Snow microorganisms and their interaction with the environment

Snow microorganisms include bacteria, algae, fungi, lichen pieces, protozoa and rotifers. The dominant forms are algal flagellates, Chloromonas and Chlamydomonas (Division Chlorophyta). Snow algae have been reported from 13 western states in mountainous regions, high elevation plateaus and high latitudes. The distribution and coloration of individual species is most regulated by irridation levels, and thus snowfields containinf algae may be red, yellow to orange, or green. Several species have been studied axenically in the laboratory, and results indicate that nutrients, pH, temperature, light and allelopathic effects from conifers may influence their growth. Studies indicate that snow algae accumulate trace metals in high concentrations. Acid precipitation may be selecting for more acidic strains of snow algae in the NE U.S. when compared to strains studied from Arizona snow. Preliminary studies in New York and Quebec indicate that snow algae appear to affect snow chemistry through metabolic processes.