By Amy Grotta, OSU Forestry & Natural Resources Extension – Columbia, Washington & Yamhill Counties

As tree planting season winds down and the weather warms, we are already starting to see buds popping on spring’s earliest bloomers. Soon the spring explosion will be in full force. It won’t be long before the hillsides are brilliant yellow – and not with daffodils.

Photo: Eric Coombs, Oregon Dept. of Agriculture,
Photo: Eric Coombs, Oregon Dept. of Agriculture,

Colorful and abundant as it is, Scotch broom is one of the more serious forest weeds that we have to contend with. The Oregon Department of Agriculture has estimated the economic impact of Scotch broom on Oregon forestland at $47 million annually – that figure includes lost forest productivity and control costs. Continue reading

By Amy Grotta, OSU Forestry & Natural Resources Extension – Columbia, Washington & Yamhill Counties

Dark and gloomy.
Dark and gloomy: the escaped Christmas trees at Tualatin River Farm

It’s a familiar story. A few acres of Christmas trees were planted on the farm, perhaps for tax purposes, or because they were perceived as a low-maintenance investment, or maybe because the market was strong at the time. Fast forward a couple decades…the land has changed hands, and the Christmas trees, well, they never did make it into someone’s living room. Now, the new owner has “escaped” Christmas trees to contend with.

This is the situation at Tualatin River Farm, a 60-acre property now under a conservation easement and being turned into a working educational and demonstration farm and riparian restoration site. About five acres of the site is in this old noble fir plantation, presumed to have been planted for Christmas trees, and estimated to be about 25 years old. The new property managers wish to transform this area into a mixed upland forest, more representative of what might naturally occur on the site. What to do, they asked? Can these trees be saved? Continue reading

By Amy Grotta, OSU Forestry & Natural Resources Extension – Columbia, Washington & Yamhill Counties

Source: Vernonia School District

Typically, northwest Oregon forests are considered in terms of their high productivity, their ecological characteristics, or their contribution to the state’s economy. But how do our forests shape the rural communities they surround? And how do these communities influence the forests?

These questions have been on my mind over the past couple years, as I’ve been working with community members in Vernonia on a study of “community vitality”*. Ninety-five percent of the land surrounding Vernonia is forest, and most is privately owned. So, it would seem natural that forests and forestry are important to the local economy and culture. We wanted to dig deeper into these assumptions, so we examined existing data plus information from surveys that we conducted last summer. Continue reading

By Amy Grotta, OSU Forestry & Natural Resources Extension – Columbia, Washington & Yamhill Counties

A free-to-grow tree coexisting with its early seral neighbors
A free-to-grow tree coexisting with its early seral neighbors

Early seral…it’s one of the biggest buzzwords in Pacific Northwest forestry these days.  But what is it? Put simply, early seral refers to the first stage in forest development following any disturbance, including wind, ice, fire or logging. An early seral, or early successional community is made up of the first colonizers of a forest opening: grasses, other herbaceous plants and broadleaf shrubs. Continue reading

rain gauge
The Extension Office’s rain gauge (on a dry day)

By Paul Wilson, Columbia County Master Woodland Manager

My cats get me up every morning by 7:30.  They get fed.   I check the rain gauge.

Then I record the amount and other observations on a website.  After more than a year, I have a habit.   It’s simple, useful, and fun.

We’re five years into reforesting a clearcut.   The early spring after our first planting was unusually dry, but the effects varied a lot even on our small forest.  Clatskanie averages almost five feet of rain a year. Even so, we lost a lot of site-adapted seedlings because they dried out – in February and March.   Soil differences played a role.  But where we were able to irrigate a bit the trees thrived.

Last fall we saw a blurb in the paper about the Community Collaborative Rain, Hail and Snow (CoCoRaHS) network.  When we checked out the CoCoRaHS website there was only one regularly reporting volunteer in Columbia County.  There are official weather stations around – the City of Clatskanie, the Kelso airport, and others, but none seemed to describe what happens right here.    Continue reading

By Amy Grotta, OSU Forestry & Natural Resources Extension, Columbia, Washington & Yamhill Counties

Our Master Woodland Manager trainee class wraps up next week, after sixty-plus hours of learning and sharing together over the past six months. As an instructor, what I’ve enjoyed the most of this experience is that over half of our instructional time has been spent in the field, doing hands-on activities designed to encourage critical thinking about the day’s topic.

Root excavation
Root excavation

For each class session, we’ve tried to hone in on a few key themes. One theme for our forest health session was the importance of being observant in diagnosing a pest or disease. Our instructor, Dave Shaw, had the class look methodically for signs and symptoms at each site we visited. Where on the tree is the problem noticeable? Was there a pattern to the damage across the stand? What’s going on at the ground level? Any signs of chewing, wounding or scraping? What else is going on in the area?

Twice that day, we learned how easy it can be to prematurely jump to conclusions about a forest health problem, without pausing to get the full picture of what’s going on around you. We went to one site where there was extensive mortality of young Douglas-fir trees. Knowing that laminated root rot is the #1 most common disease in the area, when we walked into the stand and saw symptoms consistent with laminated root rot, most of the group who had seen it before agreed that it was the likely cause. But it was not until we started excavating around some of the dead trees that we found signs of two other root diseases, as well. Continue reading

By Amy Grotta, OSU Forestry & Natural Resources Extension – Columbia, Washington & Yamhill Counties

In one word, what’s this a picture of?

Last month, the Port of Portland rejected a billboard that was proposed for the Portland airport. “Welcome to Oregon: Home of the Clearcut”, reads the ad, developed by a coalition of groups that oppose legislation that would increase timber harvests on federal lands. Now a subject of a free-speech debate, the fate of the billboard is unclear.

The billboard is meant to be provocative. But what interests me more than the billboard itself, or even the purpose behind it, is the public’s reaction, as expressed in various Letters to the Editor in the Oregonian. These letters reveal wide-ranging perceptions of what forests and forestry are (and aren’t). Continue reading

By David Shaw, OSU Extension Forest Health Specialist

western oak looper
Top left: western oak looper caterpillar; Top right: oak leaf eaten by looper; Bottom left: affected tree appears dead; Bottom right: caterpillars aggregating on a fence post. Photos: Dave Shaw

Insects of Oregon white oak are causing some damage this summer, and you may be seeing trees that look completely brown or have scattered dead branches (distinct brown foliage clumps all through the crown).  There are two different issues that have emerged around the Valley this summer:  whole tree defoliation/leaf eating by the western oak looper (Lamdina fiscellaria somniaria); and scattered branch death caused by the combination of a twig gall wasp (Bassettia ligni) and the western grey squirrel.

The western oak looper (a type of inchworm) is a flashy defoliator that is a native in the Willamette Valley.  The caterpillars are messy feeders, hang by silken threads, and leave browned mostly consumed leaves all over the tree, giving the tree the appearance of being dead.  But the oak trees usually come back the next year.  Historically, the outbreaks have been of short duration in any single area (typically one or two years) and the oak trees rarely suffer long term damage even though the defoliation may be spectacular.  However, when conifers such as Douglas-fir are intermingled with affected oaks, they can also be defoliated in an outbreak and impacts to the Douglas-fir may be more severe. Continue reading

Last week, we kicked off our Master Woodland Manager training in northwest Oregon. Over the next six months the class will explore many aspects of small woodlands management and the trainees will come away with a better understanding of their own lands as well as a foundation from which to assist others.

We started out with a field tour where we investigated the environmental factors that influence forest growth on a given site. In particular, we wanted to see how variations in climate, topography and soil shape species composition, forest productivity, and management opportunities. Continue reading

In response to last week’s post on the value of dead wood in the forest, I received this e-mail from a landowner:

“We’ve never left much on the ground in the way of dead wood…not during logging, but wind damaged, etc.  Our thought has always been that these rotting logs increase the insects in the forest, both good and bad. Is this a valid concern and if so, where is the balance between bugs and wildlife?”

He raises a point worth exploring. While calling an insect “good” or “bad” is a matter of perspective, for the purposes of this discussion let’s assume that “bad” insects are those that cause economic or environmental damage, and “good” insects are those that don’t. The vast majority of insects that inhabit western Oregon forests fall into the “good” category…with a few notable exceptions.

One of these “bad” bugs that the e-mailer might have in mind is the Douglas-fir beetle. This time of year, the adult beetles are flying around in search of Douglas-fir trees where they lay their eggs underneath the bark. Their favorite targets are large diameter, freshly downed logs—or standing trees that are weakened from another cause (root disease, soil compaction, etc.). Through the summer and winter, the eggs hatch and the larvae grow as they tunnel around under the bark (this activity is what kills the tree). The following spring, they have become adult beetles, and they fly away in search of new homes. If they can’t find another weak tree or fresh log, they will go after a healthy tree.

Douglas-fir beetle (Dendroctonus pseudotsugae ) on Douglas-fir (Pseudotsuga menziesii ) - 1587008
reddish bark dust in bark crevices is a sign of the Douglas-fir beetle (Photo: Elizabeth Willhite,

Healthy trees can withstand a low-level Douglas-fir beetle attack, and in normal circumstances there are rarely enough beetles around to cause concern. The problem arises when the beetle population builds up and lots of them infest a healthy tree at once. When does that happen? In situations where there is a lot of freshly downed or damaged wood on the ground for them to target initially – like after a winter windstorm.

Here’s a true story for illustration.

In fall 2009, a landowner in the Coast Range was hit hard by beetle kill to his otherwise healthy, 100+ year old forest. Why? Here’s how we think this may have played out.

  • The stand is adjacent to a sawmill.
  • The big windstorm of December 2007 created lots of blowdown along the coast, though this particular stand was too far inland to be damaged.
  • Some of the coastal blowdown was not salvaged until summer 2008…too late, because Douglas-fir beetles had already found them during the spring.
  • The salvaged logs were brought to the mill, along with the beetle larvae living under the bark.
  • Then, in late 2008 the recession hit and the mill curtailed operations. The logs sat in the deck…and the beetles matured.
  • In spring 2009, they emerged and flew off to the neighboring stand, where they attacked the healthy, mature trees.

It was a sad situation, especially since the landowner had to cut more trees to avert further beetle damage, and in a poor market.

So, back to the e-mailer’s question: does retaining snags and downed wood for wildlife create a forest health risk? The take-home messages are these:

  • Most insects are not forest health risks.
  • In western Oregon, the Douglas-fir beetle (the “baddest” dead wood-inhabiting insect) only thrives in FRESHLY dead or downed trees. Once the snag or downed wood has been dead for more than a year, it is no longer a target. Instead, it will become inhabited by the dozens of “good” bugs that feed wildlife.
  • There needs a LOT of this fresh down wood to pose a forest health risk – like after a storm. According to Oregon Department of Forestry, a good rule of thumb is that fewer than 3 FRESH down logs/acre does not present a hazard.

After a windstorm or other stand-damaging event, yes, prompt salvage is important in order to prevent a beetle infestation. But, when scattered trees gradually die in a stand from other causes, it is hard to imagine when this would create a risky situation with respect to bark beetles. And during harvest activities, you can be strategic about how much dead wood is left behind, and in what conditions.

We appreciate it when readers respond to our blog posts. We like your e-mails, but you can also respond by commenting directly on the blog, where other readers can contribute to the conversation.

Amy Grotta