Monday is the vernal equinox: that’s the beginning of spring, according to astronomers. For ecologists, spring isn’t just a matter of the earth’s rotation around the sun.
It has to do with events like melting snow, and the tree canopy. According to new research from the University of New Hampshire, that ecological spring, also known as the "vernal window," may be getting longer.
Research professor Alix Contosta spends a lot of timing thinking about what she calls a “philosophical” question. That is, “what is spring?”
She said historically, spring has been a brief burst of a season that starts with warming air temperatures and ends when trees have all their leaves. However, her research suggests that season may be growing longer.
“What we found,” said Contosta, “is if you have a warmer winter with less snow, spring is longer, and the time between any two transitions is longer.”
She explained that UNH has installed sensors across the state, which take incremental measurements of things like stream flow and soil temperature, then automatically dumps that data into a database.
Contosta took three years of that data and found that the warmer the winter, the longer the lag time was between events.
“So the time from when the snow starts to melt to when leaves emerge on trees, that’s a longer period.”
In addition to asking existential questions, like “what is spring,” Contosta said, she also thinks about what a longer, more drawn out spring could mean.
“If soils are really warm for a long time before trees are active, then all those nutrients that are turning over in the soil might be lost before plants can take them up,” said Contosta. “That’s what I think about when I have my scientist hat on.”
When she takes her scientist hat off – she’s still thinking about the longer-spring. Will it be too muddy to go hiking in spring? Will it mean more or less maple syrup?