Foraging sustainably. Looking for basic small books or blogs relaying general principles and guidelines for specific plants.

Like many here I try foraging as a hobby. But I would like to do so in a sustainable manner.

Here is a good example. Prickly pear fruit. How many of them could I take off of the cactus?

What percentage of them should I plant? How many should I plant close to(basic heuristic) vs far from the patent plant?

Mushrooms. How do I reseed them around the area?

Sour Grass and miners lettuce. How would I reseed those?

How reducible to a pattern can I make reseeding?