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.

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Field Notes: What’s in the Woods Today? April 22, 2019

by Area Forester Lisa Deaton

Two Snake Day!

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Last week the sun was shining, and the fresh spring foliage and flowers were lovely.  The road in the photo above was a Gloucester County state road until Beaverdam Reservoir was built in 1989,  submerging a section of this road.

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Pawpaw blooms (Asimina triloba)

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Eastern redbud blooms can resemble tiny hummingbirds. (Cercis canadensis)

Then I almost stepped on a copperhead snake heading in my direction.  We both jumped backwards.  This is the first copperhead I have seen on the Middle Peninsula after four years of working here.   They are one of Virginia’s few species of venomous snakes.

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As you can imagine, I was more alert after this snake encounter.  Yet, I was still surprised to come across one more snake as I was leaving the woods (below and cover photo).  I believe this one was a northern black racer, judging by the descriptions at the Virginia Herpetological Society website.  The snake retreated to this tree hollow and tapped its tail back and forth rapidly under some leaves to create a rattling sound.

It is not super common to see snakes while walking in the woods, but they seem to be less cautious and easier to find during the first few weeks of warm, 80-degree weather.

 

Field Notes: What’s in the Woods Today? March 18 2019

By Area Forester Lisa Deaton

Parasitic Plants

parasitic plants1American or eastern mistletoe, Phoradendrum leucarpum, is a common parasite of oaks and maples in the Coastal Plain of Virginia. Birds carry the sticky white mistletoe seeds from tree to tree.  The seeds sprout and their roots grow into the host tree to extract water and nutrients.parasitic plants2

In our eastern deciduous forests, winter provides a clearer view into the woods.  The deciduous leaves are gone, and we can see all of the things hidden by summertime foliage.parasitic plants3

For instance, it was quite a surprise to see this eastern redcedar tree, Juniperus virginiana, growing in a black walnut branch 20 feet above the ground (center of photo above).  This is especially unusual because black walnut, Juglans nigra, is famous for its competitive advantage of releasing a juglone chemical that is toxic to plants growing over the top of its root system.  Evidently, this branch presented the perfect sprouting conditions for an eastern redcedar berry.  Cedar berries are not sticky, but they sprout more readily after passing through the digestive tract of birds and animals.  This cedar has thrived for 4-5 years according to the landowner.parasitic plants4

The burl on this scarlet oak, Quercus coccinia, was also easy to see from a long distance away (below).  Burls are not parasites; they are wood formations in response to injuries or stress such as a virus, fungus, mold, insect or a gnarly combination of stressors. parasitic plants5