The terrestrial Arctic is often treated as a uniform biome of low biological diversity. It is true that species richness as well as the diversity of functional groups declines with increasing latitude within most organism groups (Matveyeva and Chernov 2000). However, trends in other less studied aspects of biological diversity, such as genetic diversity within species, might well turn out to be comparable to other biomes (Callaghan et al. 2004, The ACIA report 2005), at least on certain spatial scales.
When exploring patterns of diversity at different levels of biological organisation it is important to consider how they vary at different scales in time and space in relation to variability of the environmental factors that affect diversity. Typical for the Arctic is the overriding role of abiotic factors in shaping the environment experienced by the organisms in most habitats, and the large topographic impact on theses factors, thereby creating large environmental heterogeneity at various spatial scales (Jónsdóttir 2005).