FRANKFORT, Ky. — The state’s bourbon industry is experiencing tremendous growth, with many distilleries using homegrown commodities such as corn to give the spirit a real Kentucky flavor.

But there is another “crop” all producers must use to create true bourbon: White oak for the chard barrels used in the aging process. According to the Kentucky Distillers Assoc., 1.2 million barrels of bourbon were produced in the state in 2013, with inventories topping 5.3 million barrels, the highest since 1977.

With so many barrels being used, forestry experts are beginning to look at the white oak population to ensure there will be plenty to go around not only for bourbon makers but for all the other wood products that come from this specific hardwood.

Jeff Stringer, a University of Kentucky (UK) College of Agriculture, Food and Environment professor and extension specialist in the Department of Forestry, said oak trees dominate Kentucky’s forests, with white oak having been an important part of the wood industry for some time.

“There is a wide range of uses for this wood for the production of veneer, lumber and stave logs (wood used to manufacture barrels or casks), while white oak is also used for lower-quality products, too, like a tie log for example. Our industry is very dependent on it, especially for the manufacturing of barrels. It’s critically important for that,” he explained.

The white oak population is stable for the most part, but the issue of keeping it that way has arisen with an increase in demand and signs of slight decreases in tree numbers.

“Fortunately, we do have a very good monitoring system that provides detailed information on our forest, and that includes information at the species level,” said Stringer.

“We in fact can make estimations of the number of white oak trees we have in the state, the timber volume of white oak, the different sizes and its different grades of quality.”

That massive amount of data come via the Kentucky Division of Forestry (KDF) and on the national level from the U.S Forest Service, which provides assistance to all states in keeping track of their forestlands. “KDF has crews that specifically do nothing but monitor the forests,” he said.

“They survey 20 percent of the state a year, so every five years we have a total update on our numbers. We are fortunate we have a tracking and monitoring mechanism that can indicate whether we are losing species or not, whether there are changes in the size of the trees and the volume of the trees.”

Knowing this information becomes invaluable in an industry that impacts the state’s economy to the tune of $12.8 billion annually. Because of that, Stringer said the importance of what the KDF does in monitoring and collecting this information cannot be overstated.

As with most state government agencies, however, budget cuts have been a concern and have decreased the number of people available to collect this data. While the division has been able to maintain this Forest Inventory Analysis, as it is known, continued budget adjustments could impact the ability to monitor.

“When I’m posed the question as to whether we need to be concerned about the white oak population in this state, in order for me to be able to answer that the KDF needs to remain viable,” said Stringer. “That’s critical as we move forward with this issue.”

Tree numbers vs. volume

In keeping track of the different tree species in the state for timber purposes, Stringer said it is more important to know the “stocking level” of a specific species as opposed to an exact number – in other words, how much space in the woods a particular kind of tree is taking up. Larger trees, even if smaller in numbers, would represent more volume and take more growing space.

“Woods cover roughly half of the land in the state and the majority of that, 88 percent, is owned privately and the majority of that, 78 percent, is owned by non-industrial private land owners,” he said. “We are currently growing between 1.5 and 2 times the amount of wood that is being removed, in terms of volume.”

While that is good news, Stringer said there are a couple of questions to answer: is this volume increasing or decreasing, and what is the grade or quality of what is growing? Stave logs, for example, are of a higher quality so white oak trees that are hollow or crooked cannot be used for wood that would go into barrel production.

The concern for the industry lies in the fact the percentage of white oaks that are the right size to harvest and Grade 1, high quality, is relatively small compared to the total volume of this species.

“We may have a lot of volume out there but only 14 percent of it is the grade that could be utilized for stave logs,” said Stringer. “That’s what we really watch – our ability to grow high quality timber.”

Through analysis, it was determined from 1988-2005 white oak had slipped and lost ground in terms of volume. This was in contrast to an earlier analysis examining the years from 1975-88, when the white oak volumes had increased slightly.

Stringer noted these were not major changes, but increased demand for quality white oak timber coupled with a slight decrease in volumes is cause enough to open a conversation about the situation.

“It’s not alarming … our issue with white oak is not in the immediate future, but there is an issue long-term because we’re not seeing enough white oak re-generation as we did at one time,” he explained.

Combating the issue starts with good land management by landowners, something the KDF can help with. “The way to ensure good supplies in the future for the forest industry is good management and that the forest is being protected and managed well,” he said.

“That means you don’t burn the woods, you harvest sustainably and you conduct rudimentary good forest management. If landowners are doing this, we’ll not only be able to maintain levels of white oak, but other trees, as well.”

Stringer said in addition to the work the KDF has been doing to keep data coming, the bourbon industry has been a helpful partner in discussing solutions today about an issue that could become a problem in the future.