Glenn Ahrens, OSU Forestry and Natural Resources Extension Agent – Clackamas, Marion, and Hood River Counties

At Hopkins Demonstration Forest we have an area of maturing forest – 80 or more years old – that we would like to manage with continued thinning or selective cutting rather than clearcutting. As I discussed in Part 1 of this story, this is a common situation for family forest owners. Many are interested in periodic selective harvesting of trees or small patches and keeping options open for the future. There are many challenges and tradeoffs to consider, but now we have to choose an option for our Hillside Forest stand at Hopkins.

Like many woodland owners, we have to balance the need for revenue with our other goals for aesthetics, recreation, and wildlife. In our case, goals for education and demonstration are also a high priority. This year in particular, we have major financial challenges to sustaining our woodland enterprise due to the COVID-19 pandemic. We have accumulated valuable timber inventory over the years since we don’t cut all of our annual growth. So, we are considering how much to draw upon our timber account to get us through hard times. And what kind of silvicultural options do we want to demonstrate in the process?

Forest Stand Conditions – The forest stands in question are two units of similar size, collectively called the Hillside Forest, occupying about 25 acres on the slope from hilltop (700 foot elevation) to stream bottom (400 foot elevation). The stands are composed of second-growth western redcedar and Douglas-fir regenerated after logging in the late 1930’s. The stands have been thinned three times over the last 30 years, maintaining many well-spaced trees with good crowns. They should be relatively stable when they are retained after thinning. There are also clumps of intermediate canopy trees and scattered gaps with brush and bigleaf maples. Current stand density is approaching the upper end of the “optimal management zone” based on average DBH (22 inches) and trees per acre (100). Read more about competition levels and on this approach to density management here.

80-year-old stand of Douglas-fir on upper slope of Hillside Forest at Hopkins.

The forest type changes from a drier Douglas-fir/cedar stand on the upper slope to a more moist cedar dominated stand on the lower slope. While cedar grows a little slower than Douglas-fir, it is now a major co-dominant component of our forest because of the residual cedar left after logging in the 1930’s (many of the cedars are over 100 years old now). Shade tolerant cedar provides the opportunity to manage for regeneration and multiple aged cohorts with thinning and smaller gaps, while Douglas-fir requires larger openings for good regeneration.

Denser patches of western redcedar targeted for thinning in Hillside Forest.

Goals and Objectives – Hopkins is managed to provide an “accessible example of sustainable forestry” and to support “science-based education to enhance understanding of, and appreciation for the complexities and benefits of woodland management.”  It is a working forest managed for multiple objectives including:

  • hands-on woodlands education for diverse audiences,
  • timber resources and revenue from timber harvests to help support the organization,
  • wildlife and fish habitat to accommodate a diverse natural fauna,
  • soil and water resources to maintain or enhance soil productivity and water quality,
  • and recreation opportunities, in conjunction with project development and educational activities.

For the Hillside Forest stands, we are focused on demonstrating the “complexities and benefits” of trying to meet all objectives in one stand with thinning and selective management of a mature forest. On the majority of the Hillside Forest, we are planning a relatively light thinning, removing about 25% of the trees and a similar portion of the standing volume, to reduce stand density to the lower end of the “optimal density management zone”. Such that the trees we leave should be able to refill the growing space. While we are at it, extra work to clear some of the brushy gaps and provide new regeneration of cedar is also planned. In one area of about 5 acres, where trees are widely spaced and there are more brush-filled gaps, we will cut most trees and regenerate a mix of Douglas-fir and cedar. The target for timber volume removal is about 4,000-5,000 board feet per acre in thinned areas and 15,000-20,000 board feet per acre in the larger clearing.

A key question for the longer-term is how long to continue thinning the large overstory trees and whether or not to do more regeneration harvesting to start new stands of Douglas-fir. Theoretically, we could just keep thinning the overstory and grow the stand from the current 22 inch average diameter to 30 inches (~30-35 years out) or 40 inches (~70-80 years out), at which point about 30 to 35 trees per acre would fully occupy the site. Another option is to convert some areas to uneven aged management, with individual tree selection to regenerate cedar, along with larger patches (>3 acres) of regeneration harvest to provide new cohorts of Douglas-fir. For now, the plan for most of the Hillside Forest is to maintain individual tree crown vigor with thinning and keep options open for continued thinning in the future.neven-aged conditions.

Scattered clumps of younger trees along with brushy gaps in Hillside Forest.

Tradeoffs and Costs – Felling and yarding tall timber (100-140 feet tall) while protecting residual trees  requires careful and skillful operations. That and the relatively low volume removed per acre will increase logging costs compared to clearcutting. But the larger, older Douglas-fir and especially the cedar have potential to be higher value. In terms of timber value, cedar logs are even more valuable than Douglas-fir ($1,000-1,500/mbf vs. $500-800/mbf delivered log prices over the last ten years). We also hope to produce higher value Douglas-fir sawlogs and transmission poles with this mature-forest management system.

While the planned thinning is relatively light, there is still a risk of loss or damage to residual trees from sudden exposure to sun and wind. The cedar may be particularly vulnerable to sun and heat exposure, which seems to be an increasing challenge for cedar at low-elevations in the Willamette Valley margins. There is also the potential for damage to soils, roots, stems, and crowns during thinning, especially with the large size of some trees being felled and yarded.

Help is needed to measure and mark trees for the thinning at Hopkins Demonstration Forest.

Educational opportunity – In keeping with our objective for hands-on woodland education and “learning while doing”, we would like to involve people in preparation and execution of the thinning project. Tasks include meeting with foresters, log buyers, and loggers to develop the operational plan for access, skid trails, and tree selection. We need help conducting pre-harvest inventory, marking stand boundaries, and selecting and marking which trees to leave or cut to meet our thinning target. Given the challenges of in-person events during the COVID-19 pandemic, we anticipate limited opportunities for a few people at a time in the woods. We also would like to capture some of the work on video to share with others online. If you are interested in participating, please contact me at To follow our progress, stay tuned for the next installment of this story.

We are pursuing this more challenging and costly style of management to see if we can “have it all” in one beautiful 25-acre hillside forest – timber revenue, species diversity, mature forest habitat, recreation value, and public education. Whatever happens, we will learn from the process.

Brad Withrow-Robinson, OSU Forestry & Natural Resources Extension for Benton, Linn and Polk Counties.

Family woodland owners (like farmers, ranchers, beekeepers and others) typically have busy spring schedules with lots to do in the woods.  Many of those activities come with acres of physical distancing  from others outside their families, so life remains busy.

Although our offices are closed, OSU Extension remains an available and useful source of information for doing many spring woodland activities such as weed control, fire preparedness and prevention, developing wildlife habitat.  We remain available by phone or email to answer questions and direct you to the information you need.  

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

Slash is the term used to describe the treetops, limbs and other woody material left behind after a timber harvest. The amount of slash left behind will depend on several factors, including the size and quality of the harvested trees. Universally, how the slash is dealt with is an important consideration in the logging process. Heavy amounts of slash left on the ground can be a fire hazard and it makes tree planting more difficult and more costly.

Piling and burning is the most common method of slash treatment nowadays. However, some landowners are looking for alternatives to burning for various reasons. Pile burning can be challenging due to weather conditions or smoke restrictions. When logging contractors are busy, they may be reluctant to include pile burning in their contract due to the time involved, leaving it up to the landowner. And, there are greenhouse gas considerations with burning slash. For all of these reasons, it is worth looking at the pros and cons of other methods of slash treatment.

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

If you’ve ever been out on a field tour with a bunch of foresters, you probably heard one of them use the term “site productivity” in describing a particular forest, or comparing two different forests. But to the person without a lot of formal forestry background, site productivity may be a vague concept at best. However, it is an underlying attribute that turns out to explain a lot of what we observe in our forests: what types of trees thrive, which seem to have problems, what amount of competition our seedlings face, and more. So let’s take a closer look at site productivity. Continue reading

Brad Withrow-Robinson, Forestry & Natural Resources Extension agent for Benton, Linn and Polk Counties.

The woods are full of living things, all contributing to the forest’s diversity: Trees; check. Shrubs; check. Woodland flowers; check. Birds; check. Obvious enough, right?
But there are all sorts of less-obvious things which are seen only occasionally, such as mushrooms (fungus), many often-tiny things like insects, or secretive things such as amphibians. All add to the diversity, and many play important roles in how a forest functions
Let’s take a look at some more obscure but fascinating members of the forest community: lichens. We’ve all seen them. They are everywhere, including your woods. But what is a lichen? Continue reading

Brad Withrow-Robinson, Forestry & Natural Resources Extension  agent for Benton, Linn and Polk Counties.

In a previous post , I wrote about the value of roads for a woodland owner, as well as the responsibly to maintain roads to protect their value as well as our water resources.  Many family forest landowners have older, “legacy” roads.  These older roads were likely not built to today’s engineering standards, have lost some of their function over time, so are deserving of some attention and stewardship.

So what does that involve?

It likely begins with observation.  Make it a habit to get out and inspect your road system regularly.  Since water is a key element and force causing damage to roads, get out in the wet season.  Bring paper, make notes and keep them as a reminder of what you saw and did.

When on your walk, you should be looking for signs of drainage issues:  Water standing on the road, trapped water running down the road forming ruts, and water pooling in the uphill road ditch all indicate drainage issues that may leader to bigger more damaging (more expensive) problems. Continue reading

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

We’ve discussed ongoing drought stress a number of times on this blog.  But when do we consider it dry enough to be called a drought?  There’s actually a system for that. The United States Drought Monitor updates and releases a national map each week, showing which areas of the country are experiencing drought, and how extreme the conditions are.  A variety of data sources go into their models, which I won’t begin to explain here, but their website has a lot of good information on how they determine drought conditions. In fact, all the data and visual tools on the Drought Monitor website feed the data geek in me; so if you like this sort of thing I encourage you to check it out.

If it seems like this blog has been a broken record stuck on the drought track the last few years, you’re not imagining things. But today, I want to highlight that in northwest Oregon we begin 2019 in a state of Moderate Drought, according to the Drought Monitor (see figure below; click to enlarge), even though we are in the midst of the rainy season. Continue reading

An Interview with Cory Garms, PhD Student – Oregon State University

Edited by Lauren Grand, OSU Forestry & Natural Resources Extension Agent – Lane County

Drones are becoming more popular to use in forestry. With recent innovations, small landowners are beginning to gain more affordable access to this useful new technology. I spoke to Cory Garms, a PhD student at Oregon State University, about what small acreage landowners might want to know about using drones to survey their own property.

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Brad Withrow-Robinson, Forestry & Natural Resources Extension agent for Benton, Linn and Polk Counties.

Fire Season will soon be in effect in much of the Tree Topics reading area, as declared by the State Forester according to regional fire conditions (usually by early July). Here are some fire season basics to keep in mind:

To find out when an area is declared, you can visit the ODF Wildfire website and click on Forest Restrictions and Closures  section. There you can find links to an overview of the Industrial Fire Precaution Level (IFPL), closures and other information about fire regulations and restrictions.

If you choose the Current IFPL/Public Use (Regulated Closure) Chart you can find the fire level precaution for each of the ODF Forest Protection Districts by clicking on that district. Changes in precaution level and closures will be posted there over the summer, so it is a good idea to monitor this information throughout the season.

Please remember that even a Level 1 precaution requires you to carry fire equipment when in the woods. The motor vehicle or light truck (<=26,000 pounds GVW) requirements are:

  1. A) 1 shovel with a minimum 8-inch wide face and a minimum 26-inch length handle, ready for immediate use.
    B) 1 axe or Pulaski with a minimum 26-inch length handle, ready for immediate use.
    C) 1 approved A,B,C extinguisher, 2.5 pounds or larger (preferably 5 pound minimum), ready for immediate use.
    D) Exhaust system with muffler in good operating condition.

photo: ODF

Be sure you, your family or others using vehicles on your property are aware of this.  I generally make it a habit to carry these tools in my vehicle all summer.

Additionally, if you are using a chainsaw, each saw must have a shovel (meeting above standards), ready for immediate use; an 8-ounce (larger preferred) fire extinguisher, ready for immediate use; the standard exhaust system (spark arrester screen) must be in good operating condition; and the operator must stop the saw before fueling and move the saw at least 20 feet from fueling location prior to starting.

Please be FireWise, alert, aware, and pro-active in fire prevention. Be aware of how and where you park your vehicle, since exhaust system components have been known to ignite dry grass.  We’ve had a number of reminders recently that western Oregon is primed for wildfire each summer.  You don’t want to be part of the next one.


Brad Withrow-Robinson, OSU Forestry & Natural Resources Extension agent, Benton, Linn and Polk Counties.

We have been dedicating a fair amount of screen space and class time lately to the idea that many family forest landowners would benefit from thinning their young stands. We explored the reasons to consider young stand thinning (YST) as well as some approaches in a series of posts on YST .  YST is consistent with the situation and goals of many family forest landowners, which often include growing older and more diverse forests.

That said, like many other well-grounded activities, YST is not without some potential drawbacks.

Few of them are significant enough to justify not thinning at all, but each requires some thought and consideration to avoid unintended consequences. We present some of those potential drawbacks that you need to consider when planning a YST, along with some links to other information, below. Continue reading