Declining winter and spring snow cover in parts of the Northern Hemisphere poses a growing threat to the plant and animals species that depend on the snow to survive harsh winters, a new study says. Writing in the journal Frontiers in Ecology and the Environment, a
team of scientists reports that shorter snow seasons and decreased snow depths are altering the so-called subnivium, a seasonal microenvironment beneath the snow that provides refuge for a variety of life forms, from microbes to bears. In the last four decades, snow cover in the Northern Hemisphere has declined by as much as 3.2 million square kilometers during the months of March and April. Spring melting has accelerated by nearly two weeks, and the period of maximum snow cover has shifted from February to January, the scientists say. If exposed to temperature fluctuations as a result of disappearing snow, reptiles and amphibians could emerge from winter torpor prematurely, and plant species would be subject to harmful freeze-thaw cycles.