Comparative phylogeography of two keystone species: a mistletoe and a marsupial

AMICO, G. C.; VIDAL-RUSSELL, R.

Bariloche, Rio Negro, Argentina

Congreso; VI Southern Connection congress; 2010

Mistletoes are aerial parasitic plants that are intimately dependent on hosts for water and nutrients. Most of these plants depend obligatory on vectors for transporting seeds form the parent plant to branches of a host plant; without dispersal most mistletoes will not complete their life cycle. Hence, complex associations with animals that disperse their seeds evolved. Mistletoes can be keystone species that determine community structure and diversity. The mistletoe Tristerix corymbusus (Loranthaceae) has a unique animal as seed disperser along all the temperate forest of southern South America. Contrary to what is found in most mistletoe, dispersal by bird, T. corymbusus is actually dispersed by the endemic marsupial Dromiciops gliroides (Microbiotheriidae). This marsupial is also considered as a keystone species because it disperses several plant species in the forest. We did a comparative phylogeographic study of the marsupial and the mistletoe along the overlapping distribution of these closely associated species. Both species have some haplotypes with a wide distribution while others are only found in restricted areas. There are some localities where both species have unique derivate haplotypes, which suggest they share glacial refugia. Given the high dependence in this two species and their important role in the community, it can be considered that places proposed as refugia for the mistletoe and marsupial were also refugia for other plants in the Andean forest.