KINGMAN – It’s arid, rocky and seemingly lifeless. The rough wilderness landscapes of Mohave County and the Mojave Desert are unlikely places to find thriving ecosystems. But in fact, the deserts and mountains in the area have been home to a wide variety of plants, animals and even humans for thousands of years.
Until the last century, the one creature that has been conspicuously absent was fire. However, records maintained by government agencies since 1980 indicate that fires have become very common during recent decades. This has sparked concern about fires’ impact on native plant communities and on threatened or endangered species such as the bighorn sheep.
“Prior to our influence on the land… those Mojave Desert areas rarely burned because there just wasn’t the continuous grass cover we get now after a wet winter,” said Wade Reaves, a fuels specialist with the Kingman Office of the Bureau of Land Management.
An unusually wet 2004-05 winter produced an abundance of fuel for wildland fires, making last summer one of the most destructive fire seasons on record. The Southwest Coordination Center predicts another fierce season this summer largely due to plenty of those same fuels remaining.
Last summer had all the right components for a record fire season – a wet winter that created an abundance of invasive annuals followed by a dry summer that turned them into fuel and a monsoon season that produce plenty of lightning but little rain.
“We still have an awful lot of country that didn’t burn,” said Kevin Morgan, a habitat program manager for the Arizona Game and Fish Department. “Because this habitat has been altered and it’s full of dry weeds, a lightning strike will catch those weeds on fire.”
A total of 179 individual fires burned more than 170,000 acres of land administered by the Kingman and Phoenix BLM offices last year.
Wildland fires’ increased devastation is a two-fold problem but with one underlying cause – human behavior. In the 1800s, settlers introduced grasses and plants native to Mediterranean Europe into the Mojave region. Much more recently, prescribed burns have cleared vast swaths of land that have created ideal conditions for those exotic plants to compete with native species.
Wildland fires threaten people’s homes and damage infrastructure. However, decades of fire suppression removed an integral part of a long-term natural process.
“A lot of our grasslands evolved with fire, and every 10 to 30 years, a fire would come through and it’d knock down all the shrubs and burn up all the grass,” Morgan said. “The seeds were tolerant to fire and they’d resprout. But we’ve taken fire out of the equation.”
Foreign plants comprise a relatively small proportion of the Mojave Desert flora, but a few species dominate plant communities and are threatening the ecosystem’s integrity.
Exotic annuals such as cheat grass, fiddle neck and red brome are among the most widespread and common invasive plants in the Mojave Desert and contributed to the fire activity in the Black Mountains and Golden Valley last summer, Morgan said.
On the other side of the coin, increasing the cycle of fires with prescribed burns favors annual species at the expense of many native perennials. Annual-fueled fires result in the loss of native species in invaded areas, thus creating conditions that are ideal for increased growth of the unwanted weeds.
Annuals replenish much quicker than perennials and complete their life cycle within a year, though they need only two months to germinate and spread before they die, Morgan said. When they decay, they slowly create the ideal kindling for wildland fires.
“The native ecosystem wasn’t adapted to fire. These desert plants’ adaptations are built to withstand drought, but they have no immunity to fire,” Morgan said.
The BLM has tentatively planned prescribed burns in the Hualapai Mountains this week to alleviate some of the risk that another intense fire season would bring. Reaves said the exact date would depend upon the weather, however, residents would be informed in advance.
“We will be asking residents to clear dead grass and brush away from their homes and properties as fire season will begin very early if the dry weather continues,” he said.