University Place

Oak Woodland Management

[Steven Swenson, Director of Conservation, Aldo Leopold Foundation]

Welcome, everybody. I’m Steve Swenson. I’m the Director of Conservation at the Aldo Leopold Foundation in Baraboo, Wisconsin. It’s my pleasure to introduce our next speaker, who’s going to talk to us about managing these oak woodlands.

Kevin Schilling is the La Crosse County Private Lands Forester with the Wisconsin Department of Natural Resources. He has a Bachelor of Science degree in forestry from UW-Stevens Point. He started his appointment with Wisconsin DNR in the early 1990s and has spent the majority of his career in the driftless of Wisconsin. Welcome, Kevin.

[Kevin Shilling, Forester, La Crosse County, Wisconsin Department of Natural Resources]

Good morning.

[audience]

Good morning.

[Kevin Shilling]

So, as the title implies, we have a problem getting oak regeneration that all of you who are landowners probably know this already. You just don’t see the oak that you used to have. What I’m going to do is I’m going to go just briefly through the basics because this is really too big of a topic to spend we’d spend a lot of time on it if we wanted to cover it in depth. But just to give you the basics of what the some of the management techniques are.

A couple things I’m going to start with just to give you background on to understand why we do some of the practices that we do. I’m going to cover a little bit of oak biology. So,me of the things you’ve already heard today, and you will hear later today.

Oak is a disturbance-oriented species. It likes to have full sunlight for good growth. It will tolerate some shade, but it doesn’t tolerate it as well as other species. For regeneration purposes, oak acorns or the acorn crop is not real consistent for most species. So, we don’t get good crops every year. Some of the species, like black oak, are pretty consistent. Every two to three years we’ll have a pretty good acorn crop. The intervening years it’s average to low. White oaks are on the other end of the spectrum. They’re probably our least consistent species. On average, about every four to 10 years before between good acorn crops. And in the intervening years, it’s average to poor.

And that’s kind of important because we really need to have a bumper acorn crop in order to have anything left for regeneration. On an average year, virtually everything gets eaten by something. A lot of animals like acorns. They’re this juicy little nugget of energy, So, they mostly get eaten. Things from bugs all the way up to bears like acorns. So, we really have to plan our practices for a real good acorn crop to have anything left.

I’m going to talk about basically three different categories of techniques. We’re going to talk about intermediate treatments, we’ll talk about regeneration, and we’ll talk about harvesting. But the regeneration and harvesting will actually be sort of combined because they really go hand in hand. So, we’ll start with intermediate management.

Release is a term that just refers to it’s a non-commercial thinning. If the trees were big enough to be commercially harvested for a product, we’d call it thinning. This tells us that it’s actually not to that stage yet.

It it’s used for stands that are pretty young yet. Usually five to 15 years old. They are growing. They may be a little bit too dense. We want to make sure that everything still has enough room to grow, that there’s not too much competition, So, we’ll go in and we’ll do a release of those young stands.

Now, if you for any practice that you’re going to do, whether it’s release or the other practices, and you’ve heard this already today but I’m going to reiterate it here, is the first thing you need to do is you really need to have an overarching goal for your property. What do I want out of this? Whether it’s a property objective or goal or if it’s stand by stand, you need to know what you’re trying to accomplish. And it might be it might simply be timber production. It’s an investment property and I wanted to grow high quality saw timber. It might be aesthetics. It might be wildlife. It’s really based based on what your interests are. Once you have that, then you can move on to actually figuring out what practices apply to your stands or your property because you might have a couple of different choices. What you can do with the stand and its sound forestry, but one choice will take you in one direction and the other choice will take you in another direction.

So, once you have that, you know what your goals are, and, in this case, for today, I’m just going to talk about perpetuating oak and making sure that our oak thrive. That’s going to be it’s a very simple goal, but that’s what I’m going to work with because that’s what the day is about here.

Assuming that we have good stocking and the stand actually needs to be released, and forestry would be able to help you figure that out, release is actually pretty simple. All you’re doing is you’re choosing your crop trees, and a crop tree can be based on a number of different characteristics. Here I’m going to talk mostly about oak perpetuation because that’s what we’re talking about. But it could be maybe your goals are more wildlife oriented or aesthetics or Something else. But you want to find the trees that you want to make sure survive and thrive and become dominate trees later. So, those are your crop trees.

You picked your crop trees, and then simply all you’re doing is you’re making sure that the trees that are directly competing with your crop trees are taken out of competition. So, if you have a crop tree and you have another tree that’s touching the top at the crown or the branch area of the tree, you just cut down the competing tree. If there are a couple of them, you cut down a couple of them. If there’s nothing competing with your crop tree, you don’t do anything. You just leave it alone. It’s not necessary to go through the woods and cut down every tree that doesn’t look good or has damage or anything. It’s not only not necessary but it’s not even advantageous. It would be detrimental to what you’re trying to accomplish.

All you want to do is make sure that your crop trees have enough space to keep growing. And you don’t need to have a lot of crop trees either. If you had 100 per acre which is approximately 20-foot by 20-foot spacing, that’s enough. When we start out, if you have a well-stocked stand, a seedling/sapling stand, you may have thousands of stems per acre. Well, they’re small. You can fit that many per acre. When they get big, you’re going to be down well, for example, youll if you had all 16-inch diameter trees, if you had 70 per acre, you’re fully stocked. That’s all you’re going to fit on that stand. So… you don’t need to have a lot of them. 100 per acre is plenty. If you only have fewer than that, that’s fine too.

So, release is actually pretty easy. With all these practices I will say that, and this one included, is you want to do it outside of oak wilt season. Here in Southern Wisconsin, oak wilt season runs from April 1st through July 15th. You just dont want to do anything in your woods at that point. You dont want to run the risk of getting oak wilt into your stand. Its hard to get rid of once youve got it. So, prevention is key there.

If you really want to hedge your bets, you start from, say, early spring into the fall. Just that whole season is off the board. Its a lot nicer to do woods work in the late fall and winter anyway. The temperature is just plain nicer to be out there.

The next intermediate treatment is thinning, and this implies that this is a commercial stand. The trees are big enough to be harvested and sold. Its basically the same idea. Youre making growing space for the trees that are going to remain, but there are a lot more decisions that actually get made when youre doing thinning versus a release.

Now, we dont have to spend a lot of time on this chart. This is called a stocking chart. All of our commercial species have one developed for them. The main point I want to make is that there there is science involved with choosing your trees that get harvested and choosing the trees that stay.

If you look at the chart, on a toward the upper side theres a dark line. Its called the A line. For – this is the red oak chart. That tells us for a for a diameter of a tree, what stocking level or how many trees per acre we can tolerate before it gets too dense. And you look a little bit further down, the middle dark line toward the bottom of the chart, thats the B line. Thats the other of the bottom end of where we want our stocking level.

We can have if our stands are anywhere between those two lines as far as density goes, theyre probably producing as well as they can. Its just where the growth is going. If its going on more smaller trees or fewer larger trees. If were higher than the A line, if the stand is too dense, youre going to have a lot of trees, but they are not going to be very productive. Theyre going to be competing with each other so hard that theyre going to be under stress, susceptible to insect and disease. We just dont want to let our stands get up that high.

If we have them down too open or below the B line, yeah, the trees are fine, theyre growing as fast as they can, but you have so few trees per acre that youre not really using all your space very efficiently. Plus, not having some side competition, the trees tend to grow up more like big bushes than like trees. So, we want to stay in that nice, middle area for our management purposes.

So, if youre going to do a thinning, assuming that you need to, and a forester would be able to help you determine where you fall on this chart, and this chart also helps us, once we know where our stand is, it helps us know what our target stocking level should be. Once we know that, then we can actually go out in the woods. We already have our long, big picture, overarching goals for the stands so we know what were trying to accomplish. We know what our target stocking level should be. Then we go to the Standard Order of Removal.

And I want to spend a little time on this slide. I realize this is not a great presentation slide. Theres way too much text, and not only that, but Im going to read some of it to you. But I really want to stress this. This is the Standard Order of Removal. It should be applied to any thinning. It doesnt matter what species that were working with. And we may use part of this list of criteria; we may use almost none of it, depending on our stand density.

Now if you happen to walk into a little pocket, our woods are rarely uniformly stocked throughout; youre going to have thick areas and thin areas. You walk into a little area, lets say youre already at your target stocking; youre done. You dont mark anything. Youre already down near that B line. But but, obviously, the whole stand isnt like that because otherwise you wouldnt be there. So, you need to take some trees out. The very first thing you look for is what trees are at risk of not surviving until the next entry. For hardwood thinning its usually fifteen to twenty years depending on other criteria. Anything not going to make it that long, lets mark it, take it out now. If that takes us down to our target density, were done.

It probably doesnt.

The next thing that we look at is those crop trees. We want to make sure that theyre thriving. So, we want to open them up the same way we did during release. Mark the trees that are competing with them. Does that take us to our target stocking? If not, we keep going right down this list. Look at the vigor. The vigorous trees are going to grow better than the non-vigorous trees. If we still need to remove some, get rid of the non-vigorous trees. Stem form and quality. You know, forks, seams, splits, anything wrong. Well get rid of those and we keep working down. If at any point we hit our our target density, we quit. If not, we just keep going down the list.

There are certain circumstances, not very common, but on occasion lets say you have a a pine plantation that has good survival and its been thinned a number of times, you may not have anything to do with the first five steps there because all the poor trees, all the suppressed trees, all the non-desirables were taken out in earlier thinnings. All youve got are crop trees. Well, now youre just making space. All youre doing is making sure that the remaining trees have room to grow.

The point I want to make by going through these step-by-step is youll notice nowhere on this list does it say cut all the good trees and ignore all the junky trees. Thats called high grading. Its taking the high-grade trees out of your woods and leaving the poor grade trees there. You dont want that to happen. It also doesnt say were just going to pick a diameter and everything bigger than that gets cut. Thats just another form of high grading. Unfortunately, for the first cut and for the logger, frankly, high grading is a very profitable way to go. Youre taking out the valuable trees and not worrying about the poor trees.

For a landowner, high grading is a profitable too one time. Then youve degraded your stand, and you have much less to work with for all the remaining harvests after that. Now, unfortunately, its been very common. High grading has happened to a lot of woods, and it probably has happened to yours at some point in the history of the ownership. While thats not good, I guess I wouldnt say that dont feel depressed that theres no hope. Thats all the more reason that you want to apply these rules because you need to improve this stand, and this sort of work will help you improve the structure and the productivity of your stand. Its just that you dont want to let that happen to your woods again. Its very destructive.

So, thats those are the intermediate treatments. And we just do those until the stand is mature enough to be regenerated. And now this slide says regeneration methods, but Im going to be talking a lot about harvesting. But harvesting by necessity has to go hand in hand with regeneration because once you harvest, you need to get the next stand started.

Our our best method for getting oak regeneration back is the Shelterwood technique. And what a Shelterwood is, it has this kind of kind of a warm, fuzzy name. You know, it’s really protective. It’s a shelterwood. You really should think of it more as a two or a three-stage clear cut. When it’s done, your existing big trees are going to be gone and new trees will be there to replace them.

So, we’re just assuming we have a mature stand. Got a lot of trees out there. These are ready to go. They’re not getting any better. Time to harvest. There’s not much on the ground. Nothing in the understory. First cut is to just get rid of a lot of your trees. You’re going to be taking out most of what you have. The target for shelterwood is between 40% to 60% crown closure. And usually when a forester marks a shelterwood, they mark the trees that are staying because fewer trees will be staying than will be getting cut. And the trees that get marked are your best. Your best trees are staying because they’re the ones that you want to reproduce. You don’t want a poor tree to be seeding, and that’s going to be your next generation forever. You want the biggest, nicest, best producing trees to be providing the seed.

We’ll be talking about site preparation a little bit to get the oak started. Usually this is when that site preparation would happen. It it everybody’s woods is a little bit different. Sometimes the site preparation happens before the first cut. Frequently it happens at this point, but we’ll talk about that in a little bit.

So, you open it up, you wait, maybe do some site preparation. You get those young trees started, and this may take a few to several years for this to happen. Once you have it and you’re confident that you’re regeneration is successful enough that it’s going to stay, it won’t die right away, then you just take off the overstory, you have a new woods, it’s a young woods but it’s a new woods, and you give them direct sunlight and off they go.

In order to make this work, though, you need to deal with the mid-story of a stand. And that, for example and this is not a particularly thick stand. You can see a lot of big trees in there and some some smaller trees in the front there. If we harvested the big trees out of this stand, we wouldn’t really have enough trees left to have a good stand. It’d be pretty sparse, but we would have enough to interfere with the next stand. So, we do need to deal with them somehow, and there are a couple different ways you can do this.

The first one is chemically. Just go through and you treat with herbicide anything that you don’t want to reproduce or that won’t be harvested during the harvest. So, this is something that, actually as a landowner, you can do. It doesn’t take special equipment. All it takes is time and herbicide and a backpack sprayer. It works pretty well. You can get complete kill because you can go to each individual stem. It works better in stands like this that aren’t that thick. If it’s really thick with an understory, well, that’s a lot to treat, maybe more work than you want to take on.

So, one of the benefits of chemical treatment or herbicide treatment is it doesn’t take special equipment. You can do it. One of the drawbacks is that you don’t get any site disturbance and that oaks, for the most part, the red oaks, in particular, really need a mineral soil seed bed to germinate. They just don’t work very well if they drop on leaf litter. White oaks can tolerate a light leaf litter, but they really prefer a mineral soil seed bed too. So, you want to you have to somehow provide a way for these acorns to get down to the ground, and this kind of treatment won’t do it for you.

You can do a mechanical treatment.

Whoops.

There we go. In a perfect world, this is how it would get done, is during the the harvest. This isn’t the best slide because ideally you would have it happening in the fall, not a winter harvest, because you want the soil to be fogged so you can stir this up and mix acorns in. We know we don’t have consistent acorn crops, so you really have to time this with a bumper acorn crop, and you want them there when the acorns are dropping before the animals get in there and eat them all for you. So, in a perfect world, you’d get the logger there. This is the year. We’ve got great acorns. You know, they’re starting to drop. Come, do my harvest, drag trees through the woods and stir it all up. It doesn’t cost you anything. It’s done. It’s easy.

It’s almost impossible to get a logger at that with that kind of timing. It just doesn’t work very well because they’ve got schedules that they’ve got to meet. It’s a tough one to crack that way. So, if if that’s not available to you, there are a couple other ways you can do it. One is to use a small bulldozer to just uproot and push around the things that you don’t want to reproduce. You don’t tend to get quite as clean a job as you would with a chemical treatment because you can’t get every little nook and cranny with a bulldozer. It does take a small one because you a big one is just too cumbersome in the woods, but it does work. Now, you’re not putting the blade in the ground. You don’t want them pushing dirt. You just want them uprooting the things that you want to kill, and by pushing them out of the way a little bit they stir things up. So, that works.

Another method is using this implement here in the lower right. It’s called an anchor chain. It’s a big, heavy beam with three heavy, heavy anchor chains coming off it that have metal rods welded through the links. And this is pulled by a skidder or a dozer through the woods. And it just really, just churns things up as it goes through the woods. And it probably is the best method for getting good scarification. It has a few problems in that you can’t back up when you’re pulling this thing through the woods. So, the slope has to be gentle enough where they can go on the side hill. You you just can’t back up. If you have a steeper slope where you can only back like a bulldozer up the hill and come straight back down, well, then that’s your choice for a piece of equipment. But it it does work pretty well.

Now, these three techniques that I’ve talked two techniques that I’ve talked to you about so far, the scarification and the chemical treatment, there are people that do these things. Some of them you could do yourself. The the small dozer there are contractors that have them for hire. You can get that done. The anchor chain is a specialized piece of equipment. Most folks, well, most, nobody around here has one of those. There is one, though, that is available in the state. I know Columbia County has a smaller version of this that they rent out to landowners. If anyone in this area wants to use a piece of equipment, if this applies to your property, we’ll get it up here to make it available to you.

So, that’s mechanical scarification. The last one is not exactly scarification, but it is site preparation, is fire. Most of our oak oak woods evolved with fire. That’s how they got here in the first place. Fire does a great job of site preparation. It gets rid of that leaf litter. It kills off competition. As a species, while we can kill oak with fire, it is more tolerant of fire than a lot of other species. There’s no steep or there’s no slope that’s so steep you can’t run a fire up it. So, it does work.

Now, there are some drawbacks to it. There are some inherent risks, obviously. We’ve never had a piece of equipment escape control and go to the neighbors and take the barn down for them.

[laughs]

Fire can do that for you if you’re not careful. So, you want somebody who knows what they’re doing. There are people that do this professionally in the area. So, you can get this done. Works. One of the issues with fire, though, is it’s not a one-shot deal. This will be a longer process. You will be burning at least a few times and maybe several times over several times several years in order to get good regeneration, but if you have that time frame and willingness to do it, it does work.

A couple other harvest methods, regeneration methods. The coppice method. Probably never heard this term before. If you saw one, you would think this is a clear cut. It looks exactly like a clear cut. It the practice is done exactly like a clear cut. The difference, though, is, the implication is we’re relying on stump sprouts to get a regeneration back. Works not so well in good soils, like we have right around here. It works much better in light sandy soils, like the central sands part of the state.

Easy to do.

Works.

The one drawback to it is that you will never have as many oaks after the harvest as you had before the harvest because not all the trees are going to sprout. Trees, that as they age and as they get bigger in diameter, the probability of sprouting goes down. You know, a small, young tree, it’s almost sure going to resprout. A larger tree, the probability is much less.

It but for some areas it’s just the best opportunity to do it. That’s one way.

Another harvest method is called patch selection. It’s a good forestry harvesting practice. It’s used a lot in this area. It’s not the greatest oak regeneration practice. And what we have here, if you look at the black outline in the screen there, that’s the stand, and all the little orange well, I call them polygons the little orange pockets there are little patch clear cuts. This is an example of one. With the patch selection, the clear cuts are relatively small. A half-acre to two acres in size. We’re standing on one side looking across at the other. A couple of drawbacks to it are that, you know, you see the shade coming in from the side into here. Well, the smaller the patch, the more shade you’re going to be getting in this stand. And things that tolerate shade better than oak are going to have an advantage where they are shaded.

The other problem is that any stumps that sprout or any acorns that sprout within this pocket, that’s it. That’s all you’re going to get. You’re not going to have acorns drifting in from the rest of the woods. Whereas the rest of the woods that’s all around this pocket, any light seeded species are going to be letting seed, you know, like maples and ash, boxelder, anything like that, they’re going to be sending seed into this patch. So, there’s going to be a lot of competition within this patch. It’s a good forestry practice, not our best oak management practice.

Clear cut. Looks the same as the coppice. It’s what most people think of when they hear the or when they see something that’s completely cut. Again, it’s a its a good forest management practice. It has a very bad name. People think it’s destroying the forest. Well, no, it’s trading in your old forest for a young forest.

It can work for oak regeneration. It’s not a great one for us, though, in that if all the stars align and you have a bumper acorn crop and the harvest is done right when the acorns are coming down and they get good scarification and other competition gets killed in the process if all if only that happens, well then it can work. If that doesn’t all come into place, you’ll have trees, but they probably won’t be oak, they’ll be other species. So, it’s its a good practice, but it’s its not our best for oak management or oak regeneration.

I’m going to shift away a little bit from harvesting to just how we get oaks to start with. Tree planting: I’m going to focus mostly on planting in the open because it frankly, I’m not a big fan of trying to plant trees in the woods. There’s a lot of competition in the woods. It’s hard to plant trees in the woods. There are roots and brush and sticks and there’s just so many obstacles in the way. It’s hard to get a lot of trees put in the ground. So, I’m going to focus mostly on planting out in the open.

What we have here is a companion planting. Pine and oak together. And this one, I’m showing this slide because this is successful. They did protect their trees from the deer by putting tree tubes on them. Otherwise the deer will work your oaks. Oak is a preferred browse for deer, and they just hammer them. In this case, the tubes probably helped.

Tubes work. They’re a little bit expensive. There is some maintenance involved. They’re not a theyre not an end all or a silver bullet. They’re just another tool for getting oak started. This individual chose to use them, not everybody will.

I guess the last point I’d make about this slide is that, if you are planting trees, you really need to do some site preparation and some maintenance. Sod is a tough competitor with young trees.

We if you just put them in the ground and think they’re going to grow, the weeds and the grass are going to swallow them up, and you’ll have relatively poor survival. And, as you’ve already heard today, we also, have to deal with deer. This is a a nice planting. The guy did a good job. He has good survival. That’s another companion planting. White oak, or, I’m sorry, white pine and red oak. It’s probably 10-12 years old. The pine are 8-10 feet tall. They’re doing well. The oak are two feet tall. Every year the deer come in there and they nip the tops off of them and they just can never escape; they’re all alive, they’re still there, but because oak doesn’t tolerate shade very well, eventually the pine are going to get ahead of them, they’re going to start to close over top of them, and then they’re done. So, you really do have to control for deer and the weeds. And I guess the this same thing goes on in the woods. You’re going to get deer browse in the woods, it’s a problem. It’s just that this was a slide that really showed it well is why I used the plantation instead.

Another form of planting is direct seeding. It a a couple benefits to direct seeding is that your seedlings don’t go through transplanting shock. You know, if you think about it, you’ve got this little seedling, it’s been growing in a nursery, gets pulled out of the ground, gets the dirt knocked off, it’s sorted, handled, stuffed in a box, shipped, probably sits in the garage for a week, until the weekend so you can have some time to plant it, gets pulled back out of the box, stuffed in a tree planting machine, that’s pretty hard on a seedling. By using seed itself, you don’t go through that transplanting shock. The tree stays right where it’s planted.

The other benefit to it is that you can put in much higher densities pretty easily to plant trees at this kind of stocking level. The rows are real close and within the rows the seedlings are very close. It’s pretty cost prohibitive and just way too time consuming, whereas doing it with direct seeding, it works pretty well.

It a really there’s probably only one drawback to direct seeding, and that is it does take site preparation because you’re planting in a sod area. And because we know that acorn crops aren’t real consistent, it might you know, if we happen to have a season where there just aren’t many acorns and you’ve done all your site preparation, you might not be able to find the seed. Whereas, with the seedlings, you’re going to know in the fall if you can get the seeds or not.

It’s not a bad way to go, though.

One last comment I’ll make on this is that going back to the companion planting, you know, you’ll notice that this this situation here, it doesn’t have any conifers in it. It’s purely hardwoods. The companion planting of hardwoods and conifers really works well when you don’t have a deer problem. If you have any deer in the area, it doesn’t work nearly as well.

We’ve done a lot of those companion plantings over the years, and a few of them have been successful. More of them have not been successful. Planting, a situation where you have all of one species, and I don’t want to say that this whole field is a monoculture. You can have an area of red oak and then another species, whether it’s hickory or white oak or whatever it is, in another area. Where, because trees grow at different rates, you don’t want, you know, your oaks to get swallowed up by the walnuts that are planted right next to them because walnuts simply just grow faster. So, we’ve kind of done away with the companion planting idea. Even if you’re planting trees, I guess I recommend going more toward one species, and that’s what you have here.

That’s pretty it much it. It’s kind of a whirlwind tour through oak management. I guess, with that, I’ll take any questions.

[applause]