I heard someone make a statement recently that puzzles me. The statement made was that the Corps of Engineers lake, which has been in existence for 40 years, posed a threat to 100 year old post oaks. The lake supposedly raised the water table of surrounding land and the tap root of the oak, which for many years had been in relatively dry subsoil, was now in saturated soil and the tree would probably die. It was my understanding that the tap root in large trees was mainly to secure the tree in the soil so it would not be damaged by high winds. Can anyone explain this theory?

Reply to post by B Miller, on October 29, 1999 at 15:07:25:

This may be somewhat off the point, but I have seen many kinds of seedling tree roots as I have had to eradicate them as unwanted volunteers. None of them were post oak. However, My general understanding is that a tap root is the remnant (sometimes quite large) of the young tree's attempt to secure itself quickly and deeply, to have access to deeper soil moisture and resist uprooting. As the tree develops buttress roots and wider spreading feeder roots, the tap root may be of smaller significance to the overall success of the tree.
Of course generalities are often wrong when applied to every situation. Why, do you suppose, would any typical Ailanthus tree seedling develop an initial root that takes a ninety degree turn to the side almost as soon as in reaches a few inches depth?

Reply to post by B Miller, on October 29, 1999 at 15:07:25:

There is alot of info here about post oak, including drought and flooding tolerance and rooting habit...
http://willow.ncfes.umn.edu/silvics_manual/volume_2/quercus/stellata.htm

Reply to post by B Miller, on October 29, 1999 at 15:07:25:

It is my understandeing that if water table rises then water will exclude oxygen from the soil. This asphyxiates root material, which must constantly respirate. Fungi etc. move in and eat the dying wood of the roots. As the heartroots, or descending roots, a.k.a. tap roots (properly used for seedlings only, I am told)are devoured, the tree blows over.

Reply to post by B Miller, on October 29, 1999 at 15:07:25:

My undestanding is that some trees that are native to areas that have periodic droughts have a decending root system that is a secondary deffence, it puts out ephemerals in the dry periods to utilize the water in the deeper soil.

will there be geater aeration of deep soil with surface soils drying ad cracking?

Reply to post by jps, on October 29, 1999 at 15:07:25:

I believe that aeration would be greater in the cracking soils you mention. Also, I have read that some desert trees/shrubs have put roots down to 60 ft. deep. I only suggest that these should not be called taproots anymore, because the scienteists and writers of books have changed the nomenclature. Like they did with suckers vs. watersprouts, you know.

Reply to post by Peter Torres, on November 01, 1999 at 20:18:47:


" I only suggest that these should not be called taproots anymore, because the scienteists and writers of books have changed the nomenclature. Like they did with suckers vs. watersprouts, you know."


OK. I give up. What did they do? \


Dim Bulb Bob

Reply to post by Wulkowicz, on November 04, 1999 at 23:23:29:

It's all suckers now, or is it vise versa?

Reply to post by jps, on November 06, 1999 at 10:42:17:


Is that what happened?

Did we combine them for our convenience--that it was too much trouble to remember. or that the growths to some small minds were the same?

I remember complaining that we should get rid of basipetal.

I assume we kept sucker because it's a shorter word than water sprout (?)

yuck!

Reply to post by Bob w, on November 08, 1999 at 22:36:53:

You know. Suckers are from roots. Even though watersprouts suck out of the tree stem. Why water sprouts, anyway? What doesn't have water in it? When a customer talks about suckers in the tree, I do not correct anyone, because it is a better term than "watersprouts". I will work with any terminolgy. I just wanted to mention the old use of "taproot" was no longer inn favor by writers of important books. Peter

Reply to post by Mark Goodwin, on October 29, 1999 at 15:07:25:

I agree that there are many myths about tap roots, now for the other discussion, what about epicormic shoots or growth? And what should we call sucker growth or panic growth on trees that have been lion tailed or topped?,as the growth is usually very abnormal. Ken

Reply to post by jps, on October 29, 1999 at 15:07:25:

All very interesting, but what about my questions as to the raising of the water table by the nearby lake? Is that significant? And is it harmful? After 40 years?