To be strictly accurate, there will be variation from species to species. However, I believe the figure that is most often accepted is 3X below ground as above. I do not have a citation handy for this however.

Arktrees

I've seen pictures of tree downed by tornadoes, and some of the biggest trees had the puniest root systems.

Good link and interesting question.

When I dug up the crap myrtle the other week the tree was larger above ground than what I removed from below by about 2 to 1. I did not remove roots six feet below the ground.

Now I severed many roots. The question is how far did they go? And who would know.

What is the largest tree ever bare rooted? Anyone do horticultural science like this?

so.. safe to say.. i didnt dream it.. lol

and safe to say.. i am not exaggerating when i say it ...

yeah rhiz.. i know the drawing you are talking about.. probably some old hippy drawing from way back.. the mirror image .... green man.. druids.. etc ...

whatever.. glad i am not having auditory or dreamal hallucinations..

to take is a step further ... i am thinking about instant gratification or tree planting .. and the argument that the smaller the transplant .. tree .. the faster it gets established.. and can probably outgrow a large transplant.. say the instant gratification 2 inch caliper type ... in a given 5 year span .. and i am figuring that it all has something to do with the ratio of root loss to the plant itself ... [i havent read the link above yet]

ken

Here is a link that might be useful: a cursory review seems to indicate that not a single one is close to reality .. of which i reject yours.. and substitute my own ...

Actually, ken, the drawing in that link is an accurate depiction of a tree's root system, lol.

This is what I picture. Perhaps a could extra large structural roots but pretty much the one on the right.

what are you talking about rhiz???? .. there are 3.3 million pix at my link .. which did you choose to comment on???

or am i missing something??

try this link

ken

Here is a link that might be useful: {{gwi:334981}}

lolol...we are BOTH missing something. I meant the picture in MY post, from UMN. THAT'S the one that is accurate. Tornado's picture is a good one.

this is really weird.. when i hit the rhiz link above here in GW.. i get all words .....

but when i hit the link in the reply to my email.. i get a different link ...

here is what i get here:

http://edis.ifas.ufl.edu/wo017

oohh crude.. you have two links there.. only one hotlinked.. what a dullard .. lol ... never mind.. as whats here name used to say ...

ken

Here is a link that might be useful: check this one rhiz

Keep in mind, whoever said that they see the largest trees have the smallest root systems (When blown over), that the majority of the root system did not end up in that tipped-up root plate. Most were torn asunder in the event.

Or did I just want to say 'torn asunder'?

+oM

From personal observations, the roots of blown over Willow Oaks in swampy areas in Lousisana are not as substantial as those of excavated Live Oaks in hot dry central Texas. Neither one looked like it would be 2 time the size of what is above ground. The hill-country live oak roots gave the impression that they were about the same size as the above-ground parts of the tree.
Have read that Bur Oak can have as much volume below ground as above ground but have not seen any proof of it.
Perhaps Bald Cypress would be apt to have more volume in roots than in top. These trees along with Live Oaks are highly rated for resistance to hurricanes along the coast.

Keep in mind, too, that tree in urban and suburban locations often have SEVERELY compromised root systems. Simple compaction, excavation, construction, and a host of activities damage and diminish the health of a natural root system.

Although it varies by species, site, and individual tree, in most instances the root system makes up less than half of the total biomass of a tree - often a lot less than half (see link below). But I would agree that the roots often spread out much farther than the distance of the canopy.

Here is a link that might be useful: Biomass and utilization of trees

Average composition is: 5 percent fine or feeder roots, 15 percent
larger or transport roots, 60 percent trunk
or main stem, 15 percent branches and twigs,
and 5 percent leaves (Bray, 1963; White et al.,
1971; Meyer and Gottsche, 1971).

Ken scores twice: I liked that article on turf grasses and trees. Learned something new. and ......oh, Gilda Radner! Her name or a quote comes up at least once a week in our house because "it's always something"

thank you mrs loopner.. lol ... ken

Does root extension approximate the crown shape? E.g. less on the narrower sides of an oblong crown. I am inclined to think that not. I prefer factual information to guessual.

its more in a pancake shape ... usually in the first foot or two of the soil ... depending on the soil of course ...

here is a pic of a neighbors silver maple roots... in sand ... ken

how that for some sand.. lol ...

All things being equal - same soil conditions, no obstructions or obstacles and no sigificant competition - the shape of any tree's root system will be roughly circular, spreading out equally from the trunk on all sides. Has nothing to do with the shape of the above ground portion of the tree.

I agree with different trees are different.

Out on my sandy land in the country there was very little top soil and usually 15-20 ft of pure sand underneath, before you hit water.

When we dug holes for septic systems and test holes for wells, there were long 1/2"-3/4" +-diameter roots, running deep in the sand, 10-12 ft down.

Jack Pine (Pinus banksiana) is what grew around there, so apparently that's where they came from. Not thick bunches of roots, just these long rope like lengths, running here and there underground.

I pulled many of these types of roots, out of sand holes, that were 10 ft long and were almost the same diameter from start to end.

The tap roots of Jack pines only went down about 3 ft or so before branching off into smaller roots. I know because I pulled many large 'Jacks' out by the stumps and they all were pretty much the same. The side feeder roots went out along the top soil many, many feet.

I don't think these deep running roots were looking for nutrients in pure sand so they probably were down there for the water.

The shape of this Pines root system, were not anywhere the shape of the tree crown, AFAICT.

Perhaps the soil-volume coverage of the roots is greater than the tree crown coverage, but the mass of the tree-wood is much greater above ground than below.

Yes, well I've noticed that fast-growing trees like Crape Myrtles, Chinaberries, and unsurprisingly, Silver Maples (based on the photo above), have small root systems. Which is one main reason why they're far more prone to blowing over in storms, etc.

For example, here's an example of a large Crape Myrtle that was downed in a storm. You can clearly see how relatively small its root ball is compared to its trunks. In addition, Crape Myrtles also have very heavy, wet, weak wood - that makes them additionally prone to breakage.

And I've also easily pulled ~8' tall Chinaberry saplings straight out of the ground manually with ease!

Whereas a lot of stronger, native trees like Pecans have deep taproots that can make even just a 1' tall seedling impossible to manually pull out of the ground!

Although another big, independent factor apart from tree type is the soil type. Where the same plant that would grow deep roots in friable soil, will only be able to grow much shallower roots in rockier terrain...

Exactly!

Soil depths and soil nutrients affect depth of root mass.

Also, when you see some of those big old trees that blow over in a storm, some at least appear to have some sort of root damage from disease that made these 'ready to go' in the next windstorm.