Plants, and lots of them.
These would slowly create a life sustaining soil, atmosphere and climate.
I agree that the Moon is a foolish place to build such a base - Mars at least does not have to worry quite as much about impact events and solar radiation.
Apart from that, water is a pre-requisite for life. Mars has polar ice caps that may be sufficient to maintain life for a while. Transporting water to these bases has huge logistical problems - much better to have water on site