The technical term, as mentioned in the article, is refugium: https://en.wikipedia.org/wiki/Refugium_(population_biology). Using the term oases is mildly irking, haha.

Though I have extreme reservations about the current state of conservation science (on questions of nature and it's own agency), this is precisely why conservation is extremely important. We must protect what we have left to let nature adjust to what we become and want to be: https://eos.org/features/critical-zone-science-comes-of-age

Source: I work in palaeoecology.