In a permaculture garden, biomass is usually grown in zones 3 and/or 4. Basically, a garden of trees that supplies many uses to the homestead.
Im practicing the "Ruth Stout" method in my beds-DEEP mulching. The mulch is applied to 12 inches deep to help retain moisture and nutrients. In the desert this is a must!
Since i dont have a forest or wooded area on my property i have to buy or bring in the biomass (mulch) for my beds. Thats A LOT of money and a high carbon footprint (with all the driving to pick it up)..
By planting a biomass grove of native trees i will lesson,if not eliminate, my dependency on outside biomass. In addition to providing mulch, the grove will also shade my livestock paddock,provide firewood for the winters and foraging for the critters.
Yes-this is a long way off. But this is a way of life-Plan and execute now for a more sustainable future.
The species im looking at planting are Pinion Pine, cottonwood, and tagasaste ( tree lucerne) if i can get my hands on it.