pics showing lightning damage would be cool. sounds like this one is too damaged to keep if cracked on 2 sides, but lightning-struck trees with less damage should be assessed. Here is one protocol, from this month's TCI magazine (story on page 8 here
http://www.tcia.org/PDFs/TCI_Mag_June_07.pdf:
Lightning-Struck Tree Assessment and Mitigation.
When lightning strikes a tree, the owner will often assign an arborist to help determine the appropriate response. Depending on the tree and on the arborist, what they hear will range from “It’s going to die, so we should remove it”, to ”It looks okay for now, let’s wait and see.” Neither of these extremes adequately addresses the owner’s or the tree’s needs. Both neglect useful tree care techniques for assessing and mitigating lightning damage:
1. Bark inspection. Tap the bark with a mallet to determine whether it is detached from the wood. Measure the detached areas. Probe any cracks in the xylem with a thin instrument to determine the depth. If the damage to the lower trunk is not extensive, inspect the crown.
2. Consider the species’ relative tolerance to lightning strikes, based on its compartmentalization qualities, grain pattern, and genetic vigor.
3. Consider the individual specimen’s vitality, and its location relative to people and property. Assess the risk.
Present treatment options to the owner, providing a prognosis of recovery if the treatments move forward. If the client is an insurance company, the arborist is often asked to make a recommendation because the tree work is part of a claim. If the owner decides the risk is acceptable, these steps can be taken:
1. Reattach the bark if it is still moist inside. Thin bark may move enough if it is wrapped tightly for a few weeks. Thicker bark may be reattached with fasteners such as staples.
2. If the bark cannot be reattached, it should be trimmed—“traced”—back to the point where it is attached to the xylem, so there will be no hollow area as callus tissue grows over the wound. This applies to all the bark, from the top of the tree down to the buttress roots.
3. The exposed wood should be treated to repel insects. Reapply as needed
4. The soil around the roots, especially those that carried the current, should be aerated as needed and inoculated with beneficial microorganisms such as mycorrhizal fungi. Any mineral element that is lacking should also be applied
5. Mulch the root system 2-4” with organic material, and irrigate as needed.