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Toto, I don’t think we’re in Oregon anymore…

TreeTopics - Thu, 05/10/2018 - 2:11pm

By Amy Grotta and Brad Withrow-Robinson, OSU Forestry & Natural Resources Extension

Last week, a large contingent of the OSU Forestry & Natural Resources Extension team traveled to the Gulf Coast of Mississippi for a biennial conference of natural resources Extension professionals. Besides the chance to exchange ideas with our colleagues from across the country, these meetings afford the opportunity to learn about the ecology and natural resources issues that define the geography of the meeting location.

We learned that the forests of Mississippi are quite diverse. They are defined by their topography, proximity to the coast, and (as in Oregon) landowner objectives. While on the surface they seem about as far from Oregon’s forests as you can get, there are some similarities to the forest systems and issues we have back home. We thought we’d share a bit about the interesting forests that we saw and learned about on our visit.

Swamp Forests

Low lying areas near the Gulf Coast are covered by slow moving water in bayous and swamps. There are a number of trees that are adapted to these inundated conditions, creating otherworldly forests. As you move farther inland, the salinity of the water decreases and the vegetation also changes. Marsh grasslands give way to bald cypress trees, which in turn become mixed with a variety of other trees adapted to standing water. Really the best way to explore these forests is by boat, which is what we did.

Many of these trees feature large buttresses at their base. I suppose this contributes to their stability in mucky conditions. Bald cypress is a deciduous conifer with strange “knees” that jut out of the water around them. The knees are a part of the tree’s roots, but their function is debated.

Bald cypress stand along the Pascagoula River, a few miles up from its outlet into the Gulf of Mexico A bit further upstream, the forest became more mixed, featuring hardwoods and dwarf palmetto in the understory. In the foreground are the bald cypress knees. How many alligators do you think are lurking in there? Here’s a freshwater water tupelo forest created by an oxbow of the Pearl River in central Mississippi.


Pines in Lines

The Southeast produces more wood fiber than any other region in the U.S., and much of that is in southern yellow pine plantations on private forestlands. Southern yellow pine can refer to one of several pine species, depending on the location, but the biggest plantation species are loblolly and slash pine. They are fast-growing, and rotations can be as short as 25 years. We didn’t visit these plantation forests, but drove past some and heard various references to “pines in lines” throughout the conference.  We learned that in light of declining pine markets, Extension services in the South are encouraging smaller private forest owners to manage mixed hardwood-conifer systems that have potential for diverse revenue streams. In addition, southern yellow pine plantations have been hard hit by hurricanes. These issues felt somewhat familiar to us.

Loblolly pine plantation. Photo: David Stephens,


Longleaf Pine Restoration

Longleaf pine forests and savannas once dominated the sandy lowlands of Mississippi and much of the South. Longleaf pine now covers only a tiny percent of its former area, having been replaced by agriculture and plantations of loblolly and slash pine. Eliminating fire (another familiar story) has allowed many hardwood trees and shrubs to fill in, altering the open habitat structure upon which many local wildlife species depend.

We visited the De Soto National Forest which is now actively restoring longleaf pine in many areas. Managers are harvesting older loblolly plantations, planting or leaving longleaf seed trees, and importantly, restoring fire to the landscape with an active prescribed fire program.  This work is benefiting local species including the gopher tortoise and red cockaded woodpecker while also producing a significant amount of forest products.

A recently burned site in De Soto NF showing fire-killed hardwoods in foreground, surviving young pine trees in background.

We got a nice look at the effects of frequent prescribed fires in coastal wet longleaf pine savanna after 40 years of active restoration management at the Mississippi Sandhill Crane National Wildlife Refuge northeast of Biloxi.

Restored long leaf pine savanna at the Mississippi Sandhill Crane National Wildlife Refuge. Note the many insectivorous pitcher plants in the foreground.

Longleaf pine has an interesting fire adaptation strategy. It starts life in a “grass stage” which keeps the sensitive growing point below ground and safe from fire, generally for several years.  Once it has built a strong root system, it puts on a growth spurt to get its buds up above the reach of fire.

Long leaf pine in grass stage.

So that’s our photo tour of the forests of southern Mississippi. In 2020, when this meeting comes to central Oregon (hosted by OSU Forestry & Natural Resources Extension), we’ll have a chance to showcase Oregon’s diverse forests to our national colleagues.

The post Toto, I don’t think we’re in Oregon anymore… appeared first on TreeTopics.

Categories: TreeTopics

Recap of the 2018 Oregon Forest Health Conference

TreeTopics - Mon, 03/05/2018 - 3:18pm

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

Last week I attended Forest Health: State of the State, a biannual conference put on by OSU College of Forestry. A packed agenda covered insects, diseases, fire, drought, invasive species, climate change, and other topics. I always look forward to this meeting as an opportunity to brush up on my knowledge of these issues. The speakers came from various backgrounds, representing the many forest ecosystems and ownership types we have across the state, and the audience was equally diverse. With that in mind, I’ve tried to distill the takeaways from the conference that seem most relevant to small woodland ownerships in northwest Oregon.

ODF conducts an annual insect and disease aerial survey. Click on the image to be taken to a short video from the air.

What is forest health, anyways?  Our own Extension Specialist Dave Shaw kicked things off by reminding us that forest health is subjective, and based on our experiences, instincts, and goals. It’s easy to agree on whether an individual tree is healthy, but forest health is less concrete.

Resilience:  A common theme across many speakers was that of resilience: that a healthy forest is one that is capable of recovering after a stressful episode, such as a drought, fire, or insect outbreak, and is still able to provide the benefits that the owner and society desire.  A.J. Kroll, a wildlife biologist from Weyerhaeuser, suggested that resilience includes maintaining the productive capacity of a site. Using coarse woody debris (CWD) to illustrate his point, he suggested that a resilient forest has the ability to produce large trees that will eventually become CWD. While he didn’t elaborate, I interpreted that to include maintaining soil quality and productivity. Austin Himes, another speaker with industry background, added that forests also must be resilient to market changes or societal pressures.

“There’s a universe of small things that rely on coarse woody debris” said A.J. Kroll. CWD retained after a clearcut will later provide shelter for long-toed salamanders, once the forest regrows. Left photo: Amy Grotta; Right photo: Kathy Munsel, Oregon Dept of Fish & Wildlife A bumble bee on a salal flower. Photo: Jim Rivers,

Pollinators:  Maintaining populations of pollinating insects is a key to the resilience of our society: without pollinators, we wouldn’t have many of the foods that we eat every day. Jim Rivers from OSU summarized some of the new and ongoing research about the value of westside forests to native pollinators. Most of our native bees nest in the ground, and of course they need flowering plants. Therefore, the short window of approximately four years post-harvest can be very valuable for pollinators.  This is when flowering plants thrive in full sun, and there are more areas of exposed ground for nesting sites.

Beyond these big-picture concepts, there was plenty to hear about “bugs, crud, and critters” – the things that often come to mind as forest (or tree) health issues.

Insects:  Forests on the westside have far fewer insect problems than east of the Cascades. Christine Buhl from the Oregon Department of Forestry emphasized that the best management of insect pests is preventative, by maintaining vigorous trees. This includes managing the Douglas-fir beetle, our primary westside insect pest, which likes stressed trees. But, Michelle Agne, another PhD researcher pointed out that climate change may create conditions that increase Douglas-fir beetle damage in the future. That’s because with hotter, drier summers, trees will be living in more stressful conditions; and as extreme weather events such as storms become more frequent, major windthrow episodes which precipitate beetle outbreaks could become more common.

The intensity of Swiss needle cast in any given year is often weather dependent. Map: Swiss Needle Cast Cooperative

Diseases:  Swiss needle cast can be found everywhere in western Oregon, but currently it only impacts tree growth on the west side of the Coast Range and a few isolated spots in the Cascade foothills. That’s because for the fungus to thrive and spread it needs warm, moist conditions in the winter and spring like those along the foggy coast. These types of conditions are likely to be more common in the future, so Swiss needle cast severity is likely to intensify in the areas where it is currently a problem. Whether the impacted zone will expand eastward is less certain.

Invasive species:  Exotic species of plants, insects, and pathogens are introduced all the time through the commerce and transport of live plants, wood packing material (such as pallets and crates), and firewood. Some of these become invasive and create huge problems (see: sudden oak death). The Oregon Invasive Species Hotline is an easy way for anyone to submit a report of an unfamiliar plant or insect that you think might be an invasive species. An expert will review your report and respond appropriately.

Browsing animals:  There is an interesting and complicated study now in its sixth year, looking at the interaction between herbicide use in young plantations and deer and elk browse. Thomas Stokely, a PhD candidate at OSU explained the results. Some, including myself, have wondered whether reducing herbicide use after a clear-cut could help reduce deer and elk browse on seedlings, because there would be other forage for them to eat. However, in Thomas’s study, seedlings were browsed regardless of the level of herbicide application. And, where it was applied lightly, seedlings didn’t perform as well, due to the double whammy of being browsed and competition from other vegetation.

Are more trees dying in Oregon?  The perception around here may be “yes”, but the research says “no”. Forest mortality rates have remained relatively constant (around 2%) since the late 1990’s, says Andy Gray of the US Forest Service.

With that, I feel a little more educated about forest health for the time being, and I hope you do too. May your forests be healthy…and resilient.

The post Recap of the 2018 Oregon Forest Health Conference appeared first on TreeTopics.

Categories: TreeTopics

Potential drawbacks of Young Stand Thinning

TreeTopics - Wed, 02/07/2018 - 4:21pm

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.

Weeds. Yes, blackberries and other weeds can make YST difficult, and may slow the growth of your trees, but do not change the need for YST if you find that you have more trees per acre (tpa) than your desired target.  YST is  probably a better justification for keeping ahead the weeds, than weeds are a justification for delaying or not doing YST.

Sunscald, yes your trees can be burned if young tender bark is abruptly exposed to the sun and gets too hot.  We see it particularly on warm, dry, south facing sites, and it is more commonly seen because of pruning than thinning.  If your site meets that description, it might be wise to thin and prune separately.  Consider modifying the pruning operation (do smaller lifts, leave a SW facing branch or two in exposed places like south facing road sides, don’t prune those areas in late summer).

Insects and diseases are the most significant concerns related to YST.  There is the potential to create a bug problem while trying to avoid a density related stress problems.  The outcome depends on the amount, timing and handling of the slash produced.  The cause for concern varies by tree species.

Valley ponderosa pine.  We have written about problems with slash and the ips beetle before and also directed people or one or another excellent ODF bulletin about ips and also about slash management. These destructive bark beetles thrive on stress and also disturbances that produce debris they use to multiply.  Creating lots of slash in a thinning operation can easily lead to an ips outbreak, and certainly represents the biggest single challenge to managing pine.

Douglas-fir. Black stain root rot is an increasing problem in some areas in western Oregon.  It is caused by a fungus, but it is carried

Black stain signs at root crown.  Photo by William Jacobi, Colorado State University,

by insects that are keyed-in on stress and disturbance (just like the ips).  Local outbreaks in young plantations may be associated with nearby disturbances such as harvests, road construction or brushing.  It can also be associated with YST.  Where other local disturbances or presence of disease cause concern, the most significant management recommendation is to avoid attracting and feeding the insect vectors by thinning in summer, after the insects’ breeding season.  Look for more about this disease in future blogs/articles.

Swiss Needle Cast is present throughout western Oregon, but it is most significant along the coast where it must be considered as part of every management decision. Potential implications of SNC to young stand thinning include retaining alternate species, and selecting among Douglas-fir based on needle retention.

Young stand thinning is an important woodland management practice that can help you keep your woodland vigorous and resilient to drought and other stress. A little caution can help it deliver on that promise.

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Categories: TreeTopics

Bringing nature to the city

TreeTopics - Mon, 02/05/2018 - 3:28pm

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

Taking a walk through my NE Portland neighborhood recently, I came across something new in our local park. Portland Parks and Recreation is renovating an underutilized section of Alberta Park as a “Nature Patch”.

Alberta Park was part of a Homestead Act land claim over 150 years ago, and became a park in 1917. (Check out a local historian’s writeup for the details.) So over 150 years of human use, the land is far from the forest that once grew there. The Nature Patch could be thought of as a re-engineering project.

Alberta Park in 1929 and 2018. If you look closely, you’ll see the lamp posts are still there. 1929 Photo courtesy City of Portland archives.

Like many of Portland’s parks, Alberta Park is dominated by towering Douglas-fir trees which cast shade on the playgrounds, lawns, off-leash areas, and other park amenities. But walking on the new gravel path through the one-acre Nature Patch, I saw how elements of a functioning, diverse forest are being reintroduced. Dead trees have been felled and left in place as downed wood, or cut to a safe height to remain as a snag. Understory planting is in progress, with pollinator-friendly plants like Oregon-grape, ninebark, and snowberry, as well as ferns and even herbaceous forest plants like oxalis. When the understory fills in, I think it will be quite lovely and a vast improvement over the muddy, sparse grass that had a hard time growing under the Douglas-firs’ shade.


A dead or declining tree was turned into a snag, safely away from the pedestrian path.


Oregon-grape is one of the earliest blooming woodland plants. It needs some sun to produce flowers.

Why am I writing about an urban park on a blog for small woodland owners? Well, I think there are some parallel lessons that woodland owners can draw from the Alberta Nature Patch.

  1. The designers did an excellent job of working with their existing urban forest landscape to introduce structural and biological diversity. Indeed, many of the elements we wrote about in previous blog posts are on display here: snags, downed woody debris, and understory shrubs and forbs.
  2. It also demonstrates a concept we discussed in a previous case study: that not all acres of your woodland (or park) need to serve all of your management objectives at the same time. You can compartmentalize if you need to. An off-leash area, a playground, and a ball field – all areas that are critical to the recreation mission of the site – border the Nature Patch at Alberta Park. You can have some areas that you manage more intensively for timber, and others, maybe those that are inherently less productive, for habitat.

    The Nature Patch in the foreground with the playground behind it

  3. This project illustrates that no area is too small or too urban for wildlife to benefit. Particularly, pollinators such as bees, who need our help. We’re still learning about how bees and other pollinators use forests. But they frequent open, sunny areas where flowering plants flourish. These might be along your roadsides, forest edges, or in a recently logged area. A new publication from OFRI outlines some steps woodland owners can take to make forests pollinator-friendly.
  4. Perhaps the greatest value of the Nature Patch lies in public exposure. Living on a small woodland, it can be easy to forget that many people in cities, especially those who don’t have a car, don’t have easy access to nature. For some people who have always lived in an urban environment, forests might even feel unfamiliar or intimidating. Bringing a bit of native forest to the city park exposes park users to a setting that woodland owners take for granted. I like to think that exposure gives way to appreciation. We in the forest sector need ALL Oregonians to appreciate forests.
  5. Like Alberta Park, the land that many small woodland owners care for often has seen many previous uses. If your woodland was once a farm, pasture, or even an industrially managed forest, many elements of a native forest are missing. Reintroducing diversity to a forest requires intention. But if it can be done in an urban park, surely it can be done on a small woodland. Where is the “Nature Patch” on your place?

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