On microrefugia and cryptic refugia

The existence of microrefugia and/or cryptic refugia has been proposed to explain the colonization patterns of temperate continents after the Last Glacial Maximum, as well as to gain an understanding of the present genetic structure of species and their populations. The concepts ‘microrefugia’ and ‘cryptic refugia’ largely overlap but do not fully coincide, which may lead to terminological duplication and eventual semantic misconceptions. Here, after a terminological and conceptual analysis, it is proposed that most situations currently characterized as cryptic refugia can be accommodated within the definition of microrefugia, with one single exception, for which some alternative terms are suggested. Moreover, the concept and definition of cryptic refugia are considered to be more imprecise, perishable and subjective than those of microrefugia, which is the preferred term in the current context.