I was thinking of the comical image of a fully armored, bearded, blood and vomit-soaked dwarf in a tropical biome and then I had an epiphany. Banana farmer dwarf. But bananas grow on trees, not shrubs. Then the solution of orchards became clear.
Aside from the obvious lumber farms which have been desired ever since the move to 3D I think, there is also the aforementioned tropical fruit plantation. This led to some other amusing ideas such as a fort in the tundra importing pineapple tree seeds and then the farmers getting quite frustrated at the pineapple's inability to grow through the permafrost. Solution: Greenhouses.
Dwarves could build glass floors on a z level over a channel exposed to the sun and presto! Papayas in the arctic! I know that normally it would have to be heated as well, but one step at a time people. The greenhouse would obviously be more work than it's worth at this point in development so it would be mostly for bragging rights. Eventually though, a variety in diet could create a happy thought, or just the accomplishment of making something grow outside its normal biome could fill a wee dwarf with pride.
Also you could have some more traditional style orchards such as apples, oranges, pears, cherries and all that, the banana example was just to illustrate the stream of thought. Some of these fruit could be used for alcohol, hard apple cider, cherries used to make bounce, things like that. Others might be used to make juices for children, export, or to help with the infirm in their recovery. Vitamins and all that. I realize that in the case of children some may yell "Sacrilege!" at the removal of juvenile alcoholism.
Edit: Maybe the way I explained the greenhouse was shoddy, the way I was thinking is you would have a room carved out on the z level below the surface, either by channeling or by mining, and then exposing the room with a channel. The room could then have a floor/ceiling put over it with glass. And the room should have to be soil or irrigated.
[ March 06, 2008: Message edited by: viskaslietuvai ]