I don't know how well it scales, but trees perspire and also provide shade and root systems that keep groundwater from leeching out of the soil. They may not su

I don't know how well it scales, but trees perspire and also provide shade and root systems that keep groundwater from leeching out of the soil. They may not survive, but the ones that do I imagine will help as long as they're of the right varieties. An example would be olive trees, but hey there's a whole wikipedia article about it that definitely knows more than me: https://en.wikipedia.org/wiki/Desert_greening https://en.wikipedia.org/wiki/Desert_greening "Trees store water, raise water from underlying aquifers, reduce evaporation after a rain, attract animals (and thereby fertility through feces), and they can cause more rain to fall (by temperature reduction and other effects), if the planted area is large enough."