Timber stand improvement (tsi) is something I get asked about quite a bit. Allot of landowners hear about it and wonder if they need it.
What is tsi?
Timber stand improvement is really just a heading under which a few different forest management practices fall.
Crop tree release is one such prescription and is a major practice under the general heading of “tsi”.
Crop tree release means, basically, just what it says.
The process is done by selecting certain trees that the forest manager decides to keep, called “crop trees”. These desired trees are then marked with a band of tree paint (Or a big dot on 4-sides. The dots are usually reserved just on the really big trees, to save paint!).
These crop trees are your “keepers” – the one’s you’ll be managing for. Most of the time these are young trees, those that appear in good health, are vigorously growing, and have, at least, good potential for lumber and/or wildlife value.
What crop tree release calls for, then, is to “release” the canopies of the selected crop trees. This means that any and all trees that have a canopy that is within a few feet of the crop tree should be killed. You heard me right — killed! This scares the daylights out of some people. And I know exactly how they feel. It’s not easy winding your way around a white or red oak with your old Jonsered chainsaw roaring! It’s especially not easy the first time you do a tsi job. I mean it’s hard to think about killing good tree species!
But the truth is, one has to kill lots of trees to make room for the fewer good ones that the site can adequately support. And support in terms of allowing the crop trees to grow to their full capability. This 4-sided kill “releases” the crop tree to receive full sunlight to all the leaves on all four sides of the tree. Thus, crop tree release is done to enhance sunlight to the canopies of the chosen trees.
It has been shown that this process can increase oak mast – acorn — production by 7-10-times the normal amount and, also, can increase the speed of growth by up to 2-times that of comparable trees that have not been released. Crop Tree Management (PDF from ISU) (tons of great Info Here!)
The value of crop tree release TSI is HUGE to most Iowa forestland acres and there is very little, if any, debate in regard to the benefits of crop tree release tsi.
It is a win-win procedure!
A win for the landowner, in terms of forestland value. (And let’s not forget that cost-share dollars are readily available for various tsi procedures across the state — these can pay you up to 75% of the cost to do a procedure!)
And a win for the wildlife, in terms of fruit and mast production.
Not only is forestland mast production increased, but also the ground cover on the forest floor is enhanced via crop tree release.
However, make no mistake, the GOAL of crop tree release tsi, from a pure forestry perspective, is that of enhanced tree value, growth, and mast production, it is really not to thicken ground cover. That is a wildlife goal and is one that just sort of happens by default in many situations when crop tree release is implemented properly.
So the wildlife and forestry managers all get good results through crop tree release, in most cases (If the wildlife goal is not to thicken the understory, though, crop tree release may not be a wise choice).
Another prescription that falls under the general “TSI” heading is understory release or site preparation for natural regeneration (SPNR)
This practice is specifically done just prior to, or right after, a major tree harvest. The goal here is to get rid of all undesirable small trees and shrubs that exist (example ironwood, young elms, plums, prickly ash, multi-flora rose, Japanese honeysuckle, etc., down to about 1- inch in diameter). These are not desired because they will shade out and kill the growth of any natural, desired, regeneration that exists on the forest floor (seedling oaks, hickory, walnut, etc.,).
To be sure, and as you may imagine, site preparation for natural regeneration is hard work that is very labor intensive. Again, this procedure is usually done only just before or after major canopy, tree-top, areas are opened up from a harvest or other factor (such as wind damage).
Most Iowa woodlands can greatly benefit from some sort of TSI – most commonly the crop tree release procedure.
In regards to the wildlife end of things – and whitetail deer in particular – both TSI prescriptions really provide a boon to deer.
The increase in sun-light coming down to the forest floor after a tsi procedure encourages a thicker habitat – this means more food for deer. It also means more security cover as well! The end result is that the forested acres become more attractive to whitetails at all times of the year – not just when the acorns are dropping. The result is an increase in deer carrying capacity of your property.
And, think about this, if your timber produces 7-10 times more acorns than does your neighbor’s woods, guess where most of the deer will be during hunting season?
Guess where most of the giant bucks will prefer to be?
And, not just because they get more food and cover there but because that is where most of the does are as well. You guessed it – on your land!
No doubt about it – TSI is not only a HUGE boon for your trees but it’s also a HUGE boon to your deer population! Just to let you know, in case you may be wondering, timber stand improvement in general, and crop tree release tsi in particular, are the first things I do when I acquire a property. It just makes your property better and more valuable!
Instead of asking why do tsi, the better question is why in the world not do timber stand improvement?
It’s certainly a win-win deal!
Many Iowa landowners are really into managing wildlife and wildlife resources on their properties these days. That’s really good! And many landowners really understand the value of doing wise forest management. That’s fantastic too! But, while all intentions are good, many Iowa landowners could probably use a little help with tree identification. Let’s face it, identifying trees is no easy task, especially in the wintertime when most of the leaves are on the ground. Let’s take a look at a few quick pointers that should help you in your wintertime Iowa woods in regard to tree identification:
1). Walnut vs. Cottonwood
That’s right – these two species often get confused. Sometimes really confused! In fact, a forester friend of mine recently told me of a class he was teaching a while back on marking timber sales. The class members were let loose on a property and came back with over one-hundred thousand dollars worth of value on a bunch of big black walnut trees – some with veneer quality! They turned out to be all cottonwoods, with little to no value!
And these were forestry students with allot of education under their belts. This makes it pretty clear that you aren’t alone if you are getting the two species confused in your wintertime Iowa woodland. Check out the photo above for a quick way to tell the two apart with a little help of your pocket knife. Note, too, that ash can also be easily confused with black walnut. The same knife technique works on the bark — the ash has a light colored inner bark while that of the walnut is dark. The same knife technique works on the bark — the ash has a light colored inner bark while that of the walnut is dark.
2). Bitternut hickory:
This is a common understory tree in southern Iowa and if can get big, too. It doesn’t just stay in the understory like hophornbeam (ironwood). You’ll find bitternut hickory in the uplands mixed in with various oaks, You’ll find it in upland timber areas, commonly, mixed in with various oaks, hickory, and other species. It’s common on moist slopes and in bottomland areas too. You can recognize it in the understory by the mustard-colored buds (picture above).
3). American Elm
This tree, believe it or not, can be confused with white oak. And it’s best not to do that if you are doing timber stand improvement on your land! Elm has a thinner outer bark and smaller buds and twigs, than does white oak. American elm also, often, has somewhat of an exposed buttress root system. This can help separate it from white oak which too, which are less likely to have this trait.
4). White vs Red oak
There are two oak groups in Iowa. The red oak group and the white oak group. The white oak group has five species and the red oak group has six species in Iowa. The white oak group has – which oak, chinkapin oak, bur oak, post oak and swamp white oak. The red oak group has red oak, black oak, pin oak, northern pin, blackjack oak, shingle oak A quick guide to separate the two groups is – and you probably saw this one coming – the color of the bark. The white oaks have whitish or lighter colored bark, as you may have also guessed. The red oak species have darker bark (usually). (See pictures above). Black oaks – a member of the red oak group, are a typical species in southern Iowa that mix in with the red oaks.
Unfortunately, Oak Wilt kills many really nice red and black oak trees in Iowa. It’s a disease that can be contained somewhat through good management practices but it still can reak havac on your forestland acres. Fortunately, the white oaks are pretty resistent to oak wilt and it doesn’t effect them very much normally. Oak Wilt PDF (ISU)
The bark of black oak tends to be rougher than that of true red oaks and black oaks tend to have more lower branches – on average – than do the white oaks. True red oaks often have flat and fairly smooth ridges that are often lighter in color than the rest of the bark — ridges that may form sort of a loose diamond pattern on the tree trunk. Black oak and red oak can hybridize and take on characteristics of both. You tend to find more red oaks on north and east slopes and black oaks tend to occupy the dryer sites. White oak and black oaks often occur in roughly the same areas.
5). Shingle oak (red oak family)
Members of the red oak family tend to hold onto their leaves well into, and even throughout, winter until the buds start to swell in the spring. That’s something good to remember. And for sure, shingle oak, black oak, and pin oak can look allot alike! But, you can tell shingle oak easily by the leaf. Shingle oaks have a single, elliptical, oval, shaped leaf with no “lobes”. (picture above). No other Iowa oak has a leaf that looks anything like this.
6). Ironwood (Hophornbeam)
Ironwood can fool you into thinking that you are looking at a young white oak. Ironwood is a common understory tree and often forms dense stands. It often carries leaves in the winter that resemble elm (not oak). Also, the bark is thinner than oak and so are the twigs and buds.
I remember as a kid riding my motocross bike up and down our gravel driveway with my friends. We had a lot of fun racing them around that’s for sure. Though, I’m not quite sure how much the neighbors loved the noise! It’s a weird recollection to be sure, but every time I see the bark of a big old ash tree it reminds me of the tread I used to see on the back tire of my friends Suzuki RM 80 that always seemed to be in front of me! If you examine the bark of an ash, especially on a big older tree, you’ll also notice that it forms a diamond sort of arrangement across the surface, and the “peaks” sort of look like the tread of a dirt bike (sort of, you have to use your imagination a bit!) And as you can see from the picture above — the knife in your pocket will separate this tree from any possible confusion with this tree and the black walnut.
As for the twigs on ash trees, they have an opposite arrangement. This is a dead giveaway, in comparison to walnut and some others they may be confused with. (picture below) Also, the dreaded emerald ash borer is killing ash trees all over Iowa. The young ash tree pictured below — bottom right — is a recent victom and is showing signs of the disease. Unfortunately, there are several diseases and insects that kill trees of various species across the state. You can find out more about all sort of tree diseases/pests/problems.
Hackberry tree often have deep cuts and ridges in the bark forming a very rough outer bark layer. A common tree with a good wildlife value – various animals eat the seeds. No other tree really looks that much like it, in Iowa, that I can think of. But you still need to know what it looks like to identify it!
9). The dreaded honey locust!
The thorns on the honey locust can run up to 8- inches or so and are very sharp. One interesting thing about these trees is that bout 10% of them, in Iowa, are thornless. The trees that do have thorns can easily go right through your boot or tractor tire, so watch out! But, honey locusts are great trees to leave for deer because whitetails love eating the seed pods in winter. Deer often seem to favor pods off certain trees vs. other for some reason. This one is easy to I.D! (Black locust trees may seem similar but tend to form straighter trunks and have smaller spines, than that of honey locust trees. Black locusts were often planted in the “pioneer” days for fence posts and firewood, and you can see groups of black locust tree, often, around homesteadsteds.
10). Shagbark Hickory
This one is pretty easy for most folks to I.D., because of the long scaly bark. A common upland tree in Iowa, occurs in groups of mixed with oaks. Can dominate dryer sites.
For more help identifying tree in Iowa be sure to check out ISU’s interactive tree guide!
We also have lots of useful resources on our resources page (makes sense, right?)
You might want to get Iowa Trees and Plants Iowa Trees and Plants (PDF)
His name was Brad.
It was one of those first-thing-out-of-bed and my hair-is-still-wet from the shower phone calls.
You know what I mean.
A still I’m very groggy and I-haven’t-had-a-cup-of-coffee yet phone call.
“I just came back from Iowa and I am really excited about finally being able to buy some land out there,” he quipped excitedly. He was calling from out of state – way, way, way – out of state. And had just come back from a successful Iowa deer hunt.
Sounds great, I said. I’m glad you had a great hunt. How much land are you looking for and in what part of the state?
“I’m looking for about 200 acres with a good mix of tillable and timber for hunting. I’m looking to spend up to $400,000 tops, and preferably, less.” he continued. “I need some good tillable to support my mortgage payment on the land; I need to get a really good rental rate of those acres to an area farmer.”
I really need to have something that brings in at least $20,000 per year in income,” Brad said. “I’m really excited about this and I’m ready to buy right away if I can find what I am looking for.”
“By the way,” Brad continued. What is this thing called CSR that a friend told me about the other day and what does it have to do with the value of land”?
We talked and talked for probably an hour-and-a-half and we covered a lot of bases in regard to his questions.
In the end, though, long story shorter, Brad did not end up buying any land at all – something in regard to a family situation popping up, I guess. But his call got me thinking of all the questions regarding Iowa’s CSR index — or corn suitability index — that I’ve had over the years.
The CSR index is unique to Iowa and I’ve found that many folks don’t really know what it is. So, I thought it was due time to shed some light on that.
Corn Suitability Rating examined:
The Corn Suitability Rating (CSR) was established in 1971 by Iowa State University as a means to rate the productivity of Iowa tillable soils.
With this system, soil are segregated in a meaningful way based on similar physical properties and are arranged into mapping units. Corn suitability rating (CSR) is based upon these different soil mapping units (smu’s), average weather conditions for the area, and upon the frequently of use of the soil for row crops.
Corn suitability rating’s range from 5-100. Five being soils that are severely limited in being able to be row cropped. And, with 100 being soils with few or with no physical limitations on being row cropped, having little or no slope, and that can be continuously row cropped.
As you can see, basically, the higher the CSR unit of the land the more valuable, from a production standpoint, it is to the farmer and to the landowner in general.
Something else to note about the CSR index is that it has gotten more accurate over time, as the overall knowledge base and classification of soils has become more refined.
The New Corn Suitability Rating:
In 2013, Iowa State University came out with a new version of CSR called the CSR2. You might deem this the new and improved CSR index.
Well, sort of.
The major difference between the old CSR and the new CSR2 has to do with rainfall. That being, the CSR2 value does not include a rainfall correction factor, built in, as did the old corn suitability rating.
It seems that, over time, rainfall rates have generally increased across Iowa so that having the correction factor was not needed.
Interestingly, that, in general, at least, CSR2 values tend to be higher in north-central and in northwest Iowa, than CSR values. For the rest of the state, the two indicators are very similar.
Keep in mind that with both indexes these assumptions exist: soil management units are adequately managed, are artificially drained when required and that there is no land leveling or terracing.
(Note: part of the above was taken adapted from Sassman, Buras and Miller – “A Comparison of Iowa’s Original CSR index to the new CSR 2 index. Dept. of Agronomy, Iowa State University).
Will the new CSR2 index affect my real estate taxes?
In general “NO”.
Here’s how the county assessor deals with CSR in relation to establishing real estate taxes.
As you may imagine, from our discussion so far, CSR values are directly tied to land values. In fact, The two are generally directly related. I say generally because this is not always so clearly defined as we’ll discuss in a second.
Iowa farmland prices in relation to CSR. (Sometimes CSR in relation to land prices is discussed as dollars-per-CSR point in relation to price per acre. For example a price of $100 per CSR point on X number of acres that have a CSR value of 60: Equals 60 points x $100 per point == $6,000 per acre)
Segmentation of Acres impacts production and valuation using just CSR Index:
When a farm is segmented, as so many recreational tracts are, the relationship between CSR value, as may be examined as CSR points-per-acre becomes less clear.
A large crop field with easy access means it’s easy for the farmer to get in and out of to plant and to harvest. Lots of acres in one place also means the farmer does not have to relocate his equipment to a different location to do the same things. This saves him time and money.
Suppose we have the same amount of acres as in example A. That is, the same amount of acres but they are broken up or segmented into several smaller fields. Separated, perhaps, by a creek crossing, parcels of timber, or a few miles distance between the fields. These things mean the farmer will need more time to plant and more time to harvest the same amount of acres as in example A.
It also means more expense because of the travel between fields with big equipment. Segmented fields also have more edge. This is great for wildlife, especially deer. But it does mean that these fields will receive more browsing pressure and predation from animals.
Smaller fields, in Iowa, tend to get heavily browsed by deer.
And, also, turkeys eat lots of planted seeds. Animals like raccoons, squirrels and, even beaver, eat seed and damage crops too. These things all play against the market and production value of smaller individual fields vs bigger fields with identical CSR values and the same amount of acres.
As can be seen in this comparison, two farms, each having identical acres and identical CSR indexes, can have very different real values to the farmer and, hence, to the landowner. In the market place, these acres would also have different market values.
So, using CSR values as a direct pricing mechanism when buying and selling can be a bit tricky and subjective.
Basing the value of acres using just the CSR index alone is not really enough.
One also needs to take into account these other factors such as field size, ease of access, animal browsing potential, edge component, and total recreational potential (This is not discussed here but we’ll hit this topic in a future blog post. Do note that the recreational market value potential goes up with field segmentation, in general. Just the opposite of valuation using of such fields using just the CSR index).
Looking at a Soils map: The Letters mean Slope
Something else you will see on soils maps are letters after the soils designated classification number. You see something like 13B. The number refers to how the soils is classified by mapping unit and the letter refers to the slope of the land.
B == 2-5% slopes
C== 5-9% slopes
(no letter designates little to no effective land slope)
As you might imagine, CSR and land the slope of the land have an opposing relationship. That is, the more the land slopes the lower is the CSR value.
And, therefore, usually, too, the lower is the value of the land, from a pure crop production valuation standpoint. (Not necessarily from a recreational value standpoint).
Stay tuned to our blog, as I’m sure we’ll discuss market valuation from a recreational value perspective – instead of just an income perspective — as it relates to CSR indexes of tillable acres.
Lastly, you might check out this video on soils and soil properties.
Soil Properties Video (outside link)
It’s Prime Time for Habitat Work with your Chainsaw!
Okay, well, let’s just say that it will be in a few days when the Iowa late-muzzleloader season is over. So we are getting close.
And, I know, I know, some folks will want to wait until the deer drop their antlers to barge into the timber and start cutting. I often do this too. But, you know, the truth is, guys and girls in the timber doing chainsaw work doesn’t really bother deer.
Deer know how to sense danger. And deer know that a chainsaw is not normally associated with danger.
In fact, to a whitetail, the loud moaning of a chainsaw is often a calling card. I can’t tell you how many times we’ve downed trees in the snow and come back the next day to find the place littered with fresh deer sign. And I can’t tell you how many times, on big multi-day management projects for clients, that we’ve found fresh deer antlers shed on the very slopes that we’ve just spent hours cutting on.
So, that’s right…now is THE time to hit the woods with a saw in your hand!
Of course, you probably know some of the reasons why wintertime is often the best time to hit the woods — saw in hand.
It’s cold outside and that means no pesky bugs or stinging nettles and way less chance to make contact with poison ivy too. I can tell you what – those are three pretty good reasons right there!
In fact, those are great reasons to get out there right now with your saw. And there are more.
It’s also much more comfortable to be out there horsing and man or woman handling that saw around those trees. It’s not easy work lugging a heavy saw through the woods from tree to tree and from area to area, that’s for sure. So it’s easy to work up a sweat – even when it 15 or 20 degrees out! (don’t forget you are usually lugging a small gas can, bar oil, and maybe a few tools and some lunch around as well).
And I can tell you what, doing all of that horsing and saw lugging around when it’s mid-July and in the 90’s is not as much fun as when icicles are dangling from the trees!
Now is the time.
It’s also the best time to prevent any diseases to be spread from tree to tree via the saw blade (oak wilt).
Of course, before doing any cutting you must first identify what sort of work needs to be done.
Timber stand improvement (TSI) is one such goal.
Under this heading falls the subheadings for TSI: crop tree release, understory release/management and cull tree removal.
Lots of people talk about doing TSI to help make things thicker so that the land can hold more and bigger deer. This is generally true and is a side product of the actual process.
The main goal of doing TSI, though, usually and from a forestry perspective, is to enhance the forestry component – that is, to make certain trees grow faster and produce more mast (studies have shown that properly done crop tree release tsi can make the desired “crop” trees grow 2x as fast and with up to 10x more mast production!)
The side benefit of doing TSI is the resulting thicker habitat created because more light can hit the forest floor (so more woody vegetation/and or grasses can grow).
The more light that hits the forest floor, generally, the thicker, and more diverse, the habitat on the forest floor becomes. This creates bedding, sanctuary and thermal cover for deer and also nesting and escape cover for turkeys. It also produces better habitat for lots of non-game species like songbirds.