Impacts from shrinking cryosphere are widespread

Decreasing snowfall and snow cover is starting to take a toll on small burrowing mammals and is making the roots of some plants more susceptible to frost damage, according to a new study published in the April issue of BioScience that tracks global warming impacts from research by the Long Term Ecological Research Network. Ecosystem changes due to shrinking sea ice, snow, and glaciers have already been well-documented, especially in high-latitude regions where water is frozen for at least a month each year. In this so-called cryosphere, scientists have already recorded how some larger animals, such as penguins and polar bears, are responding to loss of their habitat. But scientists are just now starting to uncover less-obvious effects. The BioScience article outlines research showing that a decline in sea ice has decreased the abundance of diatoms at the base of aquatic ecosystems. Diatoms are a key source of food for krill, which, in turn, is important to many sea birds and and mammals. Disappearing sea ice also seems, unexpectedly, to be decreasing the sea’s uptake of carbon dioxide from the atmosphere. On land, snowpack changes can alter an area’s suitability for particular plant species. Shrinking glaciers add pollutants and increased quantities of nutrients to freshwater bodies, and melting river ice pushes more detritus downstream. The authors argue that place-based, long-term, interdisciplinary research efforts such as those supported by the Long Term Ecological Research Network will be essential if researchers are to gain an adequate understanding of the complex, cascading ecosystem responses to the changing cryosphere.