So, you read an article or watched a video about Forest Stand Improvement for deer habitat, and now you’re standing in the woods ready to work. You hold a chainsaw in one hand and a squirt bottle of herbicide in the other. You see lots of trees. They present lots of options. But which option do you choose for which trees? That’s the most common question we get about FSI.
I’ve been there, too. It’s a little bewildering to make the initial jump from concept to reality. FSI is like sculpting art from a piece of wood. You need to envision the end result so you know what to whittle off and what to leave.
When you’re applying FSI to deer habitat, you can hinge-cut smaller trees to create instant cover. You can girdle-and-spray larger trees to kill them and admit sunlight, which will drive natural plant growth. You can cut down some small trees to produce stump sprouts, which deer will browse. You can leave mast producers with extra room to grow big crowns and produce acorns and fruit. Which tree species are best for which techniques?
The best source of guidance I ever found is a table tucked away in the back of Dr. Craig Harper’s booklet, Forest Stand Improvement: Implementation for Wildlife in Hardwood Stands of the Eastern US. Decades of research in many regions, numerous published scientific studies, and the sweat of more than a dozen graduate students are summed up in this three-page table. In it, Craig rates 50 native tree species for their mast value, browse value and hinge-cut suitability.
We took that table and created an FSI Dashboard you will see below. But even with this handy guide based on University of Tennessee research, the choices aren’t always simple. Many trees can serve multiple uses. Before you dive into Craig’s ratings of tree species, here’s some principles to keep in mind.
About Timber Value
If you manage your land for both wildlife and future timber value, you should consult with a licensed forester before you begin an FSI project in woods where commercial timber harvests are a possibility. Many of the tree species in the FSI Dashboard have significant timber value, but the Dashboard is only concerned with deer habitat value. Maximizing future timber value while improving a forest for deer can be done, but let your forester assist.
About Mast Value
As Craig explains in his published table, “mast value” considers how many wildlife species use the fruit, seed or nuts of a tree species. Some listed trees have high mast value due to use by birds (including turkeys) and other wildlife but are not a significant food source for deer. Sugarberry, hackberry and pines are good examples. Personally, I want to provide habitat for diverse wildlife species beyond the ones I hunt.
Large Trees of Any Species
For safety reasons, we do not recommend hinge-cutting any tree species over 10 inches in diameter at breast height (DBH). Large trees can either be cut down using a felling cut or killed standing with girdle-and-spray injection of herbicides. Girdle-and-spray is preferred because 1) it is safer and faster than felling large trees; 2) downed trees create obstacles in your work area; and 3) standing dead trees are valuable for cavity-nesting birds and other wildlife.
Don’t Hinge-Cut These
As you’ll see in the FSI Guide, Craig gave a “poor” hinge-cut rating to species that tend to break, splinter, or split vertically up the center of the trunk when hinged. Splitting vertically is called a “barber-chair,” and it can be very dangerous for the chainsaw operator, especially with larger trees. So, a “poor” rating in the FSI Dashboard means “Don’t hinge-cut this tree.” Find other uses.
Red mulberry and persimmon, for example, are great fruit producers but poor for hinge-cutting. Leave them standing. Redbud and yellow-poplar are poor for hinging but produce medium quality deer forage and would be best used for growing stump sprouts.
Single-Use Tree Species
The FSI Dashboard is useful for highlighting a few trees that have a single best use. Sycamore, for example, hinges great but has no mast or browse value. Use smaller sycamores to produce hinge-cut cover. Those over 10 inches DBH can be girdled and sprayed to admit sunlight.
Versatile Tree Species
However, most of the trees in the FSI Dashboard offer multiple uses. Oaks, for example are good for both mast production and hinge-cutting. In an area with abundant oaks, you can select a few to leave for mast production, and hinge-cut or girdle-and-spray the others depending on size.
Blackgum is another example as it rates high for mast, forage and hinge-cutting. You can leave some for mast, stump some to produce stump-sprout forage, and hinge-cut some if you need instant horizontal cover.
Good Species Can Be Overabundant
Just because a tree in this list has high values for all three categories does not mean you never remove it. Any tree can be overabundant. When too many white oak saplings are competing for the same space, none of them do well. Pick one good individual to use the space and light, and remove the rest.
One big persimmon with ample space and a large, healthy crown will produce more fruit than a lot of struggling persimmon saplings fighting for domination. In situations like this, use the FSI guide to decide what to do with the surplus trees. Persimmons are poor hingers, but the forage value is medium. Let deer eat stump sprouts from the surplus trees.
Native vs. Non-native
There’s only one kind of tree that is always on the “remove” list – a non-native one. Non-native trees should be killed, whether you girdle-and-spray them or cut them down and spray the stump. This is especially true for any with invasive tendencies, like bradford/callery pears, Chinese tallow tree, Chinaberry, ailanthus, mimosa and many others. These trees not only steal sunlight that could produce deer forage and cover, they steal space and sunlight from native mast-producing trees. They have no place in deer habitat.
With the information in the Dashboard below, you will now have a better idea of how to use different tree species in FSI – assuming you know the trees! Keep a good app on your phone or field guide handy so you can identify the trees where you hunt and make maximum use of this University of Tennessee information. Note: Tree species are listed alphabetically by common name in our Dashboard. They are listed taxonomically in Craig Harper’s publication, which you can acquire by clicking here.
