Estação Ecológica Serra Geral do Tocantins, Avenida Beira Rio. Quadra 02. Lote 06, Bairro Centro, Rio da Conceição, TO, CEP 77303-000, Brazil. Electronic address: carolbarradas@gmail.com.
⁵ Departamento de Ecologia, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Brasília, DF, CEP 70910-900, Brazil; PEQUI - Pesquisa e Conservação do Cerrado. SRTVN Qd. 701, Ed. Brasília Rádio Center, Sala 3030, Brasília, DF, CEP: 70719-900, Brazil. Electronic address: isabels@unb.br.

PMID: 33831763
DOI: 10.1016/j.jenvman.2021.112508

Abstract

Fire is an important ecological disturbance, but anthropogenic wildfires increasingly threaten native ecosystems and human lives. In fire-prone ecosystems, zero-fire policies have been replaced by active fire management to reduce the risk of wildfires and improve ecological outcomes. The environmental drivers of fire behavior are widely known, but climate change and deforestation are changing their roles, making fires less predictable. Thus, reassessing the main determinants of fire behavior is preeminent to allow for safe and adaptive uses of fire in protected areas (PA). We did this research in collaboration with PA managers during the initial implementation of a pilot Integrated Fire Management (IFM) program in the Brazilian savanna. The program mainly aimed to prevent large wildfires in the late-dry season and included prescribed burns during the rainy, early- and mid-dry seasons to create vegetation patch mosaics with different fire histories. We assessed fire behavior and its environmental drivers during prescribed fires in the mid-dry season (MF) and experimental late-dry season fires (LF) (emulating wildfires). We applied Linear Models to test for differences in fire intensity, heat released, combustion factor and flame height between fire seasons and to check the influence of meteorological and fuel conditions in these parameters. LF had a significantly higher fire intensity (3508 vs. 895 kW m^-1), heat released (5537 vs. 3329 kW m^-2), combustion factor (90 vs. 51%) and flame height (2.5 vs. 1.9 m) than MF. Relative humidity, air temperature, wind speed and fuel load were the best predictors of fire behavior, corroborating previous research. Air temperature and relative humidity pushed the seasonal differences in fire behavior while wind speed and fuel load showed similar effects across seasons. Our results emphasize the importance of considering primarily environmental variables during fire management planning, especially in the current climate changing world where extreme events and seasonal weather fluctuations are constantly defying our knowledge about fire behavior.

Keywords: Cerrado; Climate change; Fire season; Grassland; Jalapão; Sandy soil.

MeSH terms

Brazil
Ecosystem*
Fires*
Grassland
Humans
Weather