Question
We have a Live Oak approximately 15 ft tall and the trunk is turning black. The blackness is from ground level to about 4 feet up the trunk and totally around it.  There are not any insects that I can see and no webbing on the trunk as well. There are also white fungus splotched up the black trunk part.  Is our Oak diseased??

Answer
I do not think it is a disease problem but as a tree grows older the bark will turn darker starting from the ground. The fungus looking splotches sounds like lichens.

A lichen is a plant. It has no leaves, stems or roots, but like other plants it makes its own food using energy from sunlight. Lichens resemble mosses: both are small and grow on trees or rocks as well as on the ground. Mosses are made up of slender, green stems with tiny, transparent, green leaves. Lichens, however, come in many forms: paint-like rusts; scalloped, wrinkled sheets; lace-like pads; bushy tufts; unkempt strands of black, ray or green "hair"; but they are never made up of sterns and leaves. A lichen is a fungus, but it contains one or more kinds of algae which make its food. The body of a lichen is formed by the fungus. It consists of materials similar to those in a mushroom. Inside the lichen is a layer of green or blue-green algae. The algae make food, both for themselves and for the fungus. The partnership between the algae and fungi in lichens is a classical example of a relationship known as symbiosis.

Lichens which grow on trees and shrubs do not harm them. Although the lichens are attached to the bark or penetrate a short distance, they do not enter the inner bark where food is transported, and hence do not rob the tree of nourishment. Neither do lichens cause disease.

If the tree leafs out fine this spring there is not problem--which is what I would think. It just sounds like normal happenings to a young tree and nothing to worry about.