Burning in Smoke, Smothering in Flame
Worldwide, fires in natural areas cause high environmental losses that damage global conservation efforts. The situation is no different in Brazil, where wildfires pose a threat to some regional ecosystems, jeopardizing their functioning, biodiversity and atmospheric climate-related processes. In September 2010, 15 of Brazil's 26 states and its capital were under a state of environmental emergency as more than 12,500 fires burned across the country. As media coverage of the fires increased, more than 120,000 Brazilians took to Twitter, posting under a tag to stop the burnings — #chegadequeimadas — in a window of only 48 hours.
At the end of October, the Ministry of Environment released partial numbers about the 2010 fire season in Brazil. Through August, more than 108,000 bushfires had been registered. One-third of these fires occurred in private lands, where farmers or indigenous people started fires to manage the land without taking preventive measures to avoid uncontrolled events. At one point, the satellites of the Brazilian National Space Research Institute (INPE) detected more than 260,000 active fires in the country — one "hot pixel" per minute at the fires' height.
The Brazilian government spent more than US$17 million to control the fires. This amount was spent on 5,000 firefighters and equipment, including the deployment of eight fixed-wing airplanes and seven helicopters. Unfortunately, emergency services were not able to control the majority of wildfires that went on to destroy large swathes of protected areas and hundreds of homes in north and east sections of the country.
With more than 1.5 million species, Brazil is recognized as a mega-diversity country, hosting between 10% and 20% of the species already classified in the world. The country hosts six continental biomes, two of which are known as biodiversity hotspots: the Cerrado and the Atlantic Forest. Today, all Brazilian biomes have been modified by human interventions, and their characteristic biodiversity is endangered to some level. To safeguard biodiversity, the country has rapidly increased the number of protected areas over the past few decades. Currently, nearly 300 federal protected areas — comprising more than 24 million hectares of protected lands — have been established.
Two major trends are contributing to ecosystem degradation in Brazil — fragmentation of biomes and the increasing size of extremely large fires. In the past, animals and vegetation could recover from fires due to metapopulation dynamics. Today, however, protected areas are becoming protected islands, without significant connections to other natural areas, making it impossible for wildlife to safely move to alternative areas during post-fire periods.
In 2010, a number of protected areas were affected by wildfires that represented serious threats to environmental health — the balance of ecosystem, vegetal, animal and human spheres of health. National Parks such as Ilha Grande (PR/MS), Serra da Canastra (GO), Araguaia (TO) and Brasília (DF) burned for several days, and more than 90% of the territory of Emas National Park (GO) was affected by fire.
In addition to affecting wildlife habitats, extensive burnings such as these harm numerous species. For example, armadillos (Pilosa order, formerly Xenarthra) are very sensitive to high-intensity and high-severity wildfires. Several investigations have determined that armadillos were the species most affected by wildfires in Ilha Grande National Park, due to direct and indirect fire effects, and represented the taxonomic group of medium-size mammals most susceptible to fire. Considering the burned area and the population density for armadillo species, fires caused 15% of this population's mortality in the park.
Although the dynamics of infectious diseases in armadillos is unknown, a 15% rate of mortality can be considered high and indicative that fire can also be seen as a "disease" in conservation areas. The high frequency of events and their distribution over time also indicate that fire might be considered a chronic disease in some areas because it threatens species' survival and ecological health. Extensive burnings also change the natural dynamics of the food chain and force all sizes of wildlife vertebrates to leave the protected areas, exposing them to other threats such as road kill, domestic animal diseases and illegal hunting.
Although the main cause of the fires was related to humans' illegal actions, fire is a natural part of many Brazilian ecosystems. Total suppression is the protected areas' fire policy, but in extremely dry years such as 2010 the fire-exclusion policy may become infeasible, especially within ecosystems that have high fuel accumulation. For example, the preceding wet season favored the growth of grass, which provides the most dangerous fuel for a wildfire.
Considering that fire is part of some ecosystems, this natural element should be seen as a management tool and used where appropriate to maintain the functioning of the environment. Brazilian biomes vary greatly from north to south, as do fire regimes. Fire regime conditions range from intact to degraded — even inside the same biome or eco-region. As fire's effects vary according to environmental degradation status, at the present time and considering Brazil's fragmented biomes, even intact fire regimes could pose a biodiversity threat to degraded ecosystems. Thus, fire regimes should be settled and applied to promote environmental health.
In light of the increased number and severity of uncontrollable wildfire in recent years, there is a need to review current landscape management policies. New scientific insights on fire ecology should be considered, and fire management plans should be defined according to ecological and environmental requirements and objectives. Fire management in Brazilian protected areas should combine prescribed fires with the suppression and use of human-caused and natural fires. Brazil has a great potential, widespread area that could be managed to restore fire regimes using prescribed fire — as is done in North America, Europe and Africa. More than 2 million hectares could be managed in the Cerrado domain, just within the national parks.
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