We might be saying goodbye to a bunch of spring wildflowers, says a recent study by botanists from the Carnegie Museum of Natural History, along with an international team of researchers.
The research, which was recently published in Nature Communications, warns of the devastation that warmer springs can cause to ephemeral wildflowers.
The nuts and bolts of the phenomenon are this: Warmer springs cause trees to leaf out earlier, causing shorter spring light windows for North American wildflowers that depend on that light to flower.
“The phenological dynamic is important,” says Benjamin Lee in a news release, “because wildflowers in deciduous forests often rely on leafing out before the canopy to create 50-100% of their annual carbon budget.” Lee, who is the lead author and Carnegie Museum of Natural History postdoctoral research associate, describes the problem “as if a person were to eat all the calories they needed for a year in the first three weeks.”
Dwayne Evans, expert plantsman and owner of Best Feeds Garden Center’s Ross location, agrees, but he thinks the issue also is compounded by other factors, such as deer browse, habitat loss and another condition he has noticed while hunting — a thick layer of leaf litter, smothering out seedlings.
In contrast, in areas where there is a significant wild pig population, the rooting and foraging done by the pigs, he says, allow smaller understory plants to germinate. But the pigs bring other problems, and are not the solution. He says controlled burns in state forests are also helping resolve that issue.
It’s a complicated problem that won’t easily be solved. And while Evans says the seasons are getting warmer here and his nursery is selling plants that are hardy in zone 6, one nasty cold snap and you might be replanting. This is especially true in the spring, when trees break dormancy. If the plant is shut down by low temperatures, they might not start back up. So to be safe, Evans advises gardeners to buy plants that are hardy in zones 4 and 5.
As for the wildflowers, which researchers study as preserved specimens collected together in herbarium, Lee says, “Our unexpected results, with North American wildflowers being substantially more at risk to climate change effects than wildflowers in Europe and Asia, highlight how important it is that this intercontinental research is conducted and how valuable herbarium collections are in this endeavor.”
Susan Banks is a copy editor at the Pittsburgh Post-Gazette, but she's currently on strike.