But if they're cheap and easy, and a person could make a dozen, that changes things a bit. But still, I think we're still talking about short term survival only. If that's your environment, the local flora & fauna are unlikely to be prolific enough to fill other needs without extensive effort. Unless, you know, you've got a Still suit and can call giant worms and stuff.

The thing is- this could work without intervention - and without the intention of keeping humans alive for years, thus creating a ecosystem over time. Somewhere in the middle of nowhere- watering cacti, then hardened other plants, reclaiming the moisture they loose, until bushes and trees take over these functions.

Its hard describing this fascination with self-contained or only slowly expanding pockets of life.. imagine a glass bubble , filled with small plants, beatles and life, thriving in the midst of a frozzen over wasteland like mars or a dessert like the death valley.

Its like a https://en.wikipedia.org/wiki/Bottle_garden but without the surrounding walls..

To what extent would systems like this extract moisture from the air. siphoning it off from flora/fauna that already make use of it?