I know that the oaks have a fungus and the ash have the borer, but why are so many evergreens of all types dying. At the Crest Lawn cemetery it looks like most of their evergreens (pine and spruce are dead or dying). Same is true around the county. And the maple trees too? Is this weather related? Thank you.
We do not know of a fungus killing oaks in Maryland. (Perhaps somewhere else?) Yes, ashes are dying from emerald ash borer. That in a foreign invasive species brought in by man, and for which the ashes have no defenses since they did not evolve together.
The spruces are dying because most are Colorado Blue spruce which are not adapted to Maryland's humidity and heat. They usually succumb to one fungal disease when they are around 20 years old, but the abnormally high rainfall the past year or so has lead to increased fungal diseases and they are getting a double whammy from two fungal diseases. Almost all, both old and young, are dying. We recommend replanting with something else besides a blue spruce https://extension.umd.edu/hgic/topics/whats-wrong-my-colorado-blue-spruce-tree
The pines do not have any particular disease wiping them out, but many tree species including evergreens, are dying from drowning in excessively wet soils and other factors of climate change (higher temperatures,etc.)