Do trees always uproot toward downhill?

[SkyP]

I have some land in the NC mountains with plenty of oak, poplar, locust, gum and hickory.
Lately I've become concerned because some of the trees have uprooted and fallen. I've noticed they always fall towards down hill. It seems most of the wind, which can be high at times, comes downhill from the mountain side I'm on.
So is the wind the cause or is there some other principal at work here?
The concern is because we had a big oak blow down right behind my "cabin" and it occured to me it could have smashed the cabin or even have killed us if we were in it and that oak landed on it.
So I've been working on cutting back the really big trees uphill of the cabin, mostly north. I really don't want to cut the trees south since they provide our summer shade at our cabin. But then I don't want to have my cabin smashed or die either.
Any thoughts on why they always seem to go downhill?

 

[D&B Mack]

Most of the time they fall down hill, because trees tend to grow root bases that are parallel with ground level, this causes a natural downhill lean, and then gravity takes over. But they don't always fall down hill, just most of the time. Soil erosion can be a major cause of uprooted trees on steep slopes. You will just have to inspect each tree on an individual basis and decide for yourself.

 

[buzz sawyer]

A 24" black cherry in my woods had leaning steadily for a couple years and just recently uprooted and fell into the only flat area around - 90 deg to the downhill side. An Elm the same size about ten feet away also uprooted and fell a couple years ago but it did go downhill.

 

[Toddppm]

It seems like most roots grow on the downhill side so there's no support on the uphill side....so down they go.

 

[derwoodii]

Tree root will grow where the better soil opportunity allow. Often down hill has more moisture and deeper soils. Your concern about falling trees while valid needs effort into assessing the trees whole structure and usefull life.
Find the balance of benefits vs the low incident of tree hazard. Try weight reduction of the tree side you wish to unload rather than removal, if practical.

Hey family here got a house n land NC mountains too, Maggie valley, we are tryin to sell it from OZ, not much luck at the mo.


Root hairs explore the soil in much the same way as a person would feel their way in the dark. If they come across an obstacle, they feel their way around until they can continue growing in an opening. In the meantime, the plant is held in place as the hairs grip the soil.

http://www.sciencedaily.com/releases/2008/02/080228143543.htm

 

[SkyP]

It seems impossible to tell in advance which trees might uproot. All that have fallen appear healthy and frequently have no lean to them.
Its just the root system lets go or pulls out of the wet rocky ground.
The only plus to this is I'm getting lots of free firewood for the woodstove back at home I'd really prefer not to cut any standing trees but nature is selecting plenty for me saw up when down.
Some of the trees are really pretty massive, maybe 30" at knee height on the stump and 75-100 ft tall.

 

[SkyP]

.

Hey family here got a house n land NC mountains too, Maggie valley, we are tryin to sell it from OZ, not much luck at the mo.

There is an incredible amount of land and or land/homes for sale right now in the NC mountains. Apparently many people overextended or lost their job.
I sometimes wish I wasn't afraid to buy some, I've seen land around me drop to less than half of what it was for sale for a few years ago, and it still sits unsold.
My land is near Tryon, 10 acres. Bought 5 years ago for future retirement home build, which may never happen now with the economy. I too am afraid of getting RIF'd at work and being in deep doo-doo.
Fortunately everything I have is paid for but still an uncomfortable feeling....part of the reason I went back to wood heating after a 25 year hiatus, I'm very happy to not be paying the electric company so much as I haul free wood from that 10 acres

 

[Highclimber OR]

It seems impossible to tell in advance which trees might uproot. All that have fallen appear healthy and frequently have no lean to them.
Its just the root system lets go or pulls out of the wet rocky ground.
The only plus to this is I'm getting lots of free firewood for the woodstove back at home I'd really prefer not to cut any standing trees but nature is selecting plenty for me saw up when down.
Some of the trees are really pretty massive, maybe 30" at knee height on the stump and 75-100 ft tall.

It is not impossible but it sometimes takes you a while to know what you are looking for. Some are rather obvious while some others are near impossible to detect so sometimes you know sometimes you don't

 

[forestryworks]

Typically during the day, as the air becomes heated by the sun, winds blow up slope. At night, they blow down slope.

I would cut out the dead, weakened, diseased, and trees with root pull (partial windthrows).

 

[ropensaddle]

Tree root will grow where the better soil opportunity allow. Often down hill has more moisture and deeper soils. Your concern about falling trees while valid needs effort into assessing the trees whole structure and usefull life.
Find the balance of benefits vs the low incident of tree hazard. Try weight reduction of the tree side you wish to unload rather than removal, if practical.

Hey family here got a house n land NC mountains too, Maggie valley, we are tryin to sell it from OZ, not much luck at the mo.


Root hairs explore the soil in much the same way as a person would feel their way in the dark. If they come across an obstacle, they feel their way around until they can continue growing in an opening. In the meantime, the plant is held in place as the hairs grip the soil.

http://www.sciencedaily.com/releases/2008/02/080228143543.htm

Nice post great layman's expression for geotropism and I concur after site considerations reduction or thinning could alleviate future problems and let the roots catch up with the growth as well. Very good post rep due!

 

[derwoodii]

There is an incredible amount of land and or land/homes for sale right now in the NC mountains. Apparently many people overextended or lost their job.
I sometimes wish I wasn't afraid to buy some, I've seen land around me drop to less than half of what it was for sale for a few years ago, and it still sits unsold.
My land is near Tryon, 10 acres. Bought 5 years ago for future retirement home build, which may never happen now with the economy. I too am afraid of getting RIF'd at work and being in deep doo-doo.
Fortunately everything I have is paid for but still an uncomfortable feeling....part of the reason I went back to wood heating after a 25 year hiatus, I'm very happy to not be paying the electric company so much as I haul free wood from that 10 acres

Just to let you see what we got 4sale. Twas left by a deceased family member, no rush to sell as no cost to keep just a tad too far for a weekender.
May if wife allows flyover for a visit next spring.
http://www.arboristsite.com/showthread.php?t=148045&highlight=

 

[The Count]

http://en.wikipedia.org/wiki/Tropism

 

[SkyP]

Typically during the day, as the air becomes heated by the sun, winds blow up slope. At night, they blow down slope.

I would cut out the dead, weakened, diseased, and trees with root pull (partial windthrows).

The wind up during the day and down at night is exactly what we observe.
The downhill wind seems to be averaging the strongest. Many of the trees looking at the tops, appear to be somewhat leaner on the uphill side. I wasn't sure if this was because of the wind or the southern sun or both. Of course trees like this are predisposed to fall downhill since more weight is on that side.
I suppose the best thing for our safety is to cut the ones uphill within the fall radius of our camp, I know I've layed awake many nights listening to the wind howl and the occassional crash in the woods of a falling tree, wondering if we are about to get crushed, especially after a good rain

 

[ropensaddle]

The wind up during the day and down at night is exactly what we observe.
The downhill wind seems to be averaging the strongest. Many of the trees looking at the tops, appear to be somewhat leaner on the uphill side. I wasn't sure if this was because of the wind or the southern sun or both. Of course trees like this are predisposed to fall downhill since more weight is on that side.
I suppose the best thing for our safety is to cut the ones uphill within the fall radius of our camp, I know I've layed awake many nights listening to the wind howl and the occassional crash in the woods of a falling tree, wondering if we are about to get crushed, especially after a good rain

Wind acting on trees has little to do with lean on one side unless a partial failure has occurred . Photropism "light seeeking" does and north facing hills can tend to be opposite. Water and soil conditions like derwoodi mentioned geotropisim gravitropism all bear fruit to this topic. If wind was the greatest factor the very top of the mountain would be the same as the sides which is not at all the case! Here in our tall hills the trees at the top many older than the largest trees in the valley are dwarfed due to lack of water and poor soil and mineral content in the soil.
Wind actually over the growth from sapling to adult strengthens the tree unless its hurricane or tornado force or abnormally wet year. Over crowded forest on hills have greater risks to individual failures at adulthood by creating uneven tapers. A recent logging operation adjacent cutover can place wind force upon the trees sufficient to cause many failures before the trees can react to greater wind force applied to them. Thinning and reducing the tree proper can alleviate much of the hazard while also reducing the erosion on hillsides.

 

[derwoodii]

An interesting observation about phototropism is the tree / limbs are actually growing away from the dark not as we think towards the light. Its kinda counta intuitive but I'll try to explain and using this understanding you may in time help your situation.

Your house in a clearing and so the trees seem to grow towards the opening and the light of the clearing, a problem we all encounter building next to a forest.

An auxin called indole-3-acetic acid, or IAA does a lot here
IAA is mostly manufactured at the apical meristem, at the very top of the plant. From there it travels down the stems, to the roots. Moving down the stem, it starts to get a bit darker, as you would expect. But IAA likes the dark and not the light so it triggers cell elongation on the dark side. The limbs on the sunny side IAA breaks down in light and so cell shorting.
This causes the limb to lean away from the dark, or towards the light. This is phototropism why plants appear to grow towards the light. They don’t. They grow away from the dark.
Using this you may but its not truly likely prune limbs that will open the canopy to more light and perhaps train the trees to grow away from your house.

On paper yes in real world a maybe.

 

[DangerTree]

All this science and stuff is cool but in the real world a tree is always a threat to property and people if it is within reach. Very high winds can cause branches to be stripped from trees and thrown very far. We had a storm this year on the lake that I made a killing on. Trees appeared to have been hit by a tornado but in fact it was just very gusty. The trees were dancing so hard they broke off in any direction and many were uprooted- again in all directions.The general rule is if you feel that your house is a target remove or disarm the weapon. Or move the target in the case of cars, docks sheds etc. Not saying those other guys are wrong, rather they are right as well.

 

[ropensaddle]

An interesting observation about phototropism is the tree / limbs are actually growing away from the dark not as we think towards the light. Its kinda counta intuitive but I'll try to explain and using this understanding you may in time help your situation.

Your house in a clearing and so the trees seem to grow towards the opening and the light of the clearing, a problem we all encounter building next to a forest.

An auxin called indole-3-acetic acid, or IAA does a lot here
IAA is mostly manufactured at the apical meristem, at the very top of the plant. From there it travels down the stems, to the roots. Moving down the stem, it starts to get a bit darker, as you would expect. But IAA likes the dark and not the light so it triggers cell elongation on the dark side. The limbs on the sunny side IAA breaks down in light and so cell shorting.
This causes the limb to lean away from the dark, or towards the light. This is phototropism why plants appear to grow towards the light. They don’t. They grow away from the dark.
Using this you may but its not truly likely prune limbs that will open the canopy to more light and perhaps train the trees to grow away from your house.

On paper yes in real world a maybe.

You can create less wind sail, reduce height and invigorate roots though.

 

[BC WetCoast]

Uprooting failures can generally be classified into three categories
- where the roots are ripped from the soil. This usually occurs when the soils are saturated and the soils are fine textured. Coarse textured soils will generally have fewer uprooting failures as the roots grow around the rocks which act like anchors
- where the soils around the root mass fail, usually called a rotational failure. Often there is a some form of soil type transition which fails along the transition line. It would analogous to a newly planted balled and burlaped tree being pulled over. The ball of soil rotates in the hole.
- finally where trees grow in a dense forest setting, they usually get very tall, but have a small root mass. They are held up by the rest of the stand. Wind energy in the canopies is disipated by the trees hitting each other. If the stand is cut and these trees now are on an open face, often there isn't a sufficiently large enough root mass to hold up these tall trees (which would have a very large bending moment).

 

[Marine5068]

Trees are definitely very interesting plants. They compete every minute of every day for light, water, and nutrients.
Another interesting topic here about some property values falling drastically.
This land value issue in some U.S. States that is mentioned in this post seems odd and bewildering to me though, my living in Southern Ontario.
I know WHY it's happening with the large number of property foreclosures and losses due to lay-offs, poor economy, oil price increases, wars, health care debt, and illegal immigrant problems in America., but it still seems weird to me here in Ontario to hear of half-price land where the price of land and homes here steadily increases by up to 10-15% per year.
We are running out of room in Southern Ontario and we now have some of the world's most expensive cottage country near Muskoka and and Stoney Lake areas.
I hope to buy a large chunk near me soon(50 acres or more).
Until then I keep working and saving and doing what I do.
~Stan

 

[zogger]

I love shade....

I have some land in the NC mountains with plenty of oak, poplar, locust, gum and hickory.
Lately I've become concerned because some of the trees have uprooted and fallen. I've noticed they always fall towards down hill. It seems most of the wind, which can be high at times, comes downhill from the mountain side I'm on.
So is the wind the cause or is there some other principal at work here?
The concern is because we had a big oak blow down right behind my "cabin" and it occured to me it could have smashed the cabin or even have killed us if we were in it and that oak landed on it.
So I've been working on cutting back the really big trees uphill of the cabin, mostly north. I really don't want to cut the trees south since they provide our summer shade at our cabin. But then I don't want to have my cabin smashed or die either.
Any thoughts on why they always seem to go downhill?

...just love shade. However, because I am now REALLY aware that tornadoes and big windstorms/downbursts exist, getting rid of all the big trees that can fall on you is sort of a good idea. We just went through almost getting the ultimate dirt nap with tons of red oak in the living room, as in "with us in the room at the same time, and it came in real fast like with not much notice"..big trees..you are at the right forum..think "lotsa chainsaw work in advance could save your life, plus not have to pay for having your house rebuilt". Look on the pic forum for pictures of our tornado cleanup and cabin being rebuilt action.

Ya, I know it will get hot next summer..more insulation in the roof, maybe add an attic fan.