Field Notes: Ground Truthing Forest Data

By John Pemberton, VDOF FIA Program Manager, and Ryan Hewitt, FIA Specialist

When you read facts about Virginia’s forestland, do you ever wonder where this information comes from? In many cases, the source is the Forest Inventory & Analysis (FIA) program. FIA field crews put boots on the ground to collect information such as the number of acres of forestland (approximately 16 million); the most common forest type (upland hardwood, around 80%); the most common tree species (red maple by number of trees, loblolly pine by volume), and lots more.

A Bit of History

By the early 20th century, much of the virgin forestland of the Upper Midwest, Southern Appalachians and southern longleaf pine forests had been harvested. Nationally, there was concern that a “timber famine” might be coming. In 1928, Congress passed the McSweeney-McNary Act, creating a national Forest Survey to assess the condition of the forest resource. The USDA Forest Service’s research branch was tasked with conducting these surveys. The first Forest Survey of Virginia was published in 1940, with subsequent reports in 1957, 1966, 1985 and 1992.   

In the late 1990s, there was a significant shift in the way the Forest Survey – now called Forest Inventory & Analysis – operated. Needing more current information to make resource management decisions, the state forestry agencies in the South began partnering with the USDA Forest Service Forest Inventory & Analysis program, with the states providing the field personnel and the USDA Forest Service providing the structure, processing and reporting. Now, rather than a published report every 7-9 years, there is an annual update posted online, with a more comprehensive report every 5 years.      

How does FIA collect data?

The FIA program monitors approximately one plot per 6,000 acres (roughly three miles apart), with around 5,000 total plots in the state. The plots run the gamut of Virginia’s landscape: public and privately owned lands; backyards and remote wilderness areas; young pine plantations and older hardwoods; open park-like stands and brush-choked understories; swamps and steep slopes; recent cut-overs and mature stands. Twenty percent of the plots in each county are re-measured annually, to provide an update on the condition of the forest resource.

FIA crew at work on a steep slope

FIA field crews are typically made up of one or two people. For each plot, they collect data on land use, ownership type, forest type, stand age, any disturbances or harvesting, invasive plant species, site productivity, and other factors. For individual trees on tally, they record information such as location, species, diameter, crown characteristics, bole quality, tree grade, length of bole and damages.

The use of GPS is a huge help in locating these standing plots. While most plots are simply accessed by driving into the vicinity and hiking in, reaching others can be more complicated. For example, some Great Dismal Swamp National Wildlife Refuge plots require the use of a boat or canoe, and other parts of the state require extensive off-road driving or an ATV. In addition to the typical brush and steep slopes, crews accessing plots in western VA may have to navigate around cliffs, as well as strip mine high walls on the Cumberland Plateau. 

Stuck in the mud

Like other VDOF field staff, field crews encounter other challenges in the course of their work. They deal with heat, cold, precipitation, and humidity on a daily basis. They fight through greenbrier, blackberry, rhododendron, mountain laurel, autumn olive, and oriental bittersweet. Then there are the pests: mosquitoes, deer flies, gnats, yellow-jackets, ticks, and chiggers. Sometimes there are exciting wildlife encounters – anything from timber rattlesnakes and copperheads to black bears. Since 80 percent of the plots are on private lands, the crews interact with a wide range of interesting landowners and properties in the course of their work.

Ryan Hewitt, one of VDOF’s FIA specialists, offered his perspective on field work:

I often get asked by other forestry professionals what it’s like being an FIA forester and “doing the same thing, day after day.” The truth is, it is the same every day but your office is constantly changing. One day I might be driving 3 miles behind a gated Forest Service road and having to cut trees out of the road to reach a stand of 150 year old chestnut oaks, while the next day I could be digging around stumps in a fresh cutover trying to locate tagged stumps in order to find the metal pin that marks our plot center location. It’s that change in scenery that keeps my job fresh and fun. Yes, the measurements are the same from plot to plot, but the different areas you see and the people you meet have kept me in this position for a little over 13 years now.

Some of us FIA “ninjas,” as we are called by some other DOF employees, joke that a normal day in the woods for us is something that people working in a big city high rise would pay to be able to do on a weekend. Driving rough, rocky roads, navigating rock outcrops, and crossing streams only to park the truck and then hike through the woods is something we do on a daily basis for work, while others long to do the same thing on a weekend excursion. Plenty of times, I have found myself on ridgetops with amazing views, and I think to myself, “This is a pretty good job, getting paid to do and see these things that most people never get to experience.”

Scenic views are all in a day’s work.

Landowner interaction is a large part of FIA, and each time I knock on a door, it’s always a surprise. With these plots being randomly picked, I’ve talked to landowners that own a ¼ acre parcel of land where our plot falls to landowners who own thousands of acres. In most cases, there is never any issue with obtaining permission to access their property, and a lot of the time our conversations evolve into forest health, pests, how to go about planting trees, etc. Several times in my career, I have been invited to have lunch with landowners, been offered use of their ATV, and shown around properties these landowners are so proud of. Only a few times have I been denied permission to measure a plot, and only once have I had to listen to a landowner’s conspiracy theory on tree data collection. I commonly get told, “Be careful, there are snakes out there.” One snake is easier to work around than a nest of 50 angry yellow jackets!

The FIA program’s scientific data collection provides much more than a snapshot in time. Forest data illuminates trends and issues that inform forest management and policy decisions. Below are a couple of basic data charts showing changes in Virginia’s forest resource over time. You can download Virginia’s latest report for more fascinating FIA facts and figures.


Field Notes: January’s Least Wanted – English Ivy

By Ellen Powell, VDOF Conservation Education Coordinator

A brand new year brings a brand new feature to Field Notes! Each month, one of our posts will introduce one of Virginia’s “least wanted” – an invasive species that’s easy to spot at that time of year. It might be a plant, an insect, or a disease that’s impacting our state’s natural communities. We hope you’ll keep an eye out for the pest on your own property, treat or remove it when possible, and spread the word about it to your friends and neighbors.

English ivy in its typical juvenile form

January’s least wanted is probably familiar to everyone. Perhaps, like me, you used it as the base for your Christmas wreath. It’s English ivy (Hedera helix), and it’s easy to see why European colonists brought it here with them. Viewed objectively, ivy is an attractive evergreen groundcover and climbing vine. But it’s harder to be objective when you know the dark side of English ivy.

Ivy in suburban woodland

Ivy in forests reduces plant biodiversity. The plant is highly shade tolerant and can completely cover the forest floor, to the exclusion of native understory plants and tree seedlings. Vines may climb as high as 90 feet, meaning ivy can easily overtop trees, blocking photosynthesis, which eventually starves the tree. Ivy also weighs down branches, making trees susceptible to breakage and windthrow during storms. If all that wasn’t bad enough, ivy is also a host for bacterial leaf scorch, a disease that affects oaks and other native trees.

In yards, ivy creates problems for homeowners. Its sticky aerial roots adhere to surfaces and retain moisture, potentially damaging any structure it climbs. The sprawling vines create thick mats that may harbor rats, mosquitoes, and other unwanted pests.

If allowed to grow unchecked, English ivy will eventually undergo a Jeckyll-to-Hyde transformation. It reaches its adult form around ten years of age, if the vines have achieved sufficient height and sunlight. The leaves change shape, losing their lobes to become more ovate. More importantly, the plant begins to flower and produce fruit.

Adult form, with flower cluster, top left, and fruits

Ivy produces a lot of berries (technically, they’re drupes, for those of us who like nerd words), which are highly visible this time of year. The fruits are toxic if eaten by humans, and they’re thought to be mildly toxic to birds as well; but, given their availability as a winter food source, birds eat them anyway. The seeds germinate best when the pulp has been removed. Interestingly, one study showed the best germination from seeds that had been regurgitated by birds, but passing through a bird’s gut works, too. Either way, new seeds tend to be dropped wherever birds perch, and soon new vines are making for the canopy.  

If English ivy makes your least-wanted list, you can get rid of it with some good old manual labor. Whether you choose to eliminate or simply control ivy, don’t allow it to reach its adult, fruiting form. If the ivy is simply running along the ground, mowing it regularly can keep it under control. Even better, remove vines by pulling them up, which is easier when the ground is moist. Be sure to wear long sleeves and heavy gloves; English ivy is NOT related to poison ivy, but the vines can cause contact dermatitis in some people. Pull climbing vines away from the base of trees or structures and clip every stem. Don’t try to rip vines off the whole tree, as you’ll probably remove a good deal of bark along with the ivy. Just be patient – the entire plant above the cuts will die back, eventually turning brown and losing leaves.

Unfortunately, none of these control tactics is a one-and-done solution. The plant will resprout from the roots, or from nodes of ground-running vines. Complete control can take years in some cases. English ivy’s waxy leaves are resistant to herbicides. If you choose to use a chemical, make sure you get a product recommendation from your local Extension Office or from the USDA Forest Service’s A Management Guide for Invasive Plants in Southern Forests.

Ivy in neighborhood common area

Unfortunately, ivy is still sold in nurseries. Given its prevalence in the landscape, you probably won’t have to look far to find an ivy infestation – tree trunks covered in green really stand out in the winter woods. Ivy is often obvious in neighborhood common areas – the wooded strips between home sites. How about a new year’s resolution to remove ivy from your property? If you spread the word about ivy’s downsides, maybe your homeowners’ association will follow suit.

A Christmas Present for Stony Creek

The walking track in Sussex County’s Stony Creek Park is a well-used community resource. Citizens use it for exercise, and for years, the Virginia Department of Forestry (VDOF) has used it for firefighter pack tests.

Walking the open track in the summer heat gave Zach Dowling, Senior Area Forester for VDOF’s Waverly work area, an idea. Last summer, Zach mentioned to town council member Mike Moody that shade trees would be a great addition to the park. In addition, planting trees in the park would be the first step in establishing a riparian buffer along Stony Creek, which flows into the Nottoway River.

The town didn’t have the money for trees, but VDOF’s Urban & Community Forestry (U&CF) program offered Water Quality Impact Assessment (WQIA) funds to support the planting project. Zach presented the idea at a town council meeting in August, and the members unanimously approved it.

Lara Johnson, VDOF Urban & Community Forestry Program Manager, came up with a plan for spacing trees through the park surrounding the track. Species were chosen for site suitability, shade potential, and seasonal color. They included willow oak, baldcypress, downy serviceberry, Eastern redbud, sweetbay magnolia, river birch, eastern hophornbeam, and black gum. The grant not only paid for the trees, mulch, stakes, and cages, but also allowed for a contractor to pre-dig the planting holes.

VDOF planters at work

On December 2, a team of local VDOF staff planted 25 balled and burlapped trees purchased from a Richmond nursery. The planting crew consisted of Zach Dowling, Travis Tindell and Austin Babb (Area Foresters), Jim Blackwell and Jay Bassett (Forest Technicians), Lara Johnson, Molly O’Liddy (U&CF Partnership Coordinator), Brian Lacy (Pine Resource Specialist), Jim Schroering (Southern Pine Beetle/Longleaf Pine Coordinator), and Bryant Bays (Eastern Regional Forester).

A cage helps protect a newly planted tree from deer and mowers.

The group planted, mulched, staked, and caged all 25 trees in three hours, creating an early Christmas gift for residents of Stony Creek to appreciate for years to come. Future VDOF pack testers will also breathe a little easier in their shade!