What does “patchiness” mean in this context?

Addressing this question from HelloTalk:

What does “patchiness” mean in this passage? Is there a similar word in Spanish?

“Many ecologists now think that the relative long-term stability of climax communities comes not from diversity but from the “patchiness” of the environment; an environment that varies from place to place supports more kinds of organisms than an environment that is uniform.”

I often see people use double quotes on an expression when the writer is grasping to find a word that precisely describes the writer’s intended meanig.

1. It’s possible that the word does not exist in this language, and instead of using “the word”, a flshed out out explanation must be provided instead.
2. Maybe the writer just doesn’t know the word.
3. The writer feels that a particular word would be a close approximation of the intended meaning, but it’s not quite there. So the writer uses the word, but puts it in double quotes to indicate that the exact intended meaning is the word plus some additional the context.
4. The word that the writer is using may be a slang or generally not recognized in the specific environment as the class of word to use. (For example, if using a soccer metaphor while describing politics)
5. The word that the writer picked may be something close to “private language” – something known in a close circle of friends, or a small specialized segment of the population and the writer is aware that this population does not intersect at all with the intended readership.

In this case, however, it’s easier – there is a semicolon, and the flow of the sentence shows us that what follows the semicolon is the definition of the word “patchiness” as intended by the writer. “an environment that varies from place to place”. However, interpretation of the overall sentence reveals a contradiction, which is puzzling:

A. Ecologists think that stability comes from “patchiness”, not from diversity

B. An environment has “patchiness” when it varies from place to place. An environment that has patchiness is not uniform.

Isn’t the concept of an environment that varies from place to place (B) very close to the idea of a diverse environment(A)? What’s going on here?

Maybe the writer is trying to differentiate between what we would usually imagine when we think environmental diversity (just things being different and varied all over the place) with “patchiness” – possibly the overall environment having multiple, smaller areas within – these smaller areas are uniform internally, but each area is different from other areas. This concept also nicely aligns with the visual image of patches of cloth. You have worn jeans, and patch it up with a square piece of cloth. Now imagine a jean made up with many patched pieces of cloth..

I can also think of another concept that is similar to this – when people describe urban landscapes, an interesting concept is the idea of “microneighborhoods” – the idea that there are neighborhoods, just a couple blocks wide, each being pretty homogenous within each microneighborhood, but wildly shifting in demographic makeup, architecture, and mood when moving to another nearby microneighborhood.