On San Clemente Island, a restricted training ground run by the United States Navy has doubled as a conservation zone, helping revive a rare “butcher bird,” the loggerhead shrike.
I have been scuba diving off San Clemente several times. While there, we were visited by Navy helicopters and jets. The offshore wildlife is also doing very well, likely due to restrictions.
Sometimes the safest place for wildlife is where people aren’t allowed, and even live-fire can’t compete with isolation.
Consider the Rocky Mountain Arsenal - a Cold War nerve gas factory - just in the NE burbs of Denver. Now it's a nature preserve.
Also Rocky Flats. Once the US plutonium widget factory, it closed ~1990 and now has some of the better preserved prairie in the Colorado front range. Without the "bomb factory" that whole space between Broomfield and Boulder would now be a subdivision like everywhere else in the area.
In both cases, safety and security requirements provided for a pretty huge untouched buffer space around a small core of industrial-scale work on WMD stuff.