Natural observations set spring’s arrival earlier this year

Spring has officially sprung, according to the astronomical calendar, which marked the Northern Hemisphere’s equinox on Tuesday at 11:06 EDT, but its actual arrival may be more in the eye of the beholder.

In fact, spring’s arrival might be old news to those who consider its arrival with the blooming of a specific type of flower, the arrival of a favorite songbird, or the emergence of mushrooms or butterflies; observances fall into the category of phenology.

National Phenology Week, March 1822, comes on the tails of some areas in the nation reporting the earliest signs of spring in 30 years, especially in Iowa, Illinois, and Nebraska. According to USA National Phenology Network maps, portions of Oklahoma saw springtime events up to eight and ten days earlier than usual. Further, the maps indicate some parts of the state see early arrivals every four to five years.

Ecological phenomena If “phenology” is not a part of your regular vocabulary, you’re not alone.

“People think it is a funny word. We, honestly, sometimes think we’d like to change it to ‘seasonology,’ which might be a little more intuitive,” joked Erin Posthumus, partnerships and projects manager for the Phenology Network at the University of Arizona.

With the world’s climate changes growing more impactful, the timing of things like bird and insect migrations and the leaf-out and blooming of trees and plants is of heightened importance for habitat reclamation projects, agriculture, and biologists worldwide. She said the Phenology Network pulls together scientific data to understand those changes better and predict trends.

While phenology’s origins date back to the 1800s, the first longterm data set comes from Montana State University, which tracked dates of lilac leaf-out and blooms from 1956 to 1992. As that effort expired, a University of Wisconsin-Milwaukee geographer enlisted nationwide volunteers to observe lilacs of a single genetic strain.

“It is a little bit odd because lilacs are not a native species, but they were very popular and early bloomers,” Posthumus said. “Removing genetic differences just removed that factor from the equation.”

Posthumus said current trends are gauged against the latest 30-year trend of leaf-out and bloom dates for lilac, honeysuckle, and other early-season bloomers. The Network produces maps and statistical data that reflect differences, year-to-year, and the long-term data trends allow the Network to predict when leaf-out and bloom are most likely to occur in the future.

While commonly referred to as “spring,” Posthumus said the records essentially reflect a combination of local climates.

Citizen science projects “What it tells you is the amount of warmth that has accumulated, say, ten days ahead of schedule, which might have consequences for other things,” she said.

In addition to producing trend maps and gathering official data, the Network coordinates citizen-science projects open to the public. Volunteers with Nature’s Notebook observe and note changes in plant and animal seasonal activity timing and can participate in campaigns targeting specific species, such as redbuds, oaks, birds, and flowers for pollinators and the emergence of mayflies.

The network also works with groups like Tribal Alliance for Pollinators and Okies for Monarchs in Oklahoma on the Time To Restore project.

Climate and plant-life information can help wildland rehabilitators understand which species to plant to provide nectar during critical periods. Knowing how certain species will adapt to changing conditions can help with long-term planning.

Gary McManus, Oklahoma Climatological Survey state climatologist, said temperatures in some regions of Oklahoma this year have regularly shot up above normal since January, sometimes 25 to 35 degrees statewide, which likely helped “spring” arrive earlier.

“The cold air has been bottled up farther to the north,” he said. There just have not been a lot of dips in the jet stream from the polar regions, and when we did have cold periods, it has not really been true arctic air. We just did not have a typical February.”

While a “false spring” that can yield to a period of extreme cold or even snow is always possible, the later in March the calendar rolls, the less likely that becomes, he said.

He said it’s rare, but we have had some “bigtime snow” the last week of March.

“You can’t always count that out, but eventually, it’s just spring,” he said.

The Oklahoma Ecology Project is a nonprofit dedicated to in-depth reporting on Oklahoma’s conservation and environmental issues. Learn more at okecology. org