Fundamentals of Timber Stand Improvement

Fundamentals of Timber Stand Improvement

I recently received a question on the Ask Winke part of the site regarding tips for Timber Stand Improvement (TSI).  My answer got pretty involved as there is no easy way to offer advice on this subject quickly and concisely. So, I thought it might be useful to add that discussion to this part of the site and elaborate a bit more.

Creating habitat (TSI being just one of the ways this is done) is the most important thing you will do with any deer hunting property. You can change the food available in one year with good food plots (that’s easy), but it can take a decade (or more) to really fine-tune the habitat.  You don’t have time to do it wrong and then find out ten years later you should have done something else.  Ouch.

So, be super careful in this process, but don’t wait too long as every year you wait just delays the time when you will reach your ultimate goal of a great whitetail property.

When I started doing TSI back in the mid-90s, there was not much information available. Mostly we learned from seeing the aftermath of commercial timber cuttings and from foresters who, mostly, had a mind only for improving timber value and not for improvement of wildlife habitat.

MY EARLY LEARNING CURVE

I never relied on a specific source of information when I first set out to do Timber Stand Improvement.  There wasn’t much at the time (if any).  My first project was in 1998.  That was on a farm I co-owned.  Not much had been published on the subject back then so we looked for help.

The district forester marked the trees to cut with the goal of improving the timber value of key crop trees.  Pure forestry goals usually result in less junk trees being removed because the forester only releases specific crop trees and then only removes the competition directly surrounding them.

The forester we worked with was not at all focused on overall habitat improvement and walked right past areas where there weren’t any crop trees to release.  Those large areas really needed better habitat, but that was not his goal.

That might be old school thinking as today’s foresters (especially the younger ones) are very likely more in tune with hunting-related goals. 

But, that first TSI was a starting point. I got to see how the forest responded to those cuttings in a very low risk way. I was impressed with how the habitat around those released trees improved in just one growing season. That really inspired me to take this habitat work seriously.

Then in the early 2000s, I started buying my own land (no partners).  I didn’t have to “get permission” from anyone to be aggressive and focus on hunting-related habitat goals rather than strictly timber value. Despite this fact, I did start slowly. The first year I only did about 10 total acres (at the most).  I looked at that area the next summer to see how the habitat responded and then increased the number trees we (I hired a small crew) cut and did another 10 to 20 acres the next winter.

After a couple years of this, I had a pretty good idea how the habitat would respond to different levels of cutting and then I hired a larger crew and over the next two to three years they worked over the entire 800 acres of timber on that farm.

I tapped into government cost share dollars to help pay for this. Some of those programs are still out there and when you accept that help you are not taking that money straight from the taxpayers. Don’t feel bad about it. The funds are already committed. They are going to be spent – so they may as well be spent on your farm.

CONTROL THE INVASIVES FIRST

The main thing I learned (unfortunately, the hard way) was the importance of identifying existing problems first.  In other words, if there was an invasive species trying to make a go of it under the canopy of junk trees and then we removed those junk trees, those invasive species went wild.

I had that happen on three or four sites with a total of around 15 to 20 acres and it really bugged me that I didn’t see the problem and fix it first. Those areas were basically ruined unless I dedicated many hours to fixing them – and then with uncertain results. I now have a very deep hatred for invasive species.

When you open up the canopy, the plants that will thrive are the ones that are already there on the ground level. What you see a little of now, you will see a lot of in a year or two.  If those existing plants happen to be invasive species, you are in for a big headache down the road. It is best to eradicate all invasives before cutting down (or killing) any trees.

I should have treated the invasives first and focused my Timber Stand Improvement in other areas until I had the offending plantsw subdued (it can take a few years to clear them).  That would have saved a huge problem later when those plants (mostly bush honeysuckle in that area) took off. 

Controlling invasives is at least as big of a priority as deciding which junk trees to cut.

You need to be able to identify all the invasives in your part of the country.  For example, where I live, I would do an online search under “Invasive plants Iowa” to learn what to look for. Here is an example of what pops up.

They are all bad, but some are worse than others. In my area, Autumn Olive and Bush Honeysuckle can destroy a woodland faster than anything you can imagine if they get opened up. Garlic mustard is another one to eradicate first, if possible.

Despite its name, Tree of Heaven is really bad too. Again, they are all bad, but it is likely you won’t be able to remove them all.  Make your list, confer with a local forester and then focus on the worst offenders.  That will be a big enough challenge to bite off.

Fortunately, most invasives stay active well past the first frost giving you an opportunity to spot them (they are the only thing in the woods still green).  Once you find areas that have invasives, do a number of searches online to determine the best ways to eradicate each of them. In most cases the prescribed treatment will call for a spray of glyphosate after other species are dormant (usually in November in the Midwest) or cut them down and squirt the stump with something like Tordon or Garlon. 

I know guys who actually paid to spray glyphosate from crop duster airplanes to cover big areas of their timber after all the “good” species had gone dormant. I guess it worked, but is pretty expensive. No matter what you do, it will take a few years to really get a grip on those areas most affected by invasive species. 

Believe it or not, I have actually looked at farms and walked away from the prospect of buying them because the understory was thinly scattered with bush honeysuckle.  Any Timber Stand Improvement work to improve habitat on those farms would have resulted in disaster. Regardless of how good those neighborhoods might have been for deer hunting, I didn’t want an open, lifeless, understory nor did I want to deal with an invasive problem long-term. That’s how big of a deal this is.

Before starting a TSI program, it is best to do any commercial logging on the property. Depending on the extent of the commercial effort, this logging may greatly open the canopy and this will reduce (or even eliminate) the need for further cutting and encourage lots of ground level undergrowth.

COMMERCIAL TIMBER HARVEST

Ideally, if you think you will do a commercial timber harvest on your property within the next four or five years, I would do it now – before you start the TSI program. The timber harvest will open up some areas that you won’t have to mess with later when doing the TSI. 

Also, timber crews hate working around all the downed timber and cut stumps typical of a TSI program.

I don’t want to get distracted by diving into commercial timber goals here, but I have never been a huge fan of cutting down oak trees.  A few here and there is fine (and probably healthy for the timber) but those trees produce acorns for deer and turkeys and take a long time to grow.

Instead, I do only a thinning cut on the oaks but really focus more on marketable walnut (where it exists) and species that don’t benefit wildlife.

The aftermath of most logging operations will look like this, lots of pockets with open canopy. This is good for encouraging ground level vegetation. That is what the deer will use for both security and browse. You can’t make any real difference in the ground story of a timber without opening up the canopy.

Even taking out big junk trees (hackberry, some hickory, cottonwood, ash are common examples) for pallet wood (you don’t get much for those trees) is still better than you having to cut them down yourself later.

Again, if there is a commercial harvest anytime in your near future, do that sooner rather than later and then do the TSI afterwards.

GET GOOD ADVICE

I would suggest asking your district forester (for example, Iowa has one for each management district) to come and mark a small TSI program for you.  There might even be government cost share in the actual cutting of the trees. 

Go along when he/she marks the TSI and ask a bunch of questions. You might mention that you not only want to focus on overall timber quality (the typical goal of TSI in the eyes of most foresters), but also habitat improvement and see if the forester will accommodate. If not, no big deal. Take what you can get.

Cutting down trees, even small ones, is very dangerous work. The saw is dangerous enough, but the tree is also a potential widow maker. Wear all the safety gear and unless you know how to fell them safely, stay away from big trees and stick with small trees. Leave the big stuff to the pros.

Unfortunately, those guys are really busy and it may take a long time to get them out there to do this work.  Another option is to hire a private consulting forester (do an online search to find them) to come and mark a small area.

Again, go along and ask tons of questions.  After he/she leaves you will have a much better feel for how to manage the rest of the property yourself.  Start slow.  And, do what I didn’t do and look really hard for invasive plants before you dive in and start opening up the canopy.

I would suggest cutting less than you think at first. Granted, you have to get sunlight to the ground to stimulate underbrush and the establishment of some of the key forest species like oak, but you can always come back a year later and recut the same area if you decide you didn’t take enough during round one. Key point: start your learning curve slowly and with patience.

I would be doing you a great disservice if I didn’t also mention the need to be super careful if you decide to cut the trees down on your own. I don’t consider myself a coward, but I am fearful when it comes to cutting down big trees.

There is so much that can go wrong if you don’t know what you are doing – even if you do.  Stick with small trees and hire a professional crew for any of the bigger stuff that needs to be removed.

Deciding what to cut is, in many ways, a personal decision, but it is almost always better to be conservative and start slow. You can always cut more the next year if you determine that you didn’t make a big enough change to encourage growth on the forest floor.

WHAT TO CUT AND WHAT TO LEAVE

As for what to cut, that is kind of a personal decision. I left all the obvious marketable timber (even if it was not a desired wildlife species).  For example, I left some big hickory trees, some big basswood (linden) and some big maples, knowing these had some value in the near future for timber harvest.

Otherwise, I left almost all the oak, walnut and cherry (walnut and cherry because of their future timber value).

My goal was habitat improvement for whitetail hunting and that meant I needed underbrush – for browse and security – and trees that drop acorns. Those were my two main priorities.

Some land managers prefer to use fire as a way to set back fast growing saplings and restore the forest to a state of early succession with lots of browse. I have used fire on my farm in spots, but I tend to favor using a saw when I come back to past TSI areas several years later.

LONG TERM MAINTENANCE

Timber Stand Improvement is not a one and done process. You will have to go back into those areas roughly every 10 years to cut out all the junk that came up when you most recently opened the canopy.

These new saplings will now be shading the forest floor eliminating those important browse plants.  This process should keep the ground level underbrush flourishing (what deer need) and eventually produce a good number of isolated oak trees (assuming there were some seed trees present to begin with).

Some landowners prefer to burn these areas every couple of years to keep them in the early successional stage of regrowth, but I don’t like the non-discriminating quality of fire (it top kills most saplings – not oak – if done correctly).

I always felt better about controlling what died and what didn’t even though it takes a lot longer to do it by hand. Also, top killing only sets back the undesired saplings, it doesn’t kill them.

Maybe I will change my position on fire someday (some land managers swear by it), but right now, I am not going to burn any of my whitetail habitat.

This is the goal, openings that feature lots of browse and good oak regeneration. At least, that has always been my goal when doing habitat work. Oak stands are disappearing across much of the country, and I am always trying to do my part to re-establish them.

MOST IMPORTANT THINGS TO REMEMBER

First, safety is a huge matter when it comes to cutting down trees. If you don’t know what you are doing, stick with small trees when doing the cut yourself. 

Further, you are way better off hiring a crew to do this work than taking the risk of having a tree kick back or fall on you. Again, this is super dangerous work! Leave the tricky stuff to the pros.

Second, start slow. I can’t over-emphasize the importance of being patient. Experiment with a small area first. Don’t hurry this early learning process.  Do a little, learn from it and then do more. Soon you will be ready to move faster and move correctly. Good luck. (2/3/22)