I've spent a lot of time lately thinking and researching about Terlingua, Texas. There is a ranch there with vast areas of inexpensive land with no restrictions and surrounded by millions of acres of Chihuahuan desert wilderness, including big bend national park. seems like a drylands paradise waiting to be made.
part of this was researching dry adapted species.
many of these would probably grow there, a few may need higher winter temps (Terlingua is around zone 9) or a bit more precipitation (Terlingua area gets 10-18"/year average depending on elevation mainly)
I was watching a couple of bill mollison videos and he talked about an abundant dryland drought proof treed system for even true deserts (less than 10" precip /year)
anyway here goes the incomplete list, a mix of latin and common names, some genus without species, etc. based on the mollison videos and some of my own research
drylands species list
seed new swales with
cucurbita foetidissima- buffalo gourd, seeds were used as a staple by native americans in texas
cucurbita pepo and moschata are north american natives
cucurbita maxima, mixta
phaseolus acutifolius (tepary bean- s.w. usa native desert adapted annual edible bean)- grown with beans and squash traditionally
I'd put these two first and second on the list for establishing shade and root biomass quickly in the desert:
Fast growing, nitrogen fixing, and extremely drought tolerant. Propagated easily from seed or cuttings.
With 10' of rain you can have a forest if you use the right plants but you will need to irrigate for the first two, maybe three, summers.
You've done a very extensive job of researching, so I doubt I have anything to add to your list that you haven't thought of already.
I used to live in El Paso, and I still travel to Big Bend once per year, in the fall, for a guy's weekend. I'm very familiar with the climate and environment there.
I had a friend once who purchased some land out there, and his strategy was unique, I thought. Research other climate zones around the world that are similar to the Chihuahuan desert. In this case, there was a certain zone in Africa that was very similar. Then, look for seeds for the zone in Africa.
How did he get all the seeds sent via US Mail and clear customs?
He bought the seeds from E-Bay as "decorations" "beads" "rattles" etc.
I live in Terlingua so I thought I would add some perspective.
First, I would say that in most years the 10" rainfall figure is closer to the norm over the whole area. Elevation does make a difference, but location also has a lot to do with it.
Second, Terlingua as zone 9 is right by the charts. Most years we get good freezes and usually have some freezing rain/sleet. Higher elevations also get colder and may get some snow. Five years ago we had a freak winter storm that took us down to 4 degrees F. for three straight days. That killed everything that wasn't very hardy. Last year our dog water bowl did not even freeze.
Third, Your species list has many things I don't recognize off hand, but remember that Bill Mollison's lists may have plants adapted to Arizona's Sonoran Desert. There are many Sonoran plants that can cross over into the Chihuahuan Desert, but Saguaro Cactus would freeze here every year unless well protected. I grow apricots, pomegranates, and figs, but fight to keep them alive during the worst summer heat. In higher elevations I know some people who grow apples. We garden, but in the fall and spring. Getting water into the soil is a big challenge out here. Much of Terlingua Ranch (TR) sits on gravel over Bentonite clay or directly on top of Bentonite. Other parts are on top of limestone, and other areas are on igneous formations. Each area has unique challenges. Almost all of TR was overgrazed at some point during the last century and recovery is very slow. Some areas will not recover IMO without help, but others are showing progress.
Fourth, Land prices appear cheap, but there are usually reasons:
a) Access is a big deal. (TR) is spread out over a couple hundred thousand acres. It is on the east and west sides of Hwy 118 for approximately 28 miles and north and south of Hwy 170 for 5+ miles. Tracts that front these highways carry a premium because they have all weather access and no access easement issues. The ranch road from Hwy 118 to TR Lodge is paved except for the last ~ 3 miles and is maintained by Brewster County. Some tracts can be accessed from North County and South County Roads. These are dirt/gravel roads maintained by Brewster County. Other than these roads there are very few other county maintained roads that I am aware of. The rest of the TR tracts are accessed via dirt/gravel roads that are maintained by TR. I believe their website says there is something like 1,200 miles of dirt roads to access all the tracts on the ranch. Dirt/gravel roads are OK until it rains hard and then you realize how many creeks/streams you must cross to get to/from your place. The more remote a tract, the less frequently the road is maintained!
b) Electricity is available to a relatively small percentage of TR tracts. If power is on a tract it will carry a premium. This is one of the reasons so many people out here live off-grid. It is cheaper to put in your solar system than to get power extended to your tract.
c) Water is never a given. In Terlingua/Study Butte/Ghost Town area the Study Butte Water Supply Corp. provides potable water along Hwy 118 and Hwy 170. There may be a thousand TR tracts that can access this water supply at this time. Everywhere else relies on rainwater catchment, hauled water and/or well water. You will find that practically everyone out here uses their roof to catch rainwater so it can be stored for later us. If it has a roof, it likely has gutters and tanks. There are some areas of TR that have subsurface water that is good water at reasonable depths. Other areas the water may have very high mineral/salt loads, be very deep e.g. 800+ feet deep, or very slow delivery rates e.g. < 1 gpm. Other areas have NOT shown water potential at any reasonable depth.
Please do the research necessary before closing on a property. Perhaps Kevin and others on the ground can be more specific; but the soil maps for Terlingua are not promising. Here is a link to the UC Davis interactive map: http://casoilresource.lawr.ucdavis.edu/gmap/
Most of the land I have found around that area is either Caliche (cemented/calcified rock) or Bedrock. Hard to grow anything with that soil profile. Not trying to discourage you; but share some information I have gained researching the same area.
Location: Kachemak Bay, Alaska (usda zone 6, ahs heat zone 1, lat 59 N, coastal, koppen Dfc)