Wildfires and their effects on the environment, wildlife, and people
Written by Akshaya, Haritha, Kavya
In 2019 there were 50, 477 wildfires that burned around 4.7 million acres of land in the United States (1).
Wildfires have been gaining in frequency over the past few decades, with a majority of them caused by humans. Despite the large number of fires, only around 2 to 3 percent of these fires burn the most acres (4). In the last article, we looked at wildfires in general and how the efforts of the firefighters in containing them. Here we will look at the historical trends and specific consequences of wildfires to better understand the situation in order to be able to brainstorm for sustainable solutions.
How are they caused/ the main aspects of wildfires?
Fire suppression, as we discussed in the last blog, is a main contributor to wildfires. Fire suppression started in 1910 when it became National Policy. In 1942 The Smokey the Bear Campaign increased the popularity of fire suppression (2). Although, initially, this led to decreased fires, fire suppression has allowed the accumulation of large amounts of dry fuel that is causing larger and longer fires now. So how does fire suppression exactly exacerbate the situation?
Prior to suppression, fires frequented the California forests anywhere between 35 to 50 years (3). So how can we predict this range? Researchers use tree rings on the tree stumps to deduce the frequency of fires during its lifetime. Fire scars, or black rings, are indicative of fires. If the tree survived the fire, then the next few tree rings would appear normal.
The natural cycle of wildfires allowed for the forests to naturally clear out the ‘debris’ and maintain a healthy ecosystem. Due to less frequent fires in the mid twentieth century, more trees took over the forest floors. As a result, the forest landscape became overcrowded with grass and shrubs, adding to the fuel that can be burned by the fire. In fact, over 1,000 trees cover the base of the forest floor per acre where historically 40 to 60 trees were maintained (3). So you might be wondering, more trees means better for the environment, right? After all, we are always told to plant more trees, why does this increase the intensity of the fires? When there are more trees in the forest, the taller trees forming the canopy tend to block out the light that reaches the forest floors. As a result, the younger trees and plants must compete for light, nutrition, and space to survive. This competition results in the death of many plants, adding to the fuel for forest fires. This also leads to what is known as crown fire (4). Crown fires reach the top of the canopy and the most intense type of fire, making it easier for the fire to spread. Therefore, it becomes a necessity to thin forests and reduce the number of trees per acre. Thinning of the forests along with prescribed fires will help maintain the forest density. It is also important to replant the forests once wildfires occur in order to ensure that greenhouse gases are being absorbed back by the forests (3).
How is wildlife affected by wildfires?
Apart from the many acres of land being burnt and peoples’ homes being destroyed, many areas have become uninhabitable by the wildlife that once thrived there. Although wildfires are part of the natural ecosystem, specifically in the western part of the United States, they can also be harmful to the many animals which cannot survive them. You may be aware that the loss of many animals during wildfires occur during the fires themselves, especially those who are older or younger, but it turns out that most of the mortalities of wildlife happen after the fires. Wildlife is harshly affected by wildfires because of the loss of habitats, and the creation of new ones which usually become very open areas with grasses and shrubs, replacing the once very dense forests which stood covering the land (5). When this happens, this leads many of the invasive species to grow in before the native ones come back, resulting in negative impacts on the land (5). Because of this, animals are left to fend for themselves in search of new habitats, often leading them to end up in human populated areas that they wouldn’t normally come to or be in.
Aside from these harmful impacts on wildlife, there are always certain positives to be reminded of. Some benefits include controlling the various insect pest species and removing huge undergrowth so sunlight can reach the forest floor, as well as allowing for the growth of fire-dependent species (4). As many studies have proven and as is generally known, most animals can sense danger and are able to move or arrive in streams to avoid the fires, while other small animals hide under rocks or dirt (5). To add on, certain predators benefit from wildfires as they are able to capture animals fleeing the danger of the fires, and some trees are even better able to spread their seeds (5). Smaller fires are actually able to allow for different microhabitats to grow which increase biodiversity, as opposed to fire suppression leading to dense forests where dead and diseased plants still are present (5). Forests burn even more because of large efforts to suppress fires within the past century, which have led to dense forests, as mentioned.
How long does it take for the forest to recover from a wildfire?
Although this depends on the amount of damage a wildfire has caused, forests are
able to recover fairly soon. This is because fires can help new species grow and to spread seeds as well. But it has also been known that although fires leave incentive for land to regrow and be able to get rid of other invasive species, they can take a long period to regrow to full capacity. This is because of our impacts on the forest soils and plant communities (7). The recovery from fires as well as logging have been found to recover through a longer period of time than thought before (7). In regards to the size of the fires, the larger the impact, the more need for efforts for recovery to help establish vegetation and with erosion prevention (6). Through ecological succession, the natural process by which forests recover from wildfires, have various stages before reaching full stability once again. It begins with ephemeral plants (weeds and wildflowers) which grow quickly after the bare ground created by the fires can be seen, and then grasses before pioneer trees appear (6). Once this process occurs, canopies form, and then the climax forest begins with better conditions for wildlife and more trees (6). Amongst the first of animals to return to the forests tend to be birds, which find shelter even in the dead trees and are able to consume the insects which return as well (even before the forests are fully restored) (6).
Wildfires in CA: Continuation (Where its happening, current conditions)/ most recent wildfires in CA and their impacts
The wildfires this year began around August 16, 2020. One of the first fires that was recorded was the August Complex fire which began after a lightning strike (8). This fire started in the counties of Mendocino, Humboldt, Trinity, Tehama, Glenn, Lake and Colusa (8). Seventy percent of the fire in the west zone has been contained and 2,200 firefighters continue to battle the fire from the air as well as the ground (8). Several forests like Shasta-Trinity National Forest, Mendocino National Forest and Six Rivers National Forest have been closed (8). After this fire, there have been 18 other fires recorded by the California Department of Fire (8). Since the beginning of this year, fires have burned 3.1 million acres of land in California, which is 26 times greater than the amount of land burned in 2019 (8). Some other prominent fires include the Glass Fire in Napa and Sonoma counties (78% contained), the Zogg Fire in Shasta county (95% contained), and the Creek Fire in Fresno and Madera (49% contained).
Although people have built homes in fire-prone areas for a long time, the fires over the last few years have caused unprecedented destruction (9). Several homes have been destroyed and people have been forced to relocate. Wildfire smoke has additionally been contributing to the worst air quality in years and is causing breathing problems (9). Minute smoke particles from wildfires, when inhaled, can cause inflammation in many parts of the body (9). This year, an orange haze in the sky was visible across the entire west coast and wildfire smoke was shown to reach all the way to the Atlantic Ocean! (9). The intense heat and drought conditions in California have been causing the wildfires to burn without ceasing (9). In 2018, $2.6 billion was spent on firefighting (9). Most of the budget that has been set aside for preventing fires is being used to fight fires (9).
How has this impacted people during the COVID-19 pandemic?
Due to COVID-19, people have been forced to practice social distancing while evacuating their homes. Firefighters have had to socially distance as well. They can’t all get onto the same firetruck and put out the fires together (10). Universities like UC Santa Cruz have been forced to evacuate and those living near the fires have boarded up all their windows and doors to prevent smoke from coming in (10). With COVID-19, staying indoors has been a hassle, but with smoke entering homes, it can’t get any worse. Families have been using a wet cloth to constantly wipe smoke-contaminated surfaces in their homes (10). Many families, however, have had to evacuate. Last month, there were about 74,000 evacuees (10). With COVID-19 spreading rapidly, the question about where these evacuees and their pets and livestock will go remains uncertain (10).
Wildfires are expected to increase in frequency and intensity as a result of climate change. It is important that each one us makes it a priority to look after our environments and create sustainable solutions in order to preserve the beauty of our world, for now and our future generations.
References:
Wildland Fire Spread and Suppression (US National Park Service)
Forest After Fire: The Forest’s Restoration & Regrowth After Wildfire
Forest soils take longer to recover from fires and logging than previously thought
Wildfires rage, Covid spreads: in California, life as we knew it has disappeared | Dana Frank
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