This is the first post in a series that attempts to think outside the box on what a profitable permaculture farm looks like by looking at products that can still be profitable, but aren't food. This is not intended for people that are just starting out in permaculture, but for people who are already reasonably versed. Of course, everyone can get something out of this...just know that if you get confused by the language or terms used, you might need to do a little research or better yet, ask some questions in the comments below.
The first thing I'd like to cover is large non-food producing over-story trees. The market for such products is largely for high quality timber but there are other products. Farmers don't usually have a retirement program. How do you plan for the end of your life when you draw income from your own labor? What about building a biological savings account? As a design-tool it obviously shouldn't be viewed one-dimensionally. In stacking functions, a slow growing large canopy shade tree could be used in paddocks near your watering station in hot dry summer climates, such as Colorado. These large trees provide deep shade in the summer and clear the canopy for winter. Taking advantage of this, you can keep a building cool in summer and not block solar gain in the winter. This is important in a state like Colorado that has such extreme seasonal temperature difference. Planting these trees specifically for harvesting high quality timber in 15-30 years is investing in your own or you children's future. Many could be harvested 5-10 years before retirement and stacked to naturally age. This wood brings a much higher premium as it's much easier to work than kiln-dried wood as the lignins have time to break down. Most species could be treated as a coppice, meaning future generations can still enjoy the trees.
There is also a whole other subset of large over-story trees, I will cover, that can be used to harvest sweet syrups. This is still a food product but still fits the planning for the long term future outlined in this post.
So, now I'm going to give some example species and their many other uses. Don't take these as the definitive work, they are just species I've studied for my own research. I'm sure many other species could be used for this function.
Alder - Alders are nitrogen fixers, can be tapped for syrup, some produce edible catkins and the wood is highly prized for the solid body instruments.
Western Soapberry - It's a workable hardwood. It's unpalatable to livestock making it usable in a paddock, it's fruit contains 37% soponins and is used as a laundry detergent substitute.
Black Gum - Flowers are great bee forage, it propagates easily from seed, very tough wood commonly used for making mauls and hammers.
Maples - Can be tapped for syrup at 30-40 years of age, desirable wood that propagates well from seed.
Birch - Can be tapped for syrup, desirable wood and propagates well from seed.
Orange Osage - Produces edible seeds, it's prized by bow makers and instrument makers alike. Bark can produce a natural yellow dye.
Black Walnut - A prized wood especially when air dried, edible nut, husks produce a natural ink and dye.
Oak - Edible nut, prized wood, white oak is used for basket weaving.
As a wood carver and wood worker myself, I can tell you that most hardwood species can be turned into beautiful, sell-able art.