Taming Wild Trees

Luqi Li Author

07/30/2020 Added

14 Plays

Description

Dr. Eric North - Taming Wild Trees

Searchable Transcript

Search:

[00:00:01.496](upbeat music)
[00:00:11.580]Hi, I'm Dr. Eric North
[00:00:13.740]Professor of Regional & Communities Forestry,
[00:00:16.250]in the School of Natural Resources.
[00:00:18.240]In this presentation we're gonna be talking about
[00:00:20.590]taming your wild trees,
[00:00:22.660]the basics of tree management in your landscape.
[00:00:25.200]We're gonna start with,
[00:00:26.260]why it's important to maintain your trees.
[00:00:28.880]Some of the consequences of not maintaining trees.
[00:00:31.110]And then we're gonna look specifically at
[00:00:33.352]pruning and planting of trees in the landscape
[00:00:36.470]for longterm tree benefits.
[00:00:41.912]Speaking of tree benefits,
[00:00:43.464]the bigger the tree, the more benefit it provides.
[00:00:47.240]That's part of it.
[00:00:49.470]Older trees also provide longer term benefits.
[00:00:52.750]So this all seems pretty obvious.
[00:00:54.330]The objective here in maintaining our trees
[00:00:57.127]and the management of trees in our landscapes
[00:00:59.230]is to get large trees that live for a long time
[00:01:02.500]and that we don't have to spend a lot of money on.
[00:01:07.450]A little bit of a sad start
[00:01:09.070]as something to think about.
[00:01:10.350]There's a real decline
[00:01:11.550]in urban and community tree cover in the United States.
[00:01:15.030]And this is talking about all of our communities
[00:01:17.680]anywhere where there's a built landscape, essentially,
[00:01:20.200]this can be golf courses, this can be small towns,
[00:01:22.840]doesn't have to be the big cities.
[00:01:24.701]This can be any small town, any small community
[00:01:28.110]with tree covering and if you notice,
[00:01:30.076]Nebraska is dark colored here,
[00:01:34.670]that Nebraska is actually in the top three
[00:01:37.800]for losing tree cover and canopy cover.
[00:01:41.000]I'm gonna look at a few reasons why that might be
[00:01:43.770]and how we can use proper tree management
[00:01:47.860]to bring Nebraska back to its status
[00:01:50.990]as the tree planter state.
[00:01:53.900]And it's important to note
[00:01:55.010]this didn't happen overnight.
[00:01:56.250]It's not that there was one storm that came through
[00:01:58.650]and took out a bunch of trees and that's the problem.
[00:02:01.470]This is more likely a longer term issue
[00:02:04.580]with how we manage trees in our landscape.
[00:02:08.120]Development practices had not always that helpful.
[00:02:11.490]You can see here, a tree has been buried.
[00:02:15.260]Nothing likes to be buried alive, right?
[00:02:18.955]This is compacting the soil
[00:02:22.183]it's potentially scraping or damaging the bark.
[00:02:25.090]Rarely do have I seen anybody dump soil very gently.
[00:02:28.619]So this is poor, can cause poor health
[00:02:32.270]in the tree later on.
[00:02:34.050]Rarely do trees die outright from this
[00:02:36.715]meaning that even once the soil is potentially removed,
[00:02:40.266]the tree might still leaf out,
[00:02:42.280]might still have green leaves for the next few years.
[00:02:44.330]Trees can oftentime from this type of damage.
[00:02:46.790]Take many years to start to decline and then die
[00:02:51.300]or decline to the point where somebody finally notices
[00:02:54.480]that the tree is doing poorly and then the tree is removed.
[00:02:58.360]So we can completely avoid this
[00:03:00.830]just by setting up protection zones and barriers
[00:03:03.780]to preserve trees
[00:03:04.917]and this starts with a preservation plan
[00:03:07.310]before the project begins
[00:03:08.820]as to which trees you wanna save
[00:03:10.580]and which trees you want to remove.
[00:03:14.620]Poor design, here you can see
[00:03:17.330]we have an Eastern white pine
[00:03:19.410]and this canopy isn't interfering with the power lines yet,
[00:03:24.840]but Eastern white pine can be a fairly large tree
[00:03:27.750]and eventually it will reach into these power lines
[00:03:31.510]and then we'll have to prune off parts of the tree.
[00:03:34.670]So this is not a great tree to plant in this location.
[00:03:38.150]So either a smaller stature tree
[00:03:40.090]or planting further away from the power line.
[00:03:42.900]So let's look at the four R's of tree planting.
[00:03:47.180]You might've heard these the right tree.
[00:03:49.150]So you gotta pick the right species,
[00:03:51.080]put it in the right place.
[00:03:52.040]So the species and the place should match up
[00:03:55.560]should be compatible.
[00:03:57.016]And we wanna reduce maintenance.
[00:03:59.992]So in this white pine case,
[00:04:02.727]by planting the tree there,
[00:04:04.180]were essentially incurring greater future management
[00:04:08.350]or maintenance costs for the amount of pruning
[00:04:10.530]that needs to happen.
[00:04:12.100]And we wanna realize those longterm benefits.
[00:04:14.660]So the more we have to prune this white pine,
[00:04:17.230]the more costs us, the fewer benefits that we get from that.
[00:04:20.910]And also the potential to reduce the longevity
[00:04:23.980]of this tree as it gets even larger
[00:04:26.230]and grows more into the power lines
[00:04:28.620]or result likely in the tree needing to be removed
[00:04:30.960]before would have to be in the landscape
[00:04:33.520]because of where it's placed.
[00:04:35.120]So keep these in mind when you're designing
[00:04:37.463]where trees might go in your landscape.
[00:04:41.570]Poor inhalation of management practices,
[00:04:43.287]look at this tree here.
[00:04:44.770]Now this is in part due to maybe bad nursery stock.
[00:04:48.010]So setting up a good, a way to inspect nursery stock,
[00:04:52.530]that comes into eliminate some of these,
[00:04:54.660]but even after the fact you've got,
[00:04:56.088]even if you get some nursery stock
[00:04:58.400]that isn't, can't always be 100%.
[00:05:00.743]This could these roots, which are now starting to in circle
[00:05:03.940]and girdle the tree, which will ultimately reduce
[00:05:07.970]the health and vitality of this tree.
[00:05:11.740]These roots could have been removed
[00:05:14.000]when the tree was first planted.
[00:05:15.710]And it also looks like this tree was planted too deep,
[00:05:18.599]and that will ultimately reduce the usefulness
[00:05:22.250]of this tree and increase some of the maintenance costs.
[00:05:24.770]And here we've got just a management issue.
[00:05:28.410]This tree was staked when it was put in
[00:05:30.727]and then nobody came back to check on the stakes
[00:05:31.840]and remove those,
[00:05:32.940]stakes should really only be on
[00:05:34.600]for maybe a season and state fairly loosely
[00:05:37.360]so that you don't start to cut into branches
[00:05:39.780]and damage the tree again, reducing its longterm benefits
[00:05:44.940]and increasing the amount of management costs
[00:05:47.560]that you have for that tree.
[00:05:50.070]Who would you, would you hire this guy
[00:05:52.710]has no PPE, I don't know what's really happening.
[00:05:55.670]There's power lines here,
[00:05:56.980]you can see it as a power line behind
[00:05:58.630]doesn't look like anything's harness.
[00:06:00.435]These cuts just kind of heading things off,
[00:06:03.891]leaving things open for decay and disaster,
[00:06:06.610]or would you rather hire an educated arborist
[00:06:08.900]you can see this woman has all the proper PPE
[00:06:12.620]she's got a helmet, she's got chainsaw chaps.
[00:06:15.160]She's nicely tied in with their chainsaw and a harness.
[00:06:18.730]This is clearly an educated professional.
[00:06:21.560]So educated and certified tree care professionals
[00:06:24.620]are really key to good tree care
[00:06:28.450]and longterm trees in our landscapes.
[00:06:32.946]Monocultured landscapes,
[00:06:34.530]so this again is thinking about
[00:06:36.440]when you're net planting and design phase.
[00:06:38.930]So along this street, we have almost entirely
[00:06:41.800]is really only two species in this picture
[00:06:43.690]in terms of the street trees.
[00:06:45.240]We have pin Oaks all along here,
[00:06:47.000]and then we have a couple of bass woods or lindens here
[00:06:50.930]and that's okay, but we can increase diversity even more.
[00:06:55.360]So what do I mean by costly management?
[00:06:58.180]Well, let's think about the emerald ash borer.
[00:07:00.870]If you had planted all ash in one small area
[00:07:04.580]or along a particular street
[00:07:06.390]or in all the way along the golf course
[00:07:08.708]now with emerald ash borer,
[00:07:10.260]you have to either remove those trees or treat those trees.
[00:07:13.924]And that just increased the cost of management.
[00:07:17.130]Again, you're gonna realize some benefits,
[00:07:18.930]but the benefit production is reduced
[00:07:21.820]based on how much you have to spend.
[00:07:23.890]So let's think about adding and maximizing diversity.
[00:07:28.210]So how many different species or genus can we get
[00:07:31.580]in a landscape to minimize the impact of things
[00:07:34.900]like emerald ash borer?
[00:07:36.308]If you're thinking well,
[00:07:37.141]emerald ash borer is gonna go away eventually,
[00:07:39.250]or we're gonna get rid of almost all of the Ash.
[00:07:41.660]And so emerald ash borer, won't be that big of deal.
[00:07:44.580]Well, there's always something,
[00:07:46.090]so it's just a matter of time.
[00:07:47.550]We have Asian Longhorn beetle, which loves Maples Maples
[00:07:50.998]and others that feeds on a lot of different plants
[00:07:55.540]and we have the spotted lanternfly, again maples and others.
[00:07:58.300]So Maples really are starting to look like
[00:08:01.527]maybe we should look at how we can reduce or minimize,
[00:08:05.280]not stop using them, but reduce our minimize
[00:08:07.870]so that if any of either of these two
[00:08:09.660]or some other future pass we don't yet know about
[00:08:12.308]come into Nebraska,
[00:08:14.060]you're still protected from your landscaping
[00:08:16.310]and you can reduce the amount of management
[00:08:18.140]or maintenance costs that go into those trees.
[00:08:22.973]So thinking about planting
[00:08:25.160]and from a biological or evolutionary perspective,
[00:08:28.130]this is really a strange thing to do to a tree.
[00:08:30.150]It hasn't evolved to be moved from one location
[00:08:33.240]all the way over to another location,
[00:08:35.060]have its roots, disturbed cut soil disturb,
[00:08:37.960]go from one soil type to another soil type.
[00:08:40.230]This is really a strange thing for a tree
[00:08:42.707]and it's one of the weirdest things that we do.
[00:08:45.570]And there are some ways that we can make this
[00:08:47.671]an easier transition for trees.
[00:08:50.931]So here we have a tree nursery stock fairly common,
[00:08:56.577]notice a few things that the roots here,
[00:09:00.160]we really see starting below the soil surface
[00:09:04.726]and they're starting to encircle.
[00:09:06.637]And some of these are getting to be fairly thick
[00:09:09.530]and they're encircling around the plant
[00:09:11.300]and notice that there are no roots in this upper zone.
[00:09:14.251]And so if we were to plant the tree right here,
[00:09:17.280]we're guaranteed to plant the tree a little too too deep.
[00:09:22.020]So we can fix this,
[00:09:24.890]so notice this is my old pruning saw,
[00:09:26.890]that I used for a root pruning saw,
[00:09:28.770]and essentially what you can do.
[00:09:31.160]If you have the tree as, think of it as a circle,
[00:09:35.750]we can just cut it, we call this box cutting.
[00:09:39.290]And this removes any of the encircling roots.
[00:09:42.370]So we essentially made a straight line cut here
[00:09:44.750]and then a straight line cut here, here
[00:09:47.700]and through here on the backside
[00:09:50.270]that allowed us to remove all of the encircling roots
[00:09:54.720]that could potentially become girdling roots.
[00:09:57.034]Also notice that I remove this top layer of soil.
[00:10:00.930]So the top layer here would have been here.
[00:10:03.900]And as a consequence, look at how much more trunk
[00:10:06.840]I got a taller tree, just from removing some of the soil.
[00:10:10.330]Now we can plant this at the proper depth
[00:10:12.980]with the first roots within one inch of the soil surface
[00:10:17.370]when it's actually in the landscape
[00:10:19.330]So you can see the trunk here,
[00:10:21.289]pushed down quite a bit further.
[00:10:23.600]We get a little bit taller tree just by,
[00:10:26.230]by making sure that we're correcting
[00:10:29.130]these things at planting issue.
[00:10:32.570]But why fix things if you don't have to
[00:10:34.760]notice the difference between these pots,
[00:10:36.570]this is a pot that is designed to work
[00:10:40.180]with how trees roots work, biologically,
[00:10:43.010]it's an air pruning pot.
[00:10:44.040]And so it's got little holes in here
[00:10:45.202]and these little ridges that help to reduce
[00:10:48.920]the amount of in circling or girdling roots that may form
[00:10:52.760]notice too when this tree was potted up,
[00:10:54.870]we have a little bit of a flair here
[00:10:57.020]indicating that it's likely planted
[00:10:59.410]in the pot at the right depth.
[00:11:01.477]This solid cited pot over here
[00:11:04.330]encourages and circling roots,
[00:11:07.020]the longer it stays in that pot.
[00:11:08.620]So the roots hit this edge
[00:11:10.480]and then they just simply start to encircle.
[00:11:14.480]And then if you plant this at the wrong depth,
[00:11:16.410]that those encircling roots
[00:11:18.367]can start to girdle the tree trunk,
[00:11:20.275]which is clearly not desirable.
[00:11:23.100]So you can either fix it,
[00:11:24.380]if you do, you still use solid sided pots,
[00:11:26.580]or you can look for growers
[00:11:28.270]that are using these air pruning pots
[00:11:30.570]and some better technology to help eliminate
[00:11:33.160]or reduce root issues at the time you purchase,
[00:11:38.310]What happens if you don't correct these things?
[00:11:40.330]Well, this is a,
[00:11:41.430]it's much harder to drive this car to work at this point.
[00:11:44.290]And we can see some oddities here.
[00:11:46.950]This came down in a storm,
[00:11:48.380]so you think, well active nature trees fall down in storms.
[00:11:52.020]That does not to be true.
[00:11:53.960]This is a storm that wasn't a tornado or anything like that.
[00:11:58.620]That might take out any tree, regardless of defects.
[00:12:00.672]Let's take a look at what it looked like.
[00:12:03.370]This is where it was planted in the ground.
[00:12:07.410]Notice that there's no it didn't rip up the soil.
[00:12:11.390]You don't see roots in the air.
[00:12:12.850]You just see this little tiny hole right here.
[00:12:15.700]And we can see this is actually root tissue right here.
[00:12:18.740]And that was pressing against the trunk.
[00:12:21.480]And we can see what that looks like here.
[00:12:24.150]This is where the root was starting to girdle.
[00:12:26.830]And you can see this indentation right here,
[00:12:29.456]and then how the trunk actually tapers down into,
[00:12:33.980]you know is almost like a pencil tip,
[00:12:36.100]but the way it's tapering down.
[00:12:37.670]And so this part of the trunk was being girdled
[00:12:40.208]and that reduces the stability.
[00:12:42.470]And if you look back in this planting hole, right in here,
[00:12:46.840]we can start to see some decay and rot.
[00:12:49.410]So this could have been completely corrected
[00:12:51.570]at time of planting.
[00:12:53.180]And you can see how large this tree is,
[00:12:55.990]so if we just look back at it,
[00:12:57.370]that's a good size tree.
[00:12:58.700]So these problems don't necessarily occur
[00:13:01.184]right after you plant them.
[00:13:02.740]They can occur years later, sometimes 10, 15, 20 years later
[00:13:07.040]under the right condition.
[00:13:08.800]And if you're thinking,
[00:13:10.000]well you know a lot of trees go down in storms.
[00:13:12.800]This is what the rest of that street looked like.
[00:13:15.110]So that was a Linden.
[00:13:16.400]Most of these along this street,
[00:13:17.980]this is actually the fallen tree
[00:13:19.500]would have been about right here,
[00:13:21.000]just outside of the picture.
[00:13:22.490]And you can see in that same storm,
[00:13:24.700]none of these other trees went down.
[00:13:26.900]And if we look at the base,
[00:13:28.140]we can see these start to have some flares.
[00:13:30.480]You can even see a little bit of flare back here.
[00:13:32.700]So we're seeing trunk flare,
[00:13:34.010]and that's an important thing to look for
[00:13:36.080]completely correctable at time of planting.
[00:13:38.740]And now you have to basically remove a tree
[00:13:41.832]that's sitting on someone's car
[00:13:44.000]and they're not gonna be happy.
[00:13:45.930]So make sure that we're planting
[00:13:48.020]and doing things at the right time
[00:13:50.090]and in the right ways to minimize these types of issues.
[00:13:55.047]`you can remediate roots or trees
[00:13:58.010]that are planted too deep.
[00:13:58.990]This is a pneumatic or an air tool here.
[00:14:01.780]And essentially it's connected,
[00:14:03.765]it's connected here with it to a compressor
[00:14:07.410]and the compressor shoots air through here,
[00:14:09.490]and we can blow away the soil.
[00:14:11.630]This is an alternative to digging
[00:14:14.050]and that way we can look at and examine the roots
[00:14:16.830]without disturbing them too severely.
[00:14:19.230]So here's what it would look like,
[00:14:20.670]we can then see that, oh, here was the soil line.
[00:14:23.140]We blew away that now we can come back in
[00:14:25.790]and either regrade if possible,
[00:14:27.560]or amend this soil with more organic material.
[00:14:31.080]So you can use this to remediate, potentially find
[00:14:33.660]or look for stem girdling roots
[00:14:34.737]and maybe cut those off if that's an option
[00:14:37.410]or improve some of the soil conditions.
[00:14:39.690]So remediation can happen,
[00:14:41.240]but again, if you don't have to fix it, that's better.
[00:14:44.170]So you wanna make sure that we're planting
[00:14:46.470]and correcting these things at time of planting,
[00:14:48.670]it's much less expensive and much easier to do a small plant
[00:14:52.190]than it is on larger trees.
[00:14:55.435]Adventitious roots, that's these right here.
[00:14:58.683]They develop a very common and floodplain species.
[00:15:01.675]You can see this is a water channel here.
[00:15:04.970]And the previous year the tree had floodline
[00:15:08.620]basically up to about here.
[00:15:10.470]We can see a flood line about here,
[00:15:12.510]and these are roots and root masses
[00:15:14.810]that have developed right off the trunk
[00:15:17.300]and trees we'll do this.
[00:15:19.250]Some trees will do this pretty readily.
[00:15:21.630]If you plant them too deep,
[00:15:23.660]they can start to develop adventitious roots.
[00:15:26.420]And it's really helpful for floodplain species,
[00:15:29.460]but when we simply plant them too deep in the landscape,
[00:15:33.860]as you can see here,
[00:15:35.629]this is actually the soil line from a pot.
[00:15:38.265]And then this is, these are the adventitious roots
[00:15:41.200]that formed because it was planted too deep.
[00:15:43.180]And this is the original root system right here.
[00:15:46.420]And so that's a problem.
[00:15:48.650]Even if we correct down to this root system,
[00:15:51.258]we still have trunk tissue here.
[00:15:53.930]And if you plant that out, now we can see we've got
[00:15:56.570]some fairly severe stem girdling roots,
[00:15:59.200]this pressure in, if it looks like a telephone pole,
[00:16:01.870]tree shouldn't look like that they should have taper.
[00:16:04.420]And so we can see roots are clearly compressing the stem
[00:16:08.140]and larger roots now doing the same thing.
[00:16:10.300]So if you plant them too deep,
[00:16:11.970]these adventitious root formation can be very problematic.
[00:16:16.880]You should have a good trunk flair, right?
[00:16:19.230]Look at this nice trunk flare coming out
[00:16:21.840]that tells us that the tree was likely planted
[00:16:23.950]at the right depth.
[00:16:25.180]And the tree will have greater stability in storms.
[00:16:29.362]Lack of trunk flare, you can see here,
[00:16:31.680]look at this, just a straight line coming down,
[00:16:34.540]nothing broken right off at the base.
[00:16:37.050]That's a clear indicator of some decay at the stem and roots
[00:16:40.820]and likely as a cause of Stem girdling roots.
[00:16:43.700]So this can be a big issue with more trees coming down.
[00:16:47.310]You know few branches in a storm is one thing,
[00:16:49.170]but an entire tree, especially a larger tree
[00:16:51.310]because of poor planting is a much, much bigger issue.
[00:16:56.650]So root depth in extent
[00:16:58.190]when you're thinking about putting trees in the landscape,
[00:17:00.520]how far out do the roots grow?
[00:17:02.230]Well, they can grow as far out
[00:17:03.830]as they have space and room for
[00:17:05.930]often extending far past the crown of the tree
[00:17:09.300]or the branches of the tree,
[00:17:10.860]going all out this way.
[00:17:12.230]And they look at these are all mostly on the surface.
[00:17:15.800]And here's another tree example.
[00:17:17.710]This tree actually did blow down in a storm,
[00:17:20.060]So it can happen where there was lots of wind
[00:17:22.920]and lots of rain making the soil very loose
[00:17:25.750]and notice there's no giant taproot coming out here
[00:17:28.460]that was broken.
[00:17:29.580]This a root system basically formed in a spiral.
[00:17:33.410]Much of that taproot can disappear,
[00:17:36.330]I'm not saying it's impossible for roots
[00:17:37.980]to be deep in the ground, clearly it does happen,
[00:17:41.010]but generally most of the root hairs
[00:17:46.430]and fine roots that absorb the water and nutrients
[00:17:49.160]that the tree needs
[00:17:50.700]are in the upper layers of the soil surface.
[00:17:53.670]And many of these roots that are there
[00:17:56.340]to help stability are also
[00:17:58.370]within the upper couple of feet of soil,
[00:18:01.520]depending on soil type Of course.
[00:18:04.450]Negatives of compaction,
[00:18:06.430]so given that the much of the water absorbing roots
[00:18:10.820]are in the upper sort of 18 inches or so of soil,
[00:18:14.800]depending again on soil type.
[00:18:16.600]When we compact the soil by driving over it,
[00:18:19.430]this really causes significant compaction
[00:18:22.460]and that limits water and oxygen from getting to the roots
[00:18:25.710]and roots need both.
[00:18:27.220]And this can cause decline,
[00:18:28.720]here you can see the canopy of this tree is declining.
[00:18:33.426]And part of that's because of at the base here,
[00:18:36.400]there was lots of compaction around it,
[00:18:38.220]this tree has now been removed.
[00:18:39.820]And this tree that is still in the landscape here
[00:18:42.450]has started to show some signs of decline
[00:18:45.870]where the canopy is dying back
[00:18:47.720]the way we see on the other tree.
[00:18:49.820]So that's a big issue, this can again be remediated,
[00:18:53.070]but better to set up protection zone around the tree.
[00:18:56.300]If the tree you want to keep in the landscape
[00:18:58.430]after the project is finished,
[00:19:02.160]this is something that I hear sometimes,
[00:19:03.700]trees can't be planted
[00:19:05.070]where there was a previous tree growing.
[00:19:07.290]Well, that's very odd, here is a,
[00:19:10.240]this is just a forest tree.
[00:19:11.578]They can see that this tree stump didn't even wait
[00:19:14.290]this the tree growing on top of it
[00:19:16.280]didn't even wait for that stump to fully go away
[00:19:18.700]before it started growing.
[00:19:20.170]I'm not suggesting that we just throw some seed
[00:19:22.980]or try to dig right on top of a stump that's already there,
[00:19:25.930]but if you get the stump ground out,
[00:19:27.710]you can certainly plant a tree right back
[00:19:29.810]in that same location.
[00:19:31.530]I prefer to usually take out some of the stump grindings
[00:19:34.870]and use that as mulch somewhere else,
[00:19:36.370]and maybe bring in some fresh top soil
[00:19:38.580]or good organic matter to help any newly planted tree
[00:19:42.180]in that space.
[00:19:43.013]But clearly biologically trees don't care,
[00:19:46.500]trees and forests grow on top of old trees all the time.
[00:19:48.858]If they didn't, there are forest,
[00:19:51.040]as soon as the tree died, nothing would ever replace it.
[00:19:53.100]So this is clearly sort of a nonsense thing
[00:19:56.030]that that has been spread around.
[00:19:57.940]So I'm not sure where that comes from.
[00:20:01.223]To give you an idea of root space and design.
[00:20:04.550]So here, this is actually in Hong Kong,
[00:20:08.720]this is a nice bike path and walking path,
[00:20:11.145]and you can see trees nicely planted over here.
[00:20:14.728]And you see trees planted over here in these little boxes
[00:20:20.590]above ground boxes.
[00:20:21.970]So these boxes were designed
[00:20:24.290]by a landscape architect who said,
[00:20:26.616]"I really liked the look of this."
[00:20:27.940]And they planted the trees in,
[00:20:29.800]well, here is a tree that was planted at the same time,
[00:20:34.230]same species.
[00:20:35.120]And this is the tree that is directly across the path.
[00:20:37.720]And you can see much taller, full, nice, full crown,
[00:20:42.260]really an attractive looking tree.
[00:20:44.160]We see a trunk flair, so that's great.
[00:20:46.380]And actually tree roots
[00:20:47.730]are probably intermingling with these other tree roots
[00:20:50.440]and biologically that's what they would do in forest.
[00:20:53.090]And so you get a healthier tree,
[00:20:55.060]you get a tree that's more stable here.
[00:20:57.100]You can see the tree is already starting to die back.
[00:20:59.900]It's excess heat, less moisture
[00:21:02.234]and in fact about every third of these boxes,
[00:21:05.060]trees had already been removed
[00:21:06.640]because they had died prematurely.
[00:21:09.020]So really making sure
[00:21:11.070]when you're designing spaces
[00:21:12.530]that you're thinking quite a lot
[00:21:14.900]about the rooting space that's available for trees
[00:21:17.800]is very, very important.
[00:21:21.300]Another bit of strange information that I came across.
[00:21:23.749]If you plant trees and square holes
[00:21:25.893]it'll make them grow faster, I disagree.
[00:21:30.240]Here's a tree in a square hole.
[00:21:31.650]Here's, it's above ground portion of that tree.
[00:21:35.320]You can see the tree behind it is in full leaf.
[00:21:37.460]This isn't a fall or winter picture.
[00:21:39.080]This is a tree that is clearly declining in the canopy.
[00:21:42.770]And so this isn't true that the other thing
[00:21:46.240]that this article claims
[00:21:47.950]is that trees won't grow in a square
[00:21:49.940]and so it'll force them out
[00:21:51.867]or they won't allow them to grow in a circle.
[00:21:54.610]But all of that is just clearly nonsense.
[00:21:56.964]Here's another tree example where we can see how roots grow.
[00:22:01.660]They just grow wherever it's conducive,
[00:22:03.449]So where there's enough oxygen and moisture.
[00:22:05.491]And here we see tree has basically grown
[00:22:09.010]along nice edge here,
[00:22:11.273]and then the same edge here.
[00:22:14.143]And then it makes almost a right hand turn.
[00:22:16.480]I mean, this looks like plumbing practically.
[00:22:18.690]So tree roots will take on any shape
[00:22:20.985]that is conducive to growth.
[00:22:23.410]And it doesn't really matter what shape the hole is in
[00:22:26.660]it's best that we make a hole
[00:22:28.220]that's large enough to fit the whole tree.
[00:22:29.940]And we amend it with organic matter
[00:22:32.690]and try to loosen the soil to keep it from being compacted.
[00:22:36.070]So roots can explore the soil all around the tree.
[00:22:41.590]Branch attachments, we're gonna look at
[00:22:43.060]how branches actually attached to the trunk
[00:22:45.870]so we can think about pruning in the tree.
[00:22:51.890]So we might look at branches that have strong attachments
[00:22:55.276]branches that will stay attached,
[00:22:57.860]even under load and load might be snow, wind, rain,
[00:23:01.440]anything that's causing mechanical force.
[00:23:04.000]So here you can see,
[00:23:05.200]this is what we call the branch bark ridge.
[00:23:07.400]So we're looking for that.
[00:23:08.290]It's where the bark basically pokes up
[00:23:10.210]just a little bit and out and on the inside,
[00:23:13.140]what that looks like.
[00:23:14.090]So here's that same piece of wood.
[00:23:15.610]Here's where that branch bark ridge is.
[00:23:17.500]We see this interweaving interconnection of wood,
[00:23:21.900]and that's what helps give a nice strong attachment.
[00:23:24.780]You've got branch would come
[00:23:26.450]and you've got trunk would coming in
[00:23:28.310]and they're blaring on top of each other.
[00:23:30.800]So it's giving a nice very good and strong connection.
[00:23:36.370]So we're looking for these types of connections
[00:23:38.279]when pruning or when trying to figure out what to prune.
[00:23:42.663]Branch attachments can start strong and then go to weak.
[00:23:47.399]So here we see a little bit of a branch bark ridge,
[00:23:51.580]and here we see the inside,
[00:23:54.007]here we see the inside is got a little bit
[00:23:56.700]of that wood to wood connection here.
[00:23:58.535]But this is a pretty close together.
[00:24:01.490]So as these branches continue to grow,
[00:24:03.607]they might start to grow together
[00:24:04.440]here we see the branches started.
[00:24:09.070]So we've got a branch here and a branch here,
[00:24:11.020]and we see this nice interweaving of wood,
[00:24:13.970]but now that the branches have gotten to a certain thickness
[00:24:16.560]with the trunk,
[00:24:17.470]we start to see that bark is included.
[00:24:20.190]So this right here is bark that's included inside.
[00:24:23.859]So we call that easily enough included bark.
[00:24:27.100]And when the bark gets in there,
[00:24:28.550]we don't see the wood to wood connection anymore.
[00:24:30.579]And so that makes a weaker connection.
[00:24:34.550]So this right here makes a weaker connection under load.
[00:24:38.040]So under a mechanical load of snow wind rain,
[00:24:39.011]rain especially if they're full in full leaf.
[00:24:45.020]So lots of issues there.
[00:24:46.530]So we're looking for those.
[00:24:47.830]And maybe we would have said, back here,
[00:24:49.940]maybe we prune this branch off
[00:24:51.632]because we can see that the size of those two,
[00:24:56.090]it's likely gonna form a weak attachment in the future.
[00:25:00.660]We have just week attachments, completely,
[00:25:03.060]all this dark line, this isn't decay.
[00:25:04.940]This is actually just bark that's in there.
[00:25:06.800]So there's no wood to wood connection at all.
[00:25:09.830]So it doesn't take as much force or effort
[00:25:11.980]to rip this branch away from this branch here.
[00:25:15.041]And this is what it looks like on the outside.
[00:25:17.281]So we see bark, that's kinda rolled in
[00:25:20.770]as opposed to being pushed up.
[00:25:23.110]And so when you see that that's a weak
[00:25:26.330]indication of a weak branch attachment,
[00:25:28.910]and those would be something you might wanna
[00:25:31.230]consider pruning off earlier rather than later,
[00:25:34.010]again, pruning a smaller branch is typically better.
[00:25:38.704]Poor and weak attachments,
[00:25:40.880]what's the big deal you might say.
[00:25:42.350]Well, here we have what we call codominant leaders.
[00:25:44.780]That's two trunks or two branches
[00:25:47.170]that are roughly the same size coming,
[00:25:49.070]originated from the same spot.
[00:25:50.500]And we can see this as wrapped in or rolling bark.
[00:25:54.400]So that's included bark and here we have the same thing.
[00:25:57.880]Well, under the right storm conditions,
[00:25:59.880]doesn't have to be a major storm,
[00:26:01.340]just a normal wind or rain or snow.
[00:26:05.260]You can see this tear out here,
[00:26:06.708]all of this dark material here,
[00:26:08.946]this wasn't, this is not decay, this is actually bark.
[00:26:13.730]So there was included bark all the way up through here,
[00:26:16.550]which means that the tree wasn't really attached up here.
[00:26:19.293]And so when enough wind and rain came,
[00:26:23.330]it was easier to tear out in that one spot.
[00:26:26.120]And here again, you can see,
[00:26:27.510]this is not decay, this is included bark,
[00:26:31.240]but this is where the tree was attached to,
[00:26:32.947]but it wasn't attached very strongly.
[00:26:35.550]So this happened to be a little early season snow storm,
[00:26:39.830]and that branch underload of too much snow
[00:26:42.590]with some still on it,
[00:26:43.780]tore out at that weak connection point.
[00:26:46.390]And again, that could have been pruned off much earlier
[00:26:49.430]in the tree's life.
[00:26:50.750]And wouldn't have to now remove the entire tree
[00:26:57.562]I'ma to talk about natural target pruning
[00:26:58.628]and what that really means.
[00:27:03.670]So natural target pruning here's a piece of my firewood
[00:27:06.930]that often gets rescued from my firewood pile
[00:27:10.070]and it gives a really nice display of the inside.
[00:27:13.920]So here's clearly a previous branch
[00:27:16.035]and it had been pruned at some point
[00:27:19.180]and it's pruned in line with the branch color
[00:27:23.250]and it's, and here we can see new tissue
[00:27:25.640]that had formed over.
[00:27:26.560]So it was starting to seal over that.
[00:27:29.200]And this, as we come down is trunk tissue,
[00:27:32.657]and you can see that as the tree was growing in,
[00:27:35.260]it was branch and trunk tissue intertwining.
[00:27:37.940]So we didn't cut the tree
[00:27:39.380]or that branch wasn't cut in straight in line
[00:27:43.410]with the trunk.
[00:27:44.243]So right here,
[00:27:45.320]that would have gone through part of that trunk tissue,
[00:27:47.370]which we wanna avoid,
[00:27:48.900]natural target pruning means we pruned just outside
[00:27:51.760]this branch collar formation,
[00:27:54.240]and that allows the tree to essentially grow
[00:27:57.820]and seal over that a little bit quicker
[00:28:00.310]and keeps any potential decay
[00:28:03.290]just in the branch tissue and out of the trunk tissue.
[00:28:07.100]So let's take a little closer look at that,
[00:28:09.480]the way we can accomplish this is with the 3-cut method.
[00:28:12.844]So right here, this thickening,
[00:28:15.450]this is what we think of as the branch collar
[00:28:18.270]and in a big branch like this,
[00:28:20.670]there's a lot of weight on it.
[00:28:21.950]And so we can make an undercut right here.
[00:28:24.760]This would be cut number one,
[00:28:27.460]and then we can do cut number two,
[00:28:29.720]and you would go all the way through,
[00:28:31.890]although oftentimes you only get to about here
[00:28:34.363]and the branch, wait will tear that off.
[00:28:37.110]As it tears off the bark because of the amount
[00:28:39.580]of weight could,
[00:28:41.293]could tear off all the way back to the trunk
[00:28:44.300]and cause damage.
[00:28:45.600]But because we've made this number one cut,
[00:28:47.953]any bark that might start to peel back ends right here,
[00:28:52.470]and that will cause a notch.
[00:28:54.720]And then the third branch cut
[00:28:56.480]would be right outside the branch collar.
[00:28:59.040]So roughly about right here.
[00:29:01.320]And then that will start to seal over
[00:29:04.560]as the tree continues to grow.
[00:29:06.630]Primarily with trunk tissue,
[00:29:08.510]as it starts to develop over that.
[00:29:10.890]And eventually that wound would not be visible.
[00:29:13.500]So that's the 3-cut method
[00:29:16.040]and here's a quick little demonstration
[00:29:17.770]of what that would look like.
[00:29:20.810]So we start with a quick undercut, just a few passes,
[00:29:24.240]the saw and a small branch, and then we go through,
[00:29:26.720]you can see the branches starting to fall,
[00:29:29.310]if that had been full leaf,
[00:29:30.440]it probably would have broken off.
[00:29:31.327]And it leaves a little like chair like Mark,
[00:29:33.850]but there's no bark that comes all the way back.
[00:29:37.350]And we look just outside the branch collar here
[00:29:41.160]and prune that off, and it should be a fairly circular,
[00:29:44.930]or it should be the same shape as the actual branch.
[00:29:49.070]And then we can see
[00:29:50.430]that we're not cutting into the trunk tissue at all.
[00:29:52.950]So none of that,
[00:29:53.920]and we've kept the entire cut just inside that branch.
[00:29:58.500]So that's what we're looking for
[00:30:00.980]and why. Well, here is a tree,
[00:30:03.020]this natural target pruning because
[00:30:05.300]this a branch had broken off a little bit
[00:30:07.980]and you can see where the tree is naturally starting to grow
[00:30:11.050]new tissue to seal over that.
[00:30:12.710]And a little bit of decay got in,
[00:30:14.640]but we see the decay is confined
[00:30:16.951]completely within this branch tissue.
[00:30:19.190]And we don't see any decay running through the trunk tissue.
[00:30:22.740]And this is just the other side of this.
[00:30:24.670]You can see that trunk tissue growing over.
[00:30:27.690]This is where the branch was running through
[00:30:30.180]and the new trunk tissue is continuing to grow over that.
[00:30:32.583]So it's really about keeping decay in that, right
[00:30:36.130]where we want it, in that old branch
[00:30:37.850]and keeping it out of the trunk.
[00:30:39.446]Now, if you lack a branch collar,
[00:30:43.070]this is research from a friend of mine,
[00:30:44.380]Jake Miesbauer, or The Morton Arboretum
[00:30:46.470]and where they have two branches or trunks
[00:30:49.550]that are codominant and are near codominant.
[00:30:51.480]And there's no clear branch collar.
[00:30:53.330]They've done some great research to look at
[00:30:55.370]what can you do about a 45 degree angle to make this cut?
[00:30:59.319]So instead of maybe cutting right here,
[00:31:02.450]which would have been done in the past recommendation,
[00:31:05.220]what if we do a 45 and does that help out?
[00:31:08.267]And what does that look like?
[00:31:09.950]Well, what they started to find
[00:31:11.450]at least with some speices and the research is ongoing
[00:31:14.100]is that this cut here, it,
[00:31:17.080]the branch started to die back all the way to here.
[00:31:20.030]And here's where we actually start to see
[00:31:22.400]a branch starting to grow and seal over.
[00:31:25.140]You can see it a little clear on this one.
[00:31:26.610]This is where that cow's or wound wood formation is.
[00:31:29.690]And so really if we'd have,
[00:31:31.200]if the 45 degree angle had been cut
[00:31:34.010]you'd remove this part
[00:31:35.460]and you wouldn't see that decay there,
[00:31:37.740]and it might actually end up sealing over
[00:31:40.010]that wound a little bit faster in this particular case.
[00:31:43.210]Here you can see with the 45.
[00:31:46.350]Now this tissue is starting to grow up and over right there.
[00:31:51.157]And so there is some evidence to suggest
[00:31:54.000]that if there's no branch collar
[00:31:55.810]and you have two branches of similar thickness
[00:31:57.840]or near similar thickness
[00:31:59.157]that doing a little bit more of a 45
[00:32:02.102]or something a little more narrow of a cut angle
[00:32:06.358]can be beneficial to the tree.
[00:32:08.490]But generally we're trying to keep outside the branch collar
[00:32:11.190]when you have a branch collar visible.
[00:32:16.276]Let's think about preemptive pruning.
[00:32:19.050]So this is pruning before a storm
[00:32:21.334]notice that, you know this is
[00:32:23.910]had been tree been climbed branches.
[00:32:26.820]These branches were primarily dead.
[00:32:28.450]There were a few that were just needed to be removed
[00:32:31.780]because of the excess weight.
[00:32:33.010]And they had been lions tailed,
[00:32:34.340]which means that all the leaves
[00:32:35.580]were just at the very ends and tips of the branches.
[00:32:38.110]So this had all removed prior to a storm.
[00:32:41.410]So what's the big deal, remove it before or after the storm.
[00:32:44.150]There's still lots of wood here to clean up
[00:32:45.820]lots of work to happen.
[00:32:47.670]Well, this is clearly a tree
[00:32:50.260]that could have been pruned or maintained before the storm.
[00:32:52.860]And I don't know about you,
[00:32:53.810]but filing insurance claims on vehicles is not fun.
[00:32:57.039]And we can prune to reduce the amount of storm damage.
[00:33:02.975]Many of the trees that are damaged in storms
[00:33:06.020]that people refer to as act of nature
[00:33:07.960]are actually something that are preventable.
[00:33:10.510]So by having better tree management
[00:33:12.991]both in the beginning stages of planting and in pruning
[00:33:17.200]we can help to reduce many of the things
[00:33:20.210]that we see after storms happen.
[00:33:23.320]Some basic wound response
[00:33:24.570]here is so all pruning is wounding.
[00:33:26.691]So here's a newly pruned branch, it's important.
[00:33:30.530]Unlike people, plants they don't heal.
[00:33:34.187]And the injury remains for the life of the tree,
[00:33:37.500]the larger the wound, the bigger the potential problem.
[00:33:40.829]And there's something called compartmentalization,
[00:33:43.780]which helps a tree seal off that wound
[00:33:46.750]and try to reduce the amount of decay.
[00:33:49.150]So here's this same wound about one year later
[00:33:51.900]not the best pruning cut.
[00:33:53.710]We should see that this wound would tissue
[00:33:56.420]being symmetric around,
[00:33:58.301]but it gives you an idea of how quickly
[00:34:00.828]trees can start to seal over wounds just one year later.
[00:34:04.740]And the big thing here is smaller cuts.
[00:34:07.372]The smaller cut you can make the better one,
[00:34:10.590]the less expensive it is,
[00:34:11.580]and the less dangerous it is
[00:34:12.880]dangerous it is for the person making the cut,
[00:34:14.950]but the tree can also seal over it much faster.
[00:34:17.628]A wound compartmentalization.
[00:34:20.180]There are four walls, conceptual walls in wounds.
[00:34:24.470]And while one is vertical,
[00:34:26.130]it helps the tree defend against vertical movement
[00:34:28.770]of disease and decay and it's the weakest wall.
[00:34:31.870]And so that's why we don't want to injure trunk tissue.
[00:34:35.000]'Cause clearly that's just going up and down
[00:34:37.195]and so we wanna avoid that.
[00:34:39.596]Wall two prevents decay moving inward.
[00:34:42.379]And so we want to make sure that
[00:34:45.220]we're not breaching those walls,
[00:34:46.610]wall three prevents the tree from moving radially.
[00:34:50.220]So from the, or the wound,
[00:34:52.972]where the wound happens from moving this way
[00:34:54.520]and wall four establishes just the new growth.
[00:34:57.550]So here you can see wall for being set up right here,
[00:35:00.810]and this is new tissue
[00:35:02.220]and that keeps the new tissue from getting the disease
[00:35:05.060]and decay that might be going through any other parts.
[00:35:07.630]So minimizing any damage to trunks
[00:35:10.315]because wall one is the weakest is very, very important
[00:35:15.480]in tree care.
[00:35:17.610]Heartwood versus sapwood.
[00:35:19.220]So when we cut off a big branch like you can see,
[00:35:22.750]these are all examples of this is a terrible pruning cut.
[00:35:25.510]This is a flush cut, now we're cutting into trunk tissue,
[00:35:28.420]not just branch tissue
[00:35:30.050]and that's not great for the tree.
[00:35:32.010]This cut here is actually not too bad.
[00:35:34.075]So I'm not sure what happened with these two cuts here,
[00:35:36.600]but both extreme examples of very, very poor cuts.
[00:35:40.076]Heartwood so here we have an oak
[00:35:43.000]and this darker material is clearly the Heartwood
[00:35:46.070]and Heartwood if you cut into branches that are large
[00:35:51.210]and have lots of Heartwood,
[00:35:52.530]what you're hoping is that that Heartwood
[00:35:54.410]is decay resistant.
[00:35:56.070]In some species, it is decay resistant.
[00:35:58.210]Some of our oaks, some of our locusts
[00:36:00.740]have decay resistant Heartwood,
[00:36:02.574]but our cottonwoods and Maples
[00:36:05.770]have really little decay resistance in their Heartwood.
[00:36:09.220]And so if you're cutting into a large branch,
[00:36:11.360]you're mostly cutting through Heartwood.
[00:36:13.440]And that means that the tree,
[00:36:15.380]if it doesn't have decay resistant wood,
[00:36:17.680]doesn't have any way to fight off the decay.
[00:36:20.300]Sapwood is where this active compartmentalization
[00:36:22.879]in the trees living portion of its defense
[00:36:26.895]can come in and prevent or reduce the amount of decay.
[00:36:30.550]So really cutting smaller branches
[00:36:33.270]is very important from a biological standpoint,
[00:36:35.854]as well as from a safety and cost standpoint.
[00:36:41.170]Decay progression,
[00:36:42.140]so this was a large silver maple that had been cut.
[00:36:45.230]You can see cut near ground line here.
[00:36:47.040]It was leaning a bit and pretty solid wood here.
[00:36:50.130]I don't see anything, no wood that looks really decayed,
[00:36:53.519]pretty good.
[00:36:54.569]Cut fell the way it's supposed to.
[00:36:57.440]So that's good, but just a little bit further up,
[00:37:01.360]maybe about two feet away from that cut,
[00:37:03.680]you can see all of this material here is decayed
[00:37:07.581]and you can see this individual's finger
[00:37:10.520]is just poking in man,
[00:37:12.760]there was nothing left, but soil honestly, on the inside.
[00:37:15.440]So really this is the only area here
[00:37:18.190]that had sound wound and for a tree that size
[00:37:20.840]that's too small
[00:37:21.990]and the the size wound on the trunk
[00:37:25.070]was really only about something in actual size
[00:37:28.010]about what I'm drawing here in this circle.
[00:37:30.480]And that was it,
[00:37:31.920]and that decay ran about 15 feet down the trunk.
[00:37:34.640]So always important to remember that decay
[00:37:37.150]can move vertically very, very quickly.
[00:37:39.580]And we need to be careful about how
[00:37:41.520]about injuries to the trunks of trees,
[00:37:43.650]especially when pruning.
[00:37:47.517]There's a tree owner's manual.
[00:37:49.040]So if you're working with homeowners
[00:37:51.510]or you're working with anybody else
[00:37:53.326]that wants to understand,
[00:37:55.030]you can download this tree owner's manual,
[00:37:56.810]there's now a Spanish version as well.
[00:37:58.910]And you can go to trees.unl look under the
[00:38:02.040]For community link and it's a free download,
[00:38:04.900]and you can also find it it's put together
[00:38:07.180]by the us forest service
[00:38:09.030]and a great resource from planting to pruning
[00:38:11.590]and gives a little calendar of events
[00:38:15.210]that you should do over the year in the life of the tree.
[00:38:19.280]And for those of you that are interested
[00:38:20.800]in studying forestry
[00:38:21.760]there's of course, community and regional forestry
[00:38:23.600]is now degree program
[00:38:24.980]in the School of Natural Resources at UNL.
[00:38:27.810]And we'd certainly encourage you to look through that
[00:38:30.680]or at least
[00:38:31.513]take a look at some of our materials that are available
[00:38:34.380]on treesdotunl.edu.
[00:38:38.310]And thank you very much for taking the time.
[00:38:41.440]If you've made it this far in the presentation,
[00:38:43.578]I certainly appreciate your attention,
[00:38:45.570]and let me know if you have any questions, thanks again.
[00:38:49.785](upbeat music)

The screen size you are trying to search captions on is too small!

You can always jump over to MediaHub and check it out there.

Comments

0 Comments

Taming Wild Trees

Description

Searchable Transcript

Comments icon comment

Related Channels

Comments