On the frequency of northern and mountain genetic variants of widespread species: Essential biodiversity information in a warmer world

Abstract

Biodiversity studies and conservation management often neglect fundamental genetic diversity, even if biodiversity loss due to reduction in genetic diversity in declining, relatively common species is probably greater than the loss resulting from disappearing rare species. Climate models suggest that global warming will especially affect high latitudes due to a higher than average temperature increase towards the poles. In widespread Northern Hemisphere species, climate warming will therefore negatively affect especially northern and mountain genetic variants (NMGVs) in the same way that it will affect species with similar distributions. To explore whether NMGVs are frequent, they were searched for in ten widespread moss species based on a wide geographical sampling in Sweden and (two-) three (-four) molecular markers per species. NeighborNet split networks and jackknife analyses showed that eight of the studied species include one or more northern or, in most cases, mountain intraspecific genetic lineages or groups of related haplotypes. Analysis of molecular variance also showed that in the two species lacking such lineages or groups the genetic composition differs between different parts of Sweden or between lowlands and mountains of the north. Haplotype or nucleotide diversity is often higher in the north or mountains than in the south or lowlands. The high incidence of NMGVs, differences in genetic composition between the study regions and the frequent high diversity in the north or mountains show that conservation of the total biodiversity must also include the genetic diversity, not just the more obvious species-level taxa with restricted northern or mountain distributions.