New York City's Central Park is as much of a melting pot as the rest of the city — even down at the microbial level. According to a study published Wednesday in the Proceedings of the Royal Society B, there are more than 100,000 species of bacteria living in the park's soil — and most of them are totally new to science.
The coolest thing about this study is that the results aren't as striking as they sound: In fact, Central Park's stunning microbial diversity is pretty on par with the rest of the world.
Researchers searched soil samples pulled from around the park and found more than 120,000 species of bacteria. They also found 1,659 archaea (organisms similar to bacteria) and 43,429 species of multicellular microorganisms such as plants, fungi and teeny-tiny critters.
When they compared the DNA of these organisms to databases of known species, they found that more than 80 percent of them were completely new. And of those that "matched" organisms in the database, it's likely that many were just closely related to existing species, and actually represented newly discovered cousins.
We don't know anything about these new microbes yet, including whether they're native to New York or came in on the feet of tourists and migrating geese, or whether they're good or bad for the health of the soil and the city. But we do know one thing: Their uniqueness isn't actually that unique.
Similar levels of biodiversity are seen all over the world, the researchers report. And the only part of the planet that didn't have some overlapping species with Central Park was in Antarctica.
"If you want to find unique diversity and if you want to find a wide range of different below-ground organisms, you don't have to travel around the world," Noah Fierer, an associate professor of ecology and evolutionary biology at CU-Boulder and corresponding author of the study, said in a statement."You can walk across Central Park."
Microbes don't have the same climate-based restrictions as visible plants and animals, Fierer said — they care more about soil acidity and carbon content than they do about humidity or heat.
"No one would ever expect to find an overlap in the types of trees we see in Central Park and the type of trees we see in a tropical forest," Fierer said. "But that doesn't seem to be true for the microbes living in the soil. We found all these community types just within Central Park. Below-ground biodiversity doesn't follow the same rules as the plants and animals living above ground."
The bacterial world is immense and largely unexplored — even when it comes to the the microbes living in our own bodies and homes — so it shouldn't come as a surprise that one of the busiest cities on the planet is home to a multitude of tiny organisms.