Archive for the ‘Forest Health’ Category

Say hello to spring, and emerging bark beetles

April 11, 2016
pine bark engraver beetle "frass"

For landowners, the sight of “frass” (sawdust and waste) from the pine engraver bark beetle is a familiar sign of spring. Photo: Brytten Steed, US Forest Service,

Temperatures are warming up, which means the pine engraver bark beetle will once again rear its ugly little head in forests and woodlots across the state. The pine engraver beetle is tiny — between 1/8 and 3/16 of an inch long — and tends to attack small pine trees or the tops of large pine trees.

The pine engraver typically infests fresh slash, wind throw, or snow-damaged trees by building “galleries” under the bark for its eggs to hatch. It takes about 40-55 days for the pine engraver to complete development from egg to adult. Each new generation of adults produced during the warm months begins fresh attacks on nearby wood. This bug prefers to munch on and lay its eggs in slash or other downed wood, but it also can go after nearby live, standing trees within its limited flight range. By late-August, the final generation of the season to emerge typically seeks out places to hibernate for the winter and the danger of infestation is reduced… until next spring, that is.

When they do occur, pine engraver outbreaks can include hundreds of trees, especially trees under stress because of drought and overcrowding. Thinning dense pine stands can help reduce the potential of a pine engraver outbreak. Thinning allows more water, sunlight, and nutrients to reach standing trees, which helps enhance their vigor and defensive capabilities, such as increased resin flow.

The pine engraver beetle is a native insect and plays in important role in the ecosystem. Landowners have a number of preventive options to manage the pine engraver bark beetle without the need to spray insecticides. These options include scheduling tree cutting to fall months, carefully managing the size and placement slash piles, and restricting tree pruning to certain times of the year. These options and others are described in the latest edition of the free e-newsletter, Forest Stewardship Notes, a co-production of DNR and the Washington State University Forestry Extension program. Read more in the latest issue of Forest Stewardship News.

Check out other free DNR e-newsletters


Follow DNR on: Facebook Fan See us on Flickr Watch us YouTube Follow us on Twitter Follow DNR Fire Twitter

Timely tree tips — insects and diseases can indicate other problems

March 29, 2016
Cherry trees on the Capitol Campus Photo: Micki McNaughton, DNR

Cherry trees on the Capitol Campus       Photo: Micki McNaughton, DNR

Trees that are damaged, stressed, unhealthy or in decline are far more susceptible to insect infestation and diseases for two reasons:

1) Physical injuries damage a tree’s protective bark tissue, providing easy access to the tree’s core for insects and pathogens; and,

2) Stressed, unhealthy or declining trees have fewer available resources to provide active defenses against insect and disease attacks.

Unhealthy trees are attractive to insects and pathogens for the same reasons that a sickly zebra is attractive prey for a predatory lion: sickly prey is weaker, easier to attack and less likely to fight back, skewing the odds in the predator’s favor.

Prescriptions for treating insect and disease problems often come in the form of pesticide applications. Pesticides can be powerful tools to address symptoms, but do little or nothing to mitigate underlying causes of a tree’s decline, and nor are they helpful in returning the tree to health.

The best antidote to tree disease is similar to the advice given to us humans: proactive attention to stress reduction and good care. Here are a few recommendations to get you and your trees started down the road to good health:

  • Plant the right tree in the right place. Choose trees that are well-suited to local soils and other site conditions with adequate growing space above and below ground.
  • Plant the tree properly with the root flare at grade. Planting too deeply is one of the leading causes of long-term tree decline, and one of the easiest to avoid.
  • Provide supplemental water when needed. Dehydration is incredibly stressful but also preventable when trees, especially newly planted ones, are provided adequate water during hot summer months.
  • Mulch trees deeply. 2″- 4″ of organic mulch in a nice, wide ring around the base of your trees can do wonders to reduce plant stress by decreasing moisture loss from the soil and cooling the rooting zone of the tree. Physical damage from mowers and string trimmers may also be lessened by keeping grass and weeds away from the tree trunk.
  • Prune trees according to best practices. Good pruning practices not only reduce the risk of storm damage, but may also limit the spread of some pests and disease organisms.

Pause before breaking out the chemicals and look for opportunities to improve tree health instead; it’s cheaper and friendlier to the environment, and the positive effects are longer lasting. Healthy trees will reward your care by fending off nasty pests and diseases on their own, as well as looking more beautiful in the landscape.

Follow DNR on: Facebook Fan See us on Flickr Watch us YouTube Follow us on Twitter Follow DNR Fire Twitter Join in the DNR Forum

Funding opportunity for restoring forest landscapes; deadline February 29

January 19, 2016
Keep urban forests in your community healthy

Keep urban forests in your community healthy. Photo: Guy Kramer

DNR is looking for projects that will help protect and restore forests across the diverse landscapes of Washington.

Working together with the U.S. Forest Service, DNR is seeking forestland restoration grant proposals for a program called Landscape Scale Restoration Competitive Grant Process (LSR). Forestland restoration projects can include rural, wildland, and urban areas.

LSR projects cross boundaries to affect any combination of federal, state, tribal, county, municipal, or private lands. For example, a riparian habitat restoration project might affect the entire length of a waterway that passes through lands which are owned and managed by different agencies, organizations, or individuals.

Eastern Washington forest

An overstocked forest in eastern Washington. Photo: DNR

Because of the funding competition, DNR wants to submit the best and most important projects that benefit the bigger goal of healthy forests.

We ask that potential partners submit letters of interest to DNR and collaborate with us to develop Landscape Scale Restoration Competitive Grant proposals that meet the national priorities.

Here is the Request for Proposal for LSR projects.

Letters of interest are due by February 29 at 4:30 p.m. (PST) and need to be submitted to:

Jonathan Guzzo
WA State Dept. of Natural Resources
1111 Washington Street SE
MS 47037
Olympia, WA  98504-7037

Funding for these projects comes from the U.S. Forest Service State and Private Forestry branch to address forest conservation, protection, and enhancement needs in priority areas identified within Washington’s Forest Action Plan.

The benefits of our forests are vast. Not only are they home to countless wildlife species, they keep our drinking water clean, control flooding, purify our air, and enhance community livability.

Follow DNR on: Facebook Fan See us on Flickr Watch us YouTube Follow us on Twitter Follow DNR Fire Twitter Join in the DNR Forum

Are you a forest landowner with trees damaged by recent winter storms?

January 4, 2016
A severe wind storm knocked down these Ponderosa pines, which are now susceptible to pine engraver beetle. Photo: State of Idaho

A severe wind storm knocked down these ponderosa pines, which are now susceptible to pine engraver beetle. Photo: State of Idaho

Severe November and December wind and snow storms in Spokane and other areas could be causing more damage than you realize. By this spring, you may notice little piles of reddish bark dust around your trees. This is a sign that bark beetles are attacking the trunks and branches of your damaged trees.

When the weather warms up, bark beetles become active, infesting and feeding on the sugary inner bark of your uprooted or broken trees. Over just a few weeks, inside the damaged logs, these beetles can build up populations, which then attack and kill neighboring healthy trees.

The chief culprits are known as the pine engraver beetle and the Douglas-fir beetle.

Prime targets

Ponderosa pine and lodgepole pine trunks and branches that are larger than three inches in diameter can be infested by the pine engraver beetle. Pine engraver beetles that infest wind-thrown trees in April and May will lay eggs that develop into adults and emerge in June of the same year. Although beetles that emerge in June often continue to infest damaged trees, the next generation of beetles that emerges in August may attack adjacent healthy trees.

The Douglas-fir beetle infests Douglas-fir trunks that are larger than about 10 inches in diameter. These beetles’ offspring require a year to mature and could infest healthy Douglas-fir trees in spring of 2017.

Both types of bark beetle are highly attracted to the thick, moist, nutritious inner-bark tissue of trees that are recently wind-thrown or have broken tops, as well as logs.

How to minimize your chance for infestations

The best option to reduce beetle infestations is to interrupt the amount of moist inner bark tissue that is available for beetles to breed. Remove damaged trees by salvaging the larger timber and safely burning or chipping smaller material. Try to increase the rate at which the inner bark dries out by cutting green logs into smaller pieces, removing branches, dispersing the woody material in a sunny area.

Leaving damaged trees or logs in the shade or in small sheltered piles lengthens the time the inner bark is suitable beetle food and habitat; it also increases the chances that the wood will become infested.

DO NOT stack green firewood next to healthy standing trees. The idea is to reduce the number of places the damaging beetles have easy access to breed this spring, so high populations won’t develop and threaten remaining trees later.

If you own forestland and need advice about tree care, contact a DNR Region Office near you or the WSU Extension Office in your county.

Follow DNR on: Facebook Fan See us on Flickr Watch us YouTube Follow us on Twitter Follow DNR Fire Twitter Join in the DNR Forum

English ivy invades Pacific Northwest forests

December 28, 2015
English ivy infestation in Olympic National Park

English ivy, like this infestation in Olympic National Park, can kill and pull down trees. Photo: Kevin Zobrist/WSU Extension.

What’s wrong with a little ivy? Plenty. The photo with this post was taken recently in Olympic National Park, demonstrating that invasive species know no boundaries. This was only a small piece of the infestation, which was killing and pulling over trees and completely destroying the native plants growing under the trees. This immense spread of ivy has very little value for wildlife, unless you’re a rat.

Native to Europe, English ivy and similar cultivars were introduced to North America by early settlers who prized it for ornamental purposes. It continues to be widely planted as an ornamental, according to the Invasive Plant Atlas of the United States. Because of its shallow, mat-like root system, ivy is a poor choice for controlling erosion, such as on hillsides.

“But I only have a little,” you say? That’s how this started out. English ivy spreads aggressively both vegetatively and by bird-disbursed seeds. There are a number of different varieties, all invasive and all brought in as ornamentals.

Getting rid of ivy

Spraying is challenging because ivy has a thick, waxy leaf, but there are some herbicides listed for use (always follow label instructions). Fortunately, English ivy pulls up (roots and all) pretty easily, so with a little elbow grease you can make good strides in eradicating it. You should wear gloves and a dust mask for this, for the sake of comfort. For ivy that is growing up and strangling trees, you don’t have to pull it all off the tree (which could damage the bark). Instead, pull the ivy off the tree up to shoulder height, making sure to sever all stems growing up the tree. Without ground contact, the remainder up the tree will die. Then work on pulling the stuff on the ground back from the tree, pulling it up by the roots. Here are two Pacific Northwest-oriented fact sheets about controlling English ivy:

Check out King County’s list of native plant alternatives to English ivy.

[This blog post was excerpted from an article in Forest Stewardship Notes by Kevin Zobrist, regional extension forestry specialist, WSU Extension Service. Forest Stewardship Notes is a free quarterly e-newsletter published jointly by DNR and WSU Extension Service. Sign up for a free subscription today.]

Timely tree tips — drought damage dynamics

August 12, 2015
Drought tree

Trees in Washington state are showing the damage caused by dry conditions. Photo: DNR.

When the rainforest in Olympic National Park catches fire, you know that Washington is dry. However, increased fire risk is not the only summertime threat to trees and forests. Drought conditions can cause cell and tissue dieback in trees and can also give pests and diseases a leg up in the battle for forest health.

According to DNR’s recently published Forest Health Highlights in Washington–2014:

“Trees experiencing drought stress can become more susceptible to insect and disease attacks and are less likely to recover from damage. In eastern Washington, trees growing in dense or overstocked stands have a higher likelihood of experiencing drought stress.”

Trees in urban landscapes that may be disproportionately affected by drought are those that are newly planted, victims of root damage, or growing in tough planting sites that are heavily compacted, poorly irrigated, or space limited.

In some cases, such as with water-dependent diseases like Sudden Oak Death, drought can hinder the growth and spread of disease organisms. However, many pests and diseases are more resilient in drought conditions than their host tree species.

For example, bark beetles thrive on drought stressed trees. In recent years, pine bark beetle populations have been exploding throughout the western U.S. as a result of drought and other complicating factors. Many types of tree diseases may also worsen in drought conditions including root rots, cankers, and wilts such as Dutch elm disease.

Check out this recent story from King5 News about the effects of drought on Seattle’s elm tree population.

For more information on this topic, consider reviewing the following resources:

Follow DNR on: Facebook Fan See us on Flickr Watch us YouTube Follow us on Twitter Follow DNR Fire Twitter Join in the DNR Forum

Small forest landowners: Learn how the FFFPP can help you

April 3, 2015

Are you a small forest landowner? Do the roads on your land block or damage fish habitat?

The Family Forest Fish Passage Program (FFFPP) is a DNR program targeted specifically to small forest landowners. The program helps landowners eliminate structures (improperly installed road culverts, for example) that prevent fish from moving freely through the stream or reaching spawning grounds. FFFPP was introduced in 2003, and has since helped more than 200 small forest landowners correct 343 barriers, reconnecting over 760 miles of stream fish habitat.

Any small forest landowner is eligible to enroll in the program and apply to have their land evaluated. Once landowners are accepted into the program, they are relieved of the responsibility to fix the barrier and will remain on the list until the state is able to fund and complete the repairs.

This video shows landowners who have used the program, explains the benefits of participating in FFFPP and how to apply.

For more information, contact Laurie Cox via email ( or phone (360-902-1404).

Follow DNR on: Facebook Fan See us on Flickr Watch us YouTube Follow us on Twitter Follow DNR Fire Twitter Join in the DNR Forum

Beetle invasions put forests at risk of wildfire

March 16, 2015

A healthy forest is a top priority in preventing wildfire, and insects are one of the things that can threaten the health of a tree. Bark beetles, such as the mountain pine beetle, feed on the inner bark of many types of pine trees, which can cause the trees to die. Although the beetles normally play an important role by attacking older or weakened trees to allow more room for younger trees to grow, the combination of warmer winters, densely packed forest stands and poor forest health conditions, such as seen across eastern Washington, puts entire forests at greater risk of destructive wildfire.

Follow DNR on: Facebook Fan See us on Flickr Watch us YouTube Follow us on Twitter Follow DNR Fire Twitter Join in the DNR Forum

Learn about the health of Washington’s forests near you

March 14, 2015
Forest Health Highlights is a report on insect and disease activity in Washington's forests.

Forest Health Highlights is a report on insect and disease activity in Washington’s forests.

Each year, all forested acres in Washington are surveyed from the air to track recent tree damage. That’s 22.4 million acres of forestland, which you can see in this three-minute video taken from 2011.

These aerial surveys are used to report the location and intensity of damage by forest insects, diseases, and other disturbances. See the results for yourself in our latest Forest Health Highlights report.

If you own forestland, use this report to understand which insects or diseases are active near your property and find out how to get maps and data covering your area.

Even if you don’t own forestland, the report helps you understand the quality and condition of forests near you. It’s so valuable in fact, that DNR and the U.S. Forest Service have conducted a forest health survey of Washington’s forests every year since 1947.

Learn more about DNR’s Forest Health Program, and check out the many resources the U.S. Forest Service has available on Western Forest Insects and Diseases.

Follow DNR on: Facebook Fan See us on Flickr Watch us YouTube Follow us on Twitter Follow DNR Fire Twitter

You can’t top a healthy tree

February 23, 2015


The practice of topping trees creates large wounds that are susceptible to disease and decay. Remember to always prune responsibly.

Follow DNR on: Facebook Fan See us on Flickr Watch us YouTube Follow us on Twitter Follow DNR Fire Twitter Join in the DNR Forum


Get every new post delivered to your Inbox.

Join 270 other followers