I'm not totally a permaculture farm, but I incorporate a lot of permie principles in what I'm doing. One is called "stacking functions". My driveway biotrash pit is one example.
This area was a giant deep hole alongside a stretch of the driveway. When the driveway was originally created, soil and rock was excavated and used to build the road, leaving behind a pit that could have easily swallowed my pickup truck. Over the course of time I gradually filled in the hole with chunks of trees, cardboard, weeds, brush trimmings, ....you name. As long as it was biodegradable farm waste, it went into the hole, thus earning the title "biotrash pit"....... rechristened "hugelkuktur pit". Yes, unbeknownst to me at the time, I was building a hugel pit.
So where does the stacking function idea come into play? The hugel pit is now used for an ideal cite for growing bamboo, which supplies me with building poles.
And banana trees, which produce bananas for us to eat, young trees for livestock feed, and green waste for compost and mulch.
Under the trees I have sweet potatoes growing, which will provide food for us and the animals.
Plus turmeric, which is just starting to sprout in the earliest planted spots. Eventually much of the hugel pit will be producing turmeric because it is a shady location.
Another function, the pit captures and absorbs any rain runoff from the driveway. I don't have much runoff on the farm except from the driveway, so the pit is perfect in collecting and storing this water -- to the benefit of the bamboo, bananas, turmeric, and sweets.
Finally, some day I see this area being mined for its soil.
So the stacked factions are:
...captures rain runoff, prevents flooding
...processes farm waste
...produces its own mulch
...supports food plants (human & animal) without the need to irrigate or fertilize
...produces a building resource (bamboo)
...eventually will be available for soil mining, if needed.
The plants utilize both horizontal and vertical space. Pretty nifty.