Wildfire Corner: Is your Burn Pile Out? Really Out?

Small burn pile.
Small burn pile. Photo courtesy of CalFire.

Did you do some outdoor burning this winter and spring? If so, please read on because outdoor burning is the leading cause of wildfire in northeast Washington state.

You may be wondering, how does a burn pile become a wildfire? One of the leading reasons is “failure to extinguish” the pile.

Did you know that a pile burned in January can start a wildfire in July? People are often surprised that a pile they burned during the winter and then saw covered by three feet of snow, followed by four inches of rain and produced no visible smoke for six months can still start a fire in summer. It is true and this is how it happens:

The conscientious landowner burns the pile when fire danger is low and outdoor burning is allowed. The pile burns down but some of the material may be mixed in the dirt beneath the ash. Due to the scarcity of oxygen at the bottom of the pile, this material may continue to burn but very, very slowly. It can burn so slowly that no smoke is seen, and the heat produced is so minute that it does not melt any snow that falls on the top of the pile. When you feel the top of the ground with the back of your hand you’ll likely feel only cold ash. But, when summer arrives and the weather warms up, a piece of that slow burning wood near an outer edge of the pile may become exposed to air. The result could be a small flame. If that flame touches nearby dry grass or other dry vegetation, you have the next wildfire.

I have worked on numerous wildfires over the years that started from a pile that the landowner said was “out” and was sure had been out for months. Many times I have walked up a burn pile that looks like it is completely out. I may see no smoke and feel no heat when I touch the ground, but when I put my shovel into the pile and dig into the ash I might find burning material six inches, or maybe even a foot, below the pile’s surface.

What can you do to help ensure your burn pile is fully extinguished?

Use a shovel to dig down into the pile. Dig in several spots in each pile you burned.

Feel the ash with the back of your hand (not your palm). We use the back of our hand because it is more sensitive to heat and, of course, we do not want to get a painful burn on our fingers or palms. If the ash you’ve uncovered feels warm at all, dig deeper to find out where the heat is coming from.

Remember a fire is out only after you dig into it with a shovel and feel no heat in what you dig up. Always dig completely through the ash layer into the dirt below to be sure you’ve haven’t missed anything.

By Guy Gifford, landowner assistance forester & fire prevention and Firewise coordinator, Washington State Department of Natural Resources, Northeast Region, guy.gifford@dnr.wa.gov

Fire and Forest Health

Although it is difficult not to think of fire from a destructive point of view, it is in fact a natural process of renewal, and a catalyst for promoting biological diversity and healthy ecosystems. Some plant species are actually adapted to fire. For instance, lodgepole pine (Pinus contorta var. latifolia) have serotinous cones (seeds are released in response to an environmental trigger such as fire). These seeds are retained in the tree canopy for long periods until a fire burns through the stand, releasing thousands of seeds as the resin seal enclosing the cones melts. This feature allows lodgepole pine to reproduce prolifically following a fire.

Fire Regimes

The Pacific Northwest includes many types of vegetation and fire regimes, from frequent surface fires to infrequent high severity fires.

High severity fire regimes are generally located in cool, wet environments at higher elevations where subalpine forests are located. These forests typically consist of subalpine fir, lodgepole pine, Engelmann spruce, and whitebark pine. Fire intervals can range greatly (100-300 years), and typically destroy entire stands.

Moderate severity fire regimes tend to occur at mid-elevation zones where dry Douglas-fir forests persist. Other tree species found within this zone include grand fir, subalpine fir, lodgepole pine, western red cedar, western hemlock and western larch. Moderate severity fires occur at intervals of 25 to 100 years and leave a mosaic of lightly burnt to severely burned areas.

Low severity fire regimes are characterized by fires that occur at frequent intervals (1-25 years). Because fuels have a limited time to accumulate in these areas, returning fires tend to be of low intensity. Ponderosa pine forests are indicative of the low severity fire regime.

giant sequoia burn scars
Burn scars (white arrows) in the cross section of a giant sequoia. The numbers represent the year each fire occurred. Photo: Tom Swetnam.

Historic Conditions

Historically, the Pacific Northwest was subject to fires of a variety of frequencies, intensities and extents. How do we know what the historic fire regimes were? Some information comes from human sources such as records of explorers or from land surveyors as they were establishing section corners. Some information comes from the forested ecosystem itself, such as the presence of charcoal layers in the soil and the even-aged character of some forests. Trees themselves record history through the growth rings that develop each year. When a fire burns through an area, the growth rings may be scarred. A fire scar tells us the year the fire occurred and may also reveal the season of fire occurrence based upon the position of the scar (photo).

Historically, the dry forests of the Pacific Northwest experienced low and mixed severity fire regimes. Low severity, frequent fires eliminated fuel ladders; elevated tree crown bases; reduced competition for site resources among surviving trees, shrubs, and herbs; promoted the growth of a low and patchy shrub and herb cover; and cycled nutrients from foliage and branches into the soil. This resulted in forests dominated by large, widely spaced, fire-tolerant ponderosa pine with little accumulation of coarse woody debris on the forest floor. Severe fire behavior and effects were uncharacteristic of dry forest-dominated landscapes.

Current Conditions

Wildfire size, severity and frequency have increased, particularly in the lower elevation dry forests. This is due in part to past and present fire suppression efforts. These forests now contain heavy fuel loads, a shift in the dominant tree species, smaller than average tree size and multi-layered canopies that act as fuel ladders. These conditions result in high intensity fires in areas that previously did not experience them.

In addition to wildfire size, severity and frequency, fire suppression efforts have affected general forest health. Douglas-fir and true firs are not as well adapted to dry sites as ponderosa pine and western larch. As a result these firs suffer physiological stress when subjected to hot, dry summers and, especially, drought. Stressed trees are more likely to succumb to insect and disease problems such as bark beetles and root disease. The presence of great numbers of stressed and dying trees offers an abundance of food to sustain insect populations and lead to insect outbreaks of epidemic proportions.

Models projecting climate change and fire patterns indicate that the frequency and extent of fire will increase due to increased temperatures, earlier spring snow melt and longer fire seasons. These projections suggest that there is an immediate need for forest managers to mitigate and adapt to increased wildfire events in order to sustain forest landscapes.

Accumulated fuels in dry forests need to be reduced so that when fire occurs, rather than becoming a conflagration that destroys the entire stand, it is more likely to burn along the surface at low-moderate intensity, consuming many small trees and restoring forest resilience to future drought, insect and disease problems and wildfire. Various combinations of thinning, slash treatments and prescribed burning can be used for restoration. Visit the Washington State Department of Natural Resources website for information about cost-share opportunities to help private landowners in eastern Washington with these tasks.

Most fires are human caused, often due to neglected campfires, sparks, irresponsibly discarded cigarettes and more often than not: debris burning. Significantly fewer fires may be started by taking greater caution. Check online for the current fire danger and outdoor burning restrictions in your county.

By Melissa Fischer, forest health specialist, Washington State Department of Natural Resources, Northeast Region, melissa.fischer@dnr.wa.gov

Wildfire Corner: Protecting your Home from Wildfire

home survived wildfire
Fire prevention steps, including several recommended by the national Firewise program, helped to spare this eastern Washington home from wildfire in 2012.

Pine needles, dry leaves, a recycle bin full of newspaper, dead plants. What do these items have in common? They can easily start on fire from a single ember.

Embers are small pieces of burning material that are carried into the air during a wildfire and can be carried over a mile before they fall to the ground. If these embers land on some dead leaves, dead needles, newspaper, cardboard or any other flammable material, they may start another fire. If this happens on your deck, roof or next to your house, that small ember could start a fire that grows and ignites your house.

Typically during a wildfire, the ember shower can spread more than a mile ahead of the main fire front. This exposes homes to the wildfire even when the smoke is still in the distance. Often, the ember shower is accompanied by high winds that blow the embers sideways. Embers going sideways instead of falling from the sky can slip under decks, porches and other places to start your home on fire.

Homeowners can take some simple steps to reduce the chances that an ember will start a fire on or next to their home.

Vents in soffits, eaves, crawlspaces and elsewhere — look for any opening around your house where an ember could possible slip through and start a fire. Make sure these vents are screened with 1/8-inch mesh.

  • Doors — even on outbuildings — should be tight fitting with no gaps around the frame.
  • Flowerboxes — keep them watered with healthy plants. Remove dried up, dead foliage.
  • Woodpiles — keep them at least 30 feet from structures.
  • Roof and rain gutters — inspect to make sure they are free of leaves, conifer needles and other burnable debris.
  • Decks and porches — install screen, siding or other material to prevent embers from blowing underneath.
  • Garbage cans and recycling bins — don’t leave them open and filled with paper or other flammable material. Use tight-fitting lids that will not blow off during the high winds typical around large wildfires.

Finally, before you leave on a summer or early fall vacation, do a fire safety check around your house at the same time that you do a security check. Look for items that could be ignited by an ember and move them away from your house.

These simple steps may help your home survive an ember shower from the next wildfire.

Click here to get more information on Be Ember Aware or call your local fire district or Washington State Department of Natural Resources office.

  • Northeast Region Office, Colville: 509-684-7474
  • Southeast Region Office, Ellensburg: 509-925-8510
  • Western Washington: 360-902-1391
  • Firewise tips and contacts on the Washington DNR website
  • Firewise Communities: a national non-profit that brings neighbors together to reduce their community’s wildfire risks

2016 Marks 25 Years Since ‘Firestorm 1991’

Firestorm 1991
Image: A Spokane-area subdivision during Firestorm 1991. Photo: historylink.org

October 16, 2016, marked the twenty-fifth anniversary of the wildfire outbreak — Fire Storm ‘91 — that demonstrated the deadly hazards that can occur when urban development encroaches on wildlands.

The City of Spokane’s fire central dispatch center received its first wildfire call of the day at 8:49 a.m. on Oct 16. By noon all available county, local and Washington State Department of Natural Resources (DNR) fire resources had been committed to contain an unprecedented outbreak of wildfires in the area. By 9:00 p.m. local dispatch centers had fielded some 2,000 fire-related calls.

When everything finally calmed down and numbers were tallied it was discovered that 92 separate wildfires had burned more than 35,000 acres over a four-county area that included Lincoln, Pend Oreille, Spokane and Stevens counties. In all, 114 homes were destroyed and two fatalities were linked to the fires.

1991 Fire Storm impactWeather was a major factor on this day. No precipitation had been recorded in the previous 41 days and northeast Washington was in its fifth year of lower than average precipitation. Wind gusts of up to 62 mph on Oct. 16 caused the fires to spread rapidly. Wind also was a factor in fire starts when gusts pushed trees into powerlines.

The National Fire Protection Association (NFPA) case study on Fire Storm ’91 concluded that homeowners can indeed take steps to reduce the risks of losing their homes and other structures to wildfire by creating “defensible space” to reduce flammability and fire intensity of the land surrounding their homes.

home-loss-vs-defensible-spaceThe NFPA also found that during Fire Storm ’91, homes that had 529 feet of defensible space had a 50 percent lower chance of being destroyed during the fire (see table: Home Loss vs. Defensible Space).

Since 1991 we have had numerous fire seasons where we lost structures. One common fact in all these fires is that homeowners can make a big difference by creating defensible space that reduces wildfire risks to their homes.

Firewise

In 2002, the Firewise Community recognition program was launched to encourage homeowners to work with neighbors to reduce the impact of wildfire to their communities. Washington state residents have taken this message to heart; our state has the third highest number of Firewise Communities in the nation at 135. In 2016, we added 23 new Firewise Communities, the highest number of new communities in the nation. By the end of 2016 both of these numbers will have increased.

Washington State DNR has a goal of making Washington state the leader with the most Firewise Communities in the nation. To help communities become Firewise-recognized DNR created the Firewise Challenge and offers grants to help communities make themselves more resilient to the next wildfire.

If you want to learn more about what you can do to protect your home or your community from the next wildfire, call your local DNR region office. Be sure to also ask about grants available to help you and your neighbors become a Firewise Community.

For more information on making your home or community safe from wildfire, please call or visit a DNR regional office near you:

  • Northeast Region Office, Colville: 509-684-7474
  • Southeast Region Office, Ellensburg: 509-925-8510
  • Western Washington: 360-902-1391
  • Washington DNR website: www.dnr.wa.gov/firewise
  • Firewise Communities: www.firewise.org

Fall is Tree Thinning Time for Forest Landowners

Ponderosa pine stand thinned and pruned
Ponderosa pine stand thinned and pruned to prevent spread of low-intensity ground-level fires into the crowns. Photo: US Forest Service.

Fall is just around the corner and for those who own forested land, if you have not already done so, you may want to consider thinning some trees out. People who own forested property are often hesitant to remove trees for various reasons. Why should you thin? What are the advantages?

Forest health

Many people think of a forest as a stand of trees existing together in harmony. In reality, a forest, particularly a young forest, contains trees competing with one another for their life-sustaining resources: sunlight, water, and nutrients.

There’s even a priority list of sorts within individual trees. It varies depending on the species but, in general, the order in which resources are allocated is, from highest priority to lowest priority:

  1. Maintenance of respiration
  2. Production of fine roots
  3. Reproduction
  4. Height growth
  5. Diameter growth
  6. Insect and disease resistance mechanisms, and
  7. Storage

A dense stand of tall, thin lodgepole pine, is a good example of a stand where there are enough available resources to allocate up to priority number 4, height growth, but not enough resources to allocate much to priority number 5, diameter growth, or beyond. This lack of resources will affect overall forest health, as the trees will not be able to allocate resources to insect and disease resistance mechanisms.

What sort of insect and disease resistance mechanisms do trees have? Let’s use bark beetles as an example, since certain species of bark beetles can cause extensive tree mortality.

In most coniferous species a resin duct system produces oleoresin when the tree is wounded, such as a broken branch. Oleoresin is basically a mixture of essential oil (turpentine) and nonvolatile solids (rosin). Oleoresin is considered the primary defense of conifers against bark beetle attack. Beetles that attempt to attack a conifer that is in good health and capable of producing adequate, pressurized oleoresin are typically immobilized in the resin or killed by drowning in it. The chemical makeup of the oleoresin is important as well, as some of the volatiles released from the oleoresin are toxic to bark beetles.

Dense stands, which tend to grow slowly, are consistently associated with bark beetle infestations. The susceptibility of a stand to bark beetle infestations may be changed by reducing competition between trees; in other words, thinning. In western North America, thinning has long been advocated as a preventative measure to reduce or alleviate the amount of bark beetle caused tree mortality. Thinning improves tree vigor and growth. It also decreases the likelihood of bark beetle attacks on individual trees by allowing the site’s available resources to be concentrated on fewer stems, which means trees will have enough resources to allocate to priority number 6 (insect and disease resistance mechanisms).

Wildfire risk reduction

Successful fire exclusion over the past 60 to 70 years has resulted in greater stand densities and a change in species composition. In that span of time, many forests in dry ecosystems, such as eastern Washington, have transitioned from fire-adapted, open ponderosa pine stands to dense pine and Douglas-fir stands. In moist forests, the change has been from open stands of western white pine and western larch to relatively short, closed stands of grand fir, western hemlock and western redcedar. These changes have led to an increase in the occurrence of crown fires (fire that spreads from treetop to treetop), the most intense type of wildfire, and often the most difficult to contain.

Thin from below
Example of thin from below. Photo A: Before thinning. Photo B: After thinning. Photos: Michelle Ensminger.

 

Ponderosa pine, western white pine and western larch all tend to be tall and self-prune (the natural removal of lower limbs that don’t receive enough sunlight to survive). Western white pine and western larch have lower volume crowns and carry their crowns well above surface fuels compared to true firs, Douglas-fir, western hemlock, and western redcedar. Because of these attributes, western white pine and western larch do not carry crown fires well and tend not to create ladder fuels (fuels in the lower canopy that carry fire up into the crowns of trees). In contrast, stands dominated by true firs, Douglas-fir, western hemlock, and/ or western redcedar do not self-prune well. They tend to carry large branches low in the canopy and have relatively voluminous crowns. Stands dominated by these species usually support crown fires.

Thinning cannot alter all variables that influence fire behavior, but it can influence factors such as species composition, available fuel, fuel arrangement, fuel moisture and surface winds. The objective of thinning in wildfire risk reduction is usually to prevent or slow the spread of crown fire by reducing surface and ladder fuels. Thinning also raises the height of overstory crowns and breaks up the connectedness of crowns, which reduces tree-to-tree spread of crown fires.

Wildlife management

Species associated with fairly open canopies and an open forest floor may benefit from thinning treatments. Thinning a stand of trees increases the amount of sunlight reaching the understory, which stimulates the growth of grasses, wildflowers and native shrubs. Elk, deer, and moose will likely benefit from the increase in forage quantity and quality. Small mammals such as chipmunks and deer mice may increase in number, particularly after thinning in Douglas-fir and ponderosa pine forests. This may be advantageous to species of hawks, owls and eagles that prey on small mammals in open forests and small clearings. Although not often considered as part of the wildlife community, pollinators such as moths and butterflies may also benefit from changes in structural diversity as a result of fuel reduction treatments that increase the amount of light reaching foliage and the forest floor.

Timber production

If you are managing your forested land for future timber production, thinning will be an important part of your management plan. Thinning releases resources to the residual trees allowing them to allocate to their fifth priority, diameter growth, which leads to an increase in tree volume. This increase in diameter growth results in an increase in overall stand value.

Thinning techniques

The tools and methods by which thinning is implemented are quite varied, and can result in significantly different stand structures. The type of thinning you select may depend on your objectives and on individual stand characteristics, such as species composition.

When managing for forest health and fuel reduction, private landowners typically use the “thin from below” method. Thinning from below consists of removing trees from the lower canopy, leaving larger trees to occupy the site. This method mimics mortality caused by competition or surface fires and concentrates available resources on larger, healthier, fire-adapted trees, while removing the stagnant, unhealthy trees.

Thinning is best accomplished in the late summer and early fall if possible. At this time trees will be least susceptible to damage from the thinning operation and the populations of insects that may be attracted to the slash created will be low. Winter also is an acceptable time to thin, but can lead to soil compaction and erosion if done at the wrong time. Thinning in spring and summer is not recommended as it can attract insects such as bark beetles and can affect wildlife, particularly nestlings.

For more information about thinning your property, please visit the Forest Stewardship Program and the Landowner Assistance Center pages on the Washington State Department of Natural Resources website.

By Melissa Fischer, Forest Health Specialist, DNR Northeast Region, Washington State Department of Natural Resources

 

Resources to  learn more:

Fettig, C.J., Klepzig, K.D., Billings, R.F., Munson, A.S., Nebeker, T.E., Negron, J.F., and Nowak, J.T. 2007. The effectiveness of vegetation management practices for prevention and control of bark beetle infestations in coniferous forests of the western and southern United States. Forest Ecology and Management. 238: 24-53.

Graham, R.T., Harvey, A.E., Jain, T.B. and Tonn, J.R. 1999. The effects of thinning and similar stand treatments on fire behavior in western forests. U.S. Forest Service, Pacific Northwest Research Station. PNW-GTR-463.

Pilliod, D.S., Bull, E.L., Hayes, J.L. and Wales, B.C. 2006. Wildlife and invertebrate response to fuel reduction treatments in dry coniferous forests of the western United States: A synthesis. U.S. Forest Service, Rocky Mountain Research Station. RMRS-GTR-173.