I may soon have a chance to plant out a reasonable sized (maybe 1/3 acre or more) hillside in SoCal that's currently bare dirt, probably pretty nutrient poor. It's about 15 miles inland in LA, SSW-facing, Zone 10b/11a. The thing is, there's no irrigation and except for establishment, there probably never will be. The hill is probably 10% grade, +/- 5% in parts. Rainfall is 5-20 inches a year, in the winter.
I'm wondering what folks think might be good trees to put in. (I have some ideas but I kind of want to hear your opinions before biasing the discussion.) I figure there might be some trees or plants that are more short term, for the sake of providing shade and getting things established, and those short-term plantings don't have to be particularly tasty. I also figure some plantings might be good for keeping the soil in place and helping direct waterflows into the soil, and for building up organic matter. I hope to get lots of tree trimmings delivered for mulch, but mulching that size of hillside will take time.
I'd especially love ideas from folks who live in similar climates elsewhere in the world, because it's nice to learn about techniques and species that have worked for you that we might not have tried here in California.