Compound impact of land use and extreme climate on the 2020 fire record of the Brazilian Pantanal

Abstract

Aim: Our aim was to quantify the influence of climate and land use on major fires that occurred during the 2020 drought over the Brazilian Pantanal region.

Increasing threat of wildfires: the year 2020 in perspective: A Global Ecology and Biogeography special issue

“…The authors further found that there was large spatial variability in post‐fire changes in carbon stocks, related to pre‐fire biomass, but also other interacting processes, most likely pre‐fire drought stress and post‐fire biotic interactions (insect defoliation). Similarly, Ferreira Barbosa et al (2022) observed large spatial variation in estimated carbon emissions from the Brazilian Pantanal fires, linked to land use, with forests estimated to produce much greater pyrogenic carbon emissions than natural or anthropogenic pastures and grasslands. Importantly, Nolan et al (2022) also found that the consequences of fire on carbon fluxes are likely to extend well beyond the initial pyrogenic carbon emissions, with some forest types exhibiting over twice the amount of dead biomass in burned compared to unburnt forest.…”

“…The Australian wildfires burned a range of forest types including drier forests where fires typically recur every 10–20 years, to rain forests that persist in fire refugia (Bowman, 2000; Le Breton et al, 2022). In the Pantanal, the fires burned both forested areas that have not burned for over 18 years, as well as grasslands that regularly burn (Ferreira Barbosa et al, 2022). Despite these differences, the 2020 megafires have raised common questions, including (a) how do we define ‘megafires’?…”

“…In the Brazilian Pantanal, Ferreira Barbosa et al (2022) identified several factors in addition to climate linked to the large burned area in 2020. These included altered hydrology, human ignition sources related to domesticated cattle and agricultural crop production, poor conservation policies resulting in altered land use, and lack of fire suppression strategies.…”

“…In the Australian Black Summer, Brazilian Pantanal and western US fires, the large burn areas were found to be a function of extremely dry conditions (Collins et al, 2022; Coop et al, 2022; Ferreira Barbosa et al, 2022; Pascolini‐Campbell et al, 2022; Safford et al, 2022). Several studies also examined the drivers of fire severity, finding that fire weather and atmospheric aridity (vapour pressure deficit), and drought stress, were all important drivers of fire severity in south‐eastern Australia and the western United States (Collins et al, 2022; Pascolini‐Campbell et al, 2022; Safford et al, 2022).…”

“…Alterations to landscape hydrology that result in floodplain dehydration, for example draining and homogenization of wetlands, can increase wildfire risk (Ferreira Barbosa et al, 2022; Pugh et al, 2022). Altered hydrology was identified by Ferreira Barbosa et al (2022) as one of the factors linked to the large burn area in the Brazilian Pantanal, one of the world's largest wetlands (Garcia et al, 2021).…”