Week 1 | Prevention
Fire-adapted ecosystems are those that experience a regular occurrence of fire, mostly to the benefit of the ecosystem. To the best of our knowledge, natural fires have not historically been a significant part of the Sonoran Desert. Unlike fire-adapted ecosystems, most of the plant and animal life in the desert is not built to withstand fire. Compounding factors such as climate change, invasive species, and a rise in outdoor recreation have contributed to an increase in major fires here in the Sonoran Desert. These larger, and often hotter fires are happening closer together in time, and do not play well with a desert that is not adapted for it. It’s estimated that the Sonoran Desert could take more than 65 years to recover after fire, and iconic species like the saguaro may not return to the burned area. Sonoran Desert that has been severely impacted by or has experienced repeated incidence of fire has the potential to shift to a very different landscape than what we know now.
In 2020, 82% of wildfires in Arizona were caused by people, making it the leading cause of wildfire in the state. Seven out of ten of the largest fires in Arizona’s history were human caused, including the recent Bush Fire in 2020 and the Woodbury Fire in 2019. The Woodbury fire alone devastated about 75% of the Superstition Wilderness. With environmental conditions increasingly favoring fire, it’s more important than ever to do our part to keep them from starting.
How can you help prevent wildfires?
EVERY SECOND COUNTS! If you see something say something. Report wildfires as soon as possible. Do not assume it has already been reported. Call 911 or 800.309.7081 for the Arizona Interagency Dispatch for wildland fires and risk incidents. Click here to learn more about reporting wildfires.
- Outdoor Recreation: Know before you go! Take the time to understand fire regulations. These are not in place to keep you from having fun, but to keep us all safe. Learn how to properly build and extinguish campfires, and never leave a fire unattended. Avoid creating bonfires. Larger fires are more difficult to manage and embers can travel for miles. Both fireworks and explosives are illegal on public lands. You can also volunteer to remove invasive plants from natural areas, which contribute to fire intensity and spread.
- Vehicle/Off-Road: Do not drive in or park on dry grass or brush. Your car is hot enough to start a fire! Check your chains, these can spark and start a fire. According to the US Forest Service, over 30 small fires were known to have started this way, with one chain lighting sparks as it went down the road. Conduct pre-ride inspections, especially to clean out weeds and other debris from around the engine and other hot components. Keep a shovel, extra water and a fire extinguisher in your vehicle and learn how to use them effectively. Do not throw lit cigarettes or butts out the window.
- Shooting: Shoot targets in areas free of dry vegetation, such as dirt or gravel, and do not shoot on hot, windy days. Use appropriate ammunition and targets. Solid copper and steel core ammunition are most likely to start a fire, whereas lead core bullets are the least likely. Incendiary or tracer ammunition should be avoided in areas prone to fire. Shooting at steel targets or rocks can cause sparks–explosive targets should not be used. Have a shovel and fire extinguisher ready.
We can all do our part to prevent wildfires and keep the desert safe for ourselves and future generations to appreciate and enjoy.
Learn more at the resources below:
Week 2 | Impact
Over time, and especially in recent years, fires have been occurring more often, burning hotter and burning much larger areas, creating megafires. This has significant impacts for a desert ecosystem not adapted to co-exists with these frequent wildfires and for the people living in it.
Immediately impacted due to the start of a fire is air quality. Fires create large increases in outdoor airborne particles and pollutants. Indoor air quality is also affected, because many living spaces are not equipped, or poorly equipped, to filter the pollution. Larger fires can increase air pollution over hundreds of square miles, leading to various health impacts, specifically respiratory, for a greater number of people. Wildfires also have a major impact on our water, not only immediately after, but for years following. Vegetation that normally holds soil together is burned away, and ash, sediment and contaminants (such as those from mining operations or burned homes) are washed into waterways and reservoirs by rain, impacting our drinking water. The loss of vegetation in burned areas leads to erosion and increases an already significant risk in the desert: flash flooding.
Wildfire directly impacts public lands, recreation and tourism. The initial impact on public lands are closures. Closures are put in place for the safety of recreationalists and for the health of the land. They can prevent injuries from unstable soil and collapsing vegetation, as well as give small seedlings a chance to grow and not be crushed. The efforts to restore burned areas, like trail maintenance and revegetation can be a major economic burden, especially for smaller municipalities. Adding to the burden, the fire impacted areas can take decades to recover and are less desirable for recreation and tourism during that time.
With the frequency and size of fires increasing, the effects on habitat can be severe. Large areas of habitat are being lost closer in time. In a matter of two years (2019-2020), about 350,000 acres have burned adjacent to each other in the Superstition Wilderness and the Tonto National Forest. To put this in perspective, that’s an area roughly the size of Phoenix. In total, about 1 million acres in Arizona were burned in 2020, an area slightly smaller than the state of Delaware. Megafires also impact wildlife, including larger mammals that can normally survive smaller fires. In the desert, reptiles that in the past could have survived smaller, more patchy fires are now likely unable to escape. Increasing frequency of fire can also mean repeat burning of the same areas, giving desert habitat less time to recover- an already slow process.
The impacts of wildfire are far-reaching, including the often less thought of, such as insurance costs and the toll on mental health. We can all do our part to prevent wildfires from happening in the Sonoran Desert.
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Plants that are fire adapted have traits to help them survive, recover or reproduce after wildfire. Examples of this include seeds that rely on heat from fire to help them germinate, thick bark that protects a tree from fire damage, or plants that can resprout from their roots after the top part of the plant has burned away. Having evolved complex heat and drought resistant features, but no real resistance to fire or an ability to survive it, points to the absence of fire in the life of plants in the Sonoran Desert. Many of these desert plants also have very specific conditions for seeds to germinate and growth is often painfully slow. This not only suggests that fire is not a normal part of their life cycle, but also that recovery after fire can be challenging.
Cactus and succulents are almost always killed outright by fire, especially low growing species like fishhook cactus (Mammillaria grahamii) and hedgehog cactus (Echinocereus spp.). Saguaros (Carnegiea gigantea), if they are not initially killed by fire, most often succumb to moderate or severe fire injury within the next decade or sooner. A study from the Tonto National Forest shows that saguaros scorched just 30% or more are likely to not recover. Saguaro seedlings and young plants are lost. It can take a decade for these icons to reach one inch in height, 50 to 60 years to reach about 6 feet, and 90 to 100 years to reach about 15 feet. It could take multiple human generations after a fire for saguaros to regain the widespread majesty of a forest, if they can. Some agaves, such as Parry’s agave (Agave parryi), may be able to survive lower intensity fire if they’ve produced several “pups” (clonal ramets) from their underground stems – the stems within that clone may survive if the low intensity fire doesn’t burn the entire clone.
Brittlebush (Encelia farinosa) and triangle-leaf bursage (Ambrosia deltoidea) are most often reduced to ash, eventually making a comeback thanks to seed from other areas. They are considered “nurse plants,” and create favorable conditions for other plants to be able to move back in and grow. Foothills palo verde (Parkinsonia microphylla) and ocotillo (Foquieria splendens) can be completely eliminated by fire and have been reported to not return in some burned areas. Even a fire that is considered low or medium intensity can be detrimental for palo verde, scorching their thin bark that they use for photosynthesis. Although plants like jojoba (Simmondsia chinensis) or creosote (Larrea tridentata) can resprout, it is not guaranteed. The plants that seem to handle fire the best and resprout vigorously, such as fairy duster (Calliandra eriophylla) and catclaw (Senegalia greggii), are often those that are also found outside of the Sonoran Desert in areas that are fire adapted.
It is important to remember that even if plants seem to have survived fire, or do not look badly damaged, they are likely to be less healthy and not live as long as they normally would. Plants that have been damaged are weakened and disease can more easily move in. Severely damaged plants can be taken down by wind, and plants that have sprouted new growth are a tasty snack for hungry wildlife looking for food after fire. Overall, wildfire has detrimental effects on Sonoran Desert plants.