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Summer 2015, DROUGHT! And Heat. A Forest Health Report

Tree Topics - Wed, 09/02/2015 - 7:23pm

By David Shaw, Forest Health Specialist, OSU Forestry and Natural Resources Extension

Douglas-fir killed by drought

The summer of 2015 is shaping up as a big year for drought and drought related forest health issues throughout Oregon, but especially in the Willamette Valley, SW Oregon, and in Eastern Oregon.

In late summer, it can be very difficult to discern whether insects, disease, or drought and heat are causing tree dieback and deaths, but we are becoming pretty confident that drought and heat together are influencing much of what we see.  In this report I outline and describe some of the more common problems we are seeing with conifers and hardwoods as of early September.

Drought related issues

In severe drought, trees may die with no associated biotic agents such as bark beetles or canker diseases. However, it is very common to find dead trees with these agents too.


Douglas-fir in the oak zone of western Oregon (the drier area of the Valley and on heavy clay and shallow dry soils at lower elevations) is having an especially hard summer, with some sites outside the oak zone also showing drought effects. The general symptoms are top dieback, branch flagging, and whole tree mortality. These symptoms may or may not be directly related to a biotic organism. The major ones are branch cankers, bark beetles, and twig weevils. All these organisms seem to do well on Douglas-fir during drought, and this year is no exception. We also believe root diseases are exacerbating the issue, but it can be difficult to discern. Twig weevils and branch canker diseases are very common on young Douglas-fir during drought, and both are known to increase attacks on drought stressed trees.

Douglas-fir twig weevil damage. Whitney Schmike photos.


Left: Douglas-fir branch flagging, likely from dought and canker interaction. Right: Douglas-fir canker. Note the brown dead bark area and green live bark. Branch is flagging.

Bark beetles

Douglas-fir beetles initiating an attack this spring. The tree had a red crown already, likely from drought. Photo Kara Shaw.

Bark beetle attacks on conifers increase during drought. This is the case for Douglas-fir, grand fir and other true firs, as well as pine. In these conifers it often results in top dieback, but can also result in whole tree mortality. We do not have the results from this year’s the statewide survey yet, but it appears that bark beetle activity is going to be really up. However, symptoms of bark beetle attack vary with beetle type and drought effect. For example, typically when a Douglas-fir is attacked by Douglas-fir beetle in April or May, the tree crown does not go red for many months, perhaps not until late fall or even early the next spring. However, this year many trees that were attacked in the spring were turning red right away, by mid-summer. This may be because they were already dying from drought, and this may also be exacerbated by existing root diseases.

Group mortality of Douglas-fir in May. Douglas-fir beetle was found in all these trees. Photo Kara Shaw

Many declining Douglas-fir trees have an associated stress cone crop, a smaller than normal abundant cone crop that is hypothesized to be related to the last gasp of the tree to reproduce before death. For a stress cone crop to hang on a tree in early 2015, means they likely formed in 2014, indicating many of the trees with top-dieback this summer have been suffering for two years or more.

Douglas-fir with stress cone crop. These cones formed in the previous year, therefore indicating stress beginning in 2014 or earlier. Photo Kara Shaw.

True fir/Grand fir

The fir engraver bark beetle attacks all true fir, but is especially important on grand fir and white fir during drought. We anticipate a lot of grand fir mortality this summer, but it will not become evident until fall, as the trees may take a few months before showing red foliage. Throughout the range of grand fir, the species has expanded its site occupancy with fire suppression, even in the Willamette Valley.   During drought, many of these sites are not suitable for fir and mortality may become very common. Root diseases may also exacerbate the mortality.

Foliage loss in conifers

Many conifers lose foliage in a drought, theoretically as an adaptation to reduce water loss through leaves. Although this is poorly understood, this summer it is quite common to see conifers like Douglas-fir or ponderosa pine losing two-year-old foliage and older. There may be interactions with foliage fungi/diseases, but it is very difficult to differentiate what is happening during mid-summer.

Foliage browning in hardwoods

Foliage browning in hardwoods is becoming more and more common throughout the region as drought intensifies this summer. Partial tree crown and whole tree crown foliage browning is already present in big leaf maple, Oregon ash, and cottonwoods. We anticipate Oregon white oak will also begin showing symptoms within the next month. We believe this is an adaption to prevent whole tree mortality, a type of early season senescence, and next spring most these trees will flush and be healthy if rains return this winter. Significant foliage browning is also being reported in California black oak in southern Oregon already this summer.


And, a few NON-drought issues…

Oregon white oak with branch flagging from Cynipid wasp and squirrel interaction.

Oregon white oak has had a big year for small branch dieback in some areas of the Willamette Valley. This is associated with a complex which involves a twig gall wasp (Bassettia ligni)(Hymenoptera: Cynipidae) in which the grubs develop under the bark of small twigs. The western gray squirrel is attracted to these areas with gall wasp grubs and the squirrel debarks the twig. If you see branch dieback in oak (red-dead foliage in clumps), check just below the dead foliage and see if you see the twig debarked. It is very characteristic and easy to see generally. This issue is common in the Valley, but year-to-year it varies in locations and intensity. This year it is particularly common in the Corvallis area and along the west side of the valley.

Bigleaf maple also begins showing branch dieback this time of year. This often is associated with western gray squirrel feeding damage, but no gall wasp is involved, the squirrels just like young maple bark. Again, to verify this is squirrel damage and not drought or other issue, check to see if the branch has been debarked below the dead leaves.

Bigleaf maple with dead branch flagging (left) and showing debarking by squirrels (right)

Swiss needle cast along the coast is still persisting and the aerial survey again showed over 500,000 acres of visible disease symptoms from the air. This was restricted to sites within about 20 to 30 miles from the coast. Occasionally young stands also show symptoms along the Cascade foothills. However, in the Willamette Valley and SW Oregon in general, the foliage loss we are seeing this summer is likely not caused by Swiss needle cast. See the Swiss Needle Cast Cooperative website.

The post Summer 2015, DROUGHT! And Heat. A Forest Health Report appeared first on TreeTopics.

Categories: OSU Extension Blogs

Register now for State of the Coast, this year in Coos Bay

Breaking Waves - Tue, 09/01/2015 - 1:55pm

Registration is open for Oregon Sea Grant’s annual State of the Coast conference, taking place Oct. 24 at Southwestern Oregon Community College in Coos Bay.

Noted author and marine biologist Dr. Wallace “J” Nichols will deliver this year’s keynote address: “What happens when our most complex organ — the brain — meets the planets largest feature — water?” Nichols will discuss the research behind his book, Blue Mind.

Registration, which includes lunch, snacks and a reception, is $35.00, $25 for students. To register, and for more information, visit www.stateofthecoast.com.

After years in Florence (where it began as the Heceta Head Coastal Conference), organizers decided to move this year to Coos Bay in response to requests to bring the event to other Oregon coast communities.

State of the Coast brings scientists, students, industry and everyday citizens together to learn, network and engage in conversations about the current and future state of Oregon’s ocean and coastal environment.

This year’s morning plenary session will provide quick updates on coastal issues including new DEQ water quality rules, marine reserves, Oregon’s shellfish initiative, changing ocean conditions, an overview of 2014 fisheries and the threat of a Cascadia subduction zone earthquake. Afternoon break-out sessions allow participants to choose a topic to explore in more depth: Forage fish, Cascadia Earthquake, “The Blob”, Innovations in Fishing, Citizen Science Opportunities, Aquatic Invasive Species, and more.

The popular student research poster session will give participants an opportunity to interact with some of the state’s brightest university students and learn about current ocean and coastal research at Oregon universities.


The post Register now for State of the Coast, this year in Coos Bay appeared first on Breaking Waves.

Categories: OSU Extension Blogs

Food Science Camp 2013 and Erik Fooladi

Bringing Food Chemistry to Life - Fri, 07/19/2013 - 1:44pm

We participate in the Oregon State U Food Science Camp for middle school students.

Part of the STEM [science technology engineering math] Academies@OSU Camps.

We teach about bread fermentations, yeast converting sugars to CO2 and ethanol, lactobacillus converting sugar to lactic and acetic acids, how the gluten in wheat can form films to trap the gas and  allow the dough to rise. On the way we teach about flour composition, bread ingredients and their chemical functionalities, hydration, the relationships between enzymes and substrates [amylases on starch to produce maltose for the fermentation organisms]; gluten development, the gas laws and CO2′s declining solubility in the aqueous phase during baking which expands the gas bubbles and leads to the oven spring at the beginning of baking; and the effect of pH on Maillard browning using soft pretzels that they get to shape themselves..

All this is illustrated by hands on [in] activities: they experience the hydration and the increasing cohesiveness of the dough as they mix it with their own hands, they see their own hand mixed dough taken through to well-risen bread. They get to experience dough/gluten development in a different context with the pasta extruder, and more and more.

A great way to introduce kids to the relevance of science to their day to day lives: in our case chemistry physics biochemistry and biology in cereal food processing.

We were also fortunate to have Erik Fooladi from Volda University College in Norway to observe the fun: http://www.fooducation.org/

If you have not read his blog and you like what we do here: you should!


endless pasta


Categories: OSU Extension Blogs

Good Cheese, Bad Cheese

Bringing Food Chemistry to Life - Wed, 07/10/2013 - 1:25pm

pH, colloidal calcium phosphate, aging, proteolysis, emulsification or its loss and their interactions lead to optimum melting qualities for cheeses. A module in this year’s food systems chemistry class.

This module was informed by this beautiful article “The beauty of milk at high magnification“ by Miloslav Kalab, which is available on the Royal Microscopical Society website.


Of course accompanied by real sourdough wholegrain bread baked in out own research bakery.

Inspired by…

“The Science of a Grilled Cheese Sandwich.”

by: Jennifer Kimmel

in: The Kitchen as Laboratory: Reflections on the Science of Food and Cooking

Edited by Cesar Vega, Job Ubbink, and Erik van der Linden


Categories: OSU Extension Blogs

February 2011- Nutrition Education Volunteers taking “vacation”

Family Food Educators of Central Oregon - Tue, 02/01/2011 - 9:24am

I’m back from maternity leave and getting resettled into some new responsibilities.  We had a staff member leave us, so Glenda and I are having to pick up the work load until we find someone new, or our responsibilites change.  Being a new mom is lots of work too, so I’ve gone part time (24 hours aweek) but am still trying to get everything done… that being said, we’ve decided to put our nutrition education volunteering on hold, until I have a managable workload.

We look forward to being able to start things back up in the summer or fall of 2011.  Thanks so much and since a few of you have been asking, here’s a photo of our boy.  He is 5 months old today!

Bundled out in the cold!

Categories: OSU Extension Blogs