Find the original infected oak and mark it for removal.
First Ring: Add the DBH of the original infected oak to the DBH of the nearest neighboring oak in question. Using the chart below, mark the tree if it is within the limiting distance shown. If there is a clump of 2+ trees, add each DBH to the total when figuring out your limiting distance (i.e. clumps will have a higher probability of being within the limiting distance).
Second Ring: Once the first ring is completely marked, begin a second ring. This time instead of using a single oak tree in the middle, use multiple oaks on the outer edge of the first ring to determine limiting distances for the second ring of trees.
Only mark non-oak species for removal if they are merchantable and within 5 feet of an oak that is being removed (due to treatment of stumps as seen below in design and mitigation measures)
When marking trees, use yellow paint and paint a full ring at DBH height (2” thick) as well as a 12” long stump mark.
Below is the chart used for limiting distances (after Bruhn et al,1991):
Combined DBH (inches) |
Inter-tree distance (feet) |
Combined DBH (inches) |
Inter-tree distance (feet) |
2 |
3.9 |
26 |
50.4 |
4 |
7.8 |
28 |
54.3 |
6 |
11.6 |
30 |
58.2 |
8 |
15.5 |
32 |
62.1 |
10 |
19.4 |
34 |
66.0 |
12 |
23.3 |
36 |
69.8 |
14 |
27.2 |
38 |
73.7 |
16 |
31.0 |
40 |
77.6 |
18 |
34.9 |
42 |
81.5 |
20 |
38.8 |
44 |
85.4 |
22 |
42.7 |
46 |
89.3 |
24 |
46.6 |
48 |
93.1 |
Severing of Root Wads (Stump Pulling)- all stumps shall be dug out of the ground, severing any root graft connections so as to prevent the spread of the Oak Wilt pathogen. All trees identified with paint as part of the included timber, are to be treated. All stumps so identified must be completely severed from the roots remaining in the ground. All severed stumps shall be left in the hole where they were extracted, and not covered or buried. An excavator works best for this requirement of the sale.
All merchantable wood shall be removed and processed by March 15, 2018. It must be sawed into boards, cut and split as firewood, chipped, or otherwise processed to prevent the incubation of the oak wilt fungus.
Submerchantable wood > 4 inches in diameter must be cut into lengths no greater than 4 feet to prevent the persistence of fungal mats in the treatment sites.