Southeast Volusia Audubon Society, P.O. Box 46, New Smyrna Beach, FL 32170;

February 2013 SJRWMD Update

Seeing the Forest for the Trees.  Technology and hands-on methods ensure accurate timber count.

Paul Hudson and Chris Oman maneuver deftly through the thick undergrowth of the forest, intuitively dodging waist-deep palmettos and ever-present gallberry bushes to reach their target.

“I see it,” says Oman, gazing through the uniform rows of slash pines. “The ribbon is on that pine straight ahead.”
Hudson and Oman wend their way to the tree and begin gathering data. Using tape measures and small handheld computers, they determine the height, diameter and number of trees in this particular plot within Lake George Forest in Volusia County. The men are pleased by their findings: their data jibes with information recorded by “cruisers” hired to conduct an annual inventory of timber on St. Johns River Water Management District lands. A cruiser is a forester who gathers timber inventory data and “cruising timber” is the act of conducting the inventory, Hudson explains.

Hudson is a District land manager; Oman, a District geographic information system analyst. During the District’s annual timber inventory, the pair serves as quality controllers, ensuring that professional foresters hired to collect information about the agency’s timber holdings are accurate in their calculations.

To meet state statutes requiring proper management of District lands, each year the District inventories 1,000 plots of wooded uplands, which represent 20 percent of the uplands tracked in the agency’s forestry database. You could count every tree to get an appraisal, but it would be costly and time consuming. The District uses the more common method of “sampling” plots of forest.

“Inventories are driven toward a harvest schedule,” Hudson explains. “The inventory helps to determine when an area is ready for harvest. It helps to understand what you have, how much you have and its value.”
Harvesting ensures the public forests will remain robust. As an added benefit, funds generated through the sales of timber are used to help operate the District’s Land Management Program.

“From an economic standpoint, our forestry database helps us project future revenues derived from timber sales,” says Steve Miller, who heads the District’s Bureau of Land Management. “The ecological drive of our decisions is making sure the forest is healthy and growing in the desired range. We want to be sure the forest has the right amount of canopy for the wildlife and understory plants to thrive there. If the canopy is too dense, it can impact the health of the trees as well as the wildlife and the ground cover. This data helps us to try and maximize the correct balance of both the ecology and economics of the forest.”

To the untrained eye, a forest may seem virtually unchanging, a place where the geometry of plank-straight planted pines are indiscernible from one another. Hudson knows otherwise. Wildfires can devastate timber, rendering the previous years’ data null and void. So can timber harvesting.

“Forests are dynamic, always evolving and changing,” says Hudson. “What exists in a forest today will be different a year from now. If we harvest a plot, for example, our data for that plot is no longer accurate.”
At Lake George Forest, Hudson and Oman quickly gather measurements of a plot, a circular area of trees measuring one-twentieth of an acre. Their Nomad handheld computers are equipped with a global positioning system (GPS), which guide them to the precise plot locations that the cruisers have inventoried.
Oman calls out measurements to Hudson: “Eight point eight.” Hudson confirms that Oman’s calculation of the width of the pine is nearly a perfect match with the cruiser’s calculation. Oman paces 66 feet away from the tree and measures the tree’s height by gazing through a clinometer, a common tool used in forestry to measure slope, vertical angles and — in combination with distance measurements — elevation change or tree heights.

“It’s all just trigonometry,” Oman says, still looking through the clinometer. “This tree is approximately 61 feet tall.”

The Information Age, not surprisingly, has improved the speed and efficiency of the inventory process. In the old days, says Hudson, foresters relied on a paper map and compass to find their way to inventory sites. The Nomads not only provide GPS locations, but allow foresters to record data in the field and download it to desktop computers at the office.

“When we measure the height of one tree in the plot, the computer will determine the heights of the rest of the trees based on their diameters,” Hudson adds.

The bottom line is that timber harvesting gives water management districts opportunities to generate revenue in an environmentally acceptable manner to offset management expenses.

“It’s amazing how fast the vegetation recovers after harvesting,” Hudson says. “When I show people a site that’s been harvested five or 10 years ago, they say, ‘It looks beautiful.’ They have a new perspective of the benefits of managing forests.”

Ed Garland