Field Notes: White Pine Monitoring in Western Virginia

By Forest Health Specialist Katlin Mooneyham

Eastern white pine is a species commonly found in forests in the western part of the state. In Virginia, eastern white pine is grown for wood production, Christmas trees, holiday garland and ornamental plantings.

In 2006, former VDOF Forester John Wright noticed that white pines were declining in his work area in Highland County. He called the forest health program manager at the time, Dr. Chris Asaro, out to collect samples. They observed trees with browning needles, crown thinning and dieback, resinosis (streaking of resin), and canker (open and exposed tissue) development on the trees. Upon closer inspection, tiny fruiting bodies or “eyelashes” were noticed on the main trunk, and branches and small round shiny dots were seen within cankers. Samples were sent off to a pathologist with the USDA Forest Service and it was determined that there was a small scale insect (round dot) called Matsucoccus macrocicatrices and a fungal pathogen (eyelashes) called Caliciopsis pinea. It is unknown what the exact interaction is between the two causal agents, but the work of both has led to this decline being labeled a complex.

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Caliciopsis pinea under magnification on a white pine branch
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Matsucoccus macrocicatrices under magnification on a white pine branch
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Symptomatic white pine in western Virginia

As Dr. Asaro started to see more symptomatic white pine, he decided to set up long-term monitoring plots to record the health and general conditions of these trees in western Virginia. Four sites were set up, one in each of the following counties: Bath, Highland, Augusta and Grayson. Within each site, four plots were established to collect data. Both the scale and pathogen have been found at each plot, and overall white pine health has been monitored since 2012.

Tree mortality in a forest is a natural process and part of natural thinning as trees mature and start to compete with each other for resources. This baseline mortality for eastern white pines in Virginia was determined to be between 12 and 14 percent. However, initial results from our VDOF white pine monitoring study indicate that there is some white pine mortality above normal baseline levels, most noticeable on smaller-sized trees. To better understand if/how this impacts larger trees, more data will need to be collected.

This spring, the VDOF Forest Health staff will return to these sites and take annual measurements. These measurements will be added to the current data set to help better understand the big picture of what is going on with this white pine scale/pathogen complex. Additionally, samples of scale and fungus will be collected and sent to researchers at the University of Georgia where they are studying the interactions between these two damaging agents (scale and fungus), as well as developing better survey techniques to continue monitoring white pine health.

Forest Health: A Small But Mighty Pest

The southern pine beetle (Dendroctonus frontalis) (SPB) is a small, seemingly innocuous beetle that brings new meaning to the phrase “small but mighty.” These beetles are known as the most destructive native forest insect in the Southeastern United States. While a single adult beetle is only about 1/8 inch long, the ability to aggregate quickly means these tiny insects can overtake a pine tree’s defenses in a short period of time. All species of southern pine are targets for SPB but favorite hosts include loblolly, shortleaf, Virginia and pitch pine.SPBpic1

Females emerge first in the spring and fly to a suitable host where they bore into the tree and start creating their infamous “S”-shaped galleries in preparation for laying eggs after mating. Shortly after, they emit a pheromone (think seductive bug perfume) and the masses begin flocking to the suitable host tree. Each female is prolific with her egg production, producing upwards of 150 eggs over the course of her life! These eggs are laid in the galleries where the developing larvae then feed on the inner bark. As trees are killed or fill up with beetles, the outbreak spreads to neighboring trees and continues until suitable host material is no longer found or control measures are taken.SPBpic2

Historically, outbreaks of these destructive insects have been cyclical, occurring on average every five to seven years. Since they are native, they have a predator complex which helps control the populations and regulate outbreaks. However, since the early 2000s these outbreaks have been less common and almost non-existent here in Virginia. Many factors may contribute to the decrease in southern pine beetle abundance, including more intensive silvicultural practices, genetically improved trees and forest fragmentation.

The last big southern pine beetle occurrence noted in Virginia was first detected in 2012, and had become a full outbreak by 2014. This took place on Chincoteague National Wildlife Refuge. The U.S. Forest Service observed the outbreak in 2016 from the air, and documented an average of 46 active SPB spots per thousand acres of host type. The average spot size calculated to be 1.5 acres. When a ground check was done, all spots visited had active adult, larvae and eggs, indicating that the population was still thriving. This area was hit particularly hard due to many factors: most of the pine was over-mature, overstocked and stressed from saltwater intrusion leading to a beetle buffet, ripe for the picking!

Unfortunately, no control efforts were enacted and the population continued to spread and the outbreak ultimately died out on its own. VDOF Forest Health staff flew the impacted area in October of 2018 and mapped 475 acres of pine mortality.

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To monitor populations and predict future beetle spots, each year VDOF Forest Health sets up traps that are baited with pheromones mimicking the ones produced by females and stressed trees throughout the state. Trapping starts in spring, around the time that beetles would start looking for suitable trees. Last year, we trapped in 10 counties, placing a total of 24 traps around the state. VDOF foresters and Virginia Department of Conservation & Recreation employees sample each week and VDOF Forest Health sorts the contents, counting the number of SPB caught as well as their associated natural predator, the clerid beetle. The good news for Virginia is that our SPB population levels continue to persist at low and static levels! We will continue to monitor these insects and their activity (or lack thereof!) and trapping efforts are planned for spring of 2019.

Field Notes: Pine Yellows

by Senior Area Forester Joe Rosetti

Every year, about 4-8 weeks after the deciduous trees lose their leaves, the pines of Virginia display a condition we will call Pine Yellows.  Pine Yellows is characterized by about half of the needles on the seemingly healthy trees turning yellow, then after 1-2 weeks falling off.  The trees do not display any other signs of disease or insect damage, and except for the changing color, appear perfectly healthy.  Upon closer inspection, you will see the needles that are turning yellow are only on the interior of the tree. The needles at the ends of the branches are staying green.  The yellow needles come off easily when pulled or brushed.  If this describes pine trees near you, then fear not.  Pine Yellows is perfectly normal.

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Pine trees, along with spruce and fir, are evergreen, so it’s generally thought they keep their needles forever.  However, the trees needles are their leaves and leaves don’t last forever.  The needles you see turning yellow and falling off now are the needles that grew in the spring of 2017.  Every spring, the trees grow their branches longer and grow new needles at the ends of the branches.  They keep the previous year’s needles and grow through the summer with the needles from this year and last year.  When fall comes, last year’s needles fall off (resulting in the condition Pine Yellows) and the trees go through winter with the needles that grew this spring.  So in our case, the needles turning yellow now are the needles that grew in 2017.  The needles staying green grew in 2018, and they will stay through the winter.  In spring of 2019, the branches will grow and grow new needles, and the 2018 needles will turn yellow and fall off in November of December of 2019.

So if your pine trees are displaying Pine Yellows, don’t worry.  You can rest assured it is perfectly normal.

Field Notes: What’s in the Woods Today? June 25, 2018

Bird’s Eye View

by Area Forester Lisa Deaton

DOA Cessna lo res (1)

Once a year, area foresters have the opportunity to fly over VDOF work areas to check for forest health issues and evaluate herbicide work from the previous summer.   We meet planes and pilots from the Virginia Department of Aviation at local airports, provide them with a flying route and then take off down the runway.

take off

The hour-long flight covers several counties, so we take a lot of photos to review back at the office.

taking photos

These flights are called “Green Streak Flights” because we are making sure tracts that were aerially sprayed with herbicide received the coverage guaranteed by the contractor.

Managing Pine

On the Middle Peninsula, the warm, rainy climate and long growing season help clearcut harvests “overpopulate” the land with natural pine and hardwood seedlings, as well as grasses, forbs, and vines.  In order to maximize pine growth, research has pointed towards several site preparation options.  One option is to spray the tract after its first full growing season with herbicide to control the natural vegetation before planting pines.

Basically, spraying a tract and planting genetically improved pine seedlings provides faster growth than would occur if the naturally seeded trees competed with each other for several years to see which ones would win the contest for enough sunshine, water, nutrients and space to survive.  We plant loblolly pine seedlings at 484 trees per acre; nature sometimes seeds in clearcuts with 2000 seedlings per acre.  It is a lot like planting a garden; you need to prepare the planting site first by removing the weeds, then planting your vegetables.

Prior to herbicide treatment, VDOF foresters map all of the tracts that will be treated and provides the aerial spray contractor with a map and Shapefile.  The VDOF foresters may also flag hard to see spray boundaries on the ground with white plastic trash bags and colored ribbon.

Safety

Aerial and ground broadcast spray application performed under VDOF contracts is not allowed within 50 feet of interstates and primary highways; within 50 feet of flowing streams or drainage ditches, or 100 feet of impoundments, except public water supply lakes where no treatment shall be allowed within 500 feet, and trout streams where no treatment shall be allowed within 200 feet; within 300 feet of any residence, store, or other building normally housing people or within 500 feet of any school, hospital, or other public gathering place unless written permission has been obtained.  These treatments are also only done during calm days when the wind is less than five miles per hour.

The View from Above

In the photo below, some “green streaks” of vegetation that were not sprayed are outlined in red.  The aerial spray contractor sent a ground crew with backpack sprayers to cover the areas missed by the helicopter.

Dame greenstreaks

Here (below) is what a “green streak” looks like on the ground.

skinny streak

The next photo shows an active southern pine beetle spot with some dead pines and red-topped dying pines.  In this case, we can contact the landowners about harvesting the beetle infestation before it spreads.

beetle spot

Our area had received several inches of rain in the weeks prior to our flight on June 6.  So, it was no surprise to see standing water in cutovers on flat terrain.  Hopefully, the puddles in the photo below will last long enough to provide water to recently planted loblolly pine seedlings without drowning their roots.

wet land

The photo below shows an area of Dragon Run State Forest that was prescribed burned to prepare the site for planting trees the following spring.  From the air, we can see a few small green patches in the cutover that did not burn so well.

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Burning as a site preparation method provides a quick return of nutrients to the soil and is a less expensive means of removing competing vegetation than herbicide.  Burning also provides a mineral seed bed for many grasses and forbs that benefit wildlife.

The Green Streaks flights are quick, but provide us with a great deal of information to help us protect and develop healthy, sustainable forest resources for Virginians.

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Southern end of Gloucester County looking south towards the York River and Yorktown.

More information on the pine management activities mentioned in this article is available at http://www.dof.virginia.gov/manage/pine/how-to.htm.

Field Notes: Field Day at Zuni Pine Barrens

by VDOF Longleaf Pine/SPB Coordinator Jim Schroering

Several VDOF staff participated in a field tour of the Zuni Pine Barrens in Isle of Wight County earlier this month. The Zuni Pine Barrens is a cooperative conservation project made up of the Blackwater Ecological Preserve (Old Dominion University) and the Antioch Pines Natural Area Preserve (Department of Conservation and Recreation).

ODU Professor of Botany and Zuni Pines Preserve Manager Dr. Lytton Musselman and Dr. Cecil Frost, retired plant ecologist, director of rare species at the NC Natural Heritage Program and private consultant for fire ecology, were instrumental in establishing the Zuni Pine Barrens over 40 years ago.

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Dr. Musselman (left) and Dr. Frost (right)

They, along with graduate students from ODU and staff from DCR’s Natural Heritage Program, led tours and discussions about rare and endangered species found on the property, current prescribed fire regimes and efforts to document and re-establish native longleaf pine on the preserve. More than 45 individuals participated in the field day.

Highlights of the tour included finding a rare archaeological site known as a ‘tarkel.”

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Dr. Musselman discusses the tarkel

Participants also looked at a crude site used to extract naval stores (pitch, turpentine, tar) from the burning of longleaf in covered pits, and a longleaf pine stump estimated to be over 350 years old.

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Field Notes: How do Trees Grow in the Nursery?

by Area Forester Manij Upadhyay

I went to Garland Gray Forestry Center, Courtland Virginia to learn about pine seedling production last week. Our nurseries have been growing quality seedlings based on research and experience for 100 years. The day that I arrived at the nursery people were lifting seedlings from the bed with the help of a machine called a lifter.

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Full bed belt lifter

Do you know how seedlings are grown in nurseries?

Selection of the best seed is the most important part of nursery production.  Seeds are collected from fast-growing, straight and disease-resistant trees. In southeast Virginia, the best time for seed sowing is spring. Regular watering and application of fertilizer is required for growth and development of the seedlings. In addition, treatment techniques to protect seedlings from various insects, diseases and weeds are used.

During the production of seedlings, shoot and root pruning practices are used. These techniques help to increase crop uniformity, control height, and prepare the seedlings for shipping.

Most bare root seedlings are taken out from the seedbed in the winter. Seedling lifters and transporters are used for lifting and transporting the plants from the field to the grading building.

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Seedling transporter

During packing, seedlings are graded separately based on size and quality.  Packed seedlings are then stored in cool temperatures. Stored seedlings go dormant for shipping. Fully dormant seedlings survive better during shipment, and after planting than non-dormant seedling.

Landowners can expect excellent survival rates on our seedlings. Our young trees can be expected to grow fast and have good form for timber production.

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Loblolly pine seedling beds

Field Notes: The Wind in the Willows, Oaks, Pines …

 VDOF Urban Forest Conservationist Jim McGlone

March 2018 came in like a lion, roaring with sustained winds of 25 to 30 miles an hour.  Predictably, trees fell on power lines causing fires that VDOF personnel worked hard to put out.  Media reports highlighted the mayhem falling trees caused; but there was another big story that didn’t make headlines: while thousands of trees fell, hundreds of millions of trees did not fall.

Wood is strong and flexible; that is why humans have been building with it for millennia. Trees have not only evolved to withstand strong wind, the wind actually makes them stronger.  Just as lifting weights can cause human muscles to grow, swaying in the wind causes wood to grow.  The alternating compression and tension on cells when a tree sways causes those cells to grow more wood.  This results in the taper at the base of a tree.

Most of the trees that fell during the early March 2018 windstorm did so because they were already dead or dying.  Most people can recognize a dead tree, at least during the growing season.  However, they may not recognize a dying tree.  The pictures show a tree that failed during in the windstorm.  Last year it had leaves on it, but when it blew over it revealed that its root system was rotten.

Kidwell Farmhouse fallen tree 2018

Can you see the root rot in the standing tree?  Look closely at the crown and notice the thinning of the leaves on the edges. To a trained eye, this is a sign of root problems.

Upright Kidwell Farmhouse tree

This is why trees, like pets and people, need to see their health care professionals regularly.  Certified arborists are tree health care professionals.

The real story of the March 2-4, 2018 windstorm is not that trees fell and caused mayhem.  It is that strong healthy trees withstood the wind.  And trees grow strong and healthy when they are properly cared for by professionals.  To find a certified arborist near you visit www.goodtreecare.com.