Media footage has shown wildfires ravaging the western United States. These fires are severe, intense, and have massive impacts on the environment and societal well-being, and go well beyond natural benefits of fires for forest health (in fire-adapted systems). Ireland regularly puts a fire warning in place. PhD student Kathleen Conroy looks at the issues surrounding wildfires...
NOAA National Centers for Environmental Information, Monthly Wildfires Report for Annual 2022, published January 2023, retrieved on May 9, 2023 - online HERE
The US and fire
Forest fires can play an important role in the health of a forest and are sometimes necessary for their well-being. In some environments in the US, fires prevent leaf litter and duff (decomposing organic materials) build-up and woody, shrubby material encroachment. Fires are needed during the life cycle of specific trees, especially pine species. For example, the lodgepole pine in California cannot reproduce without fire, the intense heat clears the resin opening the cone for seed dispersal.
Another example of reliance on fire occurs in Northern California, where conifers (ponderosa pine and sugar pine) outcompete the California black oak due to fire episodes. Fire removes the conifers and allows the black oak to re-establish from acorns that survive fire in the seed bank. Even though there is evidence of the benefits of forest fires, these are generally viewed by people as something to be contained and extinguished.
Of course, fires are destructive and terrifying for people. When European settlers began moving west in the US, establishing towns and cities in this new frontier, they did not understand the role that fires played. To them, fires were bad and needed to be extinguished immediately. From the late 19th century to the late 20th century, the US government established very strict fire suppression laws. Although these laws were established to manage fires, they had the opposite effect. Natural fires remove leaf litter, dead material, and duff. Under fire suppression laws, these highly flammable materials were no longer removed, and hence, built up. With droughts occurring more frequently due to climate change, these fuels are even more dangerous because they are extremely dry. Not only do people have to worry about natural fires (lightning strikes) but they also have to worry about human error (campfires getting out of control; electrical pole malfunctioning, etc.) (Figure 1).
To control fires, some areas are using a ‘controlled burn’ strategy, employing a highly technical but unpredictable, fire suppression technique. An example of a 'controlled burn' is the Calf Canyon/Hermits Peak Fire in 2022, which quickly got out of control and caused massive destruction throughout New Mexico, burning over 138,000ha and destroying over 900 buildings in two weeks.
Figure 1. Photo of the Dixie Fire forest in Northern California, which affected mid-day visibility up to 10km away. This fire began due to an electrical problem, burning over 380,000ha in 4 months. Sadly, there was one fatality as a result of this fire.
Are fires a threat to Ireland?
In the drier months, there is potential for wildfires to occur in Ireland (Figure 2). As droughts create drier conditions, there is a likelihood of higher fire incidences. Fires are a risk to forests and communities. Managers need to develop suitable action plans to deal with them. If you see a fire, please alert the emergency services as trained professionals are required to safely contain fires.
Figure 2. Area (HA) damaged by fire in Ireland (DAFM 2020).
References:
Department of Agriculture, Food and the Marine. 2020.
Forest Statistics Ireland 2020. DAFM, Johnstown Castle Estate, Co. Wexford.
NOAA National Centers for Environmental Information, Monthly Wildfires Report for Annual 2022, published January 2023, retrieved on May 9, 2023 - online HERE