Owning and managing timberlands can be rewarding for a variety of reasons. Many people can use their timber stands to foster healthy game populations for hunting seasons in addition to occasionally collecting a bit of income through harvesting. For landowners, understanding timber stand productivity is crucial to getting the most out of their trees.

Here are a few things for landowners to consider when it comes to timber stand productivity!

What Is a Site Index and Why Do You Need One?

To best understand the productivity of a timberland, landowners should have a site index conducted on their property. During his recent appearance on the National Land Podcast, KY Land Broker Kraig Moore shared his experience and knowledge from 20+ years of work in the forestry industry. 

Regarding site indexes for timberland properties, Moore stated the following:

“[A site index] is basically a gauge of productivity. In the central hardwoods section, it’s a measure of the average height of the dominant and codominant trees that are 50 years of age. If you’re down in Alabama or Georgia and you’re dealing with Pine, it would be at 25 years of age. So, if you have a tree that’s 50 feet tall at 50 years old, that’s a site index of 50 which would be considered pretty low-productivity by most standards.

Now if you can get a site index of around 70-80, where you’ve got a tree that’s 80 feet tall at 50 years old, that’s a pretty good rate. You can also go on web soil surveys and look up the soil types, which should tell you what the site index is for that soil and how productive that soil should be for that tree.”

Moore went on to recommend that a timber stand with a site index of above 60 is fairly productive and would be worth a landowner’s time to effectively manage. While a site index can give a landowner a good understanding of their soil quality, this isn’t the only metric that factors into timber stand productivity.

Consider the Impact of Slope Direction

One often overlooked factor that plays heavily into the productivity of a site is the direction of the site’s slope. Slope direction can be the difference between a highly productive timber stand and one that may not be worth a landowner’s time to meticulously manage. Stressing the importance of slope direction, Moore stated:

“There’s so much more that goes into the productivity of a stand. It’s not just the soil type, it’s also the direction that the slope faces. Many people don’t think about it, but if you’ve ever had a house that’s facing South, then you know at the end of the day the sun is beating your house to death and you don’t even want to go out back.

In the woods, a southern slope will get more sun which will make it drier, and different species can tolerate that dryness better than others. If a slope is facing the north, then the will rise and fall and never really directly hit it the way it would if it was facing South. So moisture stays in the soil longer because it won’t get pumped out by the trees due to excessive heat. And so this makes a tremendous difference. 

In my County here, you can be on a North slope with beautiful timber but once you cross over to the South slope, you’ll see rocks sticking up out of the ground and the productivity falls off significantly.”

In terms of how slope direction can impact a site index, Moore went on to explain that while a north-facing slope could have a site index of say 75, a south-facing slope of the same soil composition could be assigned an index of 50 or 60 instead. 

Understanding site indexing and the factors that affect it is important knowledge for any timberland owner!

Understanding Crown Spacing

Crown spacing is another important concept for timberland owners to understand, as improper management practices can significantly hinder new growth and tree productivity. Crown spacing refers to the distance between the crowns or top branches of trees adjacent to one another.

Proper spacing will allow timber stands to flourish as it reduces competition between trees for resources like sunlight, water, and nutrients. Trees that are too close together can experience stunted growth and increased vulnerability to pests and diseases. 

Conversely, giving trees too much space at the crown can cause other issues, as Moore explained, “If you give a tree too much crown space, the sun hits the bowl of the tree and it causes it to start branching out on the lower parts of the tree which will affect the overall quality.”

Through selective thinning, landowners can remove some trees that are inferior in value and quality to the dominant species and achieve crown spacing that balances tree density and resource availability.

What Types of Trees are Most Valuable?

When it comes to valuable tree species to focus on for a timber property, hardwoods are primarily where much of the value in timber lies. Moore explained this, stating, “White Oak and Walnut are the dominant value trees. White Oak especially has gone crazy, it used to be that Red Oak was worth more than White Oak. But realistically any of the major trees like White Oak, Red Oak, Ash, Poplar, or Walnut are going to be the ones you’ll really want to have.”

While these trees tend to maintain their value very well, there are a variety of factors that can impact timber value on a piece of land such as site-productivity and slope direction as discussed earlier. 

In terms of maximizing the value of a timber stand, one important thing for landowners to keep in mind is to refrain from “hydrating” a timber stand when it comes time to harvest. “Hydrating” refers to taking the best and most high-value trees while leaving the rest. By only harvesting the valuable trees, the less-desirable trees are left to reproduce which allows them to become the dominant species and will negatively impact the overall value of the timber stand.

A better understanding of what factors into timber stand productivity is essential for any landowner looking to make the most of their timberlands. If you’d like to learn more about how you can improve timber stands on your property, contact your local Land Professional today!