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Ecology

The harsh condition of glacial streams is not only because glacial streams are often located at high altitude and latitude, but also the consistently contribution of melting snow.Thus, low water temperature, variable discharge rates, unstable substrate and riverbed, and increased turbidity and sediment load are the typical condition of glacial streams.

The growth of invertebrates in glacial streams is faster characterized by higher body mass. The reasons are the low level of competition and the abundant food source due to less organisms surviving. The dominant species is Diamesinae from the chironomid subfamily. Other species able to live include Orthocladiinae, which is the second dominant species in cold streams. Besides, benthic algae and periphyton and the insect family chironomidae could also be found.

In the summer, glacial streams experience high stream flow because of ice melt. The high flow is characterized by high turbidity and sediment transport, which reduces the biomass of the resident periphyton, or the organisms living on the aquatic plants. At the end of summer, ice melt is reduced and stream flow decreases, causing an increase in the periphyton population.

Moreover, in similar latitude and altitude glacial stream, the beta diversity is similar and enhanced compared to non-glacial reaches.