"My recollection is that monoculture forests promote forest death."
Quite, and I'll venture that any form of monoculture is generally in an unhealthy state or will eventually cease to function. At best it will be sub-optimal. Diversity must be encouraged.
Whether you look at woods/forests, dogs, people, entire ecosystems, gut bacteria or whatever, you generally see rude health associated with diversity.
English is of course a (somewhat) Germanic language but as far as I know we don't even have a concept of forest-death or anything like it. We'd probably go for something like "dying-forest syndrome" instead. Actually, we'd probably call it something really stupid and contentious like: "German forest disease" or similar nonsense and then rapidly give it a Greek and Latin combo name when the sheer racism of the original name is called out.
Anyway, I recall wandering the forest near to this (1983ish): https://en.wikipedia.org/wiki/Hermannsdenkmal My Dad was a British Army Officer and he very carefully got us lost via a complex "contouring" maneuver. We escaped eventually but it is said that to get properly lost involves a British Occifer and a map. Give them a compass and you are totally doomed!
Errr, anyway, we are wandering through the woods at Herman's Denk. Lots of trees and a lot of species seen. The woods looked and felt healthy. Any decent sized wood is a pleasant place for good reason - that's where we (humans) should be. We are a species of tree huggers 8)
My company owns a bit of land and we have three huge oaks (40' plus height, at least eight foot girth) on it. I will eventually kick my local council into bestowing "tree preservation orders" (TPO) on them because allowing harm to them will we environmental vandalism.