Forests similar to Vermont’s Mansfield State Forest are experiencing snow loss
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Many forests are losing their winter snowpacks due to rising global temperatures, which can significantly hinder growth and diminish the capacity to absorb carbon dioxide from the atmosphere.
Current predictions suggest that these expectations may overestimate future carbon storage, as they fail to account for the complexities linked to winter climate shifts, according to Emerson Conrad Rooney from Boston University, Massachusetts.
Rising temperatures generally promote growth in temperate forests by enhancing decomposition and nutrient availability during warmer seasons. However, the model primarily overlooks winter changes, especially snow loss.
“The diminishing deep and insulating snowpacks cannot merely be seen as a minor change,” says Elizabeth Burakowski at the University of New Hampshire. Her findings indicate that such changes impact water storage and the health of ecosystems, warning that deep snow days could vanish from much of the U.S. by century’s end.
To better understand these cold-weather impacts, Conrad Rooney and his team modeled the effects of a 5°C increase in global temperatures on the growth of red maple trees (Acer rubrum) in a New Hampshire experimental forest. Some plots were treated with buried cables to warm the soil during the growing season, while others had their snow removed in winter, which warmed the soil and created conditions for freeze-thaw cycles.
Over a decade, trees in both scenarios exhibited more growth than those left undisturbed. However, the areas devoid of snow experienced a significant reduction in growth, halving their typical increase. Researchers attribute this disparity to root damage from exposing the soil to temperature fluctuations without snow cover.
“Snow acts as an insulating blanket, keeping the soil from freezing,” explains Conrad Rooney. “Less snow means an increase in freeze-thaw cycles.”
When researchers projected similar outcomes for northeastern U.S. forests, they estimated an anticipated loss of snowpacks by the century’s end could result in a decrease in carbon storage by about one million tons annually, in contrast to models that do not incorporate the implications of snow loss.
“The fluctuating presence of snow throughout winter undermines the stable soil conditions essential for the long-term carbon storage needed by northeastern ecosystems,” states Burakowski.
However, it’s important to note that not all snowy forests react similarly to snow loss as the deciduous trees found in the Northeast. David Bowling from the University of Utah emphasizes the necessity for accurate modeling of different ecological responses, noting, “There are many changes occurring.”
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Source: www.newscientist.com
