Soft, decaying wound on white oak

[RiverWho]

Hi, I am hoping someone might help me identify the cause of a large area of decay or rot just above soil level on a mature white oak. We bought the house recently, so I don't know much background. The leaf canopy was full and healthy-looking last summer (oh, my, the number of acorns this big thing drops...wow), but the bark does seem to shed/drop rather too readily. The spot shown in the photo is about 5 inches wide and a foot height, and it seems to start right at the soil line. No real insect activity when I poked around, just an opportunistic millipede. Of course, the season could be masking an infestation...

When I prodded the wound, I found very soft, white, brittle wood, almost the texture of a rice cake or something. The rot extended an inch or so into the wood, although I didn't poke around to deeply for fear of doing more damage. Any ideas what's going on? Thanks!

...and any tips to get those pics right side up? I haven't a clue why they loaded that way....

 

[treeseer]

cause is dirt on stem. Annex D – Managing trunks, flares, and roots affected by fill, sample specifications (This annex will not be considered part of the ANSI A300 Part 8 standard.)
D-1 Sample specifications for RCX (root collar examination) with hand tools
Scope: Trees with fill contacting the trunk.
Objective: Mitigate tree damage from the effects of fill on the trunk.
Specifications:
1. Rake any coarse woody debris or fresh mulch away from the root collar area.
2. Select tools to avoid root and trunk damage.
3. If a shovel or trowel is used, press the blade against the trunk. Slide it carefully downward until resistance is met.
4. Push the handle toward the trunk, moving the blade away from the trunk.
5. Remove individual adventitious roots and stem-girdling roots as needed. Manage larger roots per ANSI A300 (Part 8), 83.4 and 84.4. Avoid contact between the trunk and any remaining adventitious, girdling, and circling roots.
6. Lift the material away from the trunk and place it in a temporary staging area.
7. Repeat until trunk and flare are clear, out to the root collar, where buttress roots divide. Use smaller hand tools, vacuum, or compressed water or air, to complete the excavation.
8. Separate and dispose of any infertile soil and debris. Retain the fertile soil, fine roots, mycorrhizae, and decomposed mulch.
9. Commence the RCX (root collar examination).
10. Consider replanting the tree, if the flare is over 2 inches (5 cm) below grade.
11. Remove soil and fine roots outside of the root collar to make a gradual slope.
12. Consider installing a device to control erosion.
13. Apply 2-4 inches (5-10 cm) of mulch over the root collar. Avoid mulch contact with the flare.
14. Remove the fine roots, fertile soil, mycorrhizae and decomposed mulch from the staging area.
15. Incorporate the material into the outer rootzone.
16. Specify that future management will keep the flare visible.
D-2 Sample specifications for RCX (root collar examination) with pneumatic or hydraulic tools
1. Rake any coarse woody debris or fresh mulch away from the flare and root collar.
2. Select tools to avoid root and trunk damage.

 

[old_soul]

I think tree seer is right on, no root flare to be seen in that pic....

From what i've seen Oaks do not take filling over the roots very well.

Is the crown (top of tree) dying back yet?

 

[Raintree]

Cutting to the chase. What needs to be done is...

1) Call a good tree Co that offers Air-Spading.

2) Have them expose the root flair.

3) Get a tree hazard evaluation.