The Milner and Petts (1994) Conceptual Model of Community Structure Within Glacier-Fed Rivers: 20 Years On

Glacierised environments are one of the most vulnerable systems to climate change due to connections between atmospheric forcing, snowpacks/glacier mass-balance, stream flow, water quality and hydrogeomorphology (physico-chemical habitat), and river ecology. The Milner and Geoff Petts paper of 1994 examined a physicochemical habitat template of glacial rivers with characteristic seasonal and diurnal flow and water temperature regimes, sediment fluxes and channel form and morphology. By extending the latitudinal and elevational range of the Arctic and Alpine Stream Ecosystem Research (AASER) sites to the tropics, and standardising environmental harshness through the Glacial Index (GI), the relationship between taxon richness and latitude and elevation was hump shaped with a peak at mid-latitudes rather than linear as reported by Castella et al. for the AASER sites. The conceptual model of glacier-fed rivers is focused purely on the structure of the community and not how it functions.