Decline in winters or frost days could have lasting impacts on ecosystems, water supplies, the economy, tourism, and human health, says one study.
"Winter conditions are changing more rapidly than any other season and it could have serious implications," said Alexandra Contosta, a research assistant professor at UNH's Earth Systems Research Center. "Whether precipitation falls as snow or rain makes a big difference, whether it's talking about a forest stream, a snowshoe hare or even a skier."
In their study, recently published in the journal Ecological Applications – the researchers looked at the last 100 years of weather data from northern forests across the United States and Canada and the impacts on ecosystems and people.
They found a significant decrease in “frost days,” when minimum temperatures dip below freezing, and “ice days,” when maximum temperatures never rise above freezing.
Researchers say people tend to view cold and snowy weather as burdensome. Yet winter is important for many ecosystems that influence water, wildlife, forests, and people.
For instance, cold temperatures help prevent the spread of diseases like Lyme disease and West Nile virus through insects such as ticks and mosquitoes, as well as help manage insects that are detrimental to trees, such as hemlock wooly adelgid and eastern pine beetle.
A deep and long-lasting snowpack also insulates soils from frigid air temperatures, which prevents roots from freezing, promotes soil nutrient cycling and provides wildlife habitat for burrowing animals.
Snow cover is as important to the economy and culture of the northern forest as it is to its ecology, especially for timber harvesting, maple sugaring, winter recreation activities like skiing and ice skating, and hunting and fishing essential for indigenous peoples.
"What makes our work unique is that we consider the human impact of climate as well as the ecological or meteorological aspects," said Contosta. “For example, we looked at“ mud days, ”when temperatures are above freezing and no snow cover is present, which can affect not only forest soil nutrients but also loggers who are unable to reach certain areas that can only be harvested with deep snow. ”
Researchers say much of what is known about the effects of climate change on ecosystems is based on research conducted during the growing season.
Researchers say it's more common to hear about summer climates like drought index or heating degree days. They feel more research needs to be done during the so-called 'dormant' season to fill in the key gaps about how forest ecosystems respond to climate change.
(This story has been published from a wire agency feed without modifications to the text.)
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Oct 07, 2019 12:41 IST