The Post-Fire Environment in low-elevation chaparral
CASE STUDY Post-fire recovery: Nature's way or our way?
By Wayne Spencer and Richard Halsey April 4, 2004 - San Diego Union-Tribune
Five months after the October firestorms, the hills are greening again in San Diego County. Rains came and the land held firm. Chaparral shrubs are resprouting from their bases or emerging from the blackened ground as tiny seedlings. Native wildflowers not seen in years will soon color the backcountry like floral phoenixes. And wildlife populations displaced by the fires are gradually recolonizing these renewing habitats, following a natural ecological process that has repeated itself uncounted times since before human memory.
So, were the millions of dollars spent to hydromulch the hillsides, broadcast seeds, plant trees or feed the deer money well spent? Did these interventions make a difference, or would we be better off just letting nature recover on its own?
The answers aren't simple and will require more time and data to answer fully, but in most cases available facts and scientific reason indicate that these well-intentioned actions were largely unnecessary, and some may be doing more harm than good.
It's essential to understand that fire and the erosion that naturally follows are ecological processes, like water cycles and nutrient cycles – like birth and death.
Science shows that wildland fires, including fires larger than those of last October, have periodically recurred in Southern California, long before humans arrived to witness them. If chaparral has burned and recovered countless times before, why does it need our help now? Didn't deer and other wild species endure numerous fires before we arrived on the scene? If erosion carved our canyons and deposited our sandy beaches, why try to stop it? Isn't the wisest course of action after a fire, "hands off, let Mother Nature do her thing?"
Not entirely, of course. To advocate a total hands-off approach to ecological recovery following fire would be to ignore our own presence and the myriad changes we humans already have made to the environment. We've built in floodplains and on landslide-prone hills; we've dammed rivers, creating traps for silts and sands that previously washed out to sea, thus forming our estuaries and beaches; we've introduced countless alien weeds, now poised to invade fire-denuded landscapes, and we've fragmented habitats with houses and roads, impeding the natural recolonization process for wildlife displaced by fires.
Because of these changes, there are circumstances where management intervention is necessary to protect human life and property following fire, or to protect our native ecosystem from further degradation. Unfortunately, under the post-fire pressure to "just do something," it appears precious management dollars may have been wasted where intervention is neither necessary nor helpful.
For example, broadcast seeding of either native or especially nonnative species, like rye grass, in hopes of reducing erosion has been widely debunked by scientific studies. Such actions are at best a waste of money, as most broadcast seed washes away before even germinating. At worst, broadcast seeding may actually increase erosion by hindering recovery of deeper-rooted native plants that are more effective at stabilizing soils. And successfully establishing a cover of nonnative annuals – referred to by firefighters as "flash fuels" – can increase fire ignition rates. Even if done with native seed mixes, the efficacy of wholesale hydroseed mulching of Wildcat Canyon, Scripps Ranch, and other areas is questionable, at best.
Soil erosion naturally increases after fire, exposing mineral soils and frequently increasing opportunities for seed germination. However, landslides and mudslides, like the Waterman Canyon disaster in San Bernardino County, are highly localized phenomena that depend on specific geological conditions. More than $1.25 million was spent laying down strips of mulch on Viejas Mountain near Alpine, ostensibly to control erosion and prevent landslides. However, Viejas Mountain is composed of gabbro-type soils that are not prone to landslides.
Examining the Use of Hydroseeding and Mulch After Wildfires
Shortly after wildfires are extinguished, the Burned Area Emergency Response (BAER) team arrives. This is an assemblage of scientists, foresters, and representatives from various federal agencies such as the Forest Service, Bureau of Indian Affairs, and the Fish and Wildlife Service, who are charged with recommending mitigation they feel is necessary to protect communities and resources from post-fire impacts. They come after every fire. The majority of the specialists fly in from other parts of the country and may or may not have knowledge of the local environment. They typically list a series of treatments such as mulching, sediment deflectors, channel clearing, and wattles (rolls of hay held together with plastic netting) to control erosion. Fortunately, seeding is generally no longer recommended.
Significant resources and huge numbers of personnel are employed to carry out the recommendations. Rolls of wattle are strung across gullies and hillsides, mulch is sprayed from trucks and dumped from planes and helicopters, and chain saws ring out as burned trees are removed. Hydromulch is a gooey combination of wood fiber, a sticky substance known as tackifier, and green dye. This paper-mache-like substance is applied to roadcuts and hillsides until the landscape is bright green again. County agencies and the California Department of Transportation (CalTrans) apply the same types of treatments.
Does mulching or seeding do any good? Post fire mitigation is a huge business. It also provides immediate, visible evidence that the government is doing something to help victims of the fire. Although companies involved will provide their own research supporting the need for their services, independent investigations measuring the actual effectiveness of mulching have been inconclusive. The impact of seeding wildland burned areas, however, is clear. Post-fire seeding can cause severe environmental damage including increased erosion, encouraging the spread of invasive weeds, and contributing to the elimination of native plant communities.
Unfortunately, some still ignore the science. Forty-three thousand pounds of non-native rye grass seed (Lolium multiflorum) were donated and distributed throughout San Diego County after the 2003 Cedar Fire.
Studies of seeded vs. non-seeded plots in Southern California have shown no evidence that the seeding of ryegrass significantly reduces the amount of surface erosion in the post-fire environment. In addition, ryegrass growth was at the expense of native cover with the greatest negative effect being on native, fire-following annuals. The use of ryegrass has also been associated with high mortality of Ceanothus shrub seedlings. In 1980, ryegrass seeding was responsible for spreading a large fire on Otay Mountain in San Diego County which lead to the elimination of chaparral on the site.
What about "native" seed mixes? The seed mix combined with mulch used by contractors after the 2003 Cedar Fire appeared to have a full assortment of native species, but a closer examination of the actual percentages revealed a different story. Most of the mix was grass seed. The largest portion (30%) consisted of a native wild ryegrass (Elymus glaucus) and 13% Vulpia microstachys, a native typically found in disturbed areas, not chaparral.
Another concern relating to post-fire seeding practices relates to the introduction of non-native weeds. Although seed companies guarantee their mixes, in practice it has proven impossible to eliminate contamination by alien species. For example, 800,000 pounds of grass seed was aerial seeded over more than 13,400 acres by a BAER effort on the Cerro Grande Fire scar around Los Alamos, New Mexico. This was the fire in 2000 that consumed over 47,000 acres and 350 homes. It was discovered later that an estimated 1 billion cheat grass seeds (Bromus tectorum) contaminated the seed mix. Cheat grass is an extremely invasive alien species that is creating significant ecological damage in many western forests and deserts by increasing fire frequency due to the unnatural addition of flashy fuels.
Preparing communities themselves for post-fire flooding by installing such things as check dams in flood-prone streambeds and channels, assisting with sand-bagging, and coordinating disaster education efforts are the most effective uses of post-fire mitigation resources. Spending millions of dollars mulching blackened hillsides is a waste of tax payer money.
Trash Mulch. Bits of plastic, foil, candy wrappers and other trash were contained in the mulch dumped by the Forest Service after the 2008 Gap Fire in the Los Padres National Forest above Goleta, CA. Photo by Brian Trautwein of the Environmental Defense Center.
So why mulch post-fire open-space areas?
The U.S. Forest Service and other government agencies were under tremendous political pressure to recommend hydroseeding and mulching – to "just do something." Off the record, several Forest Service employees have stated, their words supported by previous Forest Service research, that these actions were largely cosmetic, with little hope of actually reducing erosion hazards or aiding ecological recovery.
What about caring for injured, displaced, or starving wildlife?
Efforts to rescue hungry deer by feeding them alfalfa or hay can lead to digestive ailments, bloating and dehydration. These unnaturally rich feeds are often dumped near roads, increasing roadkill risks for the animals attracted to them. And even if supplemental feeding does tide over starving deer in the short term, the artificially sustained population may exceed the capacity of the recovering landscape to support it, thus putting more pressure on the young vegetative growth, prolonging habitat recovery, and increasing erosion potential.
After the human losses, San Diegans grieve for the apparent destruction of our beloved natural environments. Images of the blackened landscape, the torched trees and the dead and displaced wildlife naturally raise fears that "nature has been destroyed," and "nature needs our help."
But nature is resilient. Repeated fires helped shape Southern California's native landscape, and it will rebound again on its own – except where changes we have made interfere with this natural process. In such cases, only carefully reasoned intervention, based on best available science rather than political expediency, should be applied. Otherwise, we should enjoy watching our natural environment quietly heal itself, as it has many times before.
Viejas Mountain, San Diego County.
The Post-Fire Environment in montane chaparral
The Stanislaus National Forest Damages Sensitive Post-fire Habitat through "Salvage Logging" 15,375 acres Created by the 2013 Rim Fire A burned forest is not a "destroyed" forest as frequently described, but rather a restored habitat for unique and often rare post-fire species.
The US Forest Service is logging 15,375 acres of sensitive post-fire habitat in the Rim Fire area. They justified the project as the "first step in the process of long-term forest recovery." There is no scientific support for such rationale. The Rim Fire Recovery Project represents a step backward from the US Forest Service's new Leadership Intent to focus on ecological restoration.
As a consequence, we filed suit with our partners (The John Muir Project and The Center for Biological Diversity) on September 4, 2014, and asked the court to reduce the scope of the Stanislaus National Forest’s plan. Unfortunately, our suit was rejected.
Rim Fire perimeter map showing fire history. Contrary to popular commentary, a significant amount of the area burned in the Rim Fire had been burned within the last 26 years. The claim that past fire suppression was the cause or led to the rapid spread of the Rim Fire is not supported by the facts. The fire's initial run (within the 1987 and 1996 fire scars) was through tree farms and clear cuts.
If left alone, severely burned forests are fun to watch as they explode with new life over the years. This rare, post-fire forest was saved and allowed to grow thanks to a lawsuit filed by the John Muir Project led by Chad Hanson. The suit prevented the US Forest Service from “salvage” logging the area. Location: Tahoe National Forest, after the 2008 American River Complex Fire.
Shrubs and trees live together in harmony. In a close-up of the forest floor in the previous photo, conifers and shrubs like manzanita naturally establish a healthy, biodiverse habitat. Had this been treated as usual, the area would have been sprayed with herbicides to kill the native shrubs and other naturally regenerating plant species. Then nursery-grown conifer seedlings would have been planted to establish an artificial tree plantation. Such plantations represent major fire hazards throughout the Sierra Nevada because they create extremely dense concentrations of “fuel.” Much of the Rim Fire burned intensely due to such tree farms.
This burned area was "salvage" logged and treated with herbicides. As you can see, the natural post-fire recovery and the expected explosion in biodiversity was compromised in favor of an ecological disaster. Location: Seven years after the 2004 Fred’s Fire in the American River drainage, California.
The Hazards of Post-fire Logging
After every large wildland fire there are demands from economic interests and politicians to do "something" to "help" recovery. Most of the suggested "helps" actually cause significant harm to the natural environment and increase (rather than decrease) fire hazards in the future.
Please read the letter we helped send to Congress on October 30, 2013, signed by 250 prominent scientists, summarizing fire ecology studies from around the world. The letter was especially urgent as Senator Wyden (D-Oregon) and other legislators are trying to push through legislation to increase logging on public lands in response to wildfires. In the letter, we compared four common fire myths with the evidence from around the globe. Dr. Dominick A. DellaSala, one of the lead signatories in the letter, summarizes these four myths below.
The main points: (1) forests will burn regardless of what we do; (2) politicians will propose unchecked post-fire "salvage" logging, even in national parks, as a quick fix; and (3) scientists will continue to document the incredible regeneration that takes place after fires and how post-fire logging disrupts forest renewal.
Myth 1 — Fire is catastrophic, and forests cannot recover by themselves. As a young forest ecologist, I witnessed firsthand how the media erroneously described the 1988 Yellowstone fires as "destructive." The same misconceptions led to declaring Oregon's 2002 Biscuit fire a "moonscape" in need of massive post-fire logging and tree planting. However, after decades of observations, we now know that both fires were ecologically beneficial. Following the fires, the increased plant growth provided forage for deer and elk, dead trees (snags) became habitat for woodpeckers, conifer seedlings released from intense heating of seed cones blanketed ash-covered soils, and there were increases in songbirds, butterflies and morel mushrooms even in the most severely burned areas. This fire-created web of life soon rivaled what we see in the much-celebrated old-growth forests. New forests with their abundant snags will eventually become old-growth, if we let them.
Myth 2 — Post-fire landscapes will become brush fields unless salvage logged and planted with conifers. Post-fire logging actually slows down forest renewal. Conifer seedlings are crushed as logs are dragged uphill, heavy machinery compacts fragile soils, large snags that shade seedlings are removed for economic value, and invasive weeds are transported by logging machinery, requiring costly measures to remove them, if at all possible.
Myth 3 — Salvage logging reduces fuel hazards and future fire risks. Most post-fire salvage actually increases fuel hazards. The small twigs and branches left by loggers provide kindling for the next fire while the big charred trees that are least likely to burn again are taken away. Fire risks are also much higher in densely packed tree farms planted over thousands of acres. Witness the shotgun blast pattern of replanted clearcuts the next time you fly over the Siskiyous; fires tend to burn hot and spread rapidly through them.
Myth 4 — Salvage logging is needed to prevent global warming pollution released by burning vegetation. When a forest burns, it releases carbon dioxide to the air, a greenhouse gas pollutant when in excessive amounts. Surprisingly, forest fires release only about 5 percent to 15 percent of forests' stored carbon to the atmosphere. This is because the charred trees, if left on-site, continue to retain carbon for decades to centuries, as they slowly decompose. New vegetation also comes in after fire, rapidly capturing and storing carbon while cleansing the air. In contrast, salvage logging emits much larger quantities of carbon dioxide, as logs are hauled over long distances, requiring fossil fuels in transit, and logging slash decomposes rapidly, releasing even more carbon dioxide.
Simply put: Nature has given forests unique properties to rebound even after the most severe fires. Salvage logging takes away what plants and wildlife need most after fire — large dead and live trees — and pollutes waterways from sediment runoff along roads and from logging on steep slopes.
Common ground begins with job-producing thinning of flammable tree plantations and removing flammable vegetation nearest homes. If we must salvage log for economic reasons, it should be limited to removing hazard trees along roads for safety reasons and small trees in areas that were scheduled for logging before a burn.
Forests provide diverse ecological and economic benefits beyond timber. Hillsides covered with old and new forests produce clean air, drinking water, salmon, abundant wildlife and a quality of life that is essential to attracting new businesses and the variety of jobs they are bringing to our region.
Regarding proposals to "thin" forests in an attempt to prevent high-severity fire, an important research paper makes it clear that...
"The most profound implication of this study is that the need for forest 'restoration' designed to reduce variation in fire behavior may be much less extensive than implied by many current forest management plans or promoted by recent legislation."