Plant and Animal Diversity Is Declining, But What About Microbial Diversity?

With alarms sounding about the declining diversity and populations of plants and animals, we post a related concern with equally profound implications: is the variety of microbial life, including viruses, changing too, and if so, in which direction and how fast? As plant and animal numbers shrink, some specialized microbes associated with them might vanish, too. But is there a net overall reduction occurring? If so, is it good or bad news or irrelevant for our species?