"Historically, dunes were dynamic. There were native grasses, but they weren't as dominant as the European beachgrass, so a big storm would blow out the dunes and the grasses with it.
"But Tidestrom's lupine has this absolutely amazing seed bank. The seeds can live a long time in the sand.
"During a pilot project for the dune restoration, the park's biologists dug deep into the ground and overturned the sand. Lupine seeds a meter under the ground were brought to the surface and they germinated! Those seeds must have been buried for decades," Knight says.
"So if you got one of these storms, the lupine seeds would be scarified by the blowing sand, breaking their dormancy, and so they'd germinate.
"There's no other vegetation around right after the storm, so there's not a lot of mice around either, because the mice need cover. They don't like open sand. The lupines would do really well in this windy, but mice-free zone after a storm.
"The plants hug the dune, clinging to the sand, so their flowers and fruits don't get blown around. To me this plant makes perfect sense.
"If there's a storm-free interval, the grasses will come in and the mice will come in and this plant won't do as well. But that's OK because it has already produced a bunch of seeds that are now in the seed bank waiting for the next big storm."
"I think that historically this species did just great, but we've destroyed dune habitat or modified it so much that you never get these natural dune blowouts and the species doesn't have an opportunity to shine.
"Instead, it's on the endangered species list."
The low down on lupines
Less is known about invasive species than one might think, given the media coverage they receive. The scientists conclude their Ecology paper by saying that even though invasive species are the greatest threat to biodiversit
|Contact: Diana Lutz|
Washington University in St. Louis