Many of the pine trees seem to be turning brown lately, and we have a young cypress that has gone from one brown branch to nearly the entire tree brown in two weeks. I haven't noticed any problems with oaks, liquidambar or any of the other trees. The hot and dry conditions in the Sacramento area make this tree susceptible to canker disease. Cankers can cause foliage to turn yellow or brown and wilt. Infected bark often discolors and may exude resin.
Cankers are a serious problem because they can girdle and kill limbs or the entire plant.
To identify the canker, inspect the branches where they emerge from the trunk. If visible, it will be an infection on the woody parts that are often surrounded by layers of callus tissue or resinous lesions and discolored bark. Prune out infected branches when first observed. It is a waste of time and money to plant this tree in the Sacramento area since there is no way to prevent or treat this condition. In the past few years, several gardeners have reported the death of other pine species from root rot.