Your local garden center is probably showing off its spring flower display, but nature is putting on a massive show of its own in Death Valley, where plants have broken out in a rare and gorgeous "super bloom."
"It is awesome," says Science Friday’s collaborator Christian Baker, who traveled to Death Valley to witness the park’s rare mass-bloom of flowers.
On average, Death Valley gets less than three inches of rain annually. In years of heavier winter rain, however, such as in this year's El Niño, the moisture will soak deeper into the soil, where it taps into a massive seed bank buried three to 16 inches underground.
"The super bloom is an above-average bloom of desert wildflowers," Baker says. "I can only describe [it] as a field of dancing golden wonder. It's just beautiful. But I should also point out that 'super bloom' is an unofficial term, so I personally would like to try and get that on the books as the official term. I think that would be great."
Baker, who's made a video of the super bloom, explains the science behind what makes the normally barren desert floor break out in flowers.
"If you get a lot of rain these seeds have this coating — it's a prohibitive coating, it prevents them from growing or sprouting too early, and if they get enough water, the water will actually erode the coating," Baker says, "And once this coating, which is sort of made up like a wax, or a protein or it could be even be like a natural chemical base — once that coating is eroded, then the seed can actually germinate. And presumably there's enough moisture available that it will support its full life cycle and allow it to, you know, deposit more seeds for future blooms."
But Noah Fierer, a microbial ecologist, says there's more at work than seed banks and heavy rainfall in the Death Valley super bloom.
"As the name Death Valley would suggest — we think of it as being very inhospitable to life," Fierer says. "But to microbes, they can do just fine in Death Valley because a lot of them are tolerant of the conditions that the soils in Death Valley experience and they can kind of stay dormant ... for days to weeks to months, even decades, and wait for those right conditions — that large rain event, for example."
The Death Valley "super bloom," which seems to have run its course for the year, is a rare occurrance. Death Valley National State Park ranger Alan Van Valkenberg says he's worked in the park for 25 years, and this is only the third super bloom he's witnessed. The most recent one was in 2005, and the one before that in 1998. Some scientists warn drought conditions may mean we won't see a similar show for a few decades; others wager it will only be a few years before it happens again.
But Fierer, who studies soils, says there's more to be excited about in spring then a frenzy of flowers.
"It's that smell of wet soil. That smell that most of us are probably familiar with, that smell of springtime," Fierer says. "Really, what we're smelling in most cases is actually the product of microbial activity, these microscopic organisms that are essentially very active in the springtime and feeding, and that's that smell. Only some of those compounds which we can actually detect with our relatively crude sense of smell — that's what gives that sort of characteristic wet, earthy smell."