Ice algae terrestrial ice algae occur in freshwater systems, the species composition differs greatly from that of sea ice algae. These communities are significant in that they often change the color of glaciers and ice sheets, impacting the reflectivity of the ice itself. Microbial life in sea ice is extremely diverse, and includes abundant algae, bacteria and protozoa. Algae in particular dominate the sympagic environment, with estimates of more than 1000 unicellular eukaryotes found to associate with sea ice in the Arctic. Species composition and diversity vary based on location, ice type, and irradiance. In general, pennate diatoms such as "Nitschia frigida"
Clavarioid fungi on wood or on decaying herbaceous stems and fallen leaves. Some species, particularly in the genera "Clavulina" and "Ramaria", are known to be ectomycorrhizal (forming a beneficial association with the roots of living trees). Species in the genera "Ertzia", "Multiclavula", "Lepidostroma", and "Sulzbacheromyces" are lichenized and grow in association with algae. Clavarioid fungi have a worldwide distribution, though some genera—such as "Aphelaria" and "Lachnocladium"—are principally tropical. They are one of the most common of the four fungi groupings. Clavarioid fungi The clavarioid fungi are a group of fungi in the "Basidiomycota" typically having erect, simple or branched basidiocarps (fruit bodies)