Thursday, June 5, 2014

Fire-enhanced Forests

Wildfires are a fact of life for many western landscapes.  During summer there is increased fire risk as forests and grasslands dry out. Yet as western coastal communities established more than a century ago, one of the characteristic changes was to suppress both wildfires and human-caused fires. This is critical for property protection. But it’s bad for plant communities that evolved with fire, including some conifer forests, shrub communities like chaparral, and grasslands. Now, for more than a century, fuels have built up in many natural landscapes instead of regularly burning. 

Most of our local conifers are not fire-adapted. Only Douglas-fir has thick bark, evolved to withstand fire and protect delicate cambium layers beneath. Western hemlock, western red cedar, and Sitka spruce are thin-barked species; their bark burns easily, and cambium layers beneath the bark die quickly, killing the trees even in moderately hot fires. 

Shore pine, Pinus contorta var. contorta, is a coastal cousin to lodgepole pine, Pinus contorta var. latifolia. This pine can withstand wildfire only as a large tree. It also has a mix of cones, some which open and shed seeds quickly, and some that stay tightly closed for years, and open to shed seeds after a fire. 

Lodgepole and shore pine both grow in very dense stands when young; these are called doghair stands, where the young trees ‘grow as dense as dog hair.’ In natural self-maintaining ecosystems, fires come through regularly every few years and burn out the accumulated litter, kill small to medium sized trees that are too close together, and leave larger, well spaced trees.  Likewise, chaparral shrubs like manzanita and coyote-bush burn to the ground and then resprout in following years. These fires typically move quickly over the landscape, pruning rather than clear-cutting. 

Regular small fires clear spaces between large trees and make the forest understory open and easy to walk through.  A regularly burned pine stand looks like a city park, with well-spaced large trees, a few shrubs, and turf. Once a fire burns through a stand of trees and opens it up, it takes a few decades for burnable materials to build up and support more than a cool, fast-moving fire. It’s reasonably fire-resistant in the meantime. 

A too-dense stand, on the other hand, burns hot and completely, from the crown of the trees to the ground. Wood logs and branches on the ground ignite, limbs and shrubs carry fire into tree canopies, fire moves from canopy to canopy as well as across the ground, and the result is a hot fire that kills the trees and leaves only ashes.  These stands do not recover. They start over with new seedlings, and for decades are more vulnerable to catastrophic fires, because they no longer have sturdy old trees to weather fires, provide seeds, and offer wildlife habitat. It’s not uncommon for dense pine stands to burn down again and again after a catastrophic fire. 

We live north of the forests that are dominated by fire-resistant trees and shrubs. In our area, when fires burn from dunes into forests, the forests generally burn down. The risky time for our community each year is summer, the dry season.  The solution for homeowners is regular fuel reduction, with thinning, limbing and wide spacing of remaining trees. 

Fuel for Fires Everywhere

This is one of three wildfire articles, two of which were not printed in the Chinook Observer in June 2014. I've included them as background on the serious and complex land management issue of fire prevention through fuel reduction. Remember:  Be smarter than the fire. 

We have hard-working and well-trained fire departments on the peninsula, but they can’t be everywhere at once when multiple fires start simultaneously, as can happen on a dry Fourth of July holiday. Optimal natural conditions that promote fires include a few days to weeks with no dewfall, and thousands of acres of beachgrass in proximity to dense pine forests. All plants are potential fuel sources during dry weather. Mix in tens of thousand of vacationers aiming to sit around campfires and play with fireworks, and the result is a highly flammable disaster waiting to happen. 

I’m not making this up. It happened here in July 1985. Rain stopped in May; two weeks without dewfall led up to the Fourth of July holiday. The country was bone dry. On July 3rd, Peninsula Fire District 1 crews, Department of Natural Resources (DNR) staff and State Parks staff fought a fire at Benson Beach in Cape Disappointment State Park, started in driftwood along the beach by a park visitor. The fire burned more than fifty acres south of the campground and was finally snuffed by a borate drop, flown over from Wenatchee.  

The next day, July 4th, a fire started at the north end of the Park, at Beard’s Hollow in the dunes, probably from lighted firecrackers tossed from a motorbike by a preteen. Pushed by a strong southerly wind, the fire raced north towards Seaview.  A fireman told me later the fire moved at more than thirty miles an hour. 

Fire departments mobilized quickly, holding the fire line at Willows Road and NACO West campground. Again, a timely borate drop was mobilized from Wenatchee to snuff the fire.  The DNR District Manager was nearby that day, checking the prior day’s fire near Benson Beach. It was a good bit of serendipity that he was already on site, because he was able to call for a borate flight soon after the fire call went out.  This saved hours of time. But the holiday wasn’t over, and there was no rain in sight.  

Over the next few days, fire crews responded to several dozen escaping dune and yard fires, and dozens of aid calls. Later, Chief Jack McDonald, Peninsula Fire District One, summed up the memorable holiday for the fire department by saying that all children under the age of twelve should be banned from the peninsula for the Fourth of July holiday, along with the matches and firecrackers each one probably had in his or her pockets. 

These bone-dry conditions are not normal for the coast, but they are very normal east of the Cascades. The first change afterwards on the peninsula was to ban open burning from the end of the wet season until rain returned in the fall, and to enforce it. This led to fire departments posting burn ban notices at fire halls, and more awareness of the dangers of dune fires for the public. 

In many western communities, fuel reduction around communities is a common practice. For some reason, fuel reduction in pine stands on the beach was not implemented after the summer of 1985, but it could be. The day may come when there are too many fires for our fire crews to handle, and if your beachside forest is not fire resistant, it could act as a conduit to carry the fire inland to the community’s residential areas. 

Reducing Fire Danger along the Beach

  June is Fire Prevention Month in America. Wildfires are a fact of life for many western landscapes.  During summer there is increased fire risk as forests and grasslands dry out.  This year it is particularly bad because of drought across much of the West. Only western Washington is not at elevated drought watch right now in late May. The rest of the West has moderate to severe drought conditions. 

The problem:  Dense stands of shore pine,  Pinus contorta ssp. contorta, in grasslands. Fires can easily jump from grasslands to trees under these conditions. Limbs grow to the ground, and trees are close-spaced. Photo by Kathleen Sayce

As western coastal communities established, more than a century ago, a common land management change was to suppress both wildfires and human-caused fires. This is critical for property protection. But it’s bad for plant communities that evolved with fire, including some conifer forests, shrub communities like chaparral, and grasslands. Now, for more than a century, fuels have built up in many natural landscapes instead of regularly burning out in wildfires. 

Looking east from the beach into the dunes, see some property owners take out most of the trees. Others leave dense stands. Photo by Kathleen Sayce
Ocean front property owners respond in several ways. One is to take out all the trees. Another is to leave all of them. But there is an effective middle ground:  Thin the stands, limb the trees left, and reduce the fuel load.  

The process is straightforward:   

Take out all the small trees. Cut those trees off at ground level; this disturbs the soil less than digging or pulling. Remove trees near buildings, so that tree canopies don’t overhang roofs. 
Still small enough to mow down with a brush cutter, these young pines will form a dense stand in less than five years.  Photo by Kathleen Sayce

Leave a few healthy large trees, spaced widely so that their canopies (each tree’s crown of branches and needles) do not touch. Twenty to thirty feet apart is good. 

On the large trees you leave standing, cut tree limbs up to eight to ten feet off the ground, so fires on the ground cannot easily go up into the canopy.  Cut at the collar on the branch so the wound heals quickly; don’t leave a ragged stub. This reduces entry of diseases into the limbed tree.  If you don’t know where the tree limb collar is, contact local master gardeners or arborists about pruning, they can show you how to properly limb conifers and hardwoods. 

This pine tree is out in the open, but its limbs still grow too near the ground. Photo by Kathleen Sayce
Western hemlock trees will die within ten years if limbed, from a fungal disease. It’s better to simply remove the hemlocks or leave them alone.  Other trees will survive removal of lower branches.

This pine tree has been limbed to about 6 feet, a good first step in making the tree fire-resistant. Note the tree behind it has also been limbed.
Photo by Kathleen Sayce
Chip all woody debris, and spread it out in a thin layer on the ground, or remove it from the site.  Don’t leave chips or limbs in piles; piles burn hot in a wildfire, and help the fire strengthen and spread.  Remove all large woody branches and logs for firewood or other uses.  Do not leave these  materials on the ground to provide fuel for a wildfire.  

Mow the grass each year in July, to reduce thatch and cut down any new seedling trees. If you have dense stands of salal and huckleberry, mow them down too, every 2-3 years. Also remove gorse and scotch broom shrubs, both of which burn hot and fast.  A July mowing, just as the annual summer drought gets going, removes fuel for the season. Mow a swathe around buildings. A twenty-feet-wide band is good, fifty feet is better.

When done, the stand is open, trees are widely spaced, and the burnable wood on the ground is shredded into small pieces, or gone. If a fire gets into this stand, the grass will burn quickly and lightly, and the trees will survive.  This is the opposite of good practices to enhance forest habitat, by the way; in the latter, leaving wood and chips helps promote soil fungi and build healthy soils. Fuel reduction for fire resistance is probably the only situation where good stand management includes removing woody debris from the forest. 

It's easy to see from the air how close the coastal towns are to the beach, and how serious the fire hazard from the shore pine stands is. The dark patches between the town and beach are dense shore pine stands. This photo looks west from over Hwy 101 to Seaview and south Long Beach, and the Pacific Ocean. Photo by Kathleen Sayce
I’ve written before about historic dune prairies. These grasslands were naturally patchy and low in fuel, a very different situation from today’s dense meadows of American beachgrass.  With fire suppression, lack of thinning or limbing, growth of dense thickets of gorse and Scots broom, dense beachgrasses, and now buildings all along the beaches, coastal communities have several strikes against them going into dry summers. It’s good that we’ve had damp to wet Fourth of July holidays lately!  

We can’t always count on the weather to provide moisture around major summer holidays.  We can count on our own actions to keep our community safe.  Plan ahead, and reduce your fire danger with thinning, limbing and mowing. Help our community be fire-safe each summer.  Shake down kids for matches and firecrackers if they play in the dunes.  Check with the fire departments before staring yard or debris fires. Be smart about fire. Our fire crews and community all thank you.